title: Characterization of hARD2, a processed hARD1 gene duplicate, encoding a human protein N-alpha-acetyltransferase.
abstract: BACKGROUND
  Protein acetylation is increasingly recognized as an important mechanism regulating a variety of cellular functions. Several human protein acetyltransferases have been characterized, most of them catalyzing epsilon-acetylation of histones and transcription factors. We recently described the human protein acetyltransferase hARD1 (human Arrest Defective 1). hARD1 interacts with NATH (N-Acetyl Transferase Human) forming a complex expressing protein N-terminal alpha-acetylation activity.
  
  
  RESULTS
  We here describe a human protein, hARD2, with 81 % sequence identity to hARD1. The gene encoding hARD2 most likely originates from a eutherian mammal specific retrotransposition event. hARD2 mRNA and protein are expressed in several human cell lines. Immunoprecipitation experiments show that hARD2 protein potentially interacts with NATH, suggesting that hARD2-NATH complexes may be responsible for protein N-alpha-acetylation in human cells. In NB4 cells undergoing retinoic acid mediated differentiation, the level of endogenous hARD1 and NATH protein decreases while the level of hARD2 protein is stable.
  
  
  CONCLUSIONS
  A human protein N-alpha-acetyltransferase is herein described. ARD2 potentially complements the functions of ARD1, adding more flexibility and complexity to protein N-alpha-acetylation in human cells as compared to lower organisms which only have one ARD.
authors.affiliation: Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway. Thomas.Arnesen@mbi.uib.no
authors.forename: Thomas
authors.initials: T
authors.lastname: Arnesen
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Betts
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pendino
authors.forename: David A
authors.initials: DA
authors.lastname: Liberles
authors.forename: Dave
authors.initials: D
authors.lastname: Anderson
authors.forename: Jaime
authors.initials: J
authors.lastname: Caro
authors.forename: Xianguo
authors.initials: X
authors.lastname: Kong
authors.forename: Jan E
authors.initials: JE
authors.lastname: Varhaug
authors.forename: Johan R
authors.initials: JR
authors.lastname: Lillehaug
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D003001:Cloning, Molecular; D004790:Enzyme Induction; D019143:Evolution, Molecular; D020440:Gene Duplication; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000302:isolation & purification / Q000378:metabolism; D007614:Macropodidae / Q000235:genetics; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D063209:N-Terminal Acetyltransferase A; D063213:N-Terminal Acetyltransferase E; D010802:Phylogeny; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D018626:Retroelements / Q000235:genetics; D016415:Sequence Alignment; D017385:Sequence Homology; D013045:Species Specificity; D014212:Tretinoin / Q000494:pharmacology
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C463022:NAA15 protein, human; D012333:RNA, Messenger; D018626:Retroelements; D014212:Tretinoin; D000123:Acetyltransferases; D063209:N-Terminal Acetyltransferase A; C504824:NAA10 protein, human; C511250:NAA11 protein, human; D063213:N-Terminal Acetyltransferase E