Possible Involvement of the 90-Kda Heat-Shock Protein in the Regulation of Protein-Synthesis

Rose, D. W., Welch, W. J., Kramer, G., Hardesty, B. (April 1989) Possible Involvement of the 90-Kda Heat-Shock Protein in the Regulation of Protein-Synthesis. Journal of Biological Chemistry, 264 (11). pp. 6239-6244. ISSN 0021-9258

Abstract

The heme-sensitive eukaryotic initiation factor (eIF)-2 alpha kinase regulates translational activity in reticulocytes by phosphorylation of the smallest subunit of eukaryotic peptide initiation factor 2, eIF-2. Highly purified preparations of the kinase contain an abundant 90-kDa polypeptide which appears to modulate the activity of the enzyme. The physical properties and structural characteristics of the reticulocyte 90-kDa peptide are similar to those of the 90-kDa heat shock protein (hsp 90) from HeLa and other mammalian cells. The reticulocyte and HeLa cell proteins are shown to be immunologically cross-reactive. A direct comparison of the two proteins by one-dimensional peptide mapping of large peptides generated by limited proteolysis and by reversed-phase high performance liquid chromatography analysis of tryptic peptides indicates that they represent the same protein species. Like the 90-kDa reticulocyte protein, HeLa cell hsp 90 causes increased eIF-2 alpha phosphorylation by the heme-sensitive kinase and is a potent inhibitor of protein synthesis in the reticulocyte lysate system. A potential mechanism for the latter inhibition is inferred. These results implicate hsp 90 in the regulation of protein synthesis via its interaction with and perhaps regulation of the heme-sensitive kinase and phosphorylation of eIF-2 alpha.

Item Type: Paper
Subjects: bioinformatics > genomics and proteomics > design > protein design
CSHL Authors:
Communities: CSHL labs
Depositing User: Gail Sherman
Date: April 1989
Date Deposited: 23 Jun 2017 16:27
Last Modified: 23 Jun 2017 16:27
Related URLs:
URI: https://repository.cshl.edu/id/eprint/34902

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