Apple RING E3 ligase MdMIEL1 inhibits anthocyanin accumulation by ubiquitinating and degrading MdMYB1 protein

作者：An, Jian-Ping; Liu, Xin; Li, Hao-Hao; You, Chun-Xiang; Wang, Xiao-Fei^*; Hao, Yu-Jin^*

来源：Plant and Cell Physiology, 2017, 58(11): 1953-1962.

DOI：10.1093/pcp/pcx129

• Anthocyanin
• posttranslational modification
• transcription factor MdMYB1
• ubiquitination
• ubiquitin E3 ligase MdMIEL1

MdMYB1 is an important regulator for anthocyanin accumulation in apple (Malus x domestica). Here, an apple RING E3 ligase, MdMIEL1, was screened out as a partner of MdMYB1 with a yeast two-hybrid approach. Pull-down, bimolecular fluorescence complementation and coimmunoprecipitation assays further verified the interaction between MdMIEL1 and MdMYB1 proteins. Subsequently, in vitro and in vivo experiments indicated that MdMIEL1 functioned as a ubiquitin E3 ligase to ubiquitinate MdMYB1 protein, followed by degradation through a 26S proteasome pathway. Furthermore, transgenic studies in apple calli and Arabidopsis demonstrated that MdMIEL1 negatively regulated anthocyanin accumulation by modulating the degradation of MdMYB1 protein. Taken together, our findings provide a new insight into the molecular mechanism by which MdMIEL1 negatively regulates anthocyanin biosynthesis by ubiquitinating and degrading MdMYB1 protein.

• 出版日期2017-11
• 单位作物生物学国家重点实验室; 山东农业大学