Acyl-CoA-binding proteins play important roles in plant lipid metabolism

Abstract

Lipids form components of cellular membranes, surface structures, storage compounds, and defense and signaling molecules. Proteins that bind lipids include the acyl-CoA-binding proteins (ACBPs) which bind long-chain acyl-CoA esters at their acyl-CoA-binding domain. This domain is conserved across ACBPs from eukaryotes. In each representative dicot (Arabidopsis) and monocot (rice) plant, six ACBPs have been identified. To study the function of ACBPs in these model plants, investigations have been carried out using T-DNA insertional mutants and overexpressing lines. Mutations in ACBPs resulted in adverse embryo development in Arabidopsis, reminiscent of similar mutations in mice. Furthermore, Arabidopsis mutants lacking ACBPs showed altered lipid composition, increased stress susceptibility, retarded pollen development and reduced seed weight. Our results suggest that ACBPs expressed during floral and seed development play important roles in plant reproduction.