Related Experiment Videos
Calreticulin associates with stress proteins: implications for chaperone function during heat stress
1Department of Medicine, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
Journal of Cellular Biochemistry
|March 26, 1998
Summary
Heat stress causes glycosylation of calreticulin, a prompt stress glycoprotein. This study shows calreticulin interacts with heat shock proteins during cellular recovery, suggesting a cooperative chaperone role in managing heat stress.
Area of Science:
- Cellular Biology
- Stress Response
- Protein Interactions
Background:
- Acute heat stress induces cellular damage and triggers specific molecular responses.
- Prompt stress glycoproteins (P-SGs) are rapidly synthesized under stress conditions.
- Calreticulin, a known prompt stress glycoprotein, undergoes glycosylation during heat stress.
Purpose of the Study:
- To investigate the protein interactions of calreticulin (P-SG67/64) during cellular recovery from heat stress.
- To elucidate the role of calreticulin and its associated proteins in cellular thermotolerance.
Main Methods:
- Immunoprecipitation was used to identify proteins interacting with P-SG/calreticulin.
- Chemical cross-linking with DSP was employed to study HSP-P-SG interactions.
- Gel filtration chromatography characterized the molecular mass of protein complexes.
Main Results:
- Both glycosylated and unglycosylated P-SG/calreticulin interacted with HSP90, GRP94, GRP78, and P-SG50.
- These interactions were ATP-independent.
- Cross-linked complexes of calreticulin and HSPs had an average mass of 400-600 kDa.
Conclusions:
- Calreticulin consistently associates with prompt stress glycoproteins and heat shock proteins.
- These associations suggest calreticulin is part of a chaperone network.
- This network cooperates to facilitate cellular recovery from acute heat stress.