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Binding determinants of the small heat shock protein, ?B-crystallin: recognition of the 'IxI' motif.

ABSTRACT: Small heat shock proteins (sHSPs) play a central role in protein homeostasis under conditions of stress by binding partly unfolded, aggregate-prone proteins and keeping them soluble. Like many sHSPs, the widely expressed human sHSP, ?B-crystallin ('?B'), forms large polydisperse multimeric assemblies. Molecular interactions involved in both sHSP function and oligomer formation remain to be delineated. A growing database of structural information reveals that a central conserved ?-crystallin domain (ACD) forms dimeric building blocks, while flanking N- and C-termini direct the formation of larger sHSP oligomers. The most commonly observed inter-subunit interaction involves a highly conserved C-terminal 'IxI/V' motif and a groove in the ACD that is also implicated in client binding. To investigate the inherent properties of this interaction, peptides mimicking the IxI/V motif of ?B and other human sHSPs were tested for binding to dimeric ?B-ACD. IxI-mimicking peptides bind the isolated ACD at 22°C in a manner similar to interactions observed in the oligomer at low temperature, confirming these interactions are likely to exist in functional ?B oligomers.

SUBMITTER: Delbecq SP

PROVIDER: S-EPMC3545294 | biostudies-literature | 2012 Dec

REPOSITORIES: biostudies-literature

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Binding determinants of the small heat shock protein, αB-crystallin: recognition of the 'IxI' motif.

Delbecq Scott P SP Jehle Stefan S Klevit Rachel R

The EMBO journal 20121127 24

Small heat shock proteins (sHSPs) play a central role in protein homeostasis under conditions of stress by binding partly unfolded, aggregate-prone proteins and keeping them soluble. Like many sHSPs, the widely expressed human sHSP, αB-crystallin ('αB'), forms large polydisperse multimeric assemblies. Molecular interactions involved in both sHSP function and oligomer formation remain to be delineated. A growing database of structural information reveals that a central conserved α-crystallin doma ...[more]

PMID: 23188086

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Dataset Information

Binding determinants of the small heat shock protein, ?B-crystallin: recognition of the 'IxI' motif.

Publications

Binding determinants of the small heat shock protein, αB-crystallin: recognition of the 'IxI' motif.

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