CLONING OF THE GENE ENCODING THE CATALYTIC SUBUNIT OF CASEIN KINASE-II FROM THE YEAST YARROWIA-LIPOLYTICA

Casein kinase II from the yeast Yarrowia lipolytica is a heterotetrame r of the form alpha alpha'beta(2). We report on the cloning and sequen cing of a partial cDNA and of the complete genomic DNA coding for the catalytic alpha subunit of the casein kinase II from this yeast specie s. The sequence of the gene coding for this enzyme has been analyzed. No intron was found in the gene, which is present in a single copy. Th e deduced amino acid sequence of the gene shows high similarity with t hose of alpha subunit described in other species, although, uniquely, Y. lipolytica CKII alpha lacks cysteines. We find that the alpha subun it sequence of Y. lipolytica CKII is shown greater homology with the c orresponding protein from S. pombe than with that from S. cerevisiae. We have analyzed CKII alpha expression and CKII alpha activity. We sho w that expression of this enzyme is regulated. The catalytic subunit i s translated from a single mRNA, and the enzyme is present at a very l ow level in Y. lipolytica, as in other-yeasts.