Kahali Bhaskar, Trott Regina, Paroush Ze'ev, Allada Ravi, Bishop Clifton P, Bidwai Ashok P
Department of Biology, West Virginia University, 4220 Life Sciences Building, 53 Campus Drive, Morgantown, WV 26506, USA.
Biochem Biophys Res Commun. 2008 Sep 5;373(4):637-42. doi: 10.1016/j.bbrc.2008.06.084. Epub 2008 Jul 2.
Hairy is a repressor that regulates bristle patterning, and its loss elicits ectopic bristles (neural hyperplasia). However, it has remained unknown whether Hairy is regulated by phosphorylation. We describe here the interaction of protein kinase CK2 and Hairy. Hairy is robustly phosphorylated by the CK2-holoenzyme (CK2-HoloE) purified from Drosophila embryos, but weakly by the catalytic CK2alpha-subunit alone, suggesting that this interaction requires the regulatory CK2beta-subunit. Consistent with this, Hairy preferentially forms a direct complex with CK2-HoloE. Importantly, we demonstrate genetic interactions between CK2 and hairy (h). Thus, flies trans-heterozygous for alleles of CK2alpha and h display neural hyperplasia akin to homozygous hypomorphic h alleles. In addition, we show that similar phenotypes are elicited in wild-type flies upon expression of RNAi constructs against CK2alpha/beta, and that these defects are sensitive to h gene dosage. Together, these studies suggest that CK2 contributes to repression by Hairy.
毛状体（Hairy）是一种调节刚毛模式的阻遏物，其缺失会引发异位刚毛（神经增生）。然而，毛状体是否受磷酸化调节仍不清楚。我们在此描述蛋白激酶CK2与毛状体的相互作用。从果蝇胚胎中纯化的CK2全酶（CK2-HoloE）能使毛状体强烈磷酸化，但单独的催化性CK2α亚基只能使其微弱磷酸化，这表明这种相互作用需要调节性CK2β亚基。与此一致的是，毛状体优先与CK2-HoloE形成直接复合物。重要的是，我们证明了CK2与毛状体（h）之间存在遗传相互作用。因此，CK2α和h等位基因的反式杂合果蝇表现出类似于h等位基因纯合子的神经增生。此外，我们表明，在野生型果蝇中表达针对CK2α/β的RNAi构建体时会引发类似的表型，并且这些缺陷对h基因剂量敏感。总之，这些研究表明CK2有助于毛状体的阻遏作用。
