Shao Feng, Golstein Catherine, Ade Jules, Stoutemyer Mark, Dixon Jack E, Innes Roger W
Department of Biological Chemistry, Medical School and Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA.
Science. 2003 Aug 29;301(5637):1230-3. doi: 10.1126/science.1085671.
Plant disease-resistance (R) proteins are thought to function as receptors for ligands produced directly or indirectly by pathogen avirulence (Avr) proteins. The biochemical functions of most Avr proteins are unknown, and the mechanisms by which they activate R proteins have not been determined. In Arabidopsis, resistance to Pseudomonas syringae strains expressing AvrPphB requires RPS5, a member of the class of R proteins that have a predicted nucleotide-binding site and leucine-rich repeats, and PBS1, a protein kinase. AvrPphB was found to proteolytically cleave PBS1, and this cleavage was required for RPS5-mediated resistance, which indicates that AvrPphB is detected indirectly via its enzymatic activity.
植物抗病（R）蛋白被认为可作为由病原体无毒（Avr）蛋白直接或间接产生的配体的受体。大多数Avr蛋白的生化功能尚不清楚，其激活R蛋白的机制也未明确。在拟南芥中，对表达AvrPphB的丁香假单胞菌菌株的抗性需要RPS5（一种具有预测的核苷酸结合位点和富含亮氨酸重复序列的R蛋白家族成员）和PBS1（一种蛋白激酶）。研究发现AvrPphB可蛋白水解切割PBS1，且这种切割是RPS5介导的抗性所必需的，这表明AvrPphB是通过其酶活性被间接检测到的。
