The human double-stranded DNA-activated protein kinase phosphorylates the 90-kDa heat-shock protein, hsp90 alpha at two NH2-terminal threonine residues.
The 90-kDa heat-shock protein, hsp90, is an abundant cytoplasmic protein that can be phosphorylated in vitro by a double-stranded (ds) DNA-activated protein kinase found in cells from several species. Here we show that the dsDNA-activated protein kinase from human HeLa cells phosphorylates 2 threonine residues in the sequence PEETQTQDQPME at the amino terminus of human hsp90 alpha. Hsp90 beta, which is 97% identical to hsp90 alpha but lacks both amino-terminal threonines, is not phosphorylated by the dsDNA-activated protein kinase. Mouse hsp86 and rabbit hsp90 alpha are homologous to human hsp90 alpha; both heterologous proteins are phosphorylated at the same amino-terminal threonines by the human dsDNA-activated protein kinase.
Lees-Miller
S P
SP
Biology Department, Brookhaven National Laboratory, Upton, New York 11973.
Anderson
C W
CW
D000595:Amino Acid Sequence; D000818:Animals; D003488:Cyanogen Bromide; D004247:DNA / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006367:HeLa Cells / Q000201:enzymology; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D011817:Rabbits; D013912:Threonine; D014357:Trypsin
D006360:Heat-Shock Proteins; D010446:Peptide Fragments; D010769:Phosphothreonine; D013912:Threonine; D004247:DNA; D011494:Protein Kinases; D014357:Trypsin; D003488:Cyanogen Bromide