SPIN1, a K homology domain protein negatively regulated and ubiquitinated by the E3 ubiquitin ligase SPL11, is involved in flowering time control in rice
SPIN1, a K homology domain protein negatively regulated and ubiquitinated by the E3 ubiquitin ligase SPL11, is involved in flowering time control in rice
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DOI：
10.1105/tpc.108.058610
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发表时间：
2008-06-01
期刊：
影响因子：
11.6
通讯作者：
Wang, Guo-Liang
中科院分区：
文献类型：
--
作者：
Vega-Sanchez, Miguel E.;Zeng, Lirong;Wang, Guo-Liang
水稻E3连接酶斑点LEAF11(SPL11)负调控细胞程序性死亡和抗病性。我们在这里证明了SPL11还通过与SPIN1(SPL11相互作用蛋白1)的相互作用来调节开花，SPIN1是RNA家族成员的信号转导和激活。SPIN1在体外结合RNA和DNA，并在细胞核内与SPL11相互作用。Spl11突变体在长日照条件下延迟了开花。Spin1的过表达导致开花延迟，与日长无关；对这些品系中开花标记基因的表达分析表明，SPIN1在短日照下通过HD1依赖的机制下调开花启动子基因Hd3a(Hd3a)，在长日照下靶向HD1非依赖因子，从而抑制开花。Spin1和Spl11在相反的阶段每天都受到调节。SPL11负性调节Spin1转录水平，而SPIN1也影响Spl11的表达。此外，我们还发现，Spin1mRNA的高积累与清晨和傍晚的光照相吻合才能抑制开花。SPIN1被SPL11单苷化，表明它不是降解的目标。我们的数据与SPIN1作为开花的负调控因子的模型是一致的，该模型本身受到SPL11的负调控，可能是通过泛素化。
The rice (Oryza sativa) E3 ligase SPOTTED LEAF11 (SPL11) negatively regulates programmed cell death and disease resistance. We demonstrate here that SPL11 also regulates flowering via interaction with SPIN1 (for SPL11-interacting protein1), a Signal Transduction and Activation of RNA family member. SPIN1 binds RNA and DNA in vitro and interacts with SPL11 in the nucleus. Spl11 mutants have delayed flowering under long-day conditions. Spin1 overexpression causes late flowering independently of daylength; expression analyses of flowering marker genes in these lines suggested that SPIN1 represses flowering by downregulating the flowering promoter gene Heading date3a (Hd3a) via Hd1-dependent mechanisms in short days and by targeting Hd1-independent factors in long days. Both Spin1 and Spl11 are regulated diurnally in opposing phases. SPL11 negatively regulates Spin1 transcript levels, while SPIN1 also affects Spl11 expression. Moreover, we show that coincidence of high accumulation of Spin1 mRNA with the light in the morning and early evening is needed to repress flowering. SPIN1 is monoubiquitinated by SPL11, suggesting that it is not targeted for degradation. Our data are consistent with a model which SPIN1 acts as a negative regulator of flowering that itself is negatively regulated by SPL11, possibly via ubiquitination.