among these proteins , histone h1 and a 0.75 m pca soluble polypeptide with an apparent mr of 21,000 , as revealed by electrophoretic analysis , are phosphorylated in vitro by protein kinase c in isolated nuclei purified from 3t3 cells treated for 90 min with igf-i and bombesin .
C0019644
histone h1
C0007610
nuclei