[en] Background and aims Kip-related-proteins (KRPs), negative regulators of cell division, have recently been discovered in plants but their in planta function is as yet unclear. In this study the spatial expression of all seven KRP genes in shoot apices of Arabidopsis thaliana were compared. Methods In situ hybridization analyses were performed on longitudinal sections of shoot apices from 2-month-old Arabidopsis plants. Key Results The study provides evidence for different expression pattern groups. KRP1 and KRP2 expression is restricted to the endoreduplicating tissues. In contrast, KRP4 and KRP5 expression is mainly restricted to mitotically dividing cells. KRP3, KRP6 and KRP7 can be found in both mitotically dividing and endoreduplicating cells. Conclusion The results suggest differential roles for the distinct KRPs. KRP1 and KRP2 might specifically be involved in the establishment of polyploidy. In contrast, KRP4 and KRP5 might be involved in regulating the progression through the mitotic cell cycle. KRP3, KRP6 and KRP7 might have a function in both types of cell cycle. (C) 2004 Annals of Botany Company.
Cheng M, Olivier P, Diehl JA, Fero M, Roussel MF, Roberts JM, Sherr CJ. 1999. The p21Cip1 and P27Kip1 CDK 'inhibitors' are essential activators of cyclin D-dependent kinases in murine fibroblasts. EMBO Journal 18: 1571-1583.
Corbesier L, Gadisseur I, Silvestre G, Jacqmard A, Bernier G. 1996. Design in Arabidopsis thaliana of a synchronous system of floral induction by one long day. The Plant Journal 9: 947-952.
De Veylder L, Beeckman T, Beemster GTS, Krols L, Terras F, Landrieu I, Van Der Schueren E, Maes S, Naudts M, Inzé D. 2001. Functional analysis of cyclin-dependent kinase inhibitors of Arabidopsis. The Plant Cell 13: 1653-1667.
Dunphy WG. 1994. The decision to enter mitosis. Trends in Cell Biology 4, 202-207.
Elledge SL, Harper JW. 1994. CDK inhibitors: on the threshold of check points and development. Current Opinion in Cell Biology 6: 847-852.
Harper JW, Elledge SJ. 1996. Cdk inhibitors in development and cancer. Current Opinion in Genetics & Development 6: 56-64.
Jacqmard A, De Veylder L, Segers G, de Almeida Engler J, Bernier G, Van Montagu M, Inzé D. 1999. CKS1At expression in Arabidopsis thaliana suggests a role for the protein in both the mitotic and the endoreduplication cycle. Planta 207: 496-504.
LaBaer J, Garrett MD, Stevenson LF, Slingerland JM, Sandhu C, Chou HS, Fattaey A, Harlow E. 1997. New functional activities for the p21 family of CDK inhibitors. Genes and Development 11: 847-862.
Lui H, Wang H, DeLong C, Fowke LC, Crosby WL, Fobert PR. 2000. The Arabidopsis Cdc2a-interacting protein ICK2 is structurally related to ICK1 and is a potent inhibitor of cyclin-dependent kinase activity in vitro. The Plant Journal 21: 379-385.
Mironov V, De Veylder L, Van Montagu M, Inzé D. 1999. Cyclin-dependent kinases and cell division in plants- the nexus. The Plant Cell 11: 509-521.
Morgan DO. 1997. Cyclin-dependent kinases: engines, clocks, and microprocessors. Annual Review of Cell and Developmental Biology 13: 261-291.
Norbury C, Nurse P. 1992. Animal cell cycles and their control. Annual Review of Biochemistry 61: 440-470.
Pines J. 1994. Protein kinases and cell cycle control. Seminars in Cell Biology 5: 399-408.
Pines J. 1995. Cyclins and cyclin-dependent kinases: a biochemical view. Biochemical Journal 308: 697-711.
Riou-Khamlichi C, Huntley R, Jacqmard A, Murray JAH. 1999. Cytokinin activation of Arabidopsis cell division through a D-type cyclin. Science 283: 1541-1544.
Segers G, Gadisseur I, Bergounioux C, de Almeida Engler J, Jacqmard A, Van Montagu M, Inzé D. 1996. The Arabidopsis cyclin-dependent kinase gene cdc2bt is preferentially expressed during S and G2 phases of the cell cycle. The Plant Journal 10: 601-612.
Sharma VK, Fletcher JC. 2002. Maintenance of shoot and floral meristem cell proliferation and fate. Plant Physiology 129: 31-39.
Sherr CJ, Roberts JM. 1995. Inhibitors of mammalian G1 cyclin-dependent kinases. Genes and Development 9: 1149-1163.
Sherr CJ, Roberts JM. 1999. CDK inhibitors: Positive and negative regulators of G1-phase progression. Genes and Development 13: 1501-1512.
Van de poele K, Reas J, De Veylder L, Rouzé P, Rombauts S, Inzé D. 2002. Genome-wide analysis of core cell cycle genes in Arabidopsis. The Plant Cell 14: 903-916.
Wang H, Fowke LC, Crosby WL. 1997. A plant cyclin-dependent kinase inhibitor gene. Nature 386: 451-452.
Wang H, Qi Q, Schorr P, Cutler AJ, Crosby WL, Fowke LC. 1998. ICK1, a cyclin-dependent protein kinase inhibitor from Arabidopsis thaliana interacts with both Cdc2a and CycD3, and its expression is induced by abscisic acid. The Plant Journal 15: 501-510.
Wang H, Zhou Y, Gilmer S, Whitwill S, Fowke LC. 2000. Expression of the plant cyclin-dependent kinase inhibitor ICK1 affects cell division, plant growth and morphology. The Plant Journal 24: 613-623.
Zhang P, Wong C, Liu D, Finegold M, Harper JW, Elledge SJ. 1999. p21 CIP1 and p57KIP2 control muscle differentiation at the myogenin step. Genes and Development 13: 213-224.
Zhou Y, Fowke LC, Wang H. 2002. Plant CDK inhibitors: studies of interactions with cell cycle regulators in the yeast two-hybrid system and functional comparisons in transgenic Arabidopsis plants. Plant Cell Reports 20: 967-975.
