Genetic manipulation indicates that ARD1 is an essential N-alpha-acetyltransferase in Trypanosoma brucei

N-alpha-acetylation, the most common protein modification, involves the tra nsfer of an acetyl group from acetyl-coenzyme A to the N-terminus of a prot ein or peptide. The major N-alpha-acetyltransferase in Saccharomyces cerevi siae is the ARD1-NAT1 complex. To investigate N-alpha-acetylation in Trypan osoma brucei we have cloned and characterised genes encoding putative homol ogues of ARD1 and NAT1. Both genes are single copy and ARD1, the putative c atalytic component, is expressed in both bloodstream-form and insect-stage cells. In either of these life-cycle stages, disruption of both ARD1 allele s was only possible when another copy was generated via gene duplication or when ARD1 was expressed from elsewhere in the genome. These genetic manipu lations demonstrate that, unlike the situation in S. cerevisiae, ARD1 is an essential gene in T. brucei. We propose that protein modification by ARD1 is essential for Viability in mammalian and insect-stage T. brucei cells. ( C) 2000 Elsevier Science B.V. All rights reserved.