Heat shock-regulated expression of calreticulin in retinal pigment epithelium.

Abstract

Calreticulin is a major Ca2+ binding protein in the endoplasmic reticulum of non-muscle cells. In this report we show that calreticulin protein is strongly induced by heat shock. Activation and attenuation of the heat shock transcriptional response is caused by heat shock factor that binds to 5'-flanking sequences of heat shock responsive genes, the heat shock element. The smallest stretch of DNA that shows detectable binding of heat shock factor in vitro contains a two-sequence unit nGAAnnTTCn which exists in the 5'-flanking region of calreticulin DNA (5'-gGAAccCAGcgTTC-3'). The present data provide direct evidence that calreticulin expression can be modulated by heat shock. Thus, our results strengthen the hypothesis that calreticulin, in addition to its function as a cellular Ca2+ store, is a multifunctional protein which performs at least some of its functions from the lumen of the ER.

• Authors: M Szewczenko-Pawlikowski, E Dziak, M J McLaren, M Michalak, M Opas
• Journal: Molecular and cellular biochemistry (Mol Cell Biochem) Vol. 177 Issue 1-2 Pg. 145-52 (Dec 1997) ISSN: 0300-8177 [Print] Netherlands
• PMID: 9450656 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium-Binding Proteins
• Calreticulin
• Ribonucleoproteins

Topics

• Animals
• Calcium-Binding Proteins (analysis, biosynthesis, genetics)
• Calreticulin
• Cell Line, Transformed
• Gene Expression Regulation
• Heat-Shock Response (genetics)
• Pigment Epithelium of Eye (cytology, metabolism)
• Rats
• Ribonucleoproteins (analysis, biosynthesis, genetics)