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Use of peptide tagging to detect proteins expressed from cloned genes: deletion mapping functional domains of Drosophila hsp 70.
Author(s) -
Munro S.,
Pelham H.R.
Publication year - 1984
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1984.tb02263.x
Subject(s) - biology , heat shock protein , nucleolus , hspa4 , gene , hsp70 , hspa14 , mutant , microbiology and biotechnology , fusion protein , heat shock , genetics , nucleus , recombinant dna
We have developed a technique which allows specific detection of proteins expressed from cloned genes. The method involves fusion of an oligonucleotide coding for part of the neuropeptide substance P to the 3′ end of the gene; the protein can then be detected with a monoclonal antibody that recognises this peptide. We have used this method to determine the properties of deletion mutants of the major Drosophila heat shock protein, hsp70, expressed in monkey COS cells. The results suggest that this protein has two distinct domains. Both are capable of accumulating in the nucleus of unstressed cells, but only the more highly conserved N‐terminal domain is able to bind to nucleoli following a heat shock. This implies that nucleolar binding and nuclear migration are distinct properties of the protein, and suggests that the former may be of functional importance. In addition, we observed a novel effect of heat shock on cellular metabolism: protein fragments that are normally rapidly degraded are stabilized. The effect persists for several hours after the heat shock, but does not require expression of heat shock proteins. Together with previously published data, these results suggest an intimate relationship between protein degradation and the heat shock response.