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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^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.