Proteins of the Xenopus laevis zinc finger multigene family as targets for CK II phosphorylation.
Zn finger proteins (ZFPs) of the C2/H2 type in Xenopus laevis are encoded by a multigene family comprising several hundred members. Based upon conserved sequence features outside the Zn finger region, ZFPs can be subdivided into distinct subfamilies. Two of such subfamilies are characterized by conserved, N-terminal amino acid sequences termed the FAX and the FAR Domain. Here we present data suggesting that the zinc finger proteins of the FAR-ZFP subfamily are targets for CK II mediated phosphorylation. Expression of these proteins during oogenesis coincides with CK II activity in unfertilized eggs. Additionally, we have found that XlcOF 7.1, a member of the FAX-ZFP subfamily, is also phosphorylated by CK II. The target sites for in vitro phosphorylation are localized within the conserved N-terminal domains but not within the Zn finger regions. However, amino acid sequence comparison revealed that individual phosphoacceptor sites are not generally conserved among all members of the respective ZFP subfamilies. The relevance of a potential CK II phosphorylation for the regulation of ZFP activity in vivo is discussed.
Klocke
B
B
Abt. Biochemie, Universität Ulm, Germany.
Knöchel
W
W
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D047390:Casein Kinase II; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010063:Ovum / Q000201:enzymology; D010766:Phosphorylation; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014982:Xenopus laevis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers / Q000235:genetics*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D001616:beta-Galactosidase