Ethylene- and pathogen-inducible Arabidopsis acyl-CoA-binding protein 4 interacts with an ethylene-responsive element binding protein.
Six genes encode proteins with acyl-CoA-binding domains in Arabidopsis thaliana. They are the small 10-kDa cytosolic acyl-CoA-binding protein (ACBP), membrane-associated ACBP1 and ACBP2, extracellularly-targeted ACBP3, and kelch-motif containing ACBP4 and ACBP5. Here, the interaction of ACBP4 with an A. thaliana ethylene-responsive element binding protein (AtEBP), identified in a yeast two-hybrid screen, was confirmed by co-immunoprecipitation. The subcellular localization of ACBP4 and AtEBP, was addressed using an ACBP4:DsRed red fluorescent protein fusion and a green fluorescent protein (GFP):AtEBP fusion. Transient expression of these autofluoresence-tagged proteins in agroinfiltrated tobacco leaves, followed by confocal laser scanning microscopy, indicated their co-localization predominantly at the cytosol which was confirmed by FRET analysis. Immuno-electron microscopy on Arabidopsis sections not only localized ACBP4 to the cytosol but also to the periphery of the nucleus upon closer examination, perhaps as a result of its interaction with AtEBP. Furthermore, the expression of ACBP4 and AtEBP in Northern blot analyses was induced by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, methyl jasmonate treatments, and Botrytis cinerea infection, suggesting that the interaction of ACBP4 and AtEBP may be related to AtEBP-mediated defence possibly via ethylene and/or jasmonate signalling.
School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Hong-Ye
HY
Li
Shi
S
Xiao
Mee-Len
ML
Chye
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020171:Botrytis / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005030:Ethylenes / Q000378:metabolism*; D015870:Gene Expression; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D020798:Two-Hybrid System Techniques
C495420:ACBP4 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D005030:Ethylenes; D010940:Plant Proteins; C093680:ethylene-responsive element binding protein; C036216:ethylene