title: Arabidopsis thaliana acyl-CoA-binding protein ACBP2 interacts with heavy-metal-binding farnesylated protein AtFP6.
abstract: Arabidopsis thaliana acyl-CoA-binding protein 2 (ACBP2) was observed to interact with farnesylated protein 6 (AtFP6), which has a metal-binding motif (M/LXCXXC). Their interaction and expression in response to heavy metals were investigated. Yeast two-hybrid analysis and in vitro assays showed that an ACBP2 derivative lacking ankyrin repeats did not interact with AtFP6, indicating that the ankyrin repeats mediate protein-protein interaction. Autofluorescence-tagged ACBP2 and AtFP6 transiently co-expressed in tobacco (Nicotiana tabacum) were both targeted to the plasma membrane. Reverse transcriptase polymerase chain reaction and northern blot analyses revealed that AtFP6 mRNA was induced by cadmium (Cd(II)) in A. thaliana roots. Assays using metal-chelate affinity chromatography demonstrated that in vitro translated ACBP2 and AtFP6 bound lead (Pb(II)), Cd(II) and copper (Cu(II)). Consistently, assays using fluorescence analysis confirmed that (His)(6)-AtFP6 bound Pb(II), like (His)(6)-ACBP2. Arabidopsis thaliana plants overexpressing ACBP2 or AtFP6 were more tolerant to Cd(II) than wild-type plants. Plasma membrane-localized ACBP2 and AtFP6 probably mediate Pb(II), Cd(II) and Cu(II) transport in A. thaliana roots. Also, (His)(6)-ACBP2 binds [(14)C]linoleoyl-CoA and [(14)C]linolenoyl-CoA, the precursors for phospholipid repair following lipid peroxidation under heavy metal stress at the plasma membrane. ACBP2-overexpressing plants were more tolerant to hydrogen peroxide than wild-type plants, further supporting a role for ACBP2 in post-stress membrane repair.
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong, China;State (China) Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong, China;State (China) Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Xiao
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong, China;State (China) Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Hong-Ye
authors.initials: HY
authors.lastname: Li
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong, China;State (China) Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Sai-Wah
authors.initials: SW
authors.lastname: Tsao
authors.affiliation: School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Road, Hong Kong, China;State (China) Key Laboratory of Agrobiotechnology, Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Mee-Len
authors.initials: ML
authors.lastname: Chye
mesh_terms: D017089:Ankyrin Repeat / Q000502:physiology; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D006861:Hydrogen Peroxide; D015227:Lipid Peroxidation; D026901:Membrane Transport Proteins; D019216:Metals, Heavy / Q000378:metabolism*; D017368:Protein Prenylation; D012333:RNA, Messenger / Q000096:biosynthesis; D020798:Two-Hybrid System Techniques
chemical_list: C419263:ACBP2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C534910:FP6 protein, Arabidopsis; D026901:Membrane Transport Proteins; D019216:Metals, Heavy; D012333:RNA, Messenger; D006861:Hydrogen Peroxide