Klocke B, Knöchel W
Abt. Biochemie, Universität Ulm, Germany.
Mol Cell Biochem. 1995 Jan 12;142(1):49-59. doi: 10.1007/BF00928913.
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.
非洲爪蟾的C2/H2型锌指蛋白（ZFPs）由一个包含数百个成员的多基因家族编码。基于锌指区域外的保守序列特征，ZFPs可细分为不同的亚家族。其中两个亚家族的特征是具有保守的N端氨基酸序列，称为FAX和FAR结构域。在此，我们提供的数据表明，FAR-ZFP亚家族的锌指蛋白是CK II介导的磷酸化作用的靶点。这些蛋白在卵子发生过程中的表达与未受精卵中的CK II活性一致。此外，我们发现，FAX-ZFP亚家族的成员XlcOF 7.1也被CK II磷酸化。体外磷酸化的靶点位于保守的N端结构域内，而不是锌指区域内。然而，氨基酸序列比较显示，各个磷酸化位点在相应ZFP亚家族的所有成员中通常并不保守。本文讨论了潜在的CK II磷酸化作用对体内ZFP活性调节的相关性。
