Binds medium- and long-chain acyl-CoA esters with very high affinity. Can interact in vitro with oleoyl-CoA, barely with palmitoyl-CoA, but not with arachidonyl-CoA. May function as an intracellular carrier of acyl-CoA esters. Plays a role in the biosynthesis of membrane lipids including galactolipids and phospholipids. Interacts with RAP2-3/EBP, an ethylene-responsive element binding protein. Also to the periphery of the nucleus. Mostly expressed in roots, stems, and leaves, and, to a lower extent, in flowers and siliques. By 1-aminocyclopropane-1-carboxylic acid (ACC, ethylene precursor), methyl jasmonate (MeJA), and Botrytis cinerea. Up-regulated in the light and down-regulated in constant darkness. Belongs to the ACBP family.