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N ‐myristoylation and S ‐acylation are common modifications of Ca 2+ ‐regulated Arabidopsis kinases and are required for activation of the SLAC1 anion channel
Author(s) -
Saito Shunya,
Hamamoto Shin,
Moriya Koko,
Matsuura Aiko,
Sato Yoko,
Muto Jun,
Noguchi Hiroto,
Yamauchi Seiji,
Tozawa Yuzuru,
Ueda Minoru,
Hashimoto Kenji,
Köster Philipp,
Dong Qiuyan,
Held Katrin,
Kudla Jörg,
Utsumi Toshihiko,
Uozumi Nobuyuki
Publication year - 2018
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.15053
Subject(s) - myristoylation , lipid anchored protein , palmitoylation , guard cell , bimolecular fluorescence complementation , complementation , microbiology and biotechnology , arabidopsis , protein kinase a , kinase , biology , mutant , phosphorylation , biochemistry , chemistry , gene , autophagy , enzyme , apoptosis , cysteine
SummaryN ‐myristoylation and S‐ acylation promote protein membrane association, allowing regulation of membrane proteins. However, how widespread this targeting mechanism is in plant signaling processes remains unknown. Through bioinformatics analyses, we determined that among plant protein kinase families, the occurrence of motifs indicative for dual lipidation by N ‐myristoylation and S ‐acylation is restricted to only five kinase families, including the Ca 2+ ‐regulated CDPK ‐Sn RK and CBL protein families. We demonstrated N ‐myristoylation of CDPK ‐Sn RK s and CBL s by incorporation of radiolabeled myristic acid. We focused on CPK 6 and CBL 5 as model cases and examined the impact of dual lipidation on their function by fluorescence microscopy, electrophysiology and functional complementation of Arabidopsis mutants. We found that both lipid modifications were required for proper targeting of CBL 5 and CPK 6 to the plasma membrane. Moreover, we identified CBL 5– CIPK 11 complexes as phosphorylating and activating the guard cell anion channel SLAC 1. SLAC 1 activation by CPK 6 or CBL 5– CIPK 11 was strictly dependent on dual lipid modification, and loss of CPK 6 lipid modification prevented functional complementation of cpk3 cpk6 guard cell mutant phenotypes. Our findings establish the general importance of dual lipid modification for Ca 2+ signaling processes, and demonstrate their requirement for guard cell anion channel regulation.