PT  - JOURNAL ARTICLE
AU  - De Veylder, Lieven
AU  - Beeckman, Tom
AU  - Beemster, Gerrit T.S.
AU  - Krols, Luc
AU  - Terras, Franky
AU  - Landrieu, Isabelle
AU  - Van Der Schueren, Els
AU  - Maes, Sara
AU  - Naudts, Mirande
AU  - Inzé, Dirk
TI  - Functional Analysis of Cyclin-Dependent Kinase Inhibitors of Arabidopsis
AID  - 10.1105/TPC.010087
DP  - 2001 Jul 01
TA  - The Plant Cell
PG  - 1653--1668
VI  - 13
IP  - 7
4099  - http://www.plantcell.org/content/13/7/1653.short
4100  - http://www.plantcell.org/content/13/7/1653.full
SO  - Plant Cell2001 Jul 01; 13
AB  - Cyclin-dependent kinase inhibitors, such as the mammalian p27Kip1 protein, regulate correct cell cycle progression and the integration of developmental signals with the core cell cycle machinery. These inhibitors have been described in plants, but their function remains unresolved. We have isolated seven genes from Arabidopsis that encode proteins with distant sequence homology with p27Kip1, designated Kip-related proteins (KRPs). The KRPs were characterized by their domain organization and transcript profiles. With the exception of KRP5, all presented the same cyclin-dependent kinase binding specificity. When overproduced, KRP2 dramatically inhibited cell cycle progression in leaf primordia cells without affecting the temporal pattern of cell division and differentiation. Mature transgenic leaves were serrated and consisted of enlarged cells. Although the ploidy levels in young leaves were unaffected, endoreduplication was suppressed in older leaves. We conclude that KRP2 exerts a plant growth inhibitory activity by reducing cell proliferation in leaves, but, in contrast to its mammalian counterparts, it may not control the timing of cell cycle exit and differentiation.