Control of cell proliferation, organ growth, and DNA damage response operate independently of dephosphorylation of the Arabidopsis Cdk1 homolog CDKA;1.
Entry into mitosis is universally controlled by cyclin-dependent kinases (CDKs). A key regulatory event in metazoans and fission yeast is CDK activation by the removal of inhibitory phosphate groups in the ATP binding pocket catalyzed by Cdc25 phosphatases. In contrast with other multicellular organisms, we show here that in the flowering plant Arabidopsis thaliana, cell cycle control does not depend on sudden changes in the phosphorylation pattern of the PSTAIRE-containing Cdk1 homolog CDKA;1. Consistently, we found that neither mutants in a previously identified CDC25 candidate gene nor plants in which it is overexpressed display cell cycle defects. Inhibitory phosphorylation of CDKs is also the key event in metazoans to arrest cell cycle progression upon DNA damage. However, we show here that the DNA damage checkpoint in Arabidopsis can also operate independently of the phosphorylation of CDKA;1. These observations reveal a surprising degree of divergence in the circuitry of highly conserved core cell cycle regulators in multicellular organisms. Based on biomathematical simulations, we propose a plant-specific model of how progression through the cell cycle could be wired in Arabidopsis.
Dissmeyer
Nico
N
Unigruppe am Max-Planck-Institut für Züchtungsforschung, Max-Delbrück-Laboratorium, Lehrstuhl für Botanik III, Universität zu Köln, Köln, Germany. diss@mpiz-koeln.mpg.de
Weimer
Annika K
AK
Pusch
Stefan
S
De Schutter
Kristof
K
Alvim Kamei
Claire Lessa
CL
Nowack
Moritz K
MK
Novak
Bela
B
Duan
Gui-Lan
GL
Zhu
Yong-Guan
YG
De Veylder
Lieven
L
Schnittger
Arp
A
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation; D018844:Cyclin-Dependent Kinases / Q000235:genetics* / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D019143:Evolution, Molecular; D018816:Genes, cdc / Q000502:physiology; D008433:Mathematics; D008938:Mitosis / Q000235:genetics; D010766:Phosphorylation; D018514:Plant Structures / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D016203:CDC2 Protein Kinase; C434472:CDKA1 protein, Arabidopsis; D018844:Cyclin-Dependent Kinases; D020687:cdc25 Phosphatases