SIAMESE, a plant-specific cell cycle regulator, controls endoreplication onset in Arabidopsis thaliana. Export

@article{citeulike:1082404, abstract = {Recessive mutations in the SIAMESE (SIM) gene of Arabidopsis thaliana result in multicellular trichomes harboring individual nuclei with a low ploidy level, a phenotype strikingly different from that of wild-type trichomes, which are single cells with a nuclear DNA content of approximately 16C to 32C. These observations suggested that SIM is required to suppress mitosis as part of the switch to endoreplication in trichomes. Here, we demonstrate that SIM encodes a nuclear-localized 14-kD protein containing a cyclin binding motif and a motif found in ICK/KRP (for Interactors of Cdc2 kinase/Kip-related protein) cell cycle inhibitor proteins. Accordingly, SIM was found to associate with D-type cyclins and CDKA;1. Homologs of SIM were detected in other dicots and in monocots but not in mammals or fungi. SIM proteins are expressed throughout the shoot apical meristem, in leaf primordia, and in the elongation zone of the root and are localized to the nucleus. Plants overexpressing SIM are slow-growing and have narrow leaves and enlarged epidermal cells with an increased DNA content resulting from additional endocycles. We hypothesize that SIM encodes a plant-specific CDK inhibitor with a key function in the mitosis-to-endoreplication transition.}, address = {Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA.}, author = {Churchman, M. L. and Brown, M. L. and Kato, N. and Kirik, V. and H\"{u}lskamp, M. and Inz\'{e}, D. and De Veylder, L. and Walker, J. D. and Zheng, Z. and Oppenheimer, D. G. and Gwin, T. and Churchman, J. and Larkin, J. C.}, citeulike-article-id = {1082404}, citeulike-linkout-0 = {http://dx.doi.org/10.1105/tpc.106.044834}, citeulike-linkout-1 = {http://www.plantcell.org/cgi/content/abstract/18/11/3145}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/17098811}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=17098811}, doi = {10.1105/tpc.106.044834}, issn = {1040-4651}, journal = {Plant Cell}, keywords = {arabidopsis, cell-cycle, endoreduplication, gene, mitosis, plant-biology, trichome}, month = {November}, number = {11}, pages = {3145--3157}, posted-at = {2009-04-17 22:55:06}, priority = {0}, title = {SIAMESE, a plant-specific cell cycle regulator, controls endoreplication onset in Arabidopsis thaliana.}, url = {http://dx.doi.org/10.1105/tpc.106.044834}, volume = {18}, year = {2006} }

TY - JOUR ID - citeulike:1082404 L3 - citeulike-article-id:1082404 N2 - Recessive mutations in the SIAMESE (SIM) gene of Arabidopsis thaliana result in multicellular trichomes harboring individual nuclei with a low ploidy level, a phenotype strikingly different from that of wild-type trichomes, which are single cells with a nuclear DNA content of approximately 16C to 32C. These observations suggested that SIM is required to suppress mitosis as part of the switch to endoreplication in trichomes. Here, we demonstrate that SIM encodes a nuclear-localized 14-kD protein containing a cyclin binding motif and a motif found in ICK/KRP (for Interactors of Cdc2 kinase/Kip-related protein) cell cycle inhibitor proteins. Accordingly, SIM was found to associate with D-type cyclins and CDKA;1. Homologs of SIM were detected in other dicots and in monocots but not in mammals or fungi. SIM proteins are expressed throughout the shoot apical meristem, in leaf primordia, and in the elongation zone of the root and are localized to the nucleus. Plants overexpressing SIM are slow-growing and have narrow leaves and enlarged epidermal cells with an increased DNA content resulting from additional endocycles. We hypothesize that SIM encodes a plant-specific CDK inhibitor with a key function in the mitosis-to-endoreplication transition. IS - 11 JF - Plant Cell SN - 1040-4651 AD - Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA. EP - 3157 TI - SIAMESE, a plant-specific cell cycle regulator, controls endoreplication onset in Arabidopsis thaliana. VL - 18 SP - 3145 KW - arabidopsis KW - cell-cycle KW - endoreduplication KW - gene KW - mitosis KW - plant-biology KW - trichome AU - Churchman, ML AU - Brown, ML AU - Kato, N AU - Kirik, V AU - Hülskamp, M AU - Inzé, D AU - De Veylder, L AU - Walker, JD AU - Zheng, Z AU - Oppenheimer, DG AU - Gwin, T AU - Churchman, J AU - Larkin, JC PY - 2006/11// UR - http://dx.doi.org/10.1105/tpc.106.044834 ER -