Ubiquitin is a heat shock protein in chicken embryo fibroblasts.
Clones containing heat-inducible mRNA sequences were selected from a cDNA library prepared from polyadenylated RNA isolated from heat-shocked chicken embryo fibroblasts. One recombinant DNA clone, designated clone 7, hybridized to a 1.2-kilobase RNA that was present in normal cells and increased fivefold during heat shock. Clone 7 also hybridized to an RNA species of 1.7 kilobases that was present exclusively in heat-shocked cells. In vitro translation of mRNA hybrid selected from clone 7 produced a protein product with a molecular weight of approximately 8,000. Increased synthesis of a protein of similar size was detected in chicken embryo fibroblasts after heat shock. DNA sequence analysis of clone 7 indicated its protein product has amino acid sequences identical to bovine ubiquitin. In addition, clone 7 contains tandem copies of the ubiquitin sequences contiguous to each other with no untranslated sequences between them. We discuss some possible roles for ubiquitin in the heat shock response.
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D002642:Chick Embryo; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes; D006360:Heat-Shock Proteins / Q000235:genetics*; D006609:High Mobility Group Proteins / Q000235:genetics*; D006358:Hot Temperature; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D014452:Ubiquitins / Q000235:genetics*
D006360:Heat-Shock Proteins; D006609:High Mobility Group Proteins; D012333:RNA, Messenger; D014452:Ubiquitins; D004247:DNA; D004262:DNA Restriction Enzymes