The UBP14-CDKB1;1-CDKG2 cascade controls endore-duplication and cell growth in Arabidopsis
The UBP14-CDKB1;1-CDKG2 cascade controls endore-duplication and cell growth in Arabidopsis
复制标题
UBP14-CDKB1;1-CDKG2 级联控制拟南芥中的核内复制和细胞生长
DOI：
10.1093/plcell/koac002
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发表时间：
2022-03-29
期刊：
影响因子：
11.6
通讯作者：
Li, Yunhai
中科院分区：
文献类型：
--
作者：
Jiang, Shan;Wei, Jinwei;Li, Yunhai
核内再复制是一种在没有有丝分裂的情况下发生DNA复制的过程，它存在于所有真核生物界，尤其是植物中，在植物中它被认为对细胞生长和细胞命运的维持很重要。然而，对于调控核内再复制的机制仍缺乏全面的了解。我们之前报道过，由DA3编码的泛素特异性蛋白酶14（UBP14）在细胞周期蛋白依赖性激酶B1;1（CDKB1;1）的上游起作用，影响拟南芥的核内再复制和细胞生长。da3 - 1突变体由于高倍性水平具有大的子叶和增大的细胞。在这里，我们鉴定出了da3 - 1的一个抑制因子（da3 - 1的抑制因子6；SUD6），它编码细胞周期蛋白依赖性激酶G2（CDKG2），促进核内再复制和细胞生长。CDKG2/SUD6在体内和体外都与CDKB1;1物理结合。CDKB1;1直接磷酸化SUD6并调节其稳定性。遗传分析表明，SUD6在DA3和CDKB1;1的下游起作用，以控制倍性水平和细胞生长。因此，我们的研究建立了一个由UBP14/DA3 - CDKB1;1 - CDKG2/SUD6介导的拟南芥核内再复制和细胞生长的调控级联。
Endoreduplication, a process in which DNA replication occurs in the absence of mitosis, is found in all eukaryotic kingdoms, especially plants, where it is assumed to be important for cell growth and cell fate maintenance. However, a comprehensive understanding of the mechanism regulating endoreduplication is still lacking. We previously reported that UBIQUITIN-SPECIFIC PROTEASE14 (UBP14), encoded by DA3, acts upstream of CYCLIN-DEPENDENT KINASE B1;1 (CDKB1;1) to influence endoreduplication and cell growth in Arabidopsis thaliana. The da3-1 mutant possesses large cotyledons with enlarged cells due to high ploidy levels. Here, we identified a suppressor of da3-1 (SUPPRESSOR OF da3-1 6; SUD6), encoding CYCLIN-DEPENDENT KINASE G2 (CDKG2), which promotes endoreduplication and cell growth. CDKG2/SUD6 physically associates with CDKB1;1 in vivo and in vitro. CDKB1;1 directly phosphorylates SUD6 and modulates its stability. Genetic analysis indicated that SUD6 acts downstream of DA3 and CDKB1;1 to control ploidy level and cell growth. Thus, our study establishes a regulatory cascade for UBP14/DA3-CDKB1;1-CDKG2/SUD6-mediated control of endoreduplication and cell growth in Arabidopsis.