State Key Laboratory of Crop Stress Biology for Arid Areas/College of Agronomy, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China.
Genome. 2013 Jun;56(6):315-26. doi: 10.1139/gen-2013-0032. Epub 2013 Jul 12.
The rice (Oryza sativa) OsXA21 receptor kinase is a well-studied immune receptor that initiates a signal transduction pathway leading to resistance to Xanthomonas oryzae pv. oryzae. Two homologs of OsXA21 were identified in wheat (Triticum aestivum): TaXA21-like1 located in a syntenic region with OsXA21, and TaXA21-like2 located in a nonsyntenic region. Proteins encoded by these two wheat genes interact with four wheat orthologs of known OsXA21 interactors. In this study, we screened a wheat yeast-two-hybrid (Y2H) library using the cytosolic portion of TaXA21-like1 as bait to identify additional interactors. Using full-length T. aestivum and T. monococcum proteins and Y2H assays we identified three novel TaXA21-like1 interactors (TaARG, TaPR2, TmSKL1) plus one previously known in rice (TaSGT1). An additional full-length wheat protein (TaCIPK14) interacted with TaXA21-like2 and OsXA21 but not with TaXA21-like1. The interactions of TaXA21-like1 with TmSKL1 and TaSGT1 were also observed in rice protoplasts using bimolecular fluorescence complementation assays. We then cloned the rice homologs of the novel wheat interactors and confirmed that they all interact with OsXA21. This last result suggests that interspecific comparative interactome analyses can be used not only to transfer known interactions from rice to wheat, but also to identify novel interactions in rice.
水稻（Oryza sativa）OsXA21 受体激酶是一种研究充分的免疫受体，它启动信号转导途径，导致对黄单胞菌（Xanthomonas oryzae pv. oryzae）的抗性。在小麦（Triticum aestivum）中鉴定出 OsXA21 的两个同源物：位于与 OsXA21 同源的基因座上的 TaXA21-like1，以及位于非同源基因座上的 TaXA21-like2。这两个小麦基因编码的蛋白质与已知 OsXA21 相互作用蛋白的四个小麦同源物相互作用。在这项研究中，我们使用 TaXA21-like1 的胞质部分作为诱饵筛选小麦酵母双杂交（Y2H）文库，以鉴定其他相互作用蛋白。使用全长 T. aestivum 和 T. monococcum 蛋白和 Y2H 测定法，我们鉴定了三个新的 TaXA21-like1 相互作用蛋白（TaARG、TaPR2、TmSKL1）和一个先前在水稻中已知的蛋白（TaSGT1）。另外一个全长的小麦蛋白（TaCIPK14）与 TaXA21-like2 和 OsXA21 相互作用，但不与 TaXA21-like1 相互作用。在水稻原生质体中，使用双分子荧光互补测定法还观察到 TaXA21-like1 与 TmSKL1 和 TaSGT1 的相互作用。然后，我们克隆了这些新的小麦相互作用蛋白在水稻中的同源物，并证实它们都与 OsXA21 相互作用。最后这个结果表明，种间比较互作组学分析不仅可以将已知的互作从水稻转移到小麦，还可以在水稻中鉴定新的互作。
