Gotowa bibliografia na temat „DJ-1 Family Protein”

DJ-1 mutations are rare causes of autosomal recessive early-onset Parkinson’s disease (AR-EOPD) and relatively rarely reported in the Chinese population. Here, we used the whole-exome sequencing and Sanger sequencing to investigate DJ-1 mutations in the Chinese population and confirmed the pathogenicity of the mutation using primary fibroblasts established from skin biopsies. We identified a novel homozygous mutation (c.390delA, p.D131Tfs*3) in DJ-1 in a consanguineous Chinese family. The proband in this family had parkinsonism at the age of 22. His brain MRI indicated brain iron accumulation in the basal ganglia and cerebellum. The novel mutation caused DJ-1 protein deficiency, led to mitochondrial dysfunction, inhibited cell proliferation, and anti-oxidant defense.

Loss-of-function mutations in gene encoding DJ-1 contribute to the pathogenesis of autosomal recessive early-onset familial forms of Parkinson’s disease (PD). DJ-1 is a multifunctional protein and plays a protective role against oxidative stress-induced mitochondrial damage and cell death, but the exact mechanism underlying this is not yet clearly understood. Here, using coimmunoprecipitation (Co-IP) and immunofluorescence methods, we prove that Bcl-2-associated athanogene 5 (BAG5), a BAG family member, interacts with DJ-1 in mammalian cells. Moreover, we show that BAG5 could decrease stability of DJ-1 and weaken its role in mitochondrial protection probably by influencing dimerization in stress condition. Our study reveals the relationship of BAG5 and DJ-1 suggesting a potential role for BAG5 in the pathogenesis of PD through its functional interactions with DJ-1.

Members of the DJ-1 protein family are multifunctional enzymes whose loss increases the susceptibility of the cell to oxidative stress. However, little is known about the function of the plant DJ-1 homologs. Therefore, we analyzed the effect of oxidation on the structure and function of chloroplastic AtDJ-1B and studied the phenotype of T-DNA lines lacking the protein. In vitro oxidation of AtDJ-1B with H2O2 lowers its glyoxalase activity, but has no effect on its holdase chaperone function. Remarkably, upon oxidation, the thermostability of AtDJ-1B increases with no significant alteration of the overall secondary structure. Moreover, we found that AtDJ-1B transcript levels are invariable, and loss of AtDJ-1B does not affect plant viability, growth and stress response. All in all, two discrete functions of AtDJ-1B respond differently to H2O2, and AtDJ-1B is not essential for plant development under stress.

Disturbed magnesium (Mg2+) homoeostasis and increased levels of OS (oxidative stress) are associated with poor clinical outcomes in patients suffering from neurodegenerative, cardiovascular and metabolic diseases. Data from clinical and animal studies suggest that MD (Mg2+ deficiency) is correlated with increased production of ROS (reactive oxygen species) in cells, but a straightforward causal relationship (including molecular mechanisms) between the two conditions is lacking. The multifactorial protein PARK7/DJ-1 is a major antioxidant protein, playing a key role in cellular redox homoeostasis, and is a positive regulator of AR (androgen receptor)-dependent transcription. SLC41A1 (solute carrier family 41 member 1), the gene encoding a ubiquitous cellular Mg2+E (Mg2+efflux) system, has been shown to be regulated by activated AR. We hypothesize that overexpression/up-regulation of PARK7/DJ-1, attributable to OS and related activation of AR, is an important event regulating the expression of SLC41A1 and consequently, modulating the Mg2+E capacity. This would involve changes in the transcriptional activity of PARK7/DJ-1, AR and SLC41A1, which may serve as biomarkers of intracellular MD and may have clinical relevance. Imipramine, in use as an antidepressant, has been shown to reduce the Mg2+E activity of SLC41A1 and OS. We therefore hypothesize further that administration of imipramine or related drugs will be beneficial in MD- and OS-associated diseases, especially when combined with Mg2+ supplementation. If proved true, the OS-responsive functional axis, PARK7/DJ-1–AR–SLC41A1, may be a putative mechanism underlying intracellular MD secondary to OS caused by pro-oxidative stimuli, including extracellular MD. Furthermore, it will advance our understanding of the link between OS and MD.

PD (Parkinson's disease) is an aetiologically heterogeneous disorder characterized by a clinical phenotype consisting of resting tremor, rigidity and bradykinesia. Motor symptoms are associated with a progressive loss of dopaminergic neurons, with Lewy body inclusions within surviving neurons. Although heritability studies have shown evidence of familial aggregation, twin studies have provided limited support for a genetic aetiology. Nevertheless, classical linkage methods have nominated 11 regions of the genome and pathogenic mutations have been identified in several genes, including α-synuclein, parkin, ubiquitin C-ter-minal hydrolase L1, oncogene DJ-1, PTEN-induced protein kinase 1 and microtubule-associated protein tau. Most recently, heterozygous mutations in LRRK2 (leucine-rich repeat kinase 2) were found to cause late-onset, autosomal-dominant PD. Despite their consistent clinical phenotype, family members with LRRK2 mutations can have variable α-synuclein and tau pathologies. Lrrk2 is a member of the Roc (Ras of complex proteins) family, with Ras GTPase and MAPKKK (mitogen-activated protein kinase kinase kinase) catalytic domains. Thus its discovery highlights vesicle dynamics and secondary-messenger signalling in disease pathophysiology. To diagnose a disease accurately and effectively treat it, requires an understanding of its molecular pathogenesis. Herein, we provide an overview of the genetics of PD, how these discoveries are revolutionizing long-held beliefs and more importantly how this knowledge may be translated into patient therapy.

Parkinson’s disease (PD) is a major neurodegenerative disorder for which the etiology and pathogenesis remain as elusive as for Alzheimer's disease. PD appears to be caused by genetic and environmental factors, and pedigree and cohort studies have identified numerous susceptibility genes and loci related to PD. Autosomal recessive mutations in the genesParkin, Pink1, DJ-1, ATP13A2, PLA2G6, andFBXO7have been linked to PD susceptibility. Such mutations inATP13A2, also namedPARK9, were first identified in 2006 in a Chilean family and are associated with a juvenile-onset, levodopa-responsive type of Parkinsonism called Kufor-Rakeb syndrome (KRS). KRS involves pyramidal degeneration, supranuclear palsy, and cognitive impairment. Here we review current knowledge about theATP13A2gene, clinical characteristics of patients with PD-associatedATP13A2mutations, and models of how the ATP13A2 protein may help prevent neurodegeneration by inhibitingα-synuclein aggregation and supporting normal lysosomal and mitochondrial function. We also discuss anotherATP13A2mutation that is associated with the family of neurodegenerative disorders called neuronal ceroid lipofuscinoses (NCLs), and we propose a single pathway wherebyATP13A2mutations may contribute to NCLs and Parkinsonism. Finally, we highlight how studies of mutations in this gene may provide new insights into PD pathogenesis and identify potential therapeutic targets.

Parkinson’s disease (PD) is caused by abnormal accumulation of α-synuclein in dopaminergic neurons of the substantia nigra, which subsequently causes motor symptoms. Neuroinflammation plays a vital role in the pathogenesis of neurodegeneration in PD. This neuroinflammatory neurodegeneration involves the activation of microglia, upregulation of proinflammatory factors, and gut microbiota. In this review, we summarized the recent findings on detection of PD by using inflammatory biomarkers, such as interleukin (IL)-1β, IL-2, IL-6, IL-10, tumor necrosis factor (TNF)-α; regulated upon activation, normal T cell expressed and presumably secreted (RANTES) and high-sensitivity c-reactive protein (hsCRP); and radiotracers such as [11C]PK11195 and [18F]-FEPPA, as well as by monitoring disease progression and the treatment response. Many PD-causing mutations in SNCA, LRRK2, PRKN, PINK1, and DJ-1 are also associated with neuroinflammation. Several anti-inflammatory medications, including nonsteroidal anti-inflammatory drugs (NSAID), inhibitors of TNF-α and NLR family pyrin domain containing 3 (NLRP3), agonists of nuclear factor erythroid 2-related factor 2 (NRF2), peroxisome proliferator-activated receptor gamma (PPAR-γ), and steroids, have demonstrated neuroprotective effects in in vivo or in vitro PD models. Clinical trials applying objective biomarkers are required to investigate the therapeutic potential of anti-inflammatory medications for PD.

A-factor (2-isocapryloyl-3R-hydroxymethyl-γ-butyrolactone) is a chemical signalling molecule, or microbial hormone, that triggers aerial mycelium formation and secondary metabolism in Streptomyces griseus. A-factor pro- duced in a growth-dependent manner switches on the transcription of adpA, encoding a transcriptional activator, by binding to ArpA, the A-factor receptor protein, which has bound to the adpA promoter, and dissociating the bound ArpA from the DNA. AdpA then activates a number of genes of various functions required for morphological development and secondary metabolism, forming an AdpA regulon. ArpA, which belongs to the TetR family, contains a helix–turn–helix DNA-binding motif in its N-terminal portion and an A-factor-binding pocket (5 Å (0.5 nm) diameter and 20 Å (2 nm) long) in its C-terminal portion, as implied by X-ray crystallography of CprB, an ArpA homologue. The ligand pocket, which can accommodate an entire A-factor-type molecule of γ-butyrolactone, is completely embedded in the C-terminal portion. Upon binding A-factor, a long helix connecting the A-factor-binding and ligand-binding domains is relocated, as a result of which the DNA-binding helix moves outside, resulting in dissociation from DNA. AdpA, which belongs to the AraC/XylS family, contains a ThiJ/PfpI/DJ-1-like dimerization domain in its N-terminal portion and an AraC/XylS-type DNA-binding domain in its C-terminal portion. For transcriptional activation, AdpA can bind to various positions with respect to the transcriptional start points of the target genes and sometimes to multiple sites. We show here how A-factor triggers secondary metabolism and morphological development in S. griseus, with emphasis on the two key transcriptional factors, ArpA and AdpA, in the A-factor regulatory cascade.

Dissertação de Mestrado em Biologia Celular e Molecular apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.
A doença de Parkinson (DP) é a segunda doença neurodegenerativa mais comum, sendo a mais incidente dentro das doenças do movimento, e caracterizada por uma drástica perca de neurónios dopaminérgicos na região cerebral substantia nigra pars compacta (SNpc), levando à degeneração dos circuitos dopaminérgicos nigroestriatais. Várias evidências apontam para diversas disfunções celulares importantes na patogénese da DP, incluindo o stress oxidativo. Apesar de vários estudos na área terem sido realizados para uma maior elucidação sobre a doença, a etiologia e patogénese da Doença de Parkinson continuam por estar esclarecidas. No entanto, é sabido que a causa da maioria dos casos de DP são esporádicos, e que alguns casos raros têm uma componente genética, hereditária. De facto, diversas mutações em diversos genes têm sido identificadas como causadoras da forma hereditária da doença, o que contribuiu com importantes conhecimentos sobre os mecanismos moleculares que levam à neurodegeneração. O gene dj1, associado às formas genéticas da DP, foi identificado como sendo um gene autossómico recessivo responsável pela DP familiar, que se desenvolve em idades mais novas, o que o torna um candidato para ser estudado de forma a fornecer importantes conhecimentos sobre os mecanismos moleculares da doença. Várias funções foram atribuídas à proteína DJ-1, no entanto o seu papel de neuroprotecção é o mais relevante, provavelmente devido ao seu envolvimento na proteção contra o stress oxidativo. Estudos indicam que a proteína DJ-1 opera em diversos níveis interagindo, direta ou indiretamente, com várias proteínas. Apesar dos mecanismos através dos quais a proteína exerce a sua função neuroprotetora não serem completamente conhecidos, esta aparenta ter uma importante função na mediação de vias de sinalização e na modelação do metabolismo oxidativo. Vários estudos demonstraram que de facto o stress oxidativo é a condição que despoleta a função neuroprotectiva da DJ-1, alterando a conformação da proteína para uma forma oxidada, que é considerada a sua forma ativa. Além do mais, a estabilidade da maioria das interações estudadas entre a DJ-1 e outras proteínas é influenciada pelo seu estado oxidativo. Tendo isto em mente, o interatoma dinâmico da DJ-1 foi anteriormente estudado, de forma a fornecer uma caracterização abrangente dos interatores da proteína em condições do stress oxidativo. Este estudo possibilitou a identificação de diversas proteínas que interagem com a DJ-1, nomeadamente proteínas pertencentes à família das oxidoredutases, que estão relacionadas com a resposta celular ao stress oxidativo, como a NDUFA4, PGDH e a HADHA. No entanto, as interações da DJ-1 com essas proteínas estão ainda por serem validadas. Dentro deste contexto, diversas análises complementares foram realizadas de forma a validar a interação da DJ-1 com as proteínas pertencentes à família das oxidoredutases, incluindo imunoprecipitação, pull down e imunocitoquímica seguida de uma análise por microscopia confocal, em condições fisiológicas e de stress oxidativo. através do ensaio de imunocitoquímica seguido de análise por confocal das células SH-SY5Y, foi possível validar a interação entre as proteínas in situ, o que parece confirmar que tanto a HADHA como a PGDH são interatores da DJ- 1. Além disso, os resultados obtides através da análise por pull down sugerem uma interação das proteínas HADHA e PGDH com a proteína DJ-1 recombinante, na sua forma nativa, sendo essa interação aparentemente modelado pelo stress oxidativo, o que vem corroborar a os esukltados anteriores.foi utilizado de forma a estudar o interatoma da proteína em células SH-SY5Y em células expostas ao stress oxidativo ou em condições fisiológicas, de forma a aferir o envolvimento desta proteína na resposta celular ao stress oxidativa, e para expandir o interactoma dinâmico da DJ-1. Com esta metodologia, foi possível concluir que a proteína HADHA tem um interatoma dinâmico que é modelado pelo stress oxidativo. Diversas proteínas foram identificadas como interatores, pertencendo a diversos grupos funcionais, tais como proteínas do citoesqueleto, proteínas motoras, proteínas envolvidas na reparação do DNA e expressão de genes, e proteínas envolvidas em diferentes vias de sinalização. Além disso, muitas das proteínas identificadas como potenciais interatores da HADHA foram também anteriormente identificadas como interatores da DJ-1. A generalidade das proteínas quantificadas apresentou um aumento de interação com a HADHA em condições de stress oxidativo, fornecendo informações fundamentais sobre as suas funções biológicas associada à resposta celular a essa patologia, apontando para uma nova função da proteína HADHA relacionada com a proteção neuronal contra o stress oxidativo. Estes resultados contribuíram também para o aprofundar dos conhecimentos sobre a patogénese da doença de Parkinson, as potenciais vias envolvidas no despoletar da doença e a sua progressão, podendo fornecer novos potenciais alvos para o prognóstico, terapia e progressão da DP.
Parkinson’s disease (PD) is the second most common neurodegenerative disease and the most common movement disorder, characterized by massive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc), leading to degeneration of nigrostriatal dopaminergic pathways. Evidence suggest several cellular dysfunctions important for pathogenesis in PD, including oxidative stress. Even though several efforts have been made to obtain a deeper knowledge of this disease, the etiology and pathogenesis still remain unclear. Nevertheless, there is an agreement that the majority of PD cases are sporadic and some rare cases have familial background. Indeed, mutations in several genes have been reported to cause hereditary forms of the disease, leading to valuable insights into the molecular mechanisms of neurodegeneration. Among the genetic forms, Dj1 gene was identified as an autosomal recessive gene responsible for familial early-onset PD, meaning that deeper knowledge on its physiological functions will provide important insights into molecular mechanisms of PD. Several functions have been attributed to DJ-1 protein, being its putative role in neuroprotection the most relevant, probably due to its involvement in protection against oxidative stress. Evidence indicate that DJ-1 operates at multiple levels and interact, directly or indirectly, with several partners. Although the mechanisms through which DJ-1 mediates neuroprotection is not fully understood, it seems to play a pivotal role in the mediation of signaling pathways and modulation of the oxidative metabolism. Several studies reported that indeed oxidative stress is the trigger condition for DJ-1 neuroprotective function, in a way that conformational changes to an oxidized form were pointed out as protein’s active form. Moreover, the stability of the majority of the interactions reported is also influenced by the oxidation state of DJ-1. A dynamic DJ-1 interactome screening was previously made in order to provide a comprehensive characterization of DJ-1 binding partners under oxidative stress conditions, leading to the identification of several binding partner. From those, proteins belonging to oxidoreductase family were identified, which are mainly associated with cellular response to oxidative stress, such as NDUFA4, PGDH and HADHA. However, such interactions still require validation. Based on this, complementary assays were performed to validate DJ-1 interaction with oxidoreductase proteins, such as immunoprecipitation, pull down assay, and immunocytochemistry followed by confocal analysis, in normal and oxidative stress conditions. iImunocytochemistry assay followed by confocal analysis of SH-SY5Y cells revealed that DJ-1 interacts with both PGDH and HADHA proteins in situ, thus confirming they are indeed binding partners. Moreover, pull down approach results suggested an interaction between HADHA and PGDH with recombinant WT DJ-1, which is modulated by oxidative stress., thus corroborating previous assumptions. After confirming HADHA as a DJ-1 bindings partner, an AP-SWATH approach was used to study HADHA interactome in SH-SY5Y cells exposed to normal and oxidative stress conditions, to assess this protein’s involvement in cellular response to oxidative stress, and to expand DJ-1’s dynamic interactome. With this methodology, it was possible to conclude that HADHA has a dynamic interactome that it is modulated by oxidative stress conditions. Several proteins were identified as binding proteins, like cytoskeleton proteins, motor proteins, proteins involved in DNA repair and gene expression, and in different signaling pathways. Moreover, some of the identified HADHA putative interactors were previously also identified as DJ-1 interactors. The majority ofproteins quantified showed an increased interaction with HADHA in oxidative stress conditions, thus providing insights into their biological functions in cellular response to such insult, pointing to a new HADHA role in neuronal protection against oxidative stress. Such results, also contribute to deeper knowledge on PD pathogenesis, the distinct pathways involved in the establishment and progression of the disease, highlighting potential new targets for PD prognosis, therapy and prevention.