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ESCRT‐dependent vacuolar sorting and degradation of the auxin biosynthetic enzyme YUC1 flavin monooxygenase
Author(s) -
Ge Chennan,
Gao Caiji,
Chen Qingguo,
Jiang Liwen,
Zhao Yunde
Publication year - 2019
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/jipb.12760
Subject(s) - escrt , vacuole , green fluorescent protein , microbiology and biotechnology , arabidopsis , biochemistry , auxin , integral membrane protein , protein targeting , biology , chemistry , mutant , membrane protein , gene , membrane , vesicle , cytoplasm
Summary YUC flavin monooxygenases catalyze the rate‐limiting step of auxin biosynthesis. Here we report the vacuolar targeting and degradation of GFP‐YUC1. GFP‐YUC1 fusion expressed in Arabidopsis protoplasts or transgenic plants was primarily localized in vacuoles. Surprisingly, we established that GFP‐YUC1, a soluble protein, was sorted to vacuoles through the ESCRT pathway, which has long been recognized for sorting and targeting integral membrane proteins. We further show that GFP‐YUC1 was ubiquitinated and in this form GFP‐YUC1 was targeted for degradation, a process that was also stimulated by elevated auxin levels. Our findings revealed a molecular mechanism of GFP‐YUC1 degradation and demonstrate that the ESCRT pathway can recognize both soluble and integral membrane proteins as cargoes.