Medicago falcata MfSTMIR, an E3 ligase of endoplasmic reticulum-associated degradation, is involved in salt stress response
Medicago falcata MfSTMIR, an E3 ligase of endoplasmic reticulum-associated degradation, is involved in salt stress response
复制标题
苜蓿 MfSTMIR 是一种内质网相关降解的 E3 连接酶，参与盐胁迫反应
DOI：
10.1111/tpj.14265
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Wang Tao
中科院分区：
文献类型：
--
作者：
zhang RongXue;Chen Hong;Duan Mei;Zhu Fugui;Wen Jiangqi;Dong Jiangli;Wang Tao
最近对植物内质网（ER）相关降解（ERAD） E3的研究发现，在酵母和动物中也有类似的E3。然而，目前尚不清楚植物ERAD系统是否含有植物特异性E3连接酶。mfstmir编码一种在豆科植物中高度保守的内质网膜定位的RING E3连接酶，在紫花苜蓿对内质网和盐胁迫的响应中发挥重要作用。盐和tunicamycin （Tm）诱导mfstmi1表达。mtstmir功能缺失突变体在Tm处理下表现出内质网络应激反应基因bip1 /2和bip3的诱导受损，并且对盐胁迫敏感。MfSTMIR促进了已知ERAD底物CPY*的降解。MfSTMIR与ERAD相关的泛素偶联酶MtUBC32和Sec61易位亚基MtSec61γ相互作用。MfSTMIR不影响MtSec61γ蛋白的稳定性。我们的研究结果表明，植物特异性E3连接酶MfSTMIR通过与MtUBC32和MtSec61γ相互作用参与ERAD途径，从而缓解盐胁迫下的内质网胁迫。
Recent studies on E3 of endoplasmic reticulum (ER)‐associated degradation (ERAD) in plants have revealed homologs in yeast and animals. However, it remains unknown whether the plant ERAD system contains a plant‐specific E3 ligase. Here, we report thatMfSTMIR, which encodes an ER‐membrane‐localized RING E3 ligase that is highly conserved in leguminous plants, plays essential roles in the response of ER and salt stress inMedicago.MfSTMIRexpression was induced by salt and tunicamycin (Tm).mtstmirloss‐of‐function mutants displayed impaired induction of the ER stress‐responsive genesBiP1/2andBiP3under Tm treatment and sensitivity to salt stress. MfSTMIR promoted the degradation of a known ERAD substrate, CPY*. MfSTMIR interacted with the ERAD‐associated ubiquitin‐conjugating enzyme MtUBC32 and Sec61‐translocon subunit MtSec61γ. MfSTMIR did not affect MtSec61γ protein stability. Our results suggest that the plant‐specific E3 ligase MfSTMIR participates in the ERAD pathway by interacting with MtUBC32 and MtSec61γ to relieve ER stress during salt stress.