title: CK2 phosphorylates AP-2α and increases its transcriptional activity.
abstract: Transcription factor AP-2α involves in the process of mammalian embryonic development and tumorigenesis. Many studies have shown that AP-2α functions in association with other interacting proteins. In a two-hybrid screening, the regulatory subunit β of protein casein kinase 2 (CK2β) was identified as an interacting protein of AP-2α; we confirmed this interaction using in-vitro GST pull-down and in-vivo co-immunoprecipitation assays; in an endogenous co-immunoprecipitation experiment, we further found the catalytic subunit α of protein casein kinase 2 (CK2α) also exists in the complex. Phosphorylation analysis revealed that AP-2α was phosphorylated by CK2 kinase majorly at the site of Ser429, and such phosphorylation could be blocked by CK2 specific inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) in a dose-dependent manner. Luciferase assays demonstrated that both CK2α and CK2β enhanced the transcription activity of AP-2α; moreover, CK2β increased the stability of AP-2α. Our data suggest a novel cellular function of CK-2 as a transcriptional co-activator of AP-2α.
authors.affiliation: Model Animal Research Center, MOE Key Laboratory of Model Animal for Disease Research, Medical School, Nanjing University, China.
authors.forename: Kaiqun
authors.initials: K
authors.lastname: Ren
authors.forename: Shuanglin
authors.initials: S
authors.lastname: Xian
authors.forename: Fangli
authors.initials: F
authors.lastname: He
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhang
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ding
authors.forename: Yanyang
authors.initials: Y
authors.lastname: Wu
authors.forename: Liping
authors.initials: L
authors.lastname: Yang
authors.forename: Jianlin
authors.initials: J
authors.lastname: Zhou
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D047390:Casein Kinase II / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011485:Protein Binding; D055550:Protein Stability; D021381:Protein Transport; D050656:Transcription Factor AP-2 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D050656:Transcription Factor AP-2; D047390:Casein Kinase II