title: Peptidyl-prolyl isomerization targets rice Aux/IAAs for proteasomal degradation during auxin signalling.
abstract: In plants, auxin signalling is initiated by the auxin-promoted interaction between the auxin receptor TIR1, an E3 ubiquitin ligase, and the Aux/IAA transcriptional repressors, which are subsequently degraded by the proteasome. Gain-of-function mutations in the highly conserved domain II of Aux/IAAs abolish the TIR1-Aux/IAA interaction and thus cause an auxin-resistant phenotype. Here we show that peptidyl-prolyl isomerization of rice OsIAA11 catalysed by LATERAL ROOTLESS2 (LRT2), a cyclophilin-type peptidyl-prolyl cis/trans isomerase, directly regulates the stability of OsIAA11. NMR spectroscopy reveals that LRT2 efficiently catalyses the cis/trans isomerization of OsIAA11. The lrt2 mutation reduces OsTIR1-OsIAA11 interaction and consequently causes the accumulation of a higher level of OsIAA11 protein. Moreover, knockdown of the OsIAA11 expression partially rescues the lrt2 mutant phenotype in lateral root development. Together, these results illustrate cyclophilin-catalysed peptidyl-prolyl isomerization promotes Aux/IAA degradation, as a mechanism regulating auxin signalling.
authors.affiliation: 1] State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Jing
authors.affiliation: 1] State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xuehui
authors.initials: X
authors.lastname: Liu
authors.affiliation: 1] State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Huakun
authors.initials: H
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.
authors.forename: Guojun
authors.initials: G
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jinqiang
authors.initials: J
authors.lastname: Nian
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Feng
authors.affiliation: College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xia
authors.affiliation: State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jiayang
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jianru
authors.initials: J
authors.lastname: Zuo
mesh_terms: D021983:Cyclophilins / Q000235:genetics* / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D012275:Oryza; D019696:Peptidylprolyl Isomerase / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; C046131:auxin receptor, plant; D046988:Proteasome Endopeptidase Complex; D021983:Cyclophilins; D019696:Peptidylprolyl Isomerase