Effect of partial hepatectomy and tumor-bearing on phosphorylation of nuclear protein in rats.

When nuclei from various tissues of rats were incubated at 25 degrees with ATP[gamma-32P], the amounts of 32P incorporated in histone and non-histone protein per mg DNA reached maxima at 1 hr (maximum phosphorylation level). H1 histone and over 30 species of non-histone protein were phosphorylated as detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Only some of those species of non-histone protein, which were so low in content as to be indetectable by conventional protein staining, were prominently phosphorylated; their apparent molecular weights were 106K, 82K, 71K, 62K, 39K, 38K and 28K with brain, 39K, 38K, 32K, 31K and 22K with kidney and liver, 17.5K and 11.5K with thymus, and 11.5K with Rhodamine sarcoma (tissue-specific). In phosphorylation with liver nuclei, the tissue specificity changed neither with partial hepatectomy nor upon transplanting Rhodamine sarcoma. However, the maximum phosphorylation levels of the five species of non-histone protein increased with operation and decreased with tumor-bearing, to similar extents. On the other hand, the amounts of all the species of histone per mg DNA changed neither with operation nor with tumor-bearing, whereas the maximum phosphorylation level of H1 histone increased with operation, but not with tumor-bearing.