Disease relevance of ACBP2

• These repeats, which likely mediate protein-protein interactions, could constitute a potential docking site in ACBP2 for an enzyme that uses acyl-CoAs as substrate, in vitro binding assays on recombinant (His)6-ACBP2 expressed in Escherichia coli show that it binds 14[C]palmitoyl-CoA preferentially to 14[C]oleoyl-CoA [1].

High impact information on ACBP2

• We have previously shown that Arabidopsis ACBP1 and ACBP2 are membrane-associated proteins while ACBP4 and ACBP5 contain kelch motifs [2].
• The function of the acyl-CoA-binding domain in ACBP2 has been confirmed by site-directed mutagenesis and four conserved residues crucial for palmitoyl-CoA binding have been identified [3].
• In this study, we investigated the significance of its ankyrin repeats in mediating protein-protein interactions by yeast two-hybrid analysis and in vitro protein-binding assays; we showed that ACBP2 interacts with the A. thaliana ethylene-responsive element-binding protein AtEBP via its ankyrin repeats [3].
• Co-expression of DsRed:ACBP2 and GFP:AtEBP showed a common localization of both proteins at the plasma membrane, suggesting that ACBP2 likely interacts with AtEBP at the plasma membrane [3].

Biological context of ACBP2

• Analysis of the acyl-CoA-binding domain in ACBP2 was carried out by in vitro mutagenesis [1].
• Analysis of the ACBP2 promoter revealed that, like the ACBP1 promoter, it lacks a TATA box suggesting the possibility of a housekeeping function for ACBP2 in plant lipid metabolism [1].

Anatomical context of ACBP2

• Our investigations also showed that when the transmembrane domain of ACBP1 or that of ACBP2 was fused with GFP, the fusion protein was targeted to the plasma membrane, thereby establishing their role in membrane targeting [4].
• Here, western blot analysis of anti-ACBP2 antibodies on A. thaliana protein showed that ACBP2 is located in the microsome-containing membrane fraction and in the subcellular fraction containing large particles (mitochondria, chloroplasts and peroxisomes), resembling the subcellular localization of ACBP1 [4].

Physical interactions of ACBP2

• Single amino acid substitutions at the acyl-CoA-binding domain interrupt 14[C]palmitoyl-CoA binding of ACBP2, an Arabidopsis acyl-CoA-binding protein with ankyrin repeats [1].

Other interactions of ACBP2

• We conclude that ACBP2, like ACBP1, is a membrane protein that likely functions in membrane-associated acyl-CoA transfer/metabolism [4].

Analytical, diagnostic and therapeutic context of ACBP2

• Northern blot analysis showed that the 1.6 kb ACBP2 mRNA, like that of ACBP1, is expressed in all plant organs [1].
• We show by reverse-transcriptase polymerase chain reaction (RT-PCR) analysis that ACBP3 , ACBP4 and ACBP5 are expressed in all plant organs, like ACBP1 and ACBP2 . ACBP4 and ACBP5 that share 81.4 identity and which contain kelch motifs were further investigated [5].

References