Casein kinase II from Rana temporaria oocytes. Intracellular localization and activity during progesterone-induced maturation.

A homogeneous preparation of casein kinase II has been isolated from the ribosome-free extracts of Rana temporaria oocytes by means of chromatography on heparin-Sepharose, phosphocellulose and mono Q. The enzyme consists of three subunits with molecular mass of 43 kDa, 41 kDa and 29 kDa. The protein kinase was labelled with radioactive iodine and injected back into oocytes. As shown by histoautoradiography the enzyme forms a diffuse ring around the nucleus in the oocyte cytoplasm. A part of casein kinase II is found in informosomes. During oocytes maturation casein kinase II activity increases 7 h after progesterone administration and at the final stages of maturation (20-23 h). Cycloheximide blocks the second augmentation of kinase activity and does not influence the first one.