THE CDNAS CODING FOR THE ALPHA-SUBUNIT AND BETA-SUBUNIT OF XENOPUS-LAEVIS CASEIN KINASE-II

Using a lambda-gt10 cDNA library obtained from Xenopus laevis oocytes and probes derived from the known sequences of the human and Drosophila genes, a cDNA coding for the alpha-subunit of the X. laevis casein kinase II was isolated. The coding sequence of this clone determines a polypeptide of 350 amino acids. The X. laevis sequence is 98% identical to the human and rat proteins in the first 323 amino acids. Using the polymerase chain reaction to generate a 370 nucleotide-long probe, it was possible to clone and sequence a cDNA of 900 nucleotides that coded for the X. laevis beta-subunit of casein kinase II. The derived sequence is 215 amino acids long and again shows an extraordinary degree of conservation with other species.