The characterization of a mitochondrial acyl carrier protein isoform isolated from Arabidopsis thaliana

• Published in: Plant physiology (Bethesda) Vol. 104; no. 4; pp. 1221 - 1229
• Main Authors: Shintani, D.K, Ohlrogge, J.B
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.04.1994
• Subjects: ACIDE GRAS; ACIDOS GRASOS; Acyl Carrier Protein - biosynthesis; Acyl Carrier Protein - genetics; Acyl Carrier Protein - isolation & purification; ADN; Amino Acid Sequence; Animals; Antibodies; Arabidopsis - genetics; Arabidopsis - metabolism; ARABIDOPSIS THALIANA; Base Sequence; Biological and medical sciences; BIOSINTESIS; BIOSYNTHESE; Blotting, Western; Carrier proteins; Cattle; Chloroplasts; Chloroplasts - metabolism; CLONE; CLONES; CODE GENETIQUE; CODIGO GENETICO; Complementary DNA; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA Primers; DNA, Complementary - isolation & purification; DNA, Complementary - metabolism; EXPRESION GENICA; EXPRESSION DES GENES; Fatty acids; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes. Genome; Imports; Metabolism; Mitochondria; Mitochondria - metabolism; Mitochondria, Heart - metabolism; MITOCHONDRIE; MITOCONDRIA; Molecular and cellular biology; Molecular Biology and Gene Regulation; Molecular genetics; Molecular Sequence Data; NEUROSPORA; Neurospora crassa - metabolism; Nitrogen metabolism; Plant physiology and development; Polymerase Chain Reaction; Protein Biosynthesis; Protein isoforms; Protein precursors; PROTEINAS AGLUTINANTES; PROTEINE DE LIAISON; SECUENCIA NUCLEICA; Sequence Homology, Amino Acid; SEQUENCE NUCLEIQUE; Spinach; Transcription, Genetic; Vegetables - metabolism; Nucleotide sequence; Arabidopsis thaliana; Characterization; Mitochondria; Acyl group; Complementary DNA; Cruciferae; Dicotyledones; Angiospermae; Isolation; Spermatophyta; Experimental plant; Localization; Carrier protein
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.104.4.1221

A cDNA clone was isolated from an Arabidopsis leaf cDNA library that shared a high degree of protein sequence identity with mitochondrial acyl carrier proteins (mtACPs) isolated from Neurospora crassa and bovine heart muscle. The cDNA encoded an 88-amino acid mature protein that was preceded by a putative 35-amino acid presequence. In vitro protein import studies have confirmed that the presequence specifically targets this protein into pea mitochondria but not into chloroplasts. These studies indicated that pea mitochondria were not only able to import and process the precursor protein but also possessed the ability to acylate the mature protein. The mitochondrial localization of this protein, mtACP-1, was confirmed by western blot analysis. Arabidopsis mitochondrial protein extracts contained two cross-reacting bands that comigrated with the mature mtACP-1 and acylated mtACP-1 proteins. The acylated form of mtACP-1 was approximately 4 times more abundant than the unacylated form and appeared to be localized predominantly in the mitochondrial membrane where the unacylated mtACP-1 was present mostly in the matrix fraction. A chloroplast fatty acid synthase system was used, and mtACP-1 was able to function as a cofactor for fatty acid synthesis. However, predominantly short- and medium-chain fatty acids were produced in fatty acid synthase reactions supplemented with mtACP-1, suggesting that mtACP-1 may be causing premature fatty acid chain termination