[转移贴] 拟南芥蛋白如何防御病毒感染

cao1976

原贴由hans发表于 2008-2-18 12:45
http://biosky.haotui.com/thread-3794-1-9.html


CRT1, an Arabidopsis ATPase that Interacts with Diverse Resistance Proteins and Modulates Disease Resistance to Turnip Crinkle Virus

Plant immunity frequently involves the recognition of pathogen-encoded avirulence (avr) factors by their corresponding plant resistance (R) proteins. This triggers the hypersensitive response (HR) where necrotic lesions formed at the site(s) of infection help restrict pathogen spread. HRT is an Arabidopsis R protein required for resistance to turnip crinkle virus (TCV). In a genetic screen for mutants compromised in the recognition of TCV's avr factor, we identified crt1 (compromised recognition of TCV), a mutant that prematurely terminates an ATPase protein. Following TCV infection, crt1 developed a spreading HR and failed to control viral replication and spread. crt1 also suppressed HR-like cell death induced by ssi4, a constitutively active R protein, and by Pseudomonas syringae carrying avrRpt2. Furthermore, CRT1 interacts with HRT, SSI4, and two other R proteins, RPS2 and Rx. These data identify CRT1 as an important mediator of defense signaling triggered by distinct classes of R proteins.

植物免疫性往往通过相应的植物抗性蛋白 (R) 来识别病原体编码的无毒因素，从而引发过敏性反应 (HR) ，使感染的地方形成坏死病灶来限制病原的扩散。

拟南芥抗性蛋白 (HRT) 能够抵抗芜菁皱病毒 (TCV) 的感染。在筛选识别芜菁皱病毒的无毒缺陷突变体的过程中，Kang等人发现了识别芜菁皱病毒的缺陷突变体 (CRT1) 可以在早期终止一个ATP酶蛋白。如果已经感染了芜菁皱病毒，CRT1引发的过敏性反应不能控制病毒复制和扩散，则CRT1还可以抑制ssi4诱导的类HR细胞的死亡，其中ssi4是一种由丁香假单胞菌携带的avrrpt2抗性蛋白。此外，CRT1与HRT、ssi4，以及其它两个抗性蛋白（RPS2和RX）相互作用共同抑制芜菁皱病毒的感染。

该研究表明，CRT1是抗性蛋白发出防御信号的重要媒介。相关论文发表在2008年1月17日的《细胞—宿主与微生物》（Cell Host & Microbe）杂志上。