RRC ID 33607
Author Fleckenstein T, Kastenmüller A, Stein ML, Peters C, Daake M, Krause M, Weinfurtner D, Haslbeck M, Weinkauf S, Groll M, Buchner J.
Title The Chaperone Activity of the Developmental Small Heat Shock Protein Sip1 Is Regulated by pH-Dependent Conformational Changes.
Journal Mol Cell
Abstract Small heat shock proteins (sHsps) are ubiquitous molecular chaperones that prevent the aggregation of unfolding proteins during proteotoxic stress. In Caenorhabditis elegans, Sip1 is the only sHsp exclusively expressed in oocytes and embryos. Here, we demonstrate that Sip1 is essential for heat shock survival of reproducing adults and embryos. X-ray crystallography and electron microscopy revealed that Sip1 exists in a range of well-defined globular assemblies consisting of two half-spheres, each made of dimeric "spokes." Strikingly, the oligomeric distribution of Sip1 as well as its chaperone activity depend on pH, with a trend toward smaller species and higher activity at acidic conditions such as present in nematode eggs. The analysis of the interactome shows that Sip1 has a specific substrate spectrum including proteins that are essential for embryo development.
Volume 58(6)
Pages 1067-78
Published 2015-6-18
DOI 10.1016/j.molcel.2015.04.019
PII S1097-2765(15)00301-9
PMID 26009280
MeSH Amino Acid Sequence Animals Blotting, Western Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / chemistry* Caenorhabditis elegans Proteins / classification Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Cryoelectron Microscopy Crystallography, X-Ray Heat-Shock Proteins, Small / chemistry* Heat-Shock Proteins, Small / genetics Heat-Shock Proteins, Small / metabolism Hydrogen-Ion Concentration Models, Molecular Molecular Chaperones / chemistry* Molecular Chaperones / genetics Molecular Chaperones / metabolism Molecular Sequence Data Mutation Phylogeny Protein Binding Protein Conformation* Protein Multimerization Protein Structure, Quaternary Protein Structure, Tertiary Sequence Homology, Amino Acid Temperature
IF 14.548
Times Cited 29
C.elegans tm3624 (sip-1 F43D9.4)