title: Expression of ACBP4 and ACBP5 proteins is modulated by light in Arabidopsis.
abstract: In our recent paper in Plant Physiology and Biochemistry, we reported that the mRNAs encoding Arabidopsis thaliana cytosolic acyl-CoA-binding proteins, ACBP4 and ACBP5, but not ACBP6, are modulated by light/dark cycling. The pattern of circadian-regulated expression in ACBP4 and ACBP5 mRNAs resembles that of FAD7 which encodes omega-3-fatty acid desaturase, an enzyme involved in plastidial fatty acid biosynthesis. Recombinant ACBP4 and ACBP5 proteins were observed to bind oleoyl-CoA ester comparably better than recombinant ACBP6, suggesting that ACBP4 and ACBP5 are promising candidates in the trafficking of oleoyl-CoA from the plastids to the endoplasmic reticulum (ER) for the biosynthesis of non-plastidial membrane lipids. By western blot analyses using the ACBP4 and ACBP5-specific antibodies, we show herein that the levels of ACBP4 and ACBP5 proteins peak at the end of the light period, further demonstrating that they, like their corresponding mRNAs, are tightly controlled by light to satisfy demands of lipids in plant cells.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Hong Kong, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Xiao
authors.forename: Qin-Fang
authors.initials: QF
authors.lastname: Chen
authors.forename: Mee-Len
authors.initials: ML
authors.lastname: Chye
mesh_terms: D000214:Acyl Coenzyme A / Q000235:genetics / Q000378:metabolism*; D000906:Antibodies; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D017343:Genes, Plant; D008027:Light; D008055:Lipids / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C495420:ACBP4 protein, Arabidopsis; C532782:ACBP6 protein, Arabidopsis; D000214:Acyl Coenzyme A; D000906:Antibodies; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D008055:Lipids; D012333:RNA, Messenger; D011994:Recombinant Proteins; C017585:oleoyl-coenzyme A