Studies on polyamine-dependent protein kinase in pig epidermal cells
Nemoto, O.
Hokkaido Journal of Medical Science 60(1): 57-65
1985
ISSN/ISBN: 0367-6102 PMID: 3988233 Document Number: 243412
Polyamine-dependent protein kinase (P kinase) in nuclear and cytosol fraction of pig epidermal cells were extracted. Two different protein kinases were purified from nuclei. One was cAMP-dependent protein kinase (A kinase) and another was P kinase. P kinase phosphorylated acidic non-histone protein only, while A kinase phosphorylated both exogenous histone and non-histone proteins. Among polypeptides phosphorylated by P kinase, a 180 kilodalton (K) polypeptide seemed to be a specific substrate for P kinase. In cytosol, the fraction containing P kinase exhibited multiple polypeptide bands on SDS -PAGE, including four major polypeptide bands and several minor polypeptide bands. One of minor polypeptide bands (80 K) was phosphorylated by P kinase. Authentic ornithine decarboxylase (ODC) added exogenously was also phosphorylated by P kinase. A 80 K polypeptide of ODC was comigrated with the polypeptide phosphorylated by P kinase on SDS -PAGE. Kinetic study revealed that the ODC activity decreased as ODC was phosphorylated.