SUMMARY PARAGRAPH for ARD1
Ard1p is part of an N-terminal acetyl transferase; it acts in a complex with Nat1p to catalyze the cotranslational N-terminal acetylation of many yeast proteins (3,4). Three N-terminal acetyl transferases have been identified in yeast: Nat1p/Ard1p, Nat3p, and Mak3p (9). These enzymes are responsible for the N-terminal modification of more than half of yeast proteins (9). Nat1p/Ard1p transfers an acetyl group from acetyl coenzyme A to the alpha-amino group of Ser, Ala, Gly, or Thr N-terminal residues (9, 10). Because Ard1p, Nat3p, and Mak3p share significant sequence similarity, it has recently been suggested that Ard1p may be the catalytic subunit of the Nat1p/Ard1p complex (9).
Mutations in ARD1 cause slow growth, failure to enter stationary phase, and defects in sporulation (4). Cells lacking Nat1p or Ard1p show derepression of silent mating type loci; overexpression of Sir1p, a silent information regulator, can suppress this derepression phenotype (4, 11, 12). ARD1 is also a modifier of position effect at telomeres; in ard1 mutants transcriptional repression is no longer seen near telomeres (13). These mutant phenotypes suggest that the Nat1p/Ard1p complex may modify proteins important for silenced chromatin structure and function.
The human gene (TE2), whose product shows 40% identity to Ard1p, has been identified on the X chromosome .
Last updated: 2005-07-01