State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China.
Mol Plant. 2012 Jan;5(1):270-80. doi: 10.1093/mp/ssr086. Epub 2011 Oct 12.
Plant cells frequently undergo endoreduplication, a modified cell cycle in which genome is repeatedly replicated without cytokinesis. As the key step to achieve final size and function for cells, endoreduplication is prevalent during plant development. However, mechanisms to control the balance between endoreduplication and mitotic cell division are still poorly understood. Here, we show that the Arabidopsis TCP (CINCINNATA-like TEOSINTE BRANCHED1-CYCLOIDEA-PCF)-family transcription factor gene AtTCP15 is expressed in trichomes, as well as in rapidly dividing and vascular tissues. Expression of AtTCP15SRDX, AtTCP15 fused with a SRDX repressor domain, induces extra endoreduplication in trichomes and cotyledon cells in transgenic Arabidopsis. On the contrary, overexpression of AtTCP15 suppresses endoreduplication in trichomes and other examined cells. Misregulation of AtTCP15 affects the expression of several important genes involved in cell-cycle regulation. AtTCP15 protein binds directly to the promoter regions of CYCA2;3 and RETINOBLASTOMA-RELATED (RBR) genes, which play key roles in endoreduplication. Taken together, AtTCP15 plays an important role in regulating endoreduplication during Arabidopsis development.
植物细胞经常经历内复制，这是一种修改后的细胞周期，其中基因组在没有胞质分裂的情况下反复复制。作为实现细胞最终大小和功能的关键步骤，内复制在植物发育过程中很普遍。然而，控制内复制和有丝分裂细胞分裂之间平衡的机制仍然知之甚少。在这里，我们表明拟南芥 TCP（CINCINNATA 样 TEOSINTE BRANCHED1-CYCLOIDEA-PCF）-家族转录因子基因 AtTCP15 在毛状体以及快速分裂和血管组织中表达。AtTCP15SRDX 的表达，AtTCP15 与 SRDX 抑制域融合，在转基因拟南芥的毛状体和子叶细胞中诱导额外的内复制。相反，AtTCP15 的过表达抑制毛状体和其他检查细胞中的内复制。AtTCP15 的失调会影响参与细胞周期调控的几个重要基因的表达。AtTCP15 蛋白直接结合到参与内复制的关键基因 CYCA2;3 和 RETINOBLASTOMA-RELATED（RBR）的启动子区域。综上所述，AtTCP15 在调节拟南芥发育过程中的内复制中发挥重要作用。
