High impact information on ARD1

• The ARD1 gene of yeast functions in the switch between the mitotic cell cycle and alternative developmental pathways [1].
• The ARD1 gene has been cloned and sequenced; there is weak homology between the C terminus of the ARD1 protein, the C-terminal region of MAT alpha 2, and the homeo box [1].
• For all three propeptide-deleted subunits, activity of the affected catalytic center is fully restored when the Nat1-Ard1 Nalpha-acetyltransferase is mutated [2].
• We investigated the three N-terminal acetyltransferases (NATs), Ard1p/Nat1p, Nat3p and Mak3p [3].
• All these phenotypes are identical to those of a previously characterized mutant, ard1 [4].

Biological context of ARD1

• These results suggest that NAT1 and ARD1 proteins function together to catalyze the N-terminal acetylation of a subset of yeast proteins [4].
• While the NAT1 gene product is thought to be the catalytic subunit of the enzyme, the role of the ARD1 protein has remained unclear [5].
• Despite the rapid loss of ARD1 protein, there is a prolonged delay in the expression of the ard1 mutant phenotype, suggesting that the acetylated substrates of ARD1 are metabolically stable and/or exert a long-lasting effect on processes such as the repression of the silent mating type cassettes [6].
• Mutations in the ARD1 gene prevent yeast cells from displaying G1-specific growth arrest in response to nitrogen deprivation and cause MATa haploids (but not MAT alpha haploids) to be mating defective [7].
• Here we show that ARD1(225) is not expressed in humans, suggesting that factors regulating alternative splicing of ARD1 may have evolved differently between species [8].

Anatomical context of ARD1

• Nat1p not only anchored Ard1p and Nat5p to the ribosome but also was in close proximity to nascent polypeptides, independent of whether they were substrates for N(alpha)-acetylation or not [9].

Other interactions of ARD1

• NAT1 and ARD1 are distinct genes that encode proteins with no obvious similarity [4].
• Ard1p and Mak3p are significantly related to each other by amino acid sequence, as is Nat3p, which was uncovered in this study using programming alignment procedures [3].
• This late-acting class is novel and dies after 7 days in culture, later than two previously reported stationary phase mutants, ubi4 and ard1 [10].

References