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Published on: September 30, 2011
Coordinated activation of Hsp70 chaperones
Gregor J Steel1, Donna M Fullerton, John R Tyson
1School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK.
Science (New York, N.Y.)
|January 6, 2004
Summary
Heat shock proteins 70 (Hsp70s) Lhs1p and Kar2p coordinate activities in yeast endoplasmic reticulum protein biogenesis. Their coupled ATPase activities, regulated reciprocally, are essential for cellular function.
Area of Science:
- Molecular biology
- Cellular biology
- Protein folding and homeostasis
Background:
- Heat shock proteins 70 (Hsp70s) are vital molecular chaperones.
- Lhs1p and Kar2p are essential Hsp70s for protein biogenesis in the yeast endoplasmic reticulum.
Purpose of the Study:
- To investigate the interaction and regulatory relationship between Lhs1p and Kar2p.
- To elucidate how these chaperones coordinate their functions in vivo.
Main Methods:
- Biochemical assays to study chaperone interactions.
- Enzyme kinetics to analyze ATPase and nucleotide exchange activities.
- In vivo studies in yeast models.
Main Results:
- Lhs1p and Kar2p form a specific complex.
- Lhs1p stimulates Kar2p via nucleotide exchange activity.
- Kar2p reciprocally activates Lhs1p's ATPase activity.
- The ATPase activities of both proteins are coupled and co-regulated.
Conclusions:
- Lhs1p and Kar2p exhibit a coordinated regulatory mechanism.
- This reciprocal activation is crucial for proper protein biogenesis in the endoplasmic reticulum.
- The findings reveal a novel mechanism of chaperone cooperation in cellular processes.
