InterPro domain: IPR044813

Acyl carrier protein (ACP) is a highly conserved cofactor protein required by Type II fatty acid synthases (FASs). Plant fatty acid biosynthesis occurs in both plastids and mitochondria [ 1 ]. In Arabidopsis, eight gene loci can be recognized by sequence homology to encode ACP isoforms, five of which are plastidic ACPs (ptACPs), and three of which appear to be mtACPs [ 2 ].

This entry represents the ptACPs, which includes AtACP1-5 from Arabidopsis [ 3 ]. From phylogenetic studies, they can be classified in two groups, one comprising AtACP1, AtACP2, AtACP3 and AtACP5, the other comprises AtACP4 and ACP homologues from related species. These proteins respond to different abiotic stresses such as salt, drought and deficiencies in nitrogen, phosphorus, potassium and iron [ 4 ]. AtACP1 (At3g05020), AtACP2 (At1g54580), and AtACP3 (At1g54630) are near constitutively expressed in leaves, roots, and seeds, whereas AtACP4 (At4g25050) is predominantly expressed in leaves and is induced upon illumination of plants and AtACP5 (At5g27200) is preferentially expressed in roots and down-regulated by salt stress [ 4 ].

1. Dual-Localized Enzymatic Components Constitute the Fatty Acid Synthase Systems in Mitochondria and Plastids. Plant Physiol 183, 517-529
2. Toward a functional catalog of the plant genome. A survey of genes for lipid biosynthesis. Plant Physiol 122, 389-402
3. Genes of ACYL CARRIER PROTEIN Family Show Different Expression Profiles and Overexpression of ACYL CARRIER PROTEIN 5 Modulates Fatty Acid Composition and Enhances Salt Stress Tolerance in Arabidopsis. Front Plant Sci 8, 987
4. Mitochondrial Fatty Acid Synthase Utilizes Multiple Acyl Carrier Protein Isoforms. Plant Physiol 183, 547-557