Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Plant J. 2009 Nov;60(4):666-78. doi: 10.1111/j.1365-313X.2009.03992.x. Epub 2009 Aug 8.
hMMS21 is a SUMO E3 ligase required for the prevention of DNA damage-induced apoptosis, and acts by facilitating DNA repair in human cells. The Arabidopsis genome contains a putative MMS21 homologue capable of interacting with the SUMO E2 conjugating enzyme AtSCE1a, as indicated by a yeast two-hybrid screen and bimolecular fluorescence complementation experiments. In vitro and in vivo data demonstrated that AtMMS21 was a SUMO E3 ligase. We identified the Arabidopsis AtMMS21 null T-DNA insertion mutant mms21-1, which had a short-root phenotype, and affected cell proliferation in the apical root meristem, as indicated by impaired expression of the cell division marker CYCB1:GUS in mms21-1 roots. The mms21-1 roots had reduced responses to exogenous cytokinins, and decreased expression of the cytokinin-induced genes ARR3, ARR4, ARR5 and ARR7, compared with the wild type. Thus, our findings suggest that the AtMMS21 gene is involved in root development via cell-cycle regulation and cytokinin signalling.
hMMS21 是一种 SUMO E3 连接酶，对于防止 DNA 损伤诱导的细胞凋亡是必需的，其作用是促进人类细胞中的 DNA 修复。拟南芥基因组包含一个假定的 MMS21 同源物，能够与 SUMO E2 连接酶 AtSCE1a 相互作用，这一点通过酵母双杂交筛选和双分子荧光互补实验得到了证实。体外和体内数据表明 AtMMS21 是一种 SUMO E3 连接酶。我们鉴定了拟南芥 AtMMS21 缺失型 T-DNA 插入突变体 mms21-1，该突变体具有短根表型，并且影响顶端根分生组织中的细胞增殖，这一点通过 mms21-1 根中细胞分裂标记物 CYCB1:GUS 的表达受损得到证实。与野生型相比，mms21-1 根对外源细胞分裂素的反应减弱，细胞分裂素诱导基因 ARR3、ARR4、ARR5 和 ARR7 的表达减少。因此，我们的研究结果表明，AtMMS21 基因通过细胞周期调控和细胞分裂素信号转导参与根的发育。
