Mucyn Tatiana S, Clemente Alfonso, Andriotis Vasilios M E, Balmuth Alexi L, Oldroyd Giles E D, Staskawicz Brian J, Rathjen John P
The Sainsbury Laboratory, John Ines Centre, Norwich NR4 7UH, United Kingdom.
Plant Cell. 2006 Oct;18(10):2792-806. doi: 10.1105/tpc.106.044016. Epub 2006 Oct 6.
Immunity in tomato (Solanum lycopersicum) to Pseudomonas syringae bacteria expressing the effector proteins AvrPto and AvrPtoB requires both Pto kinase and the NBARC-LRR (for nucleotide binding domain shared by Apaf-1, certain R gene products, and CED-4 fused to C-terminal leucine-rich repeats) protein Prf. Pto plays a direct role in effector recognition within the host cytoplasm, but the role of Prf is unknown. We show that Pto and Prf are coincident in the signal transduction pathway that controls ligand-independent signaling. Pto and Prf associate in a coregulatory interaction that requires Pto kinase activity and N-myristoylation for signaling. Pto interacts with a unique Prf N-terminal domain outside of the NBARC-LRR domain and resides in a high molecular weight recognition complex dependent on the presence of Prf. In this complex, both Pto and Prf contribute to specific recognition of AvrPtoB. The data suggest that the role of Pto is confined to the regulation of Prf and that the bacterial effectors have evolved to target this coregulatory molecular switch.
番茄（Solanum lycopersicum）对表达效应蛋白AvrPto和AvrPtoB的丁香假单胞菌的免疫需要Pto激酶和NBARC-LRR（Apaf-1、某些R基因产物和与C端富含亮氨酸重复序列融合的CED-4共有的核苷酸结合结构域）蛋白Prf。Pto在宿主细胞质内的效应子识别中起直接作用，但Prf的作用尚不清楚。我们表明，Pto和Prf在控制不依赖配体信号传导的信号转导途径中是一致的。Pto和Prf通过一种共调节相互作用结合在一起，这种相互作用需要Pto激酶活性和N-肉豆蔻酰化来进行信号传导。Pto与NBARC-LRR结构域之外的独特Prf N端结构域相互作用，并存在于依赖Prf存在的高分子量识别复合物中。在这个复合物中，Pto和Prf都有助于对AvrPtoB的特异性识别。数据表明，Pto的作用仅限于对Prf的调节，并且细菌效应子已经进化到靶向这个共调节分子开关。
