The single-subunit RING-type E3 ubiquitin ligase RSL1 targets PYL4 and PYR1 ABA receptors in plasma membrane to modulate abscisic acid signaling
The single-subunit RING-type E3 ubiquitin ligase RSL1 targets PYL4 and PYR1 ABA receptors in plasma membrane to modulate abscisic acid signaling
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DOI：
10.1111/tpj.12708
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发表时间：
2014-12-01
期刊：
影响因子：
7.2
通讯作者：
Rodriguez, Pedro L.
中科院分区：
文献类型：
--
作者：
Bueso, Eduardo;Rodriguez, Lesia;Rodriguez, Pedro L.
膜分隔事件对ABA信号和PYR/PYL/RCAR ABA受体起着至关重要的作用，进化枝a pp2c和SnRK2/CPK激酶调节参与ABA作用的不同质膜组分的活性。因此，PYR/PYL/RCARs在质膜附近的转换可能是影响受体功能和下游信号传导的一个步骤。在这项研究中，我们描述了一个单亚基环型E3泛素连接酶RSL1，它与质膜上的PYL4和PYR1 ABA受体相互作用。RSL1的过表达降低了ABA的敏感性，而RSL1 RNAi细胞系中一些RSL1/RFA基因家族成员的表达受损，则显示出对ABA的敏感性增强。RSL1携带一个c端跨膜结构域，其目标是E3连接酶到质膜。因此，双分子荧光互补（BiFC）研究表明，RSL1-PYL4和RSL1-PYR1相互作用定位于质膜。RSL1在体内促进PYL4和PYR1的降解，并介导受体的体外泛素化。综上所述，这些结果表明，质膜上ABA受体的泛素化过程可能通过影响其半衰期、蛋白质相互作用或运输来影响其功能。
Membrane-delimited events play a crucial role for ABA signaling and PYR/PYL/RCAR ABA receptors, clade A PP2Cs and SnRK2/CPK kinases modulate the activity of different plasma membrane components involved in ABA action. Therefore, the turnover of PYR/PYL/RCARs in the proximity of plasma membrane might be a step that affects receptor function and downstream signaling. In this study we describe a single-subunit RING-type E3 ubiquitin ligase RSL1 that interacts with the PYL4 and PYR1 ABA receptors at the plasma membrane. Overexpression of RSL1 reduces ABA sensitivity and rsl1 RNAi lines that impair expression of several members of the RSL1/RFA gene family show enhanced sensitivity to ABA. RSL1 bears a C-terminal transmembrane domain that targets the E3 ligase to plasma membrane. Accordingly, bimolecular fluorescent complementation (BiFC) studies showed the RSL1-PYL4 and RSL1-PYR1 interaction is localized to plasma membrane. RSL1 promoted PYL4 and PYR1 degradation in vivo and mediated in vitro ubiquitylation of the receptors. Taken together, these results suggest ubiquitylation of ABA receptors at plasma membrane is a process that might affect their function via effect on their half-life, protein interactions or trafficking.