[Effect of estradiol on polyamine-dependent protein kinase activity of kidney tissue and hormone-dependent mammary gland tumors].

It was demonstrated that cell cytosol and nuclei of estradiol-dependent mammary tumours and kidney of the rat contain a polyamine-dependent protein kinase whose activity is stimulated 2-5 fold by 2 mM spermine and is inhibited by heparin (8-10 micrograms/ml). This protein kinase uses acid proteins (casein) as substrates and ATP and GTP as phosphate sources. The polyamine-dependent protein kinase is eluted from DEAE-cellulose with 0.22-0.24 M NaCl. In cell nuclei the enzyme activity is 3-5 times as high as that in the cytoplasm. In cell nuclei of hormone-dependent tumours and kidney estradiol increases the activity of the polyamine-dependent protein kinase 2-5 times within 30 minutes.