Possible modulation of Arabidopsis ETR1 N-terminal signaling by CTR1.
The mitogen-activated protein kinase kinase kinase (MAPKKK) Constitutive Triple-Response1 (CTR1) plays a key role in mediating ethylene receptor signaling via its N-terminal interaction with the ethylene receptor C-terminal histidine kinase (HK) domain. Loss-of-function mutations of CTR1 prevent ethylene receptor signaling, and corresponding ctr1 mutants show a constitutive ethylene response phenotype. We recently reported in Plant Physiology that expression of the truncated ethylene receptor Ethylene Response1 (ETR1) isoforms etr1 ( 1-349)  and dominant ethylene-insensitive etr1-1 ( 1-349) , lacking the C-terminal HK and receiver domains, both suppressed the ctr1 mutant phenotype. Therefore, the ETR1 N terminus is capable of receptor signaling independent of CTR1. The constitutive ethylene response phenotype is stronger for ctr1-1 than ctr1-1 lines expressing the etr1 ( 1-349)  transgene, so N-terminal signaling by the full-length but not truncated ETR1 is inhibited by ctr1-1. We address possible modulations of ETR1 N-terminal signaling with docking of CTR1 on the ETR1 HK domain.
National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
Fang
F
Xie
Liping
L
Qiu
Chi-Kuang
CK
Wen
D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000378:metabolism*; D005030:Ethylenes / Q000494:pharmacology; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011494:Protein Kinases / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D029681:Arabidopsis Proteins; C494590:ETR1 protein, Arabidopsis; D005030:Ethylenes; D011956:Receptors, Cell Surface; C036216:ethylene; D011494:Protein Kinases; C477753:CTR1 protein, Arabidopsis