Relevant bibliographies by topics / Protein sequence evolution

Academic literature on the topic 'Protein sequence evolution'

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Published: 14 March 2023

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Journal articles on the topic "Protein sequence evolution"

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Trifonov, Edward N. "Early Molecular Evolution." Israel Journal of Ecology and Evolution 52, no. 3-4 (April 12, 2006): 375–87. http://dx.doi.org/10.1560/ijee_52_3-4_375.

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Four fundamentally novel, recent developments make a basis for the Theory of Early Molecular Evolution. The theory outlines the molecular events from the onset of the triplet code to the formation of the earliest sequence/structure/function modules of proteins. These developments are: (1) Reconstruction of the evolutionary chart of codons; (2) Discovery of omnipresent protein sequence motifs, apparently conserved since the last common ancestor; (3) Discovery of closed loops—standard structural modules of modern proteins; (4) Construction of protein sequence space of module size fragments, with far-reaching evolutionary implications. The theory generates numerous predictions, confirmed by massive nucleotide and protein sequence analyses, such as existence of two distinct classes of amino acids, and their periodical distribution along the sequences. The emerging picture of the earliest molecular evolutionary events is outlined: consecutive engagement of codons, formation of the earliest short peptides, and growth of the polypeptide chains to the size of loop closure, 25-30 residues.
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Sikosek, Tobias, and Hue Sun Chan. "Biophysics of protein evolution and evolutionary protein biophysics." Journal of The Royal Society Interface 11, no. 100 (November 6, 2014): 20140419. http://dx.doi.org/10.1098/rsif.2014.0419.

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The study of molecular evolution at the level of protein-coding genes often entails comparing large datasets of sequences to infer their evolutionary relationships. Despite the importance of a protein's structure and conformational dynamics to its function and thus its fitness, common phylogenetic methods embody minimal biophysical knowledge of proteins. To underscore the biophysical constraints on natural selection, we survey effects of protein mutations, highlighting the physical basis for marginal stability of natural globular proteins and how requirement for kinetic stability and avoidance of misfolding and misinteractions might have affected protein evolution. The biophysical underpinnings of these effects have been addressed by models with an explicit coarse-grained spatial representation of the polypeptide chain. Sequence–structure mappings based on such models are powerful conceptual tools that rationalize mutational robustness, evolvability, epistasis, promiscuous function performed by ‘hidden’ conformational states, resolution of adaptive conflicts and conformational switches in the evolution from one protein fold to another. Recently, protein biophysics has been applied to derive more accurate evolutionary accounts of sequence data. Methods have also been developed to exploit sequence-based evolutionary information to predict biophysical behaviours of proteins. The success of these approaches demonstrates a deep synergy between the fields of protein biophysics and protein evolution.
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Yomo, Tetsuya. "S12A2 Protein evolution from random sequence(Unifying Comprehension from Genome to Cells through Reconsideration of Protein)." Seibutsu Butsuri 47, supplement (2007): S17. http://dx.doi.org/10.2142/biophys.47.s17_3.

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Chang, P. C., M. L. Hsieh, J. H. Shien, D. A. Graham, M. S. Lee, and H. K. Shieh. "Complete nucleotide sequence of avian paramyxovirus type 6 isolated from ducks." Journal of General Virology 82, no. 9 (September 1, 2001): 2157–68. http://dx.doi.org/10.1099/0022-1317-82-9-2157.

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There are nine serotypes of avian paramyxovirus (APMV). Only the genome of APMV type 1 (APMV-1), also called Newcastle disease virus (NDV), has been completely sequenced. In this study, the complete nucleotide sequence of an APMV-6 serotype isolated from ducks is reported. The 16236 nt genome encodes eight proteins, nucleocapsid protein (NP), phosphoprotein (P), V protein, matrix protein (M), fusion protein (F), small hydrophobic (SH) protein, haemagglutinin–neuraminidase (HN) protein and large (L) protein, which are flanked by a 55 nt leader sequence and a 54 nt trailer sequence. Sequence comparison reveals that the protein sequences of APMV-6 are most closely related to those of APMV-1 (NDV) and -2, with sequence identities ranging from 22 to 44%. However, APMV-6 contains a gene that might encode the SH protein, which is absent in APMV-1, but present in the rubulaviruses simian virus type 5 and mumps virus. The presence of an SH gene in APMV-6 might provide a link between the evolution of APMV and rubulaviruses. Phylogenetic analysis demonstrates that APMV-6, -1, -2 (only the F and HN sequences were available for analysis) and -4 (only the HN sequences were available for analysis) all cluster into a single lineage that is distinct from other paramyxoviruses. This result suggests that APMV should constitute a new genus within the subfamily Paramyxovirinae.
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Bitard-Feildel, Tristan. "Navigating the amino acid sequence space between functional proteins using a deep learning framework." PeerJ Computer Science 7 (September 17, 2021): e684. http://dx.doi.org/10.7717/peerj-cs.684.

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Motivation Shedding light on the relationships between protein sequences and functions is a challenging task with many implications in protein evolution, diseases understanding, and protein design. The protein sequence space mapping to specific functions is however hard to comprehend due to its complexity. Generative models help to decipher complex systems thanks to their abilities to learn and recreate data specificity. Applied to proteins, they can capture the sequence patterns associated with functions and point out important relationships between sequence positions. By learning these dependencies between sequences and functions, they can ultimately be used to generate new sequences and navigate through uncharted area of molecular evolution. Results This study presents an Adversarial Auto-Encoder (AAE) approached, an unsupervised generative model, to generate new protein sequences. AAEs are tested on three protein families known for their multiple functions the sulfatase, the HUP and the TPP families. Clustering results on the encoded sequences from the latent space computed by AAEs display high level of homogeneity regarding the protein sequence functions. The study also reports and analyzes for the first time two sampling strategies based on latent space interpolation and latent space arithmetic to generate intermediate protein sequences sharing sequential properties of original sequences linked to known functional properties issued from different families and functions. Generated sequences by interpolation between latent space data points demonstrate the ability of the AAE to generalize and produce meaningful biological sequences from an evolutionary uncharted area of the biological sequence space. Finally, 3D structure models computed by comparative modelling using generated sequences and templates of different sub-families point out to the ability of the latent space arithmetic to successfully transfer protein sequence properties linked to function between different sub-families. All in all this study confirms the ability of deep learning frameworks to model biological complexity and bring new tools to explore amino acid sequence and functional spaces.
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Choi, I. G., and S. H. Kim. "Evolution of protein structural classes and protein sequence families." Proceedings of the National Academy of Sciences 103, no. 38 (September 7, 2006): 14056–61. http://dx.doi.org/10.1073/pnas.0606239103.

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Chen, Z., F. Wen, N. Sun, and H. Zhao. "Directed evolution of homing endonuclease I-SceI with altered sequence specificity." Protein Engineering Design and Selection 22, no. 4 (January 10, 2009): 249–56. http://dx.doi.org/10.1093/protein/gzp001.

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Pascual-García, Alberto, Miguel Arenas, and Ugo Bastolla. "The Molecular Clock in the Evolution of Protein Structures." Systematic Biology 68, no. 6 (April 23, 2019): 987–1002. http://dx.doi.org/10.1093/sysbio/syz022.

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Abstract The molecular clock hypothesis, which states that substitutions accumulate in protein sequences at a constant rate, plays a fundamental role in molecular evolution but it is violated when selective or mutational processes vary with time. Such violations of the molecular clock have been widely investigated for protein sequences, but not yet for protein structures. Here, we introduce a novel statistical test (Significant Clock Violations) and perform a large scale assessment of the molecular clock in the evolution of both protein sequences and structures in three large superfamilies. After validating our method with computer simulations, we find that clock violations are generally consistent in sequence and structure evolution, but they tend to be larger and more significant in structure evolution. Moreover, changes of function assessed through Gene Ontology and InterPro terms are associated with large and significant clock violations in structure evolution. We found that almost one third of significant clock violations are significant in structure evolution but not in sequence evolution, highlighting the advantage to use structure information for assessing accelerated evolution and gathering hints of positive selection. Clock violations between closely related pairs are frequently significant in sequence evolution, consistent with the observed time dependence of the substitution rate attributed to segregation of neutral and slightly deleterious polymorphisms, but not in structure evolution, suggesting that these substitutions do not affect protein structure although they may affect stability. These results are consistent with the view that natural selection, both negative and positive, constrains more strongly protein structures than protein sequences. Our code for computing clock violations is freely available at https://github.com/ugobas/Molecular_clock.
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Waters, E. R. "The molecular evolution of the small heat-shock proteins in plants." Genetics 141, no. 2 (October 1, 1995): 785–95. http://dx.doi.org/10.1093/genetics/141.2.785.

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Abstract The small heat-shock proteins have undergone a tremendous diversification in plants; whereas only a single small heat-shock protein is found in fungi and many animals, over 20 different small heat-shock proteins are found in higher plants. The small heat-shock proteins in plants have diversified in both sequence and cellular localization and are encoded by at least five gene families. In the study, 44 small heat-shock protein DNA and amino acid sequences were examined, using both phylogenetic analysis and analysis of nucleotide substitution patterns to elucidate the evolutionary history of the small heat-shock proteins. The phylogenetic relationships of the small heat-shock proteins, estimated using parsimony and distance methods, reveal the gene duplication, sequence divergence and gene conversion have all played a role in the evolution of the small heat-shock proteins. Analysis of nonsynonymous substitutions and conservative and radical replacement substitutions )in relation to hydrophobicity) indicates that the small heat-shock protein gene families are evolving at different rates. This suggests that the small heat-shock proteins may have diversified in function as well as in sequence and cellular localization.
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Haimel, Matthias, Karin Pröll, and Michael Rebhan. "ProteinArchitect: Protein Evolution above the Sequence Level." PLoS ONE 4, no. 7 (July 15, 2009): e6176. http://dx.doi.org/10.1371/journal.pone.0006176.

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Dissertations / Theses on the topic "Protein sequence evolution"

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Hollich, Volker. "Orthology and protein domain architecture evolution /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-783-9/.

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Kosiol, Carolin. "Markov models for protein sequence evolution." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614166.

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Warnecke, Tobias. "Determinants of coding sequence evolution- beyong protein function." Thesis, University of Bath, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531341.

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Guney, Tacettin Dogacan. "Prediction Of Protein-protein Interactions From Sequence Using Evolutionary Relations Of Proteins And Species." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12611058/index.pdf.

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Prediction of protein-protein interactions is an important part in understanding the biological processes in a living cell. There are completely sequenced organisms that do not yet have experimentally verified protein-protein interaction networks. For such organisms, we can not generally use a supervised method, where a portion of the protein-protein interaction network is used as training set. Furthermore, for newly-sequenced organisms, many other data sources, such as gene expression data and gene ontology annotations, that are used to identify protein-protein interaction networks may not be available. In this thesis work, our aim is to identify and cluster likely protein-protein interaction pairs using only sequence of proteins and evolutionary information. We use a protein&rsquo
s phylogenetic profile because the co-evolutionary pressure hypothesis suggests that proteins with similar phylogenetic profiles are likely to interact. We also divide phylogenetic profile into smaller profiles based on the evolutionary lines. These divided profiles are then used to score the similarity between all possible protein pairs. Since not all profile groups have the same number of elements, it is a difficult task to assess the similarity between such pairs. We show that many commonly used measures do not work well and that the end result greatly depends on the type of the similarity measure used. We also introduce a novel similarity measure. The resulting dense putative interaction network contains many false-positive interactions, therefore we apply the Markov Clustering algorithm to cluster the protein-protein interaction network and filter out the weaker edges. The end result is a set of clusters where proteins within the clusters are likely to be functionally linked and to interact. While this method does not perform as well as supervised methods, it has the advantage of not requiring a training set and being able to work only using sequence data and evolutionary information. So it can be used as a first step in identifying protein-protein interactions in newly-sequenced organisms.
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Davies, L. "Sequence database searching using structural models of protein evolution." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598371.

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Commonly used programs to search sequence databases such as BLAST, FASTA and SSEARCH identify sequence homology through pairwise alignment techniques. These programs are good at detecting closely related sequences but have problems accurately detecting homologous sequences with low sequence identity. This thesis describes a new approach that attempts to improve the detection of distantly related sequences by rejecting the assumption that all sites in a protein behave in an identical manner. This is done without the use of profile techniques, which require the preliminary collection of a set of homologs. Existing programs use general properties of proteins to generate alignment scores, which simplify calculations but may also result in a decrease in accuracy. In reality, amino acid replacement probabilities and rates, amino acid frequencies and gap probabilities all vary according to where a residue lies in a protein structure. Typical patterns of these structure-specific variations in evolutionary dynamics can be incorporated into a database search program through the use of hidden Markov models (HMMs), and hence potentially improve the detection of more distantly related sequences. In this thesis, the utility of including structure-specific evolutionary information in a database search program has been assessed. I have developed a general methodology permitting structure-based evolutionary models to be used for database searching, and specific algorithms that incorporate either solvent accessibility distinctions or protein secondary structure distinctions for globular proteins. In addition I have developed a database search algorithm for transmembrane proteins. The improvement afforded by adding the extra information has then been evaluated through the use of both simulated sequences, which exactly fit the models, and real sequences from the SCOP database. The success rate of each of these programs has been compared to a simplified model that contains the general properties of proteins but with no structural distinctions.
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Wistrand, Markus. "Hidden Markov models for remote protein homology detection /." Stockholm, 2005. http://diss.kib.ki.se/2006/91-7140-598-4/.

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Nordesjö, Olle. "Searching for novel protein-protein specificities using a combined approach of sequence co-evolution and local structural equilibration." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-275040.

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Greater understanding of how we can use protein simulations and statistical characteristics of biomolecular interfaces as proxies for biological function will make manifest major advances in protein engineering. Here we show how to use calculated change in binding affinity and coevolutionary scores to predict the functional effect of mutations in the interface between a Histidine Kinase and a Response Regulator. These proteins participate in the Two-Component Regulatory system, a system for intracellular signalling found in bacteria. We find that both scores work as proxies for functional mutants and demonstrate a ~30 fold improvement in initial positive predictive value compared with choosing randomly from a sequence space of 160 000 variants in the top 20 mutants. We also demonstrate qualitative differences in the predictions of the two scores, primarily a tendency for the coevolutionary score to miss out on one class of functional mutants with enriched frequency of the amino acid threonine in one position.
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Höglund, Pär J. "Identification, Characterization and Evolution of Membrane-bound Proteins /." Uppsala : Acta Universitatis Upsaliensis Acta Universitatis Upsaliensis, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9329.

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Dubey, Anshul. "Search and Analysis of the Sequence Space of a Protein Using Computational Tools." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14115.

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A new approach to the process of Directed Evolution is proposed, which utilizes different machine learning algorithms. Directed Evolution is a process of improving a protein for catalytic purposes by introducing random mutations in its sequence to create variants. Through these mutations, Directed Evolution explores the sequence space, which is defined as all the possible sequences for a given number of amino acids. Each variant sequence is divided into one of two classes, positive or negative, according to their activity or stability. By employing machine learning algorithms for feature selection on the sequence of these variants of the protein, attributes or amino acids in its sequence important for the classification into positive or negative, can be identified. Support Vector Machines (SVMs) were utilized to identify the important individual amino acids for any protein, which have to be preserved to maintain its activity. The results for the case of beta-lactamase show that such residues can be identified with high accuracy while using a small number of variant sequences. Another class of machine learning problems, Boolean Learning, was used to extend this approach to identifying interactions between the different amino acids in a proteins sequence using the variant sequences. It was shown through simulations that such interactions can be identified for any protein with a reasonable number of variant sequences. For experimental verification of this approach, two fluorescent proteins, mRFP and DsRed, were used to generate variants, which were screened for fluorescence. Using Boolean Learning, an interacting pair was identified, which was shown to be important for the fluorescence. It was also shown through experiments and simulations that knowing such pairs can increase the fraction active variants in the library. A Boolean Learning algorithm was also developed for this application, which can learn Boolean functions from data in the presence of classification noise.
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Randall, Ryan Nicole. "Experimental phylogenetics: a benchmark for ancestral sequence reconstruction." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48998.

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The field of molecular evolution has benefited greatly from the use of ancestral sequence reconstruction as a methodology to better understand the molecular mechanisms associated with functional divergence. The method of ancestral sequence reconstruction has never been experimentally validated despite the method being exploited to generate high profile publications and gaining wider use in many laboratories. The failure to validate such a method is a consequence of 1) our inability to travel back in time to document evolutionary transitions and 2) the slow pace of natural evolutionary processes that prevent biologists from ‘witnessing’ evolution in action (pace viruses). In this thesis research, we have generated an experimentally known phylogeny of fluorescent proteins in order to benchmark ancestral sequence reconstruction methods. The tips/leaves of the fluorescent protein experimental phylogeny are used to determine the performances of various ASR methods. This is the first example of combining experimental phylogenetics and ancestral sequence reconstruction.
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Books on the topic "Protein sequence evolution"

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Lorne Conference on Protein Structure & Function (28th 2003). 28th Annual Lorne Conference on Protein Structure & Function: Sun. 9 - Thurs. 13 February 2003. [Lorne, Vic: s.n., 2003.

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M, Stone Edwin, and Schwartz Robert J, eds. Intervening sequences in evolution and development. New York: Oxford University Press, 1990.

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Easteal, Simon. The mammalian molecular clock. New York: Springer-Verlag, 1995.

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1955-, Collet Chris, and Betty David 1953-, eds. The mammalian molecular clock. New York: Springer-Verlag, 1995.

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Abelson, John N., Melvin I. Simon, and Russell F. Doolittle. Molecular Evolution: Computer Analysis of Protein and Nucleic Acid Sequences. Elsevier Science & Technology Books, 1990.

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(Editor), John N. Abelson, Melvin I. Simon (Editor), and Russell F. Doolittle (Editor), eds. Molecular Evolution: Computer Analysis of Protein and Nucleic Acid Sequences, Volume 183: Volume 183: Molecular Evolution (Methods in Enzymology). Academic Press, 1990.

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(Editor), John N. Abelson, Melvin I. Simon (Editor), and Russell F. Doolittle (Editor), eds. Molecular Evolution: Computer Analysis of Protein and Nucleic Acid Sequences, Volume 183: Volume 183: Molecular Evolution (Methods in Enzymology). Academic Press, 1990.

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Book chapters on the topic "Protein sequence evolution"

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Koonin, Eugene V., and Michael Y. Galperin. "Genomes and the Protein Universe." In Sequence — Evolution — Function, 357–69. Boston, MA: Springer US, 2003. http://dx.doi.org/10.1007/978-1-4757-3783-7_9.

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Dokholyan, Nikolay V., and Eugene I. Shakhnovich. "Towards Unifying Protein Evolution Theory." In Structural Approaches to Sequence Evolution, 113–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-35306-5_5.

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Jörnvall, Hans, Olle Danielsson, Jan-Olov Höög, and Bengt Persson. "Alcohol Dehydrogenases: Patterns of Protein Evolution." In Methods in Protein Sequence Analysis, 275–82. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4899-1603-7_36.

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Bastolla, Ugo, Markus Porto, H. Eduardo Roman, and Michele Vendruscolo. "The Structurally Constrained Neutral Model of Protein Evolution." In Structural Approaches to Sequence Evolution, 75–112. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-35306-5_4.

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Wakabayashi, Steven T., Maksim A. Shlykov, Ujjwal Kumar, Vamsee S. Reddy, Ankur Malhotra, Erik L. Clarke, Jonathan S. Chen, et al. "Deducing Transport Protein Evolution Based on Sequence, Structure, and Function." In Protein Families, 315–39. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118743089.ch12.

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Gu, Xun. "Functional divergence in protein (family) sequence evolution." In Contemporary Issues in Genetics and Evolution, 133–41. Dordrecht: Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-010-0229-5_4.

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Robey, Frank A. "The Evolution of the Regulatory Response to Products of Recombinant DNA Technology." In Methods in Protein Sequence Analysis · 1986, 67–78. Totowa, NJ: Humana Press, 1987. http://dx.doi.org/10.1007/978-1-59259-480-1_5.

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Kocher, Thomas D., and Allan C. Wilson. "Sequence Evolution of Mitochondrial DNA in Humans and Chimpanzees: Control Region and a Protein-Coding Region." In Evolution of Life, 391–413. Tokyo: Springer Japan, 1991. http://dx.doi.org/10.1007/978-4-431-68302-5_25.

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Bastolla, Ugo, and Miguel Arenas. "The Influence of Protein Stability on Sequence Evolution: Applications to Phylogenetic Inference." In Methods in Molecular Biology, 215–31. New York, NY: Springer New York, 2018. http://dx.doi.org/10.1007/978-1-4939-8736-8_11.

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VanAntwerp, James, Patrick Finneran, Benedikt Dolgikh, and Daniel Woldring. "Ancestral Sequence Reconstruction and Alternate Amino Acid States Guide Protein Library Design for Directed Evolution." In Methods in Molecular Biology, 75–86. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2285-8_4.

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Conference papers on the topic "Protein sequence evolution"

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Shovan, S. M., and Md Al Mehedi Hasan. "Prediction of Lysine Glycation PTM site in Protein using Peptide Sequence Evolution based Features." In 2019 International Conference on Electrical, Computer and Communication Engineering (ECCE). IEEE, 2019. http://dx.doi.org/10.1109/ecace.2019.8679407.

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Kokilam, K. Vasantha, and D. Pon Mary Pushpa Latha. "A review on evolution of data mining techniques for protein sequence causing genetic disorder diseases." In 2012 IEEE International Conference on Computational Intelligence and Computing Research (ICCIC). IEEE, 2012. http://dx.doi.org/10.1109/iccic.2012.6510284.

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Sadler, J. Evan. "THE MOLECULAR BIOLOGY OF VON WILLEBRAND FACTOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643930.

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Human von Willebrand factor (vWF) is a plasma glycoprotein that is synthesized by endothelial cells and megakaryocytes, and perhaps by syncytiotrophoblast of placenta. The biosynthesis of vWF is very complex, involving proteolytic processing, glycosyla-tion, disulfide bond formation, and sulfation. Mature vWF consists of a single subunit of ∼ 250,000 daltons that is assembled into multimer ranging from dimers to species of over 10 million daltons. vWF performs its essential hemostatic function through several binding interactions, forming a bridge between specific receptors on the platelet surface and components of damaged vascular subendothelial connective tissue. Inherited deficiency of vWF, or von Willebrand disease (vWD), is the most common genetically transmitted bleeding disorder worldwide. The last two years has been a time of very rapid progress in understanding the molecular biology of vWF. Four research groups have independently isolated and sequenced the 9 kilobase full-length vWF cDNA. The predicted protein sequence has provided a foundation for understanding the biosynthetic processing of vWF, and has clarified the relationship between vWF and a 75-100 kilodalton plasma protein of unknown function, von Willebrand antigen II (vWAgll)/ vWAgll is co-distributed with vWF in endothelial cells and platelets, and is deficient in patients with vWD. The cDNA sequence of vWF shows that vWAgll is a rather large pro-peptide for vWF, explaining the biochemical and genetic association between the two proteins. vWF has a complex evolutionary history marked by many separate gene segment duplications. The primary structure of the protein contains four distinct types of repeated domains present in two to four copies each. Repeated domains account for over 90 percent of the protein sequence. This sequence provides a framework for ordering the functional domains that have been defined by protein chemistry methods. A tryptic peptide from the amino-terminus of vWF that overlaps domain D3 binds to factor VIII and also appears to bind to heparin. Peptides that include domain A1 bind to collagens, to heparin, and to platelet glycoprotein Ib. A second collagen binding site appears to lie within domain A3. The vWF cDNA has been expressed in heterologous cells to produce small amounts of functionally and structurally normal vWF, indicating that endothelial cells are not unique in their ability to process and assemble vWF multimers. Site-directed mutagenesis has been used to show that deletion of the propeptide of vWF prevents the formation of multimers. Cloned cDNA probes have been employed to isolate vWF genomic DNA from cosmid and λ-phage libraries, and the size of the vWF gene appears to be ∼ 150 kilobases. The vWF locus has been localized to human chromosome 12p12—pter. Several intragenic RFLPs have been characterized. With them, vWF has been placed on the human genetic linkage map as the most telomeric marker currently available for the short arm of chromosome 12. A second apparently homologous locus has been identified on chromosome 22, but the relationship of this locus to the authentic vWF gene is not yet known. The mechanism of vWD has been studied by Southern blotting of genomic DNA with cDNA probes in a few patients. Three unrelated pedigrees have been shown to have total deletions of the vWF gene as the cause of severe vWD (type III). This form of gene deletion appears to predispose to the development of inhibitory alloantibodies to vWF during therapy with cryoprecipitate. During the next several years recombinant DNA methods will continue to contribute our understanding of the evolution, biosynthesis, and structure-function relationships of vWF, as well as the mechanism of additional variants of vWD at the level of gene structure.
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Radolf, Justin, Sanjiv Kumar, David Smajs, Abhishek Dey, Arvind Anand, Morgan Ledoyt, Carson Karanian, et al. "LB1.1 Insights into the evolution of syphilis spirochetes within at-risk populations: sequence variation of outer membrane protein β-barrel domains in clinical samples." In STI and HIV World Congress Abstracts, July 9–12 2017, Rio de Janeiro, Brazil. BMJ Publishing Group Ltd, 2017. http://dx.doi.org/10.1136/sextrans-2017-053264.102.

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Pannekoek, H., M. Linders, J. Keijer, H. Veerman, H. Van Heerikhuizen, and D. J. Loskutoff. "THE STRUCTURE OF THE HUMAN ENDOTHELIAL PLASMINOGEN ACTIVATOR INHIBITOR (PAI-1) GENE: NON-RANDOM POSITIONING OF INTRONS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644767.

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The endothelium plays a crucial role in the regulation of the fibrinolytic process, since it synthesizes and secretes tissue-type plasminogen activator (t-PA) as well as the fast-acting plasminogen activator inhibitor (PAI-1). Molecular cloning of full-length PAI-1 cDNA, employing a human endothelial cDNA expression library, and a subsequent determination of the complete nucleotide sequence, allowed a prediction of the amino-acid sequence of the PAI-1 glycoprotein. It was observed that the amino-acid sequence is significantly homologous to those of members of the serine protease inhibitor ("Serpin") family, e.g. αl-antitrypsin and antithrombin III. Serpins are regulators of various processes, such as coagulation, inflammatory reactions, complement activation and share a common functional principle and a similar structure, indicative for a common primordial gene. The intron-exon arrangement of Serpin genes may provide a record for the structure of a primordial gene. A comparison of the location of introns among members of the Serpin family reveals that some introns are indeed present at identical or almost identical positions, however in many other cases there is no correspondence between the intron positions among different Serpin genes.Obviously, more data on the chromosomal gene structure of members of this family are required to formulate a scheme for the evolutionary creation of the Serpins. To that end, we have established the number and the precise location of the introns in the PAI-1 gene and have compared these data with those reported on other Serpin genes. For that purpose a human genomic cosmid DNA library of about 340.000 independent colonies was screened with radiolabelled full-length PAI-1 cDNA as probe. Two clones were found which contain the entire PAI-1 gene. Restriction site mapping, electron microscopic inspection of heteroduplexes and nucleotide sequence analysis demonstrate that the PAI-1 gene comprises about 12.2kilo basepairs and consists of nine exons and eight introns. Intron-exon boundaries are all in accord with the "GT-AG" rule, including a cryptic acceptor splice site found in intron 7. Furthermore, it is observed that intron 3 of the PAI-1 gene occupies an identical position as intron E of chicken ovalbumin and intron E of the ovalbumin-related gene Y. The location of the other seven introns is unrelated to the known location of introns in the genes encoding the Serpins, rat angiotensin, chicken ovalbumin (and gene Y), human antithrombin III and human al-antitrypsin. The 3' untranslated region of the PAI-1 gene is devoid of introns, indicating that the two mRNA species detected in cultured endothelial cells which share an identical 5' untranslated segment and codogenic region, but differ in the length of the 3' untranslated region, arise by alternative polyadenylation. An extrapolation of the position of the introns to the amino-acid sequence of PAI-1, and adaption of the view that the subdomain structure of the Serpins is analogous, shows that the introns of PAI-1 are non-randomly distributed. Except for intron 7, the position of the other seven introns corresponds with randon-coil regions of the protein or with the borders of β-sheets and a-helices. Extrapolation of the position of introns in the genes of other Serpins to their respective amino-acid sequences and subdomain structures also reveals a preference for random-coil regions and borders of subdomains. These observations are reminiscent of an evolutionary model, called "intron sliding", that accounts for variations in surface loops of the same protein in different species by aberrant splicing (Craik et al., Science 220 (1983) 1125). The preferential presence of introns in gene segments, encoding these variable regions, and absence in regions determining the general folding of these proteins would explain conservation of the structure during the evolution of those genes.
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SCHÜTTE, MORITZ, NIELS KLITGORD, DANIEL SEGRÈ, and OLIVER EBENHÖH. "CO-EVOLUTION OF METABOLISM AND PROTEIN SEQUENCES." In Proceedings of the 9th Annual International Workshop on Bioinformatics and Systems Biology (IBSB 2009). IMPERIAL COLLEGE PRESS, 2010. http://dx.doi.org/10.1142/9781848165786_0013.

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Kuznetsov, Vladimir A. "Stochastic Model of Evolution of Conserved Protein Coding Sequences." In UNSOLVED PROBLEMS OF NOISE AND FLUCTUATIONS: UPoN 2002: Third International Conference on Unsolved Problems of Noise and Fluctuations in Physics, Biology, and High Technology. AIP, 2003. http://dx.doi.org/10.1063/1.1584911.

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8

Giannelli, B. F. "MOLECULAR GENETICS OF HAEMOPHILIA." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643981.

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Haemophilia B, an X-linked recessive disease with an incidence of 1/30,000 newborn males, is due to defects in the gene for coagulation factor IX, which is on the long am of the X chromosome at band Xq27.1. This gene consists of approximately 34 Kb and contains 8 exons which specify a mRtfc of 2803 residues coding for a protein of 415 aa preceded by a prepro signal peptide of 46 aa. Coripanson of the functional domains of the factor IX protein with the exon structure of the gene supports the exon/protein domain hypothesis of gene evolution. The factor IX gene seems to be formed by a number of functionally and evolutionally independent modules. The signal peptide and the gla (γcarboxy-glutamic) region encoded in the first three exons are homologous to those of factor X, protein C and prothrombin. Thevfourth and fifth exons which code for the connecting peptide are homologous to one another and to the epidermal growth factor, a module that has been used in the construction of a great variety of proteins including different members of the coagulation and fibrinolytic pathways. The sixth exon encodes the activation peptide region, while the catalytic region of factor IX is coded by the seventh and eighth exon. This is at variance with other serine protease genes that have different exons for the segments containing the cardinal ami no-acids of the active centre (histidine, aspartic acid and serine).Natural selection acts against detrimental mutations of the factor IX gene and at each generation a proportion of haemophilia B genes is eliminated, as a significant number of patients does not reproduce. There appears to be no selective advantage to the heterozygote and therefore haemophilia B is maintained in the population by new mutations. Consequently, a significant proportion of patients should be born to non-carrier mothers, and unrelated patients should carry different gene defects, as recently verified by detailed analysis of individual haemophilia B genes.The defects of factor IX described so far comprise both point mutations and gene deletions. The latter affect either part or the whole of the gene and are often associated with the development of antibodies against therapeutically adninistered factor IX (the inhibitor complication). Since gene deletions may result in the complete absenceof factor IX synthesis or in the production of an extremely abnormal product, it has been suggested that mutationspreventing the synthesis of a factor IX gene product capable of inducing immune tolerance to normal factor IX is important in predisposing to the inhibitor complication.Among the point mutations described so far, those affecting the signal peptide are of particular interest. Substitutions of the arginine at positions -4 and -1 cause failure of propeptide cleavage. Thus they indicate that the propeptide consists of 18 aa an(lthat lts excision is necessary for factor IX function. It appears also that the propeptide contains a signal for γcarboxylation which has been conserved during the evolution of different γcarboxylated proteins.In spite of coagulant treatment, haemophilia B is a serious disease and one for which genetic counselling is required. Paramount for this is the detection of carriers and the diagnosis ofaffected male fetuses. DNA probes derived from the cloned factor IX gene have been used for this purpose. Carrier and first or second trimester prenatal diagnoses have been done using factors IX gene markers to follow the transmission of haemophilia B genes. Six sequence variations causing restriction fragment length polymorphisms (RFLP) in the factor IX gene have been detected and used as markers for such indirect diagnoses The efficiency of the above markers is reduced by linkage disequilibrium but, nevertheless, they offer definite carrier and nremtal diagnoses in 75-80% of the relatives of familial cases of haemophilia B.The indirect detection of gene defects is of modest help in the counselling of individuals from the families of isolated patients, but new methods for the direct detection of gene mutations promise better results in such families and also the attainment of % diagnostic success in relatives of familial cases.Finally the successful expression of recombinant factor IX genes in tissue culture and transgenic mammals raises hopes of therapeutic advances.
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Goode, Matthew, Stéphane Guindon, and Allen Rodrigo. "Modelling the evolution of protein coding sequences sampled from Measurably Evolving Populations." In Proceedings of the 19th International Conference. IMPERIAL COLLEGE PRESS, 2008. http://dx.doi.org/10.1142/9781848163324_0013.

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Strandberg, L., D. Lawrence, and T. Ny. "ISOLATION OF THE GENOMIC REGION CODING FOR TYPE-1 PLASMINOGEN ACTIVATOR INHIBITOR." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644439.

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The type-1 Plasminogen Activator Inhibitor (PAI-1) has recently been identified as a member of the Serine Protease Inhibitor family (SERPINS). This family of proteins contain many serine protease inhibitors but also functionally unrelated proteins like ovalbumin and anginotensinogen. PAI-1 inhibits both u-PA and t-PA and might therefore be an important regulator of the fibrinolytic system.In order to study the evolution of the Serpin family as well as PAI-1 gene expression we have isolated the genomic region carrying the PAI-1 gene. A cDNA sequence for PAI-1 was used as probe to screen a human genomic library. When 2 million independent phages were screened, 13 positive clones were isolated. Characterisation of these clones showed that they could be divided into 3 overlapping groups covering a genomic region of approximately 30 kb. The gene was localized and characterized by restriction enzyme analysis, southern blotting using cDNA and oligomer probes, and DNA sequencing.
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Reports on the topic "Protein sequence evolution"

1

Izhar, Shamay, Maureen Hanson, and Nurit Firon. Expression of the Mitochondrial Locus Associated with Cytoplasmic Male Sterility in Petunia. United States Department of Agriculture, February 1996. http://dx.doi.org/10.32747/1996.7604933.bard.

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The main goal of the proposed research was to continue the mutual investigations into the molecular basis of CMS and male fertility restoration [MRF], with the ultimate goal of understanding these phenomena in higher plants. The experiments focused on: (1) dissecting apart the complex CMS - specific mitochondrial S-Pcf locus, in order to distinguish its essential parts which cause sterility from other parts and study its molecular evolution. (2) Studying the expression of the various regions of the S-Pcf locus in fertile and sterile lines and comparing the structure and ultrastructure of sterile and fertile tissues. (3) Determine whether alteration in respiration is genetically associated with CMS. Our mutual investigations further substantiated the association between the S-Pcf locus and CMS by the findings that the fertile phenotype of a population of unstable petunia somatic hybrids which contain the S-Pcf locus, is due to the presence of multiple muclear fertility restoration genes in this group of progenies. The information obtained by our studies indicate that homologous recombination played a major role in the molecular evolution of the S-Pcf locus and the CMS trait and in the generation of mitochondrial mutations in general. Our data suggest that the CMS cytoplasm evolved by introduction of a urs-s containing sublimon into the main mitochondrial genome via homologous recombination. We have also found that the first mutation detected so far in S-Pcf is a consequence of a homologous recombination mechanism involving part of the cox2 coding sequence. In all the cases studied by us, at the molecular level, we found that fusion of two different cells caused mitochondrial DNA recombination followed by sorting out of a specific mtDNA population or sequences. This sequence of events suggested as a mechanism for the generation of novel mitochondrial genomes and the creation of new traits. The present research also provides data concerning the expression of the recombined and complex CMS-specific S-Pcf locus as compared with the expression of additional mitochondrial proteins as well as comparative histological and ultrastructural studies of CMS and fertile Petunia. Evidence is provided for differential localization of mitochondrially encoded proteins in situ at the tissue level. The similar localization patterns of Pcf and atpA may indicate that Pcf product could interfere with the functioning of the mitochondrial ATPase in a tissue undergoing meiosis and microsporogenesis. Studies of respiration in CMS and fertile Petunia lines indicate that they differe in the partitioning of electron transport through the cytochrome oxidase and alternative oxidase pathways. The data indicate that the electron flux through the two oxidase pathways differs between mitochondria from fertile and sterile Petunia lines at certain redox states of the ubiquinone pool. In summary, extensive data concerning the CMS-specific S-Pcf locus of Petunia at the DNA and protein levels as well as information concerning different biochemical activity in CMS as compared to male fertile lines have been accumulated during the three years of this project. In addition, the involvement of the homologous recombination mechanism in the evolution of mt encoded traits is emphasized.
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Eyal, Yoram, and Sheila McCormick. Molecular Mechanisms of Pollen-Pistil Interactions in Interspecific Crossing Barriers in the Tomato Family. United States Department of Agriculture, May 2000. http://dx.doi.org/10.32747/2000.7573076.bard.

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During the evolutionary process of speciation in plants, naturally occurring barriers to reproduction have developed that affect the transfer of genes within and between related species. These barriers can occur at several different levels beginning with pollination-barriers and ending with hybrid-breakdown. The interaction between pollen and pistils presents one of the major barriers to intra- and inter-specific crosses and is the focus of this research project. Our long-term goal in this research proposal was defined to resolve questions on recognition and communication during pollen-pistil interactions in the extended tomato family. In this context, this work was initiated and planned to study the potential involvement of tomato pollen-specific receptor-like kinases (RLK's) in the interaction between pollen and pistils. By special permission from BARD the objectives of this research were extended to include studies on pollen-pistil interactions and pollination barriers in horticultural crops with an emphasis on citrus. Functional characterization of 2 pollen-specific RLK's from tomato was carried out. The data shows that both encode functional kinases that were active as recombinant proteins. One of the kinases was shown to accumulate mainly after pollen germination and to be phosphorylated in-vitro in pollen membranes as well as in-vivo. The presence of style extract resulted in dephosphorylation of the RLK, although no species specificity was observed. This data implies a role for at least one RLK in pollination events following pollen germination. However, a transgenic plant analysis of the RLK's comprising overexpression, dominant-negative and anti-sense constructs failed to provide answers on their role in pollination. While genetic effects on some of the plants were observed in both the Israeli and American labs, no clear functional answers were obtained. An alternative approach to addressing function was pursued by screening for an artificial ligand for the receptor domain using a peptide phage display library. An enriched peptide sequence was obtained and will be used to design a peptide-ligand to be tested for its effect o pollen germination and tube growth. Self-incompatibility (SI) in citrus was studied on 3 varieties of pummelo. SI was observed using fluorescence microscopy in each of the 3 varieties and compatibility relations between varieties was determined. An initial screen for an S-RNase SI mechanism yielded only a cDNA homologous to the group of S-like RNases, suggesting that SI results from an as yet unknown mechanism. 2D gel electrophoresis was applied to compare pollen and style profiles of different compatibility groups. A "polymorphic" protein band from style extracts was observed, isolated and micro-sequenced. Degenerate primers designed based on the peptide sequence date will be used to isolate the relevant genes i order to study their potential involvement in SI. A study on SI in the apple cultivar Top red was initiated. SI was found, as previously shown, to be complete thus requiring a compatible pollinator variety. A new S-RNase allele was discovered fro Top red styles and was found to be highly homologous to pear S-RNases, suggesting that evolution of these genes pre-dated speciation into apples and pears but not to other Rosaceae species. The new allele provides molecular-genetic tools to determine potential pollinators for the variety Top red as well as a tool to break-down SI in this important variety.
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Rafaeli, Ada, Russell Jurenka, and Chris Sander. Molecular characterisation of PBAN-receptors: a basis for the development and screening of antagonists against Pheromone biosynthesis in moth pest species. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7695862.bard.

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The original objectives of the approved proposal included: (a) The determination of species- and tissue-specificity of the PBAN-R; (b) the elucidation of the role of juvenile hormone in gene regulation of the PBAN-R; (c) the identificationof the ligand binding domains in the PBAN-R and (d) the development of efficient screening assays in order to screen potential antagonists that will block the PBAN-R. Background to the topic: Moths constitute one of the major groups of pest insects in agriculture and their reproductive behavior is dependent on chemical communication. Sex-pheromone blends are utilised by a variety of moth species to attract conspecific mates. In most of the moth species sex-pheromone biosynthesis is under circadian control by the neurohormone, PBAN (pheromone-biosynthesis-activating neuropeptide). In order to devise ideal strategies for mating disruption/prevention, we proposed to study the interactions between PBAN and its membrane-bound receptor in order to devise potential antagonists. Major conclusions: Within the framework of the planned objectives we have confirmed the similarities between the two Helicoverpa species: armigera and zea. Receptor sequences of the two Helicoverpa spp. are 98% identical with most changes taking place in the C-terminal. Our findings indicate that PBAN or PBAN-like receptors are also present in the neural tissues and may represent a neurotransmitter-like function for PBAN-like peptides. Surprisingly the gene encoding the PBAN-receptor was also present in the male homologous tissue, but it is absent at the protein level. The presence of the receptor (at the gene- and protein-levels), and the subsequent pheromonotropic activity are age-dependent and up-regulated by Juvenile Hormone in pharate females but down-regulated by Juvenile Hormone in adult females. Lower levels of pheromonotropic activity were observed when challenged with pyrokinin-like peptides than with HezPBAN as ligand. A model of the 3D structure of the receptor was created using the X-ray structure of rhodopsin as a template after sequence alignment of the HezPBAN-R with several other GPCRs and computer simulated docking with the model predicted putative binding sites. Using in silico mutagenesis the predicted docking model was validated with experimental data obtained from expressed chimera receptors in Sf9 cells created by exchanging between the three extracellular loops of the HezPBAN-R and the Drosophila Pyrokinin-R (CG9918). The chimera receptors also indicated that the 3ʳᵈ extracellular loop is important for recognition of PBAN or Diapause hormone ligands. Implications: The project has successfully completed all the objectives and we are now in a position to be able to design and screen potential antagonists for pheromone production. The successful docking simulation-experiments encourage the use of in silico experiments for initial (high-throughput) screening of potential antagonists. However, the differential responses between the expressed receptor (Sf9 cells) and the endogenous receptor (pheromone glands) emphasize the importance of assaying lead compounds using several alternative bioassays (at the cellular, tissue and organism levels). The surprising discovery of the presence of the gene encoding the PBAN-R in the male homologous tissue, but its absence at the protein level, launches opportunities for studying molecular regulation pathways and the evolution of these GPCRs. Overall this research will advance research towards the goal of finding antagonists for this important class of receptors that might encompass a variety of essential insect functions.
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Mawassi, Munir, and Valerian Dolja. Role of RNA Silencing Suppression in the Pathogenicity and Host Specificity of the Grapevine Virus A. United States Department of Agriculture, January 2010. http://dx.doi.org/10.32747/2010.7592114.bard.

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RNA silencing is a defense mechanism that functions against virus infection and involves sequence-specific degradation of viral RNA. Diverse RNA and DNA viruses of plants encode RNA silencing suppressors (RSSs), which, in addition to their role in viral counterdefense, were implicated in the efficient accumulation of viral RNAs, virus transport, pathogenesis, and determination of the virus host range. Despite rapidly growing understanding of the mechanisms of RNA silencing suppression, systematic analysis of the roles played by diverse RSSs in virus biology and pathology is yet to be completed. Our research was aimed at conducting such analysis for two grapevine viruses, Grapevine virus A (GVA) and Grapevine leafroll-associated virus-2 (GLRaV- 2). Our major achievements on the previous cycle of BARD funding are as follows. 1. GVA and GLRaV-2 were engineered into efficient gene expression and silencing vectors for grapevine. The efficient techniques for grapevine infection resulting in systemic expression or silencing of the recombinant genes were developed. Therefore, GVA and GLRaV-2 were rendered into powerful tools of grapevine virology and functional genomics. 2. The GVA and GLRaV-2 RSSs, p10 and p24, respectively, were identified, and their roles in viral pathogenesis were determined. In particular, we found that p10 functions in suppression and pathogenesis are genetically separable. 3. We revealed that p10 is a self-interactive protein that is targeted to the nucleus. In contrast, p24 mechanism involves binding small interfering RNAs in the cytoplasm. We have also demonstrated that p10 is relatively weak, whereas p24 is extremely strong enhancer of the viral agroinfection. 4. We found that, in addition to the dedicated RSSs, GVA and GLRaV-2 counterdefenses involve ORF1 product and leader proteases, respectively. 5. We have teamed up with Dr. Koonin and Dr. Falnes groups to study the evolution and function of the AlkB domain presents in GVA and many other plant viruses. It was demonstrated that viral AlkBs are RNA-specific demethylases thus providing critical support for the biological relevance of the novel process of AlkB-mediated RNA repair.
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Perk, Shimon, Maricarmen Garcia, Alexander Panshin, Caroline Banet-Noach, Irina Gissin, Mark W. Jackwood, and David Stallknecht. Avian Influenza Virus H9N2: Characterization and Control Strategies. United States Department of Agriculture, June 2007. http://dx.doi.org/10.32747/2007.7709882.bard.

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Control of Avian Influenza (AI) infection is a highly topical subject of major economicimportance for the worldwide poultry industry at the national level and for international trade.H9N2 viruses are endemic in poultry throughout Asia and the Middle East, causing major losses inproduction. Moreover, these viruses pose wider threats since they have been isolated from bothswine and humans. At the same time, study of the AI viruses affords an opportunity to explore anumber of problems of intriguing scientific interest. The overall goal of this project was to developa sound control strategy for avian influenza subtype H9N2 viruses (AI H9N2) in commercialpoultry in Israel. The one-year feasibility study focused on two main goals, namely: to study themolecular characteristics of AI H9N2 circulating during the last seven years in Israel and todevelop tools enabling differentiation between the immune response to vaccination and infectionwith H9N2.Genetic and phylogenetic characterization of 29 selected AI H9N2 isolates (2000-2006)was performed by complete sequencing of hemagglutinin (HA), neuraminidase (NA), and all sixinternal genes [nucleoprotein (NP), polymerase basic 1 (PB1), polymerase basic 2 (PB2),polymerase acid (PA), matrix (M), and nonstructural (NS) genes]; comparative phylogenetic andgenetic analyses of these sequences; and comparative genetic analyses of deduced amino acidsequences of the HA, NA, NS1, and NS2 proteins. The major conclusions of the molecularanalyses were: (1) Israeli isolates, together with other H9N2 viruses isolated in Middle Eastcountries, comprise a single regional sublineage related to the G1-lineage. In addition, Israeliisolates subdivided into three different subgroups. Genetic analysis of these viruses suggests thatthey underwent divergent evolution paths.
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Fahima, Tzion, and Jorge Dubcovsky. Map-based cloning of the novel stripe rust resistance gene YrG303 and its use to engineer 1B chromosome with multiple beneficial traits. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598147.bard.

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Research problem: Bread wheat (Triticumaestivum) provides approximately 20% of the calories and proteins consumed by humankind. As the world population continues to increase, it is necessary to improve wheat yields, increase grain quality, and minimize the losses produced by biotic and abiotic stresses. Stripe rust, caused by Pucciniastriiformisf. sp. tritici(Pst), is one of the most destructive diseases of wheat. The new pathogen races are more virulent and aggressive than previous ones and have produced large economic losses. A rich source for stripe-rust resistance genes (Yr) was found in wild emmer wheat populations from Israel. Original Project goals: Our long term goal is to identify, map, clone, characterize and deploy in breeding, novel wild emmer Yr genes, and combine them with multiple beneficial traits. The current study was aiming to map and clone YrG303 and Yr15, located on chromosome 1BS and combine them with drought resistance and grain quality genes. Positional cloning of YrG303/Yr15: Fine mapping of these genes revealed that YrG303 is actually allelic to Yr15. Fine genetic mapping using large segregating populations resulted in reduction of the genetic interval spanning Yr15 to less than 0.1 cM. Physical mapping of the YrG303/Yr15 locus was based on the complete chromosome 1BS physical map of wheat constructed by our group. Screening of 1BS BAC library with Yr15 markers revealed a long BAC scaffold covering the target region. The screening of T. dicoccoidesaccession-specific BAC library with Yr15 markers resulted in direct landing on the target site. Sequencing of T. dicoccoidesBAC clones that cover the YrG303/Yr15 locus revealed a single candidate gene (CG) with conserved domains that may indicate a role in disease resistance response. Validation of the CG was carried out using EMS mutagenesis (loss-of- function approach). Sequencing of the CG in susceptible yr15/yrG303 plants revealed three independent mutants that harbour non-functional yr15/yrG303 alleles within the CG conserved domains, and therefore validated its function as a Pstresistance gene. Evaluation of marker-assisted-selection (MAS) for Yr15. Introgressions of Yr15 into cultivated wheat are widely used now. Recently, we have shown that DNA markers linked to Yr15 can be used as efficient tools for introgression of Yr15 into cultivated wheat via MAS. The developed markers were consistent and polymorphic in all 34 tested introgressions and are the most recommended markers for the introgression of Yr15. These markers will facilitate simultaneous selection for multiple Yr genes and help to avoid escapees during the selection process. Engineering of improved chromosome 1BS that harbors multiple beneficial traits. We have implemented the knowledge and genetic resources accumulated in this project for the engineering of 1B "super-chromosome" that harbors multiple beneficial traits. We completed the generation of a chromosome including the rye 1RS distal segment associated with improved drought tolerance with the Yr gene, Yr15, and the strong gluten allele 7Bx-over-expressor (7Bxᴼᴱ). We have completed the introgression of this improved chromosome into our recently released variety Patwin-515HP and our rain fed variety Kern, as well as to our top breeding lines UC1767 and UC1745. Elucidating the mechanism of resistance exhibited by Yr36 (WKS1). The WHEAT KINASE START1 (WKS1) resistance gene (Yr36) confers partial resistance to Pst. We have shown that wheat plants transformed with WKS1 transcript are resistant to Pst. WKS1 is targeted to the chloroplast where it phosphorylates the thylakoid-associatedascorbateperoxidase (tAPX) and reduces its ability to detoxify peroxides. Based on these results, we propose that the phosphorylation of tAPX by WKS1 reduces the ability of the cells to detoxify ROS and contributes to cell death. Distribution and diversity of WKS in wild emmer populations. We have shown that WKS1 is present only in the southern distribution range of wild emmer in the Fertile Crescent. Sequence analysis revealed a high level of WKS1 conservation among wild emmer populations, in contrast to the high level of diversity observed in NB-LRR genes. This phenomenon shed some light on the evolution of genes that confer partial resistance to Pst. Three new WKS1 haplotypes displayed a resistance response, suggesting that they can be useful to improve wheat resistance to Pst. In summary, we have improved our understanding of cereals’ resistance mechanisms to rusts and we have used that knowledge to develop improved wheat varieties.
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