scholarly journals Prdx1 Interacts with ASK1 upon Exposure to H2O2 and Independently of a Scaffolding Protein

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1060
Author(s):  
Trung Nghia Vo ◽  
Julia Malo Pueyo ◽  
Khadija Wahni ◽  
Daria Ezeriņa ◽  
Jesalyn Bolduc ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Protein Interaction ◽  
Specific Protein ◽  
Annexin A2 ◽  
Redox Signaling ◽  
Scaffolding Protein ◽  
Protein Protein Interaction ◽  
Protein Thiols ◽  
Vitro Protein

Hydrogen peroxide (H2O2) is a key redox signaling molecule that selectively oxidizes cysteines on proteins. It can accomplish this even in the presence of highly efficient and abundant H2O2 scavengers, peroxiredoxins (Prdxs), as it is the Prdxs themselves that transfer oxidative equivalents to specific protein thiols on target proteins via their redox-relay functionality. The first evidence of a mammalian cytosolic Prdx-mediated redox-relay—Prdx1 with the kinase ASK1—was presented a decade ago based on the outcome of a co-immunoprecipitation experiment. A second such redox-relay—Prdx2:STAT3—soon followed, for which further studies provided insights into its specificity, organization, and mechanism. The Prdx1:ASK1 redox-relay, however, has never undergone such a characterization. Here, we combine cellular and in vitro protein–protein interaction methods to investigate the Prdx1:ASK1 interaction more thoroughly. We show that, contrary to the Prdx2:STAT3 redox-relay, Prdx1 interacts with ASK1 at elevated H2O2 concentrations, and that this interaction can happen independently of a scaffolding protein. We also provide evidence of a Prdx2:ASK1 interaction, and demonstrate that it requires a facilitator that, however, is not annexin A2. Our results reveal that cytosolic Prdx redox-relays can be organized in different ways and yet again highlight the differentiated roles of Prdx1 and Prdx2.

Hypersensitive mousetraps, α1-antitrypsin deficiency and dementia

2002 ◽  
Vol 30 (2) ◽  
pp. 89-92 ◽  
Author(s):  
D. A. Lomas ◽  
A. Lourbakos ◽  
S.-A. Cumming ◽  
D. Belorgey
Keyword(s):  
Protein Interaction ◽  
Inclusion Bodies ◽  
Serine Proteinase ◽  
Specific Protein ◽  
Structural Basis ◽  
Protein Protein Interaction ◽  
Antitrypsin Deficiency ◽  
Familial Encephalopathy

α1-Antitrypsin functions as a ‘mousetrap’ to inhibit its target proteinase, neutrophil elastase. The common severe Z deficiency variant (Glu342 → Lys) destabilizes the mousetrap to allow a sequential protein-protein interaction between the reactive-centre loop of one molecule and β-sheet A of another. These loop-sheet polymers accumulate within hepatocytes to form inclusion bodies that are associated with juvenile cirrhosis and hepatocellular carcinoma. The lack of circulating protein predisposes the Z α1-antitrypsin homozygote to emphysema. Loop-sheet polymerization is now recognized to underlie deficiency variants of other members of the serine proteinase inhibitor (serpin) superfamily, i.e. antithrombin, C1 esterase inhibitor and α1-anti-chymotrypsin, which are associated with thrombosis, angio-oedema and emphysema respectively. Moreover, we have shown recently that the same process in a neuron-specific protein, neuroserpin, underlies a novel inclusion-body dementia, known as familial encephalopathy with neuroserpin inclusion bodies. Our understanding of the structural basis of polymerization has allowed the development of strategies to prevent the aberrant protein-protein interaction in vitro. This must now be achieved in vivo if we are to treat the associated clinical syndromes.

scholarly journals A Conserved LIR Motif in Connexins Mediates Ubiquitin-Independent Binding to LC3/GABARAP Proteins

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 902 ◽  
Author(s):  
Steve Catarino ◽  
Teresa M Ribeiro-Rodrigues ◽  
Rita Sá Ferreira ◽  
José Ramalho ◽  
Christine Abert ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Protein Interaction ◽  
Alternative Mechanism ◽  
Direct Communication ◽  
Protein Protein Interaction ◽  
Amino Terminal ◽  
Protein Ubiquitination ◽  
Lir Motif ◽  
Vitro Protein

Gap junctions (GJ) are specialized cell-cell contacts formed by connexins (Cxs), which provide direct communication between adjacent cells. Cx43 ubiquitination has been suggested to induce the internalization of GJs, as well as the recruitment of the autophagy receptor p62 to mediate binding to LC3B and degradation by macroautophagy. In this report, we describe a functional LC3 interacting region (LIR), present in the amino terminal of most Cx protein family members, which can mediate the autophagy degradation of Cx43 without the need of ubiquitin. Mutation of the LIR motif on Cx37, Cx43, Cx46 and Cx50 impairs interaction with LC3B and GABARAP without compromising protein ubiquitination. Through in vitro protein-protein interaction assays, we demonstrate that this LIR motif is required for the binding of Cx43 to LC3B and GABARAP. Overall, our findings describe an alternative mechanism whereby Cxs interact with LC3/GABARAP proteins, envisioning a new model for the autophagy degradation of connexins.

scholarly journals A role for annexin A2 in scaffolding the peroxiredoxin 2–STAT3 redox relay complex

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Deepti Talwar ◽  
Joris Messens ◽  
Tobias P. Dick
Keyword(s):  
Hydrogen Peroxide ◽  
Specific Protein ◽  
Annexin A2 ◽  
Scaffolding Protein ◽  
Thiol Oxidation ◽  
Protein Thiol ◽  
Target Proteins ◽  
Peroxiredoxin 2 ◽  
Signaling Domain ◽  
Membrane Signaling

Abstract Hydrogen peroxide (H2O2) is recognized to act as a signaling molecule. Peroxiredoxins (Prxs) have the ability to transfer H2O2-derived oxidizing equivalents to redox-regulated target proteins, thus facilitating the transmission of H2O2 signals. It has remained unclear how Prxs and their target proteins are brought together to allow for target-specific protein thiol oxidation. Addressing the specific case of Prx2-dependent STAT3 oxidation, we here show that the association of the two proteins occurs prior to Prx oxidation and depends on a scaffolding protein, the membrane chaperone annexin A2. Deletion or depletion of annexin A2 interrupts the transfer of oxidizing equivalents from Prx2 to STAT3, which is observed to take place on membranes. These findings support the notion that the Prx2-STAT3 redox relay is part of a highly organized membrane signaling domain.

Retinoschisis and Norrie Disease: A missing link

2021 ◽  
Author(s):  
Rahini Rajendran ◽  
Sudha Dhandayuthapani ◽  
Subbulakshmi Chidambaram ◽  
Hemavathy Nagarajan ◽  
Umashankar Vetrivel ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Functional Relationship ◽  
Direct Interaction ◽  
Specific Protein ◽  
Knock Out ◽  
Norrie Disease ◽  
Protein Protein Interaction ◽  
Protein Interactome ◽  
Molecular Relationships

Abstract Objective: Retinoschisis and Norrie disease are X-linked recessive retinal disorders caused by mutations in RS1 and NDP genes respectively. Both are likely to be monogenic and no locus heterogeneity has been reported. However, there are reports showing overlapping features of Norrie disease and retinoschisis in a NDP knock-out mouse model and also the involvement of both the genes in retinoschisis patients. Yet, the exact molecular relationships between the two disorders have still not been understood. The study investigated the association between retinoschisin (RS1) and norrin (NDP) using in vitro and in silico approaches. Specific protein-protein interaction between RS1 and NDP was analyzed in human retina by co-immunoprecipitation assay and MALDI-TOF mass spectrometry. STRING database was used to explore the functional relationship. Result: Co-immunoprecipitation demonstrated lack of a direct interaction between RS1 and NDP and was further substantiated by mass spectrometry. However, STRING revealed a potential indirect functional association between the two proteins. Progressively, our analyses indicate that FZD4 protein interactome via PLIN2 as well as the MAP kinase signaling pathway to be a likely link bridging the functional relationship between retinoschisis and Norrie disease.

scholarly journals Definition of a minimal munc18c domain that interacts with syntaxin 4

2000 ◽  
Vol 350 (3) ◽  
pp. 741-746 ◽  
Author(s):  
Julian GRUSOVIN ◽  
Violet STOICHEVSKA ◽  
Keith H. GOUGH ◽  
Katrina NUNAN ◽  
Colin W. WARD ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Full Length ◽  
Yeast Two Hybrid ◽  
Protein Protein Interaction ◽  
Interaction Studies ◽  
Syntaxin 4 ◽  
Definition Of ◽  
Two Hybrid

munc18c is a critical protein involved in trafficking events associated with syntaxin 4 and which also mediates inhibitory effects on vesicle docking and/or fusion. To investigate the domains of munc18c responsible for its interaction with syntaxin 4, fragments of munc18c were generated and their interaction with syntaxin 4 examined in vivo by the yeast two-hybrid assay. In vitro protein–protein interaction studies were then used to confirm that the interaction between the proteins was direct. Full-length munc18c1–592, munc18c1–139 and munc18c1–225, but not munc18c226–592, munc18c1–100, munc18c43–139 or munc18c66–139, interacted with the cytoplasmic portion of syntaxin 4, Stx42–273, as assessed by yeast two-hybrid assay of growth on nutritionally deficient media and by β-galactosidase reporter induction. The N-terminal predicted helix-a-helix-b-helix-c region of syntaxin 4, Stx429–157, failed to interact with full-length munc18c1–592, indicating that a larger portion of syntaxin 4 is necessary for the interaction. The yeast two-hybrid results were confirmed by protein–protein interaction studies between Stx42–273 and glutathione S-transferase fusion proteins of munc18c. Full-length munc18c1–592, munc18c1–139 and munc18c1–225 interacted with Stx42–273 whereas munc18c1–100 did not, consistent with the yeast two-hybrid data. These data thus identify a region of munc18c between residues 1 and 139 as a minimal domain for its interaction with syntaxin 4.

scholarly journals Btbd11 is an inhibitory interneuron specific synaptic scaffolding protein that supports excitatory synapse structure and function

2021 ◽  
Author(s):  
Alexei M. Bygrave ◽  
Ayesha Sengupta ◽  
Ella P. Jackert ◽  
Mehroz Ahmed ◽  
Beloved Adenuga ◽  
...  
Keyword(s):  
Inhibitory Interneuron ◽  
Nmda Receptor Antagonist ◽  
Specific Protein ◽  
Network Activity ◽  
Scaffolding Protein ◽  
Inhibitory Interneurons ◽  
Cell Type ◽  
Cell Type Specific

Synapses in the brain exhibit cell–type–specific differences in basal synaptic transmission and plasticity. Here, we evaluated cell–type–specific differences in the composition of glutamatergic synapses, identifying Btbd11, as an inhibitory interneuron–specific synapse–enriched protein. Btbd11 is highly conserved across species and binds to core postsynaptic proteins including Psd–95. Intriguingly, we show that Btbd11 can undergo liquid–liquid phase separation when expressed with Psd–95, supporting the idea that the glutamatergic post synaptic density in synapses in inhibitory and excitatory neurons exist in a phase separated state. Knockout of Btbd11 from inhibitory interneurons decreased glutamatergic signaling onto parvalbumin–positive interneurons. Further, both in vitro and in vivo, we find that Btbd11 knockout disrupts network activity. At the behavioral level, Btbd11 knockout from interneurons sensitizes mice to pharmacologically induced hyperactivity following NMDA receptor antagonist challenge. Our findings identify a cell–type–specific protein that supports glutamatergic synapse function in inhibitory interneurons–with implication for circuit function and animal behavior.

scholarly journals Methods for addressing the protein-protein interaction between histone deacetylase 6 and ubiquitin

2017 ◽  
Author(s):  
Carolina dos S. Passos ◽  
Nathalie Deschamps ◽  
Yun Choi ◽  
Robert E. Cohen ◽  
Remo Perozzo ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Stress Response ◽  
Small Molecules ◽  
Histone Deacetylase ◽  
Protein Interaction ◽  
Potential Role ◽  
Histone Deacetylase 6 ◽  
Protein Protein Interaction ◽  
Binding Function

AbstractHistone deacetylase 6 (HDAC6) is a cytoplasmic HDAC isoform able to remove acetyl groups from cellular substrates such as α-tubulin. In addition to the two deacetylase domains, HDAC6 has a C-terminal zinc-finger ubiquitin (Ub)-binding domain (ZnF-UBP) able to recognize free Ub. HDAC6-Ub interaction is thought to function in regulating the elimination of misfolded proteins during stress response through the aggresome pathway. Small molecules inhibiting deacetylation by HDAC6 were shown to reduce aggresomes, but the interplay between HDAC6 catalytic activity and Ub-binding function is not fully understood. Here we describe two methods to measure the HDAC6-Ub interaction in vitro using full-length HDAC6. Both methods were effective for screening inhibitors of the HDAC6-Ub protein-protein interaction independently of the catalytic activity. Our results suggest a potential role for the HDAC6 deacetylase domains in modulating HDAC6-Ub interaction. This new aspect of HDAC6 regulation can be targeted to address the roles of HDAC6-Ub interaction in normal and disease conditions.

scholarly journals Proximal Protein Interaction Landscape of RAS Paralogs

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3326 ◽  
Author(s):  
Benoît Béganton ◽  
Etienne Coyaud ◽  
Estelle M. N. Laurent ◽  
Alain Mangé ◽  
Julien Jacquemetton ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Protein Interactions ◽  
Biological Activities ◽  
Mammalian Species ◽  
Variable Region ◽  
Specific Protein ◽  
Protein Networks ◽  
Ras Proteins ◽  
Wild Type ◽  
Protein Protein Interaction

RAS proteins (KRAS, NRAS and HRAS) are frequently activated in different cancer types (e.g., non-small cell lung cancer, colorectal cancer, melanoma and bladder cancer). For many years, their activities were considered redundant due to their high degree of sequence homology (80% identity) and their shared upstream and downstream protein partners. However, the high conservation of the Hyper-Variable-Region across mammalian species, the preferential activation of different RAS proteins in specific tumor types and the specific post-translational modifications and plasma membrane-localization of each paralog suggest they could ensure discrete functions. To gain insights into RAS proteins specificities, we explored their proximal protein–protein interaction landscapes using the proximity-dependent biotin identification technology (BioID) in Flp-In T-REx 293 cell lines stably transfected and inducibly expressing wild type KRAS4B, NRAS or HRAS. We identified more than 800 high-confidence proximal interactors, allowing us to propose an unprecedented comparative analysis of wild type RAS paralogs protein networks. These data bring novel information on poorly characterized RAS functions, e.g., its putative involvement in metabolic pathways, and on shared as well as paralog-specific protein networks that could partially explain the complexity of RAS functions. These networks of protein interactions open numerous avenues to better understand RAS paralogs biological activities.

scholarly journals Context-Dependent Remodeling of Rad51–DNA Complexes by Srs2 Is Mediated by a Specific Protein–Protein Interaction

2014 ◽  
Vol 426 (9) ◽  
pp. 1883-1897 ◽  
Author(s):  
Anna K. Lytle ◽  
Sofia S. Origanti ◽  
Yupeng Qiu ◽  
Jeffrey VonGermeten ◽  
Sua Myong ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Specific Protein ◽  
Dna Complexes ◽  
Protein Protein Interaction ◽  
Context Dependent
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