All in the family: atypical Hsp70 chaperones are conserved modulators of Hsp70 activity.
Divergent relatives of the Hsp70 protein chaperone such as the Hsp110 and Grp170 families have been recognized for some time, yet their biochemical roles remained elusive. Recent work has revealed that these "atypical" Hsp70s exist in stable complexes with classic Hsp70s where they exert a powerful nucleotide-exchange activity that synergizes with Hsp40/DnaJ-type cochaperones to dramatically accelerate Hsp70 nucleotide cycling. This represents a novel evolutionary transition from an independent protein-folding chaperone to what appears to be a dedicated cochaperone. Contributions of the atypical Hsp70s to established cellular roles for Hsp70 now must be deciphered.
Shaner
Lance
L
Department of Microbiology and Molecular Genetics, University of Texas Medical School, 6431 Fannin St., Houston, TX 77030, USA.
Morano
Kevin A
KA
D000818:Animals; D017124:Conserved Sequence; D006023:Glycoproteins / Q000378:metabolism*; D050957:HSP110 Heat-Shock Proteins / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D011485:Protein Binding; D017510:Protein Folding
D006023:Glycoproteins; D050957:HSP110 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C098410:glucose-regulated protein 170