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Arabidopsis E3 ubiquitin ligase PLANT U‐BOX13 ( PUB 13) regulates chitin receptor LYSIN MOTIF RECEPTOR KINASE5 ( LYK 5) protein abundance
Author(s) -
Liao Dehua,
Cao Yangrong,
Sun Xun,
Espinoza Catherine,
Nguyen Cuong T.,
Liang Yan,
Stacey Gary
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14472
Subject(s) - ubiquitin ligase , biology , arabidopsis , elicitor , microbiology and biotechnology , callose , protein kinase a , biochemistry , mutant , kinase , ubiquitin , gene
Summary Long‐chain chitooligosaccharides are fungal microbe‐associated molecular patterns ( MAMP s) that are recognized by LYSIN MOTIF RECEPTOR KINASE5 ( LYK 5), inducing the formation of a complex with CHITIN ELICITOR RECEPTOR KINASE1 ( CERK 1). Formation of this complex leads to activation of the CERK 1 intracellular kinase domain and induction of plant innate immunity in Arabidopsis. We found that addition of chitooctaose induced LYK 5 protein accumulation as a result of de novo gene expression and the inhibition of LYK 5 protein degradation. Screening the putative E3 ligases for interaction with LYK 5 identified PLANT U‐BOX13 ( PUB 13), which complexed with LYK 5, but this complex dissociated upon addition of chitooctaose. Consistent with these results, LYK 5 protein abundance was higher in pub13 mutants compared with the wild type without chitooctaose treatment, while similar abundance was detected with the addition of chitooctaose. The pub13 mutants showed hypersensitivity to chitooctaose‐induced rapid responses, such as the production of reactive oxygen species ( ROS ) and mitogen‐activated protein ( MAP ) kinase phosphorylation, but exhibited normal responses to subsequent long‐term chitooctaose treatment, such as gene expression and callose deposition. In addition, PUB 13 could ubiquitinate the LYK 5 kinase domain in vitro . Taken together, our results suggest an important regulatory function for the turnover of LYK 5 mediated by the E3 ligase PUB 13.