GroES binding regulates GroEL chaperonin activity under heat shock.
Chaperonins GroEL14 and GroES7 are heat-shock proteins implicated in the molecular response to stress. Protein fluorescence, crosslinking and kinetic analysis revealed that the bond between the two otherwise thermoresistant oligomers is regulated by temperature. As temperature increased, the affinity of GroES7 and the release of bound proteins from the chaperonin concomitantly decreased. After heat shock, GroES7 rebinding to GroEL14 and GroEL14GroES7 particles correlated with the restoration of optimal protein folding/release activity. Chaperonins thus behave as a molecular thermometer which can inhibit the release of aggregation-prone proteins during heat shock and restore protein folding and release after heat shock.
Goloubinoff
P
P
Department of Plant Sciences, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel. pierre@vms.huji.ac.il
Diamant
S
S
Weiss
C
C
Azem
A
A
D000251:Adenosine Triphosphatases / Q000378:metabolism; D018835:Chaperonin 10 / Q000378:metabolism*; D018834:Chaperonin 60 / Q000378:metabolism*; D003432:Cross-Linking Reagents; D018869:Heat-Shock Response; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D011485:Protein Binding; D011489:Protein Denaturation; D017510:Protein Folding; D013696:Temperature
D018835:Chaperonin 10; D018834:Chaperonin 60; D003432:Cross-Linking Reagents; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D000251:Adenosine Triphosphatases