Degradation of the cyclin-dependent kinase inhibitor KRP1 is regulated by two different ubiquitin E3 ligases.
In animals and fungi, a group of proteins called the cyclin-dependent kinase inhibitors play a key role in cell cycle regulation. However, comparatively little is known about the role of these proteins in plant cell cycle regulation. To gain insight into the mechanisms by which the plant cell cycle is regulated, we studied the cyclin-dependent kinase inhibitor KRP1 in Arabidopsis. KRP1 interacts with the CDKA;1/CYCD2;1 complex in planta and functions in the G1-S transition of the cell cycle. Furthermore, we show that KRP1 is a likely target of the ubiquitin/proteasome pathway. Two different ubiquitin protein ligases, SCF(SKP2) and the RING protein RKP, contribute to its degradation. These results suggest that SCF(SKP2b) and RPK play an important role in the cell cycle through regulating KRP1 protein turnover.
Ren
Hong
H
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Santner
Aaron
A
del Pozo
Juan Carlos
JC
Murray
James A H
JA
Estelle
Mark
M
D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000235:genetics / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids; D030821:Plants, Genetically Modified; D044786:S-Phase Kinase-Associated Proteins / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
C081977:AXR1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; C114853:ICK1 protein, Arabidopsis; D007210:Indoleacetic Acids; D044786:S-Phase Kinase-Associated Proteins; D044767:Ubiquitin-Protein Ligases; D018844:Cyclin-Dependent Kinases