[Phosphorylation of the nuclear matrix proteins of the liver and of Zajdela's hepatoma in the rat].

The rate of protein phosphorylation in isolated nuclear matrices from liver and Zajdela's hepatoma is very high, being even slightly higher than in isolated nuclei. This indicates that active protein kinases remain tightly bound to the nuclear matrix, since the areas of phosphorylation are the same. However, during isolation of the nuclear matrix from labeled nuclei in the absence of proteolysis and dephosphorylation inhibitors, most part of the label is eliminated from nuclear matrix proteins. These proteins were phosphorylated in both the tissues, however, in Zajdela's hepatoma, two proteins with a molecular weight of 29-31 kD and four proteins with a molecular weight of 12-19 kD were phosphorylated more intensely than in the liver.