CDKB1;1 forms a functional complex with CYCA2;3 to suppress endocycle onset.
The mitosis-to-endocycle transition requires the controlled inactivation of M phase-associated cyclin-dependent kinase (CDK) activity. Previously, the B-type CDKB1;1 was identified as an important negative regulator of endocycle onset. Here, we demonstrate that CDKB1;1 copurifies and associates with the A2-type cyclin CYCA2;3. Coexpression of CYCA2;3 with CDKB1;1 triggered ectopic cell divisions and inhibited endoreduplication. Moreover, the enhanced endoreduplication phenotype observed after overexpression of a dominant-negative allele of CDKB1;1 could be partially complemented by CYCA2;3 co-overexpression, illustrating that both subunits unite in vivo to form a functional complex. CYCA2;3 protein stability was found to be controlled by CCS52A1, an activator of the anaphase-promoting complex. We conclude that CCS52A1 participates in endocycle onset by down-regulating CDKB1;1 activity through the destruction of CYCA2;3.
Boudolf
Véronique
V
Department of Plant Systems Biology, Flanders Institute for Biotechnology, 9052 Ghent, Belgium.
Lammens
Tim
T
Boruc
Joanna
J
Van Leene
Jelle
J
Van Den Daele
Hilde
H
Maes
Sara
S
Van Isterdael
Gert
G
Russinova
Eugenia
E
Kondorosi
Eva
E
Witters
Erwin
E
De Jaeger
Geert
G
Inzé
Dirk
D
De Veylder
Lieven
L
D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism / Q000502:physiology; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D019925:Cyclin A / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D056751:Cyclin A2; D018844:Cyclin-Dependent Kinases / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D015536:Down-Regulation; D049452:Green Fluorescent Proteins / Q000032:analysis; D055550:Protein Stability; D011993:Recombinant Fusion Proteins / Q000032:analysis
D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D019925:Cyclin A; D056751:Cyclin A2; C540491:FZR2 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; C543427:cyclin A2;3 protein, Arabidopsis; D049452:Green Fluorescent Proteins; C434472:CDKA1 protein, Arabidopsis; D018844:Cyclin-Dependent Kinases