Drosophila CK2 phosphorylates Hairy and regulates its activity in vivo.
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.
Kahali
Bhaskar
B
Department of Biology, West Virginia University, 4220 Life Sciences Building, 53 Campus Drive, Morgantown, WV 26506, USA.
Trott
Regina
R
Paroush
Ze'ev
Z
Allada
Ravi
R
Bishop
Clifton P
CP
Bidwai
Ashok P
AP
D000483:Alleles; D020816:Amino Acid Motifs; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D047390:Casein Kinase II / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D020035:Holoenzymes / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D034741:RNA, Small Interfering / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
D051792:Basic Helix-Loop-Helix Proteins; D047390:Casein Kinase II; D029721:Drosophila Proteins; D020035:Holoenzymes; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C489235:hairy protein, Drosophila