title: Modulation of human checkpoint kinase Chk1 by the regulatory beta-subunit of protein kinase CK2.
abstract: Protein kinase CK2 is a serine/threonine protein kinase involved in various aspects of cellular regulation. The regulatory beta-subunit of CK2 exerts a central role not only in mediating formation of tetrameric CK2 complexes but also as a docking partner for several protein kinases. In this study, CK2beta is found to interact with the human cell cycle checkpoint kinase Chk1. The Chk1-interacting region of CK2beta is localized at the C-terminus and the complex between CK2beta and Chk1 is devoid of the catalytic CK2alpha-subunit. The interaction between CK2beta and Chk1 leads to an increase in the Cdc25C phosphorylation activity of Chk1. The screening of several cell lines has revealed that the association between CK2beta and Chk1 also occurs in vivo at a different degree. Collectively, these studies confirm the implication of the regulatory beta-subunit of protein kinase CK2 in cell cycle regulation and identify a novel mechanism for the activation of Chk1 protein kinase.
authors.affiliation: Division of Biological Sciences 0322, University of California, San Diego, CA 92093-0322, USA. bag@bmb.sdu.dk
authors.forename: Barbara
authors.initials: B
authors.lastname: Guerra
authors.forename: Olaf-Georg
authors.initials: OG
authors.lastname: Issinger
authors.forename: Jean Y J
authors.initials: JY
authors.lastname: Wang
mesh_terms: D016475:3T3 Cells; D000818:Animals; D019556:COS Cells; D047390:Casein Kinase II; D020134:Catalytic Domain / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology; D000071877:Checkpoint Kinase 1; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D051379:Mice; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011494:Protein Kinases; C000605867:CHEK1 protein, human; D047390:Casein Kinase II; D000071877:Checkpoint Kinase 1; C000605869:Chek1 protein, mouse; D017346:Protein Serine-Threonine Kinases