6fhk
From Proteopedia
Structure of a modified protein containing a genetically encoded phosphoserine
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 PubMedHsp72 is a member of the 70-kDa heat shock family of molecular chaperones (Hsp70s) that comprise a nucleotide-binding domain (NBD) and a substrate-binding domain (SBD) connected by a linker that couples the exchange of adenosine diphosphate (ADP) for adenosine triphosphate (ATP) with the release of the protein substrate. Mitotic phosphorylation of Hsp72 by the kinase NEK6 at Thr(66) located in the NBD promotes the localization of Hsp72 to the mitotic spindle and is required for efficient spindle assembly and chromosome congression and segregation. We determined the crystal structure of the Hsp72 NBD containing a genetically encoded phosphoserine at position 66. This revealed structural changes that stabilized interactions between subdomains within the NBD. ATP binding to the NBD of unmodified Hsp72 resulted in the release of substrate from the SBD, but phosphorylated Hsp72 retained substrate in the presence of ATP. Mutations that prevented phosphorylation-dependent subdomain interactions restored the connection between ATP binding and substrate release. Thus, phosphorylation of Thr(66) is a reversible mechanism that decouples the allosteric connection between nucleotide binding and substrate release, providing further insight into the regulation of the Hsp70 family. We propose that phosphorylation of Hsp72 on Thr(66) by NEK6 during mitosis promotes its localization to the spindle by stabilizing its interactions with components of the mitotic spindle. Mitotic phosphorylation regulates Hsp72 spindle localization by uncoupling ATP binding from substrate release.,Mukherjee M, Sabir S, O'Regan L, Sampson J, Richards MW, Huguenin-Dezot N, Ault JR, Chin JW, Zhuravleva A, Fry AM, Bayliss R Sci Signal. 2018 Aug 14;11(543). pii: 11/543/eaao2464. doi:, 10.1126/scisignal.aao2464. PMID:30108182[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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