생쥐 섬 유아세포에서 70 kDa 고온충격 단백질의 CDNA 클로닝과 염기서열 분석

Isolation and Characterization of a CDNA Encoding a Protein Homologous to the Mouse 70 kDa Heat Shock Protein

Hsp70, a 70 kDa protein, is the maior protein expressed when cells are heat-shocked. A cDNA library from mouse ID13 cells was screened with the human hsp70 gene as a probe, and a positive clone was obtained. The positive clone was subcloned into puc19 and the precise restriction was obtained. The CDNA was sequenced by the Sanger's dideoxv termination method. Single open reading frame that codes for a protein of 70 kDa was found. The DNA sequence of the cloned mouse DNA shows great homology (66-90%) with other mouse hsp70 genes and somewhat less homology (50",) with E. coli hsp70 gene (dnak). With the exception of one amino acid, the protein sequence deduced from the CDNA is identical to the mouse that shock cognate protein 70 (hsc70) that is constitutivelv expressed at normal temperature. The result suggests that the cloned CDNA encodes a hsc70 family rather than a heatinducible family.mily.