Chromatin-associated protein kinases in human normal and benign hyperplastic prostate.

Nuclear phosphoproteins and protein kinases of human normal and benign hyperplastic prostate (BPH) were studied in an effort to delineate their properties and to identify any underlying differences therein. Chromatin-associated protein kinases active towards phosvitin, lysine-rich histone, and endogenous nonhistone proteins were characterized in human prostatic nuclei. The general properties of the human chromatin-associated prostatic protein kinases were similar to those of rat ventral prostate chromatin. Polyamines stimulated the phosphorylation of endogenous nonhistone proteins and phosvitin. Protein kinases active towards phosvitin and lysine-rich histones were unaltered in chromatin from BPH tissue as compared with the normal prostate. However, phosphorylation of chromatin-associated nonhistone proteins was markedly enhanced (average, 123%) in BPH tissue as compared with the normal tissue. The results indicate a change in the protein kinase reaction specifically involving chromatin-associated nonhistone proteins of BPH tissue as compared with normal human prostate.