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, SCFSKP2 and the RING protein RKP, contribute to its degradation. These results suggest that SCFSKP2b and RPK play an important role in the cell cycle through regulating KRP1 protein turnover.
Document Type: Research Article
Affiliations: 1: Department of Biology, Indiana University, Bloomington, IN 47405, USA, 2: Dpt. Biotecnología, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 28040 Madrid, Spain, and 3: Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
Publication date: March 1, 2008