title: Genetic framework of cyclin-dependent kinase function in Arabidopsis.
abstract: Cyclin-dependent kinases (CDKs) are at the heart of eukaryotic cell-cycle control. The yeast Cdc2/CDC28 PSTAIRE kinase and its orthologs such as the mammalian Cdk1 have been found to be indispensable for cell-cycle progression in all eukaryotes investigated so far. CDKA;1 is the only PSTAIRE kinase in the flowering plant Arabidopsis and can rescue Cdc2/CDC28 mutants. Here, we show that cdka;1 null mutants are viable but display specific cell-cycle and developmental defects, e.g., in S phase entry and stem cell maintenance. We unravel that the crucial function of CDKA;1 is the control of the plant Retinoblastoma homolog RBR1 and that codepletion of RBR1 and CDKA;1 rescued most defects of cdka;1 mutants. Our work further revealed a basic cell-cycle control system relying on two plant-specific B1-type CDKs, and the triple cdk mutants displayed an early germline arrest. Taken together, our data indicate divergent functional differentiation of Cdc2-type kinases during eukaryote evolution.
authors.affiliation: VIB Department of Plant Systems Biology, B-9052 Gent, Belgium.
authors.forename: Moritz K
authors.initials: MK
authors.lastname: Nowack
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Harashima
authors.forename: Nico
authors.initials: N
authors.lastname: Dissmeyer
authors.forename: Xin'Ai
authors.initials: X
authors.lastname: Zhao
authors.forename: Daniel
authors.initials: D
authors.lastname: Bouyer
authors.forename: Annika K
authors.initials: AK
authors.lastname: Weimer
authors.forename: Freya
authors.initials: F
authors.lastname: De Winter
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.forename: Arp
authors.initials: A
authors.lastname: Schnittger
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D042846:CDC2-CDC28 Kinases / Q000235:genetics / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D008855:Microscopy, Electron, Scanning; D008938:Mitosis / Q000502:physiology; D009154:Mutation; D018517:Plant Roots / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D016196:S Phase / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C487568:RBR1 protein, Arabidopsis; D042846:CDC2-CDC28 Kinases; C434472:CDKA1 protein, Arabidopsis; C435712:CDKB1;2 protein, Arabidopsis; D018844:Cyclin-Dependent Kinases