title: Arabidopsis D-type cyclin CYCD4;1 is a novel cyclin partner of B2-type cyclin-dependent kinase.
abstract: B-type cyclin-dependent kinases (CDKs) are unique to plants and are assumed to be involved in the control of the G2-to-M phase progression and mitotic events. However, little is known about their cyclin partners. In Arabidopsis, we isolated cDNA encoding the D-type cyclin CYCD4;1 by a yeast (Saccharomyces cerevisiae) two-hybrid screening using CDKB2;1 as bait. In vitro pull-down assay showed that CYCD4;1 bound to CDKB2;1 and CDKA;1. Protein complexes of CYCD4;1-CDKA;1 and CYCD4;1-CDKB2;1 in insect cells exhibited histone H1-kinase activity. Promoter analysis using the luciferase reporter gene showed that CDKB2;1 was expressed from early G2 to M phase, whereas CYCD4;1 was expressed throughout the cell cycle. In situ hybridization of plant tissues revealed that both CDKB2;1 and CYCD4;1 transcripts accumulated in the shoot apical meristem, leaf primordia, vasculature of leaves, and tapetal cells in anthers. Our results suggest that CDKB2;1 and CYCD4;1 may form an active kinase complex during G2/M phase and control the development of particular tissues.
authors.affiliation: Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kono
authors.forename: Chikage
authors.initials: C
authors.lastname: Umeda-Hara
authors.forename: Jeongkyung
authors.initials: J
authors.lastname: Lee
authors.forename: Masaki
authors.initials: M
authors.lastname: Ito
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Uchimiya
authors.forename: Masaaki
authors.initials: M
authors.lastname: Umeda
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D056741:Cyclin D; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D035264:Flowers / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018515:Plant Leaves / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D056741:Cyclin D; D016213:Cyclins; C478558:D-type cyclin CDCD4.1, Arabidopsis; D012333:RNA, Messenger; D018844:Cyclin-Dependent Kinases