Artykuły w czasopismach na temat „Motifs riches en leucines”
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Ollendorff, V., T. Noguchi i D. Birnbaum. "Des protéines à motifs riches en leucine définissent une cinquième famille de molécules d'adhérence". médecine/sciences 9, nr 10 (1993): 1102. http://dx.doi.org/10.4267/10608/2814.
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Nufer, Oliver, Svend Guldbrandsen, Martin Degen, Felix Kappeler, Jean-Pierre Paccaud, Katsuko Tani i Hans-Peter Hauri. "Role of cytoplasmic C-terminal amino acids of membrane proteins in ER export". Journal of Cell Science 115, nr 3 (1.02.2002): 619–28. http://dx.doi.org/10.1242/jcs.115.3.619.
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Export of membrane proteins from the ER is believed to be selective and require transport signals, but the identity of such signals has remained elusive. The recycling type I membrane protein ERGIC-53 carries a C-terminal diphenylalanine motif that is required for efficient ER export. Here we show that this motif can be functionally substituted by a single phenylalanine or tyrosine at position -2, two leucines or isoleucines at position -1 and -2 or a single valine at position -1. These motifs are common among mammalian type I membrane proteins. A single C-terminal valine, but none of the other motifs,accelerates transport of inefficiently exported reporter constructs and hence operates as an export signal. The valine signal is position, but not context,dependent. All transport motifs mediate COPII binding in vitro with distinct preferences for the COPII subunits Sec23p, Sec24Bp, Sec24Cp and p125. These results suggest that cytoplasmic C-terminal amino-acid motifs, either alone or in conjunction with other transport determinants, accelerate ER export of numerous type I and probably polytopic membrane proteins by mediating interaction with COPII coat components.
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Zhang, Yue, i Joseph T. Barbieri. "A Leucine-Rich Motif Targets Pseudomonas aeruginosa ExoS within Mammalian Cells". Infection and Immunity 73, nr 12 (grudzień 2005): 7938–45. http://dx.doi.org/10.1128/iai.73.12.7938-7945.2005.
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ABSTRACT Type III cytotoxins contribute to the ability of bacterial pathogens to subvert the host innate immune system. ExoS (453 amino acids) is a bifunctional type III cytotoxin produced by Pseudomonas aeruginosa. Residues 96 to 232 comprise a Rho GTPase activating protein domain, while residues 233 to 453 comprise a 14-3-3-dependent ADP-ribosyltransferase domain. An N-terminal domain (termed the membrane localization domain [MLD]) targets ExoS to the Golgi-endoplasmic reticulum (Golgi-ER) of mammalian cells. This study identifies an amino acid motif that is responsible for the membrane binding properties of the MLD. Deletion mapping showed that the MLD included a symmetrical leucine-rich motif within residues 51 to 77 of ExoS. The terminal dileucines and internal leucines and an isoleucine within the MLD, but not charged or other hydrophobic residues, targeted a reporter protein to the Golgi-ER region of HeLa cells. Mutations of the leucines within the MLD did not affect type III secretion or translocation into HeLa cells but limited the ability of ExoS to ADP-ribosylate Ras GTPases. Mutations of charged residues within the MLD did not affect type III secretion, delivery into HeLa cells, or the ability of ExoS to ADP-ribosylate Ras GTPases. The organization of the leucines within the MLD of ExoS is different from that of previously described leucine-rich motifs but is present in several other bacterial proteins. This implies a role for intracellular targeting in the efficient targeting of mammalian cells by type III cytotoxins.
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Gu, Howard H., Xiaohong Wu, Bruno Giros, Marc G. Caron, Michael J. Caplan i Gary Rudnick. "The NH2-terminus of Norepinephrine Transporter Contains a Basolateral Localization Signal for Epithelial Cells". Molecular Biology of the Cell 12, nr 12 (grudzień 2001): 3797–807. http://dx.doi.org/10.1091/mbc.12.12.3797.
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When expressed in epithelial cells, dopamine transporter (DAT) was detected predominantly in the apical plasma membrane, whereas norepinephrine transporter (NET) was found in the basolateral membrane, despite 67% overall amino acid sequence identity. To identify possible localization signals responsible for this difference, DAT–NET chimeras were expressed in MDCK cells and localized by immunocytochemistry and transport assays. The results suggested that localization of these transporters in MDCK cells depends on their highly divergent NH2-terminal regions. Deletion of the first 58 amino acids of DAT (preceding TM1) did not change its apical localization. However, the replacement of that region with corresponding sequence from NET resulted in localization of the chimeric protein to the basolateral membrane, suggesting that the NH2-terminus of NET, which contains two dileucine motifs, contains a basolateral localization signal. Mutation of these leucines to alanines in the context of a basolaterally localized NET/DAT chimera restored transporter localization to the apical membrane, indicating that the dileucine motifs are critical to the basolateral localization signal embodied within the NET NH2-terminal region. However, the same mutation in the context of wild-type NET did not disrupt basolateral localization, indicating the presence of additional signals in NET directing its basolateral localization within the plasma membrane.
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Singh, Nisha, Megha Ujinwal, Sapna Langyan, R. Z. Sayyed, Hesham Ali El Enshasy i Ahmed A. Kenawy. "Genome-wide exploration of sugar transporter (sweet) family proteins in Fabaceae for Sustainable protein and carbon source". PLOS ONE 17, nr 5 (13.05.2022): e0268154. http://dx.doi.org/10.1371/journal.pone.0268154.
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Sugar transporter proteins (STPs) are membrane proteins required for sugar transport throughout cellular membranes. They plays an imperative role in sugar transmission across the plant and determinants of crop yield. However, the analysis of these important STPs Sugars Will Eventually be Exported Transporters (SWEET) family in legumes is still not well-documented and remains unclear. Therefore, the in-silico analysis of STPs has been performed to unravel their cellular, molecular, and structural composition in legume species. This study conducted a systematic search for STPs in Cajanus cajan using the Blastp algorithm to understand its molecular basis. Here, we performed a comprehensive analysis of 155 identified SWEET proteins across 12 legumes species, namely (Cajanus cajan, Glycine max, Vigna radiate, Vigna angularis, Medicago truncatula, Lupinus angustifolius, Glycine soja, Spatholobus suberectus, Cicer arietinum, Arachis ipaensis, Arachis hypogaea, Arachis duranensis). The amino acid composition and motif analysis revealed that SWEET proteins are rich in essential amino acids such as leucine, valine, isoleucine, phenylalanine, and serine while less profuse in glutamine, tryptophan, cysteine, and histidine. A total of four main conserved motifs of SWEET proteins are also highly abundant in these amino acids. The present study deciphered the details on primary physicochemical properties, secondary, tertiary structure, and phylogenetic analysis of SWEETs protein. Majorities of SWEET proteins (72.26%) are in stable form with an average instability index of 36.5%, and it comprises a higher fraction of positively charged amino acid Arg + Lys residues. Secondary structure analysis shown that these proteins are richer in alpha-helix (40%) than extended strand (30%) and random coil (25%), respectively. Furthermore, to infer their mechanism at a structural and functional level which play an essential roles in growth, development, and stress responses. This study will be useful to examine photosynthetic productivity, embryo sugar content, seed quality, and yield enhancement in Fabaceae for a sustainable source of essential amino acids and carbon source.
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Alfiannurdin, Nurlaila, Pipin Tresna i Cucu Ruhidawati. "WARISAN BUDAYA CIREBON: MENGUNGKAP SEJARAH DAN MOTIF BATIK TRUSMI". NUSRA: Jurnal Penelitian dan Ilmu Pendidikan 5, nr 1 (28.02.2024): 415–23. http://dx.doi.org/10.55681/nusra.v5i1.2267.
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This article uses a literature study approach to explore in depth the history and motifs attached to Trusmi batik, one of the unique cultural heritages of Cirebon. Using a literature study method, this research details the evolution of Trusmi batik making techniques as well as identifying and analyzing the meaning behind its distinctive motifs. The research results illustrate how this textile art reflects the traditional values and rich culture of Cirebon. The implications of these findings not only provide in-depth insight into Trusmi batik art but also provide a strong basis for efforts to preserve and develop local culture. This article has value as a guide for researchers, artists, and cultural observers who are interested in preserving cultural riches through traditional art, especially in the context of Trusmi batik in Cirebon. We can better appreciate and preserve the uniqueness of Cirebon culture for future generations by studying the background and motifs of Trusmi batik. This cultural heritage shows how well Indonesia has done in cultivating regional customs that influence textile arts and highlights the diversity and resilience of Indonesian culture, both of which should be respected and preserved.
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Jusman, Yessi, Iqbal Tawaqal i Maryza Intan Rahmawati. "Classification of Weaving Motifs Based on Their Area of Origin Using the Support Vector Machine Algorithm". E3S Web of Conferences 519 (2024): 03034. http://dx.doi.org/10.1051/e3sconf/202451903034.
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Indonesia has many cultural riches in the form of traditional fabrics, one of which is woven fabrics. Woven fabrics from each region showcase distinctive motifs, manifesting the local community’s daily life, culture, natural conditions, and beliefs. The diverse weaving motifs pose a challenge in determining the origin of the woven fabrics. It highlights the necessity of a system to detect and identify woven fabrics. Texture analysis was performed using the Gray Level Co-occurrence Matrix (GLCM). A classification method based on a Support Vector Machine (SVM) consisting of four models: Linear SVM, Quadratic SVM, Cubic SVM, and Fine Gaussian SVM was developed in this research. The images of woven fabrics came from three regions in Indonesia: Sumatra, Kalimantan, and Nusa Tenggara. This research utilized 240 training images and 12 testing images. The testing results unveiled that the Cubic SVM model, which achieved a 100% accuracy rate in 1.0835s, was the optimum SVM model for the weaving classification.
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HAYES, H. "ADN et chromosomes". INRAE Productions Animales 13, HS (22.12.2000): 13–20. http://dx.doi.org/10.20870/productions-animales.2000.13.hs.3806.
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Chaque chromosome contient une seule molécule d’ADN. L’ADN déroulé d’un noyau de cellule humaine mesurerait environ 1,8 m : chaque molécule d’ADN est enroulée et compactée en plusieurs étapes, grâce à l’association de différentes protéines, et loge dans le noyau de 6 µm de diamètre. Le degré de condensation de l’ADN est variable selon les régions chromosomiques et les régions les moins condensées sont les plus riches en gènes. L’ADN est composé d’une variété de séquences codantes ou non et répétées ou non dont l’organisation dans le chromosome est caractéristique de la métaphase. Certaines séquences peuvent être corrélées en partie avec les motifs de bandes spécifiques de chaque paire chromosomique produits par les techniques de marquage chromosomique.
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Hwang, Moonsun, Jae-kyun Ko, Noah Weisleder, Hiroshi Takeshima i Jianjie Ma. "Redox-dependent oligomerization through a leucine zipper motif is essential for MG53-mediated cell membrane repair". American Journal of Physiology-Cell Physiology 301, nr 1 (lipiec 2011): C106—C114. http://dx.doi.org/10.1152/ajpcell.00382.2010.
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We recently discovered that MG53, a muscle-specific tripartite motif (TRIM) family protein, functions as a sensor of oxidation to nucleate the assembly of cell membrane repair machinery. Our data showed that disulfide bond formation mediated by Cys242 is critical for MG53-mediated translocation of intracellular vesicles toward the injury sites. Here we test the hypothesis that leucine zipper motifs in the coiled-coil domain of MG53 constitute an additional mechanism that facilitates oligomerization of MG53 during cell membrane repair. Two leucine zipper motifs in the coiled-coil domain of MG53 (LZ1 - L176/L183/L190/V197 and LZ2 - L205/L212/L219/L226) are highly conserved across the different animal species. Chemical cross-linking studies show that LZ1 is critical for MG53 homodimerization, whereas LZ2 is not. Mutations of the conserved leucines into alanines in LZ1, not in LZ2, diminish the redox-dependent oligomerization of MG53. Live cell imaging studies demonstrate that the movement of green fluorescent protein (GFP)-tagged MG53 mutants (GFP-LA1 and GFP-LA2) is partially compromised in response to mechanical damage of the cell membrane, and the GFP-LA1/2 double mutant is completely ineffective in translocation toward the injury sites. In addition to the leucine zipper-mediated intermolecular interaction, redox-dependent cross talk between MG53 appears to be an obligatory step for cell membrane repair, since in vivo modification of cysteine residues with alkylating reagents can prevent the movement of MG53 toward the injury sites. Our data show that oxidation of the thiol group of Cys242 and leucine zipper-mediated interaction among the MG53 molecules both contribute to the nucleation process for MG53-mediated cell membrane repair.
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Anderson, Damon S., Pratima Adhikari, Katherine D. Weaver, Alvin L. Crumbliss i Timothy A. Mietzner. "The Haemophilus influenzae hFbpABC Fe3+ Transporter: Analysis of the Membrane Permease and Development of a Gallium-Based Screen for Mutants". Journal of Bacteriology 189, nr 14 (11.05.2007): 5130–41. http://dx.doi.org/10.1128/jb.00145-07.
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ABSTRACT The obligate human pathogen Haemophilus influenzae utilizes a siderophore-independent (free) Fe3+ transport system to obtain this essential element from the host iron-binding protein transferrin. The hFbpABC transporter is a binding protein-dependent ABC transporter that functions to shuttle (free) Fe3+ through the periplasm and across the inner membrane of H. influenzae. This investigation focuses on the structure and function of the hFbpB membrane permease component of the transporter, a protein that has eluded prior characterization. Based on multiple-sequence alignments between permease orthologs, a series of site-directed mutations targeted at residues within the two conserved permease motifs were generated. The hFbpABC transporter was expressed in a siderophore-deficient Escherichia coli background, and effects of mutations were analyzed using growth rescue and radiolabeled 55Fe3+ transport assays. Results demonstrate that mutation of the invariant glycine (G418A) within motif 2 led to attenuated transport activity, while mutation of the invariant glycine (G155A/V/E) within motif 1 had no discernible effect on activity. Individual mutations of well-conserved leucines (L154D and L417D) led to attenuated and null transport activities, respectively. As a complement to site-directed methods, a mutant screen based on resistance to the toxic iron analog gallium, an hFbpABC inhibitor, was devised. The screen led to the identification of several significant hFbpB mutations; V497I, I174F, and S475I led to null transport activities, while S146Y resulted in attenuated activity. Significant residues were mapped to a topological model of the hFbpB permease, and the implications of mutations are discussed in light of structural and functional data from related ABC transporters.
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Makris, Constantin, Jaclyn L. Roberts i Michael Karin. "The Carboxyl-Terminal Region of IκB Kinase γ (IKKγ) Is Required for Full IKK Activation". Molecular and Cellular Biology 22, nr 18 (15.09.2002): 6573–81. http://dx.doi.org/10.1128/mcb.22.18.6573-6581.2002.
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ABSTRACT IκB kinase γ (IKKγ) (also known as NEMO, Fip-3, and IKKAP-1) is the essential regulatory component of the IKK complex; it is required for NF-κB activation by various stimuli, including tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1), phorbol esters, lipopolysaccharides, and double-stranded RNA. IKKγ is encoded by an X-linked gene, deficiencies in which may result in two human genetic disorders, incontinentia pigmenti (IP) and hypohidrotic ectodermal dysplasia with severe immunodeficiency. Subsequent to the linkage of IKKγ deficiency to IP, we biochemically characterized the effects of a mutation occurring in an IP-affected family on IKK activity and NF-κB signaling. This particular mutation results in premature termination, such that the variant IKKγ protein lacks its putative C-terminal Zn finger and, due to decreased mRNA stability, is underexpressed. Correspondingly, IKK and NF-κB activation by TNF-α and, to a lesser extent, IL-1 are reduced. Mutagenesis of the C-terminal region of IKKγ was performed in an attempt to define the role of the putative Zn finger and other potential functional motifs in this region. The mutants were expressed in IKKγ-deficient murine embryonic fibroblasts (MEFs) at levels comparable to those of endogenous IKKγ in wild-type MEFs and were able to associate with IKKα and IKKβ. Substitution of two leucines within a C-terminal leucine zipper motif markedly reduced IKK activation by TNF-α and IL-1. Another point mutation resulting in a cysteine-to-serine substitution within the putative Zn finger motif affected IKK activation by TNF-α but not by IL-1. These results may explain why cells that express these or similar mutant alleles are sensitive to TNF-α-induced apoptosis despite being able to activate NF-κB in response to other stimuli.
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Överby, Anna K., Vsevolod L. Popov, Ralf F. Pettersson i Etienne P. A. Neve. "The Cytoplasmic Tails of Uukuniemi Virus (Bunyaviridae) GN and GC Glycoproteins Are Important for Intracellular Targeting and the Budding of Virus-Like Particles". Journal of Virology 81, nr 20 (1.08.2007): 11381–91. http://dx.doi.org/10.1128/jvi.00767-07.
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ABSTRACT Functional motifs within the cytoplasmic tails of the two glycoproteins GN and GC of Uukuniemi virus (UUK) (Bunyaviridae family) were identified with the help of our recently developed virus-like particle (VLP) system for UUK virus (A. K. Overby, V. Popov, E. P. Neve, and R. F. Pettersson, J. Virol. 80:10428-10435, 2006). We previously reported that information necessary for the packaging of ribonucleoproteins into VLPs is located within the GN cytoplasmic tail (A. K. Overby, R. F. Pettersson, and E. P. Neve, J. Virol. 81:3198-3205, 2007). The GN glycoprotein cytoplasmic tail specifically interacts with the ribonucleoproteins and is critical for genome packaging. In addition, two other regions in the GN cytoplasmic tail, encompassing residues 21 to 25 and 46 to 50, were shown to be important for particle generation and release. By the introduction of point mutations within these two regions, we demonstrate that leucines at positions 23 and 24 are crucial for the initiation of VLP budding, while leucine 46, glutamate 47, and leucine 50 are important for efficient exit from the endoplasmic reticulum and subsequent transport to the Golgi complex. We found that budding and particle generation are highly dependent on the intracellular localization of both glycoproteins. The short cytoplasmic tail of UUK GC contains a lysine at position −3 from the C terminus that is highly conserved among members of the Phlebovirus, Hantavirus, and Orthobunyavirus genera. Mutating this single amino acid residue in GC resulted in the mislocalization of not only GC but also GN to the plasma membrane, and VLP generation was compromised in cells expressing this mutant. Together, these results demonstrate that the cytoplasmic tails of both GN and GC contain specific information necessary for efficient virus particle generation.
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Kaykas, Ajamete, Kathleen Worringer i Bill Sugden. "LMP-1's Transmembrane Domains Encode Multiple Functions Required for LMP-1's Efficient Signaling". Journal of Virology 76, nr 22 (15.11.2002): 11551–60. http://dx.doi.org/10.1128/jvi.76.22.11551-11560.2002.
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ABSTRACT The latent membrane protein-1 (LMP-1) of Epstein-Barr virus (EBV) contributes to the proliferation of infected B lymphocytes by signaling through its binding to cellular signaling molecules. It apparently mimics members of the tumor necrosis factor receptor family, in particular, CD40, by binding a similar set of cellular molecules as does CD40. LMP-1 differs dramatically in its structure from CD40. LMP-1 has six membrane-spanning domains as opposed to CD40's one. LMP-1 also differs from CD40 in its apparent independence of a ligand for its signaling. We have examined the role of LMP-1's membrane-spanning domains in its signaling. Their substitution with six membrane-spanning domains from the LMP-2A protein of EBV yields a derivative which neither coimmunoprecipitates with LMP-1 nor signals to increase the activity of NF-κB as does wild-type LMP-1. These observations indicate that LMP-1 has specific sequences in its membrane-spanning domains required for these activities. LMP-1's first and sixth membrane-spanning domains have multiple leucine residues potentially similar to leucine-heptad motifs that can mediate protein-protein interactions in membranes (Gurezka et al., J. Biol. Chem. 274:9265-9270, 1999). Substitution of seven leucines in LMP-1's sixth membrane-spanning domain has no effect on its function, whereas similar substitutions in its first membrane-spanning domain yielded a derivative which aggregates as does wild-type LMP-1 but has only 3% of wild-type's ability to signal through NF-κB. Importantly, this derivative complements a mutant of LMP-1 with wild-type membrane-spanning domains but no carboxy-terminal signaling domain. These findings together indicate that the membrane-spanning domains of LMP-1 contribute multiple functions to its signaling.
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Mubin, Ilmiawan. "MAKNA SIMBOL ATAU MOTIF KAIN TENUN KHAS MASYARAKAT DAERAH BIMA DI KELURAHAN RABA DOMPU KOTA BIMA PROPINSI NUSA TENGGARA BARAT." Historis | FKIP UMMat 1, nr 1 (15.02.2018): 21. http://dx.doi.org/10.31764/historis.v1i1.205.
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Indonesia sebagai negara kepulauan, yang terdiri dari ribuan pulau yang membentang mulai Sabang hingga Merauke. Sebagai negara yang beribu-ribu pulau tentu memiliki potensi dan kekayaan alam untuk dikembangkan. Kita tahu berbagai potensi dan kekayaan alam banyak dijumpai diseluruh daerah di tanah air. Salah satu potensi dan kekayaan Nusantara terdapat di propinsi Nusa Tenggara Barat, tepatnya di Kota Bima yang memiliki sejarah dan leluhur yang mempunyai nilai eksotis untuk dapat dikembangkan, salah satunya yaitu Tenun Khas Bima.Budaya masyarakat Bima pada umumnya menjunjung tinggi adat istiadat dan tradisi serta modernisme di aktivitas formal, misalnya dalam acara hari ulang tahun lahirnya Kota Bima, dan acara lain yang bernuansa kelokalan. Atas dasar realita tersebut, keberadaan tenun daerah Bima di dalam acara tersebut sangatlah berperan sebagai pakaian formal kedaerahan dalam upacara adat dan tradisi Kota Bima.Keahlian membuat kain tenun khas Bima serta bentuk-bentuk motif dan makna nilai simbol yang merupakan warisan turun temurun yang hanya dimiliki oleh masyarakat daerah Bima, umumnya sebagai anak bangsa Indonesia, maka wajib mempertahankan keberadaan budaya tersebut serta ditumbuh kembangkan. Indonesia as an archipelago, consisting of thousands of islands stretching from Sabang to Merauke. As a country with thousands of islands of course has the potential and natural wealth to be developed. We know the various potentials and natural wealth are found throughout many regions in the country. One of the potentials and riches of the archipelago is found in the province of West Nusa Tenggara, precisely in the city of Bima which has a history and ancestors that have exotic value to be developed, one of which is Typical Woven Bima.Budaya community culture generally uphold the customs and traditions and modernism in formal activities, for example in the birthday event of the birth of Kota Bima, and other events that have nuances of localization. On the basis of the reality, the existence of weaving Bima area in the event is very role as a regional formal clothing in traditional ceremonies and traditions of Bima City. Expertise to make woven cloth Bima typical and forms of motifs and symbols of meaning that is a hereditary heritage that is owned only by the Bima local community, generally as a child of the nation of Indonesia, it is mandatory to maintain the existence of the culture and grown to develop.
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Sharma, Shilpi, Moein Jafari, Amandip Bangar, Karen William, John Guatelli i Mary K. Lewinski. "The C-Terminal End of HIV-1 Vpu Has a Clade-Specific Determinant That Antagonizes BST-2 and Facilitates Virion Release". Journal of Virology 93, nr 11 (13.03.2019). http://dx.doi.org/10.1128/jvi.02315-18.
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ABSTRACTThe cellular protein bone marrow stromal antigen-2 (BST-2)/tetherin acts against a variety of enveloped viruses by restricting their release from the plasma membrane. The HIV-1 accessory protein Vpu counteracts BST-2 by downregulating it from the cell surface and displacing it from virion assembly sites. Previous comparisons of Vpus from transmitted/founder viruses and between viruses isolated during acute and chronic infection led to the identification of a tryptophan at position 76 in Vpu (W76) as a key determinant for the displacement of BST-2 from virion assembly sites. Although present in Vpus from clades B, D, and G, W76 is absent from Vpus from clades A, C, and H. Mutagenesis of the C-terminal region of Vpu from two clade C viruses led to the identification of a conserved LL sequence that is functionally analogous to W76 of clade B. Alanine substitution of these leucines partially impaired virion release. This impairment was even greater when the mutations were combined with mutations of the Vpu β-TrCP binding site, resulting in Vpu proteins that induced high surface levels of BST-2 and reduced the efficiency of virion release to less than that of virus lackingvpu. Microscopy confirmed that these C-terminal leucines in clade C Vpu, like W76 in clade B, contribute to virion release by supporting the displacement of BST-2 from virion assembly sites. These results suggest that although encoded differently, the ability of Vpu to displace BST-2 from sites of virion assembly on the plasma membrane is evolutionarily conserved among clade B and C HIV-1 isolates.IMPORTANCEAlthough targeted by a variety of restriction mechanisms, HIV-1 establishes chronic infection in most cases, in part due to the counteraction of these host defenses by viral accessory proteins. Using conserved motifs, the accessory proteins exploit the cellular machinery to degrade or mistraffic host restriction factors, thereby counteracting them. The Vpu protein counteracts the virion-tethering factor BST-2 in part by displacing it from virion assembly sites along the plasma membrane, but a previously identified determinant of that activity is clade specific at the level of protein sequence and not found in the clade C viruses that dominate the pandemic. Here, we show that clade C Vpu provides this activity via a leucine-containing sequence rather than the tryptophan-containing sequence found in clade B Vpu. This difference seems likely to reflect the different evolutionary paths taken by clade B and clade C HIV-1 in human populations.
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Hughes Jovanović, Elizabeth. "The Haywain Triptych: A Painted Sermon on the Fruits of Avarice". ЧАСОПИС ПРАВОСЛАВНОГ БОГОСЛОВСКОГ ФАКУЛТЕТА СВ ВАСИЛИЈЕ ОСТРОШКИ 8, nr 21 (8.11.2022). http://dx.doi.org/10.7251/cpbfsvo2221036.
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The Haywain Triptych is a set of three painted oil on oak panels that contain a complete frontispiece on the exterior and a three-part composition on the interior. It dates to approximately 1510–1516. It was painted by Hieronymus Bosch as a visual ser- mon that discusses the various evils that arise from avarice, most notably violence and aggression. The imagery that is used is drawn from several theological sources. Bosch uses motifs mostly inspired by the Modern Devotion movement and popular theological literature of his time, including the Vulgate translation of the Bible, Augustine, Aquinas, à Kempis, Chrysostom, and Bernard of Clairvaux. The most significant image used is the allegory of hay as a representation of temporal wealth, which is a motif sourced from the Dutch translation of the Vulgate and the popular literary imagery of Bosch’s time. The triptych is a judgment scene that follows original sin, the situation of fallen humanity with regard to avarice, and the ultimate result of sin through death. It also contains a message of entreaty to put aside the sins that come from worldly riches and to follow the righteous path through poverty toward Christ.
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Li, Yimeng, Shu Shen, Liangbo Hu, Fei Deng, Just M. Vlak, Zhihong Hu, Hualin Wang i Manli Wang. "The Functional Oligomeric State of Tegument Protein GP41 Is Essential for Baculovirus Budded Virion and Occlusion-Derived Virion Assembly". Journal of Virology 92, nr 12 (11.04.2018). http://dx.doi.org/10.1128/jvi.02083-17.
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ABSTRACTgp41, one of the baculovirus core genes, encodes the only recognized tegument (O-glycosylated) protein of the occlusion-derived virion (ODV) phenotype so far. A previous study using a temperature-sensitive Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) mutant showed that GP41 plays a crucial role in budded virion (BV) formation. However, the precise function of GP41 in the baculovirus replication cycle remains unclear. In this study, AcMNPV GP41 was found to accumulate around the ring zone (RZ) region within the infected nucleus and finally assembled into both BVs and ODVs. Deletion ofgp41from the AcMNPV genome showed that BVs were no longer formed and ODVs were no longer assembled, suggesting the essential role of this gene in baculovirus virion morphogenesis. In infected cells, besides the 42-kDa monomers, dimers and trimers were detected under nonreducing conditions, whereas only trimeric GP41 forms were selectively incorporated into BVs or ODVs. Mutations of all five cysteines in GP41 individually had minor effects on GP41 oligomer formation, albeit certain mutations impaired infectious BV production, suggesting flexibility in the intermolecular disulfide bonding. Single mutations of key leucines within two predicted leucine zipper-like motifs did not interfere with GP41 oligomerization or BV and ODV formation, but double leucine mutations completely blocked oligomerization of GP41 and progeny BV production. In the latter case, the usual subcellular localization, especially RZ accumulation, of GP41 was abolished. The above findings clearly point out a close correlation between GP41 oligomerization and function and therefore highlight the oligomeric state as the functional form of GP41 in the baculovirus replication cycle.IMPORTANCEThe tegument, which is sandwiched between the nucleocapsid and the virion envelope, is an important substructure of many enveloped viruses. It is composed of one or more proteins that have important functions during virus entry, replication, assembly, and egress. Unlike another large DNA virus (herpesvirus) that encodes an extensive set of tegument components, baculoviruses very likely exploit the major tegument protein, GP41, to execute functions in baculovirus virion morphogenesis and assembly. However, the function of this O-glycosylated baculovirus tegument protein remains largely unknown. In this study, we identified trimers as the functional structure of GP41 in baculovirus virion morphogenesis and showed that both disulfide bridging and protein-protein interactions via the two leucine zipper-like domains are involved in the formation of different oligomeric states. This study advances our understanding of the unique viral tegument protein GP41 participating in the life cycle of baculoviruses.