Sun Tongjun, Zhang Qian, Gao Minghui, Zhang Yuelin
Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
Plant J. 2014 Mar;77(5):748-56. doi: 10.1111/tpj.12425. Epub 2014 Feb 6.
Receptor-like kinases play diverse roles in plant biology. Arabidopsis BAK1-INTERACTING RECEPTOR-LIKE KINASE 1 (BIR1) functions as a negative regulator of plant immunity. bir1-1 mutant plants display spontaneous cell death and constitutive defense responses that are dependent on SUPPRESSOR OF BIR1,1 (SOBIR1) and PHYTOALEXIN DEFICIENT4 (PAD4). Here we report that mutations in three components of ER quality control, CALRETICULIN3 (CRT3), ER-LOCALIZED DnaJ-LIKE PROTEIN 3b (ERdj3b) and STROMAL-DERIVED FACTOR-2 (SDF2), also suppress the spontaneous cell death and constitutive defense responses in bir1-1. Further analysis revealed that accumulation of the SOBIR1 protein is reduced in crt3-1 and erdj3b-1 mutant plants. These data suggest that ER quality control plays important roles in the biogenesis of SOBIR1, and is required for cell death and defense responses in bir1-1.
类受体激酶在植物生物学中发挥着多种作用。拟南芥BAK1相互作用类受体激酶1（BIR1）作为植物免疫的负调控因子。bir1-1突变体植株表现出自发性细胞死亡和组成型防御反应，这些反应依赖于BIR1的抑制因子1（SOBIR1）和植物抗毒素缺陷4（PAD4）。在此，我们报道内质网质量控制的三个组分，钙网蛋白3（CRT3）、内质网定位的类DnaJ蛋白3b（ERdj3b）和基质衍生因子2（SDF2）的突变，也能抑制bir1-1中的自发性细胞死亡和组成型防御反应。进一步分析表明，crt3-1和erdj3b-1突变体植株中SOBIR1蛋白的积累减少。这些数据表明内质网质量控制在SOBIR1的生物合成中起重要作用，并且是bir1-1中细胞死亡和防御反应所必需的。
