Chemical modifications of a recombinant bovine stress-inducible 70 kDa heat-shock protein (Hsp70) mimics Hsp70 isoforms from tissues.
A cDNA clone for the stress-inducible 70 kDa heat-shock protein (Hsp70) has been isolated from a bovine skeletal-muscle cDNA library. This mRNA encodes a protein with a calculated molecular mass of 70250 Da. The cDNA has one continuous open reading frame capable of encoding a 641-amino-acid protein. Expression of this cDNA in a bacterial expression system produced a protein with a mobility identical with that of the inducible Hsp70 protein from bovine skeletal muscle as determined by SDS/PAGE. Two-dimensional gel electrophoresis demonstrated this protein to have focusing properties identical with that of a minor isoform from bovine skeletal muscle. Upon carbamylation of this bacterially expressed protein, a train of charged proteins with charge differences of -1 were produced. These carbamylated proteins were shown to have similar focusing mobilities to the Hsp70 isoforms isolated from bovine skeletal muscle. These results demonstrate the identification of a skeletal-muscle inducible Hsp70 gene and suggest that the presence of multiple Hsp70 isoforms may be the product of post-translational modifications to the Hsp70 proteins.
Gutierrez
J A
JA
Department of Animal Sciences, University of Arizona, Tucson 85721.
Guerriero
V
V
D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002219:Carbamates / Q000378:metabolism; D002417:Cattle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D007536:Isomerism; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological / Q000378:metabolism*
D001426:Bacterial Proteins; D002219:Carbamates; D018076:DNA, Complementary; D018840:HSP70 Heat-Shock Proteins; D011994:Recombinant Proteins