| Structural highlights
Function
HS71A_HUMAN In cooperation with other chaperones, Hsp70s stabilize preexistent proteins against aggregation and mediate the folding of newly translated polypeptides in the cytosol as well as within organelles. These chaperones participate in all these processes through their ability to recognize nonnative conformations of other proteins. They bind extended peptide segments with a net hydrophobic character exposed by polypeptides during translation and membrane translocation, or following stress-induced damage. In case of rotavirus A infection, serves as a post-attachment receptor for the virus to facilitate entry into the cell. Essential for STUB1-mediated ubiquitination and degradation of FOXP3 in regulatory T-cells (Treg) during inflammation (PubMed:23973223).[1] [2] [3]
Publication Abstract from PubMed
The J-domain co-chaperones work together with the heat shock protein 70 (HSP70) chaperone to regulate many cellular events, but the mechanism underlying the J-domain-mediated HSP70 function remains elusive. We studied the interaction between human-inducible HSP70 and Homo sapiens J-domain protein (HSJ1a), a J domain and UIM motif-containing co-chaperone. The J domain of HSJ1a shares a conserved structure with other J domains from both eukaryotic and prokaryotic species, and it mediates the interaction with and the ATPase cycle of HSP70. Our in vitro study corroborates that the N terminus of HSP70 including the ATPase domain and the substrate-binding beta-subdomain is not sufficient to bind with the J domain of HSJ1a. The C-terminal helical alpha-subdomain of HSP70, which was considered to function as a lid of the substrate-binding domain, is crucial for binding with the J domain of HSJ1a and stimulating the ATPase activity of HSP70. These fluctuating helices are likely to contribute to a proper conformation of HSP70 for J-domain binding other than directly bind with the J domain. Our findings provide an alternative mechanism of allosteric activation for functional regulation of HSP70 by its J-domain co-chaperones.
The C-terminal helices of heat shock protein 70 are essential for J-domain binding and ATPase activation.,Gao XC, Zhou CJ, Zhou ZR, Wu M, Cao CY, Hu HY J Biol Chem. 2012 Feb 17;287(8):6044-52. Epub 2012 Jan 3. PMID:22219199[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Perez-Vargas J, Romero P, Lopez S, Arias CF. The peptide-binding and ATPase domains of recombinant hsc70 are required to interact with rotavirus and reduce its infectivity. J Virol. 2006 Apr;80(7):3322-31. PMID:16537599 doi:http://dx.doi.org/80/7/3322
- ↑ Liu X, Liu D, Qian D, Dai J, An Y, Jiang S, Stanley B, Yang J, Wang B, Liu X, Liu DX. Nucleophosmin (NPM1/B23) interacts with activating transcription factor 5 (ATF5) protein and promotes proteasome- and caspase-dependent ATF5 degradation in hepatocellular carcinoma cells. J Biol Chem. 2012 Jun 1;287(23):19599-609. doi: 10.1074/jbc.M112.363622. Epub, 2012 Apr 23. PMID:22528486 doi:http://dx.doi.org/10.1074/jbc.M112.363622
- ↑ Chen Z, Barbi J, Bu S, Yang HY, Li Z, Gao Y, Jinasena D, Fu J, Lin F, Chen C, Zhang J, Yu N, Li X, Shan Z, Nie J, Gao Z, Tian H, Li Y, Yao Z, Zheng Y, Park BV, Pan Z, Zhang J, Dang E, Li Z, Wang H, Luo W, Li L, Semenza GL, Zheng SG, Loser K, Tsun A, Greene MI, Pardoll DM, Pan F, Li B. The ubiquitin ligase Stub1 negatively modulates regulatory T cell suppressive activity by promoting degradation of the transcription factor Foxp3. Immunity. 2013 Aug 22;39(2):272-85. doi: 10.1016/j.immuni.2013.08.006. PMID:23973223 doi:http://dx.doi.org/10.1016/j.immuni.2013.08.006
- ↑ Gao XC, Zhou CJ, Zhou ZR, Wu M, Cao CY, Hu HY. The C-terminal helices of heat shock protein 70 are essential for J-domain binding and ATPase activation. J Biol Chem. 2012 Feb 17;287(8):6044-52. Epub 2012 Jan 3. PMID:22219199 doi:http://dx.doi.org/10.1074/jbc.M111.294728
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