| Literature DB >> 1597196 |
S Iijima1, H Teraoka, T Date, K Tsukada.
Abstract
Autophosphorylation of a DNA-activated protein kinase (DNA-PK) in Raji Burkitt's lymphoma cells generated a band that corresponded to a phosphoprotein of about 300 kDa on SDS/PAGE. This band corresponds to a 300-350-kDa DNA-PK found previously in HeLa cells. In addition to the 300-kDa phosphoprotein, the band of a highly phosphorylated 58-kDa protein was detected by SDS/PAGE of partially purified DNA-PK preparations after the phosphorylation reaction in the presence of double-stranded DNA. This phosphoprotein was specifically immunoprecipitated by phosphoprotein nor detectable activities of other kinases, phosphorylated recombinant c-Myc proteins in the presence of DNA. The c-Myc phosphorylation by DNA-PK was markedly stimulated by relaxed, double-stranded DNA, but neither by single-stranded DNA nor by RNA. Phosphopeptide mapping and phosphoamino acid analysis indicated that DNA-PK phosphorylates c-Myc in vitro at several serine residues.Entities:
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Year: 1992 PMID: 1597196 DOI: 10.1111/j.1432-1033.1992.tb16964.x
Source DB: PubMed Journal: Eur J Biochem ISSN: 0014-2956