【背景和目的】植物未折叠蛋白应答(Unfolded protein response,UPR)信号通路在植物生长发育调控、逆境胁迫应答、内质网压力缓解等过程中起到重要作用,其中的bZIP60蛋白在该通路中起到关键核心作用。为了检测本氏烟UPR机制中bZIP60蛋...【背景和目的】植物未折叠蛋白应答(Unfolded protein response,UPR)信号通路在植物生长发育调控、逆境胁迫应答、内质网压力缓解等过程中起到重要作用,其中的bZIP60蛋白在该通路中起到关键核心作用。为了检测本氏烟UPR机制中bZIP60蛋白的表达,制备其抗血清用以探究其生物学功能。【方法】通过RT-PCR方法从本氏烟中克隆了bZIP60基因,然后将该基因连接至原核表达载体pET28a上,导入大肠杆菌BL21(DE3)菌株中,经1 mM IPTG诱导表达分子量约35 kDa的融合蛋白,用Ni-NTA亲和柱纯化获得靶标蛋白。最后以纯化的bZIP60蛋白辅以佐剂皮下免疫新西兰大白兔制备抗血清。【结果】Western blot分析表明,制备的抗血清具有较好的特异性和灵敏度,可以特异性检测到由喷施DTT引起本氏烟中bZIP60蛋白的表达。【结论】本研究通过原核表达技术成功获得融合His标签的bZIP60重组蛋白并制备了相应的抗血清,为下一步深入探究病原物与植物互作中bZIP60的分子机理提供研究基础。展开更多
UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the in...UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the interplays between UPR and plant DNA viruses remain unknown.Using tomato yellow leaf curl China virus(TYLCCNV)and its associated betasatellite(TYLCCNB)as a model,we indicate that TYLCCNBβC1 is a major inducer of UPR and can upregulate the expression of b ZIP60,a transcription factor in Nicotiana benthamiana plants.Treatment using ER stress inducers or overexpression of Nbb ZIP60 increasesβC1 accumulation and benefits TYLCCNV/TYLCCNB infection in N.benthamiana plants,and vice versa.In the TYLCCNV/TYLCCNB-infected or theβC1-expressing cells,Nbb ZIP60 is exported from the nucleus to the nuclear periphery via the XPO1 pathway,and blocking the XPO1 pathway inhibited TYLCCNV/TYLCCNB infection.We have found that the Nbb ZIP60-regulated pro-survival genes could promote virus infection,and the pro-death gene plays a contrasting role in virus infection.This study reveals that geminivirus infection activates UPR and utilizes the up-regulated molecular chaperons to promote viral infection,and then induces the nuclear export of Nbb ZIP60 to evade plant defense response,which is a distinct virulence strategy exploited by plant pathogens.展开更多
The membrane-associated transcription factor, bZlP28, is relocated from the endoplasmic reticulum （ER） to the Golgi and proteolytically released from the membrane mediated by two proteases, SlP and S2P, in response ...The membrane-associated transcription factor, bZlP28, is relocated from the endoplasmic reticulum （ER） to the Golgi and proteolytically released from the membrane mediated by two proteases, SlP and S2P, in response to ER stress in Arabidopsis. The activated N-terminal domain recruits nuclear factor Y （NF-Y） subunits in the nucleus to regulate ER stress downstream genes. Little is known about the functions of the bZIP28 C-terminal lumen-facing domain. Here, we provide novel insights into how the ER lumen-facing domain affects the biological function and organelle-to-organelle movement of bZIP28 in the ER stress response. First, we demonstrated the functional redundancy of bZlP28 and bZIP60 by generation and analysis of the bZIP28 and bZIP60 double mutant zip28zip60. Subsequent genetic complementation experiments in zip28zip60 background with deletions on bZlP28 lumen-facing domain highlighted the importance of lumen-facing domain for its in vivo function of bZIP28 in the ER stress response. The protein subcellular localization and Western blotting results further revealed that the bZIP28 lumen-facing domain contains ER retention signal which is important for the proteolytic activation of bZIP28. Thus, the bZIP28 lumen-facing C-terminus plays important roles in the ER-to-Golgi movement of bZlP28, which may contribute to the sensing of the ER stress.展开更多
文摘【背景和目的】植物未折叠蛋白应答(Unfolded protein response,UPR)信号通路在植物生长发育调控、逆境胁迫应答、内质网压力缓解等过程中起到重要作用,其中的bZIP60蛋白在该通路中起到关键核心作用。为了检测本氏烟UPR机制中bZIP60蛋白的表达,制备其抗血清用以探究其生物学功能。【方法】通过RT-PCR方法从本氏烟中克隆了bZIP60基因,然后将该基因连接至原核表达载体pET28a上,导入大肠杆菌BL21(DE3)菌株中,经1 mM IPTG诱导表达分子量约35 kDa的融合蛋白,用Ni-NTA亲和柱纯化获得靶标蛋白。最后以纯化的bZIP60蛋白辅以佐剂皮下免疫新西兰大白兔制备抗血清。【结果】Western blot分析表明,制备的抗血清具有较好的特异性和灵敏度,可以特异性检测到由喷施DTT引起本氏烟中bZIP60蛋白的表达。【结论】本研究通过原核表达技术成功获得融合His标签的bZIP60重组蛋白并制备了相应的抗血清,为下一步深入探究病原物与植物互作中bZIP60的分子机理提供研究基础。
基金supported by the National Key Research and Development Program of China (2021YFD1400400)the National Natural Science Foundation of China (32172385,31930089)。
文摘UPR is a conserved response in eukaryotes and can alleviate endoplasmic reticulum(ER)stresses induced by abiotic and biotic stresses.The interactions between UPR and plant RNA viruses have been documented,while the interplays between UPR and plant DNA viruses remain unknown.Using tomato yellow leaf curl China virus(TYLCCNV)and its associated betasatellite(TYLCCNB)as a model,we indicate that TYLCCNBβC1 is a major inducer of UPR and can upregulate the expression of b ZIP60,a transcription factor in Nicotiana benthamiana plants.Treatment using ER stress inducers or overexpression of Nbb ZIP60 increasesβC1 accumulation and benefits TYLCCNV/TYLCCNB infection in N.benthamiana plants,and vice versa.In the TYLCCNV/TYLCCNB-infected or theβC1-expressing cells,Nbb ZIP60 is exported from the nucleus to the nuclear periphery via the XPO1 pathway,and blocking the XPO1 pathway inhibited TYLCCNV/TYLCCNB infection.We have found that the Nbb ZIP60-regulated pro-survival genes could promote virus infection,and the pro-death gene plays a contrasting role in virus infection.This study reveals that geminivirus infection activates UPR and utilizes the up-regulated molecular chaperons to promote viral infection,and then induces the nuclear export of Nbb ZIP60 to evade plant defense response,which is a distinct virulence strategy exploited by plant pathogens.
基金This study was financially supported by grants from the National Basic Research Program of China （973 Program, 2012CB910500）, the National Natural Science Foundation of China （#31171157 #31070233 #31222008）, and the Shanghai Pujiang Talent Program （11PJ1400700）. No conflict of interest declared.
文摘The membrane-associated transcription factor, bZlP28, is relocated from the endoplasmic reticulum （ER） to the Golgi and proteolytically released from the membrane mediated by two proteases, SlP and S2P, in response to ER stress in Arabidopsis. The activated N-terminal domain recruits nuclear factor Y （NF-Y） subunits in the nucleus to regulate ER stress downstream genes. Little is known about the functions of the bZIP28 C-terminal lumen-facing domain. Here, we provide novel insights into how the ER lumen-facing domain affects the biological function and organelle-to-organelle movement of bZIP28 in the ER stress response. First, we demonstrated the functional redundancy of bZlP28 and bZIP60 by generation and analysis of the bZIP28 and bZIP60 double mutant zip28zip60. Subsequent genetic complementation experiments in zip28zip60 background with deletions on bZlP28 lumen-facing domain highlighted the importance of lumen-facing domain for its in vivo function of bZIP28 in the ER stress response. The protein subcellular localization and Western blotting results further revealed that the bZIP28 lumen-facing domain contains ER retention signal which is important for the proteolytic activation of bZIP28. Thus, the bZIP28 lumen-facing C-terminus plays important roles in the ER-to-Golgi movement of bZlP28, which may contribute to the sensing of the ER stress.
