耻垢分枝杆菌ClpC和ClpX敲低表达菌株的构建及表型分析*

蛋白质平衡稳定对细菌的生长繁殖以及应对宿主免疫压力十分重要。Clp蛋白酶复合体在结核分枝杆菌的蛋白质降解和平衡稳定中发挥重要作用。Clp蛋白酶中负责识别底物蛋白并将其解折叠的蛋白质有两种:ClpC和ClpX。为初步探究分枝杆菌中ClpC和ClpX各自的功能特点,运用CRISPRi的方法成功构建了耻垢分枝杆菌的ClpC和ClpX诱导型敲低表达菌株,并对其生长相关表型进行分析。结果显示:与野生菌株相比,ClpC和ClpX的低表达均能严重影响耻垢分枝杆菌的生长。ClpC低表达可导致菌株丧失生物膜的形成能力,而ClpX低表达则导致菌株无法维持正常细胞形态,电镜显示细胞壁不完整且细胞呈丝状化,提示ClpC和ClpX可能在分枝杆菌中具有不同的生理功能。可为后期深入开展ClpC和ClpX对分枝杆菌生理调控功能研究及新型抗结核药物筛选提供基础。     

微生物学“六化”教学理念和管理模式的构建及实施

针对微生物教学中存在的问题进行一系列改革,总结出了"六化"教学理念和管理方式:教师团队层次化,兴趣引导文学化,微生物史纵横化,知识讲解形象化,实验选题生活化,考核方式多元化。教学改革涉及教学方法、教学内容以及考核方式等多方面,取得显著效果。学生不仅在专业知识的学习上取得进步,而且综合素质得到了全面提升。     

The E3 Ligase APIP10 Connects the Effector AvrPiz-t to the NLR Receptor Piz-t in Rice

Although nucleotide-binding domain, leucine-rich repeat (NLR) proteins are the major immune receptors in plants, the mechanism that controls their activation and immune signaling remains elusive. Here, we report that the avirulence effector AvrPiz-t from Magnaporthe oryzae targets the rice E3 ligase APIP10 for degradation, but that APIP10, in return, ubiquitinates AvrPiz-t and thereby causes its degradation. Silencing of APIP10 in the non-Piz-t background compromises the basal defense against M. oryzae. Conversely, silencing of APIP10 in the Piz-t background causes cell death, significant accumulation of Piz-t, and enhanced resistance to M. oryzae, suggesting that APIP10 is a negative regulator of Piz-t. We show that APIP10 promotes degradation of Piz-t via the 26S proteasome system. Furthermore, we demonstrate that AvrPiz-t stabilizes Piz-t during M. oryzae infection. Together, our results show that APIP10 is a novel E3 ligase that functionally connects the fungal effector AvrPiz-t to its NLR receptor Piz-t in rice.