title: Association of NMT2 with the acyl-CoA carrier ACBD6 protects the N-myristoyltransferase reaction from palmitoyl-CoA.
abstract: The covalent attachment of a 14-carbon aliphatic tail on a glycine residue of nascent translated peptide chains is catalyzed in human cells by two N-myristoyltransferase (NMT) enzymes using the rare myristoyl-CoA (C(14)-CoA) molecule as fatty acid donor. Although, NMT enzymes can only transfer a myristate group, they lack specificity for C(14)-CoA and can also bind the far more abundant palmitoyl-CoA (C(16)-CoA) molecule. We determined that the acyl-CoA binding protein, acyl-CoA binding domain (ACBD)6, stimulated the NMT reaction of NMT2. This stimulatory effect required interaction between ACBD6 and NMT2, and was enhanced by binding of ACBD6 to its ligand, C(18:2)-CoA. ACBD6 also interacted with the second human NMT enzyme, NMT1. The presence of ACBD6 prevented competition of the NMT reaction by C(16)-CoA. Mutants of ACBD6 that were either deficient in ligand binding to the N-terminal ACBD or unable to interact with NMT2 did not stimulate activity of NMT2, nor could they protect the enzyme from utilizing the competitor C(16)-CoA. These results indicate that ACBD6 can locally sequester C(16)-CoA and prevent its access to the enzyme binding site via interaction with NMT2. Thus, the ligand binding properties of the NMT/ACBD6 complex can explain how the NMT reaction can proceed in the presence of the very abundant competitive substrate, C(16)-CoA.
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA esoupene@chori.org.
authors.forename: Eric
authors.initials: E
authors.lastname: Soupene
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kao
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Cheng
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA.
authors.forename: Derek
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Biochemistry and Biophysics, University of California at San Francisco and Howard Hughes Medical Institute, San Francisco, CA.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Greninger
authors.affiliation: Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA.
authors.forename: Giselle M
authors.initials: GM
authors.lastname: Knudsen
authors.affiliation: Department of Biochemistry and Biophysics, University of California at San Francisco and Howard Hughes Medical Institute, San Francisco, CA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: DeRisi
authors.affiliation: Children's Hospital Oakland Research Institute, Oakland, CA.
authors.forename: Frans A
authors.initials: FA
authors.lastname: Kuypers
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000378:metabolism*; D000214:Acyl Coenzyme A / Q000378:metabolism*; D000215:Acylation; D000217:Acyltransferases / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins; D003065:Coenzyme A / Q000378:metabolism; D005227:Fatty Acids / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D019814:Myristic Acid / Q000378:metabolism*; D010171:Palmitoyl Coenzyme A / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D013379:Substrate Specificity
chemical_list: C530903:ACBD6 protein, human; D018528:ATP-Binding Cassette Transporters; D000214:Acyl Coenzyme A; D002352:Carrier Proteins; D005227:Fatty Acids; D008563:Membrane Lipids; D010743:Phospholipids; D019814:Myristic Acid; D010171:Palmitoyl Coenzyme A; C040349:S-tetradecanoyl-coenzyme A; D000217:Acyltransferases; C050480:glycylpeptide N-tetradecanoyltransferase; D003065:Coenzyme A
keywords: N-myristoyltransferase 2; binding protein; coenzyme A; membranes; phospholipids; protein acylation; protein interaction