A-Raf kinase is a new interacting partner of protein kinase CK2 beta subunit

In a search for protein kinase CK2 beta subunit binding proteins using the two-hybrid system, more than 1000 positive clones were isolated. Beside clones for the alpha' and beta subunit of CK2, there were clones coding for a so far unknown protein, whose partial cDNA sequence was already deposited in the EMBL database under the accession numbers R08806 and Z17360, for the ribosomal protein L5 and for A-Raf kinase. All isolated clones except the one for CK2 beta showed no interaction with the catalytic a subunit of CK2. A-Raf kinase is a new interesting partner of CK2 beta. The isolated A-Raf clone represented amino acids 268-606, but also a full length A-Raf clone interacted with CK2 beta. At the site of CK2 beta, residue 175 and amino acids between residues 194 and 200 are likely to be involved in direct interaction. (C) 1997 Federation of European Biochemical Societies.