Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid signaling.
Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid signaling.
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体细胞胚胎发生受体激酶在油菜素类固醇信号传导中不可或缺作用的遗传证据
DOI：
10.1371/journal.pgen.1002452
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发表时间：
2012-01
期刊：
影响因子：
4.5
通讯作者：
Li J
中科院分区：
文献类型：
--
作者：
Gou X;Yin H;He K;Du J;Yi J;Xu S;Lin H;Clouse SD;Li J
拟南芥体细胞胚胎发生受体激酶(SERKs)由5个成员组成，SERK1至SERK5，属于富含亮氨酸重复序列的受体亚家族II(LRR-RLK II)。SERK3由于在体内与油菜素类固醇(BR)受体BRI1直接相互作用而被命名为BRI1相关受体激酶1(BAK1)，而SERK4也因其与BAK1功能冗余而被命名为BAK1样蛋白(BKK1)。在这里，我们提供了遗传和生化证据来证明SERK对于BR信号的早期步骤是绝对必要的。5个SERK中的4个-SERK1、SERK2、SERK3/BAK1和SERK4/BK1-的过表达抑制了中间突变体BRI1-5的表型。另一方面，在BRI1-5背景中，这四个基因的激酶死亡版本的过度表达导致了典型的显性阴性表型，类似于BRI1缺失突变体。我们分离和产生了单、双、三和四个突变体，并详细分析了它们的表型。虽然四重突变体是胚胎致死的，但SERK1 bak1 BKK1三个零突变体表现出与零BRI1突变体类似的极端去黄化表型。虽然BRI1的过表达可以显著促进野生型植物下胚轴的生长，但过表达BRI1不会改变SERK1 bak1 BKK1三重突变体的下胚轴生长。生化分析表明，在SERK1bak1BKK1中BRI1的磷酸化水平不能感知外源BR的作用。结果，BES1的非磷酸化水平已经失去了对BR处理的敏感性，表明BR信号通路在三个突变体中已经完全被取消。这些数据清楚地表明，SERK对于BR信号的早期事件是必不可少的。
The Arabidopsis thaliana Somatic Embryogenesis Receptor Kinases (SERKs) consist of five members, SERK1 to SERK5, of the leucine-rich repeat receptor-like kinase subfamily II (LRR-RLK II). SERK3 was named BRI1-Associated Receptor Kinase 1 (BAK1) due to its direct interaction with the brassinosteroid (BR) receptor BRI1 in vivo, while SERK4 has also been designated as BAK1-Like 1 (BKK1) for its functionally redundant role with BAK1. Here we provide genetic and biochemical evidence to demonstrate that SERKs are absolutely required for early steps in BR signaling. Overexpression of four of the five SERKs—SERK1, SERK2, SERK3/BAK1, and SERK4/BKK1—suppressed the phenotypes of an intermediate BRI1 mutant, bri1-5. Overexpression of the kinase-dead versions of these four genes in the bri1-5 background, on the other hand, resulted in typical dominant negative phenotypes, resembling those of null BRI1 mutants. We isolated and generated single, double, triple, and quadruple mutants and analyzed their phenotypes in detail. While the quadruple mutant is embryo-lethal, the serk1 bak1 bkk1 triple null mutant exhibits an extreme de-etiolated phenotype similar to a null bri1 mutant. While overexpression of BRI1 can drastically increase hypocotyl growth of wild-type plants, overexpression of BRI1 does not alter hypocotyl growth of the serk1 bak1 bkk1 triple mutant. Biochemical analysis indicated that the phosphorylation level of BRI1 in serk1 bak1 bkk1 is incapable of sensing exogenously applied BR. As a result, the unphosphorylated level of BES1 has lost its sensitivity to the BR treatment in the triple mutant, indicating that the BR signaling pathway has been completely abolished in the triple mutant. These data clearly demonstrate that SERKs are essential to the early events of BR signaling.
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影响因子：
11.6
作者：
Albrecht, C;Russinova, E;de Vries, S
通讯作者：
de Vries, S
影响因子：
64.8
作者：
Chinchilla, Delphine;Zipfel, Cyril;Boller, Thomas
通讯作者：
Boller, Thomas
影响因子：
7.4
作者：
Albrecht, Catherine;Russinova, Eugenia;de Vries, Sacco C.
通讯作者：
de Vries, Sacco C.
影响因子：
56.9
作者：
He, JX;Gendron, JM;Wang, ZY
通讯作者：
Wang, ZY
影响因子：
64.5
作者：
Li, J;Wen, JQ;Walker, JC
通讯作者：
Walker, JC