Induction of apoptosis in human cells by RNAi-mediated knockdown of hARD1 and NATH, components of the protein N-[alpha]-acetyltransferase complex

• Published in: Oncogene Vol. 25; no. 31; pp. 4350 - 4360
• Main Authors: Arnesen, T, Gromyko, D, Pendino, F, Ryningen, A, Varhaug, J E, Lillehaug, J R
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group 20.07.2006
• Subjects: Apoptosis; Chemotherapy; Enzymes; Inhibitor drugs; Oncology; Proteins
• ISSN: 0950-9232; 1476-5594
• DOI: 10.1038/sj.onc.1209469

Protein N-epsilon-acetylation is recognized as an important modification influencing many biological processes, and protein deacetylase inhibitors leading to N-epsilon-hyperacetylation of histones are being clinically tested for their potential as anticancer drugs. In contrast to N-epsilon-acetyltransferases, the N-alpha-acetyltransferases transferring acetyl groups to the alpha-amino groups of protein N-termini have only been briefly described in mammalians. Human arrest defective 1 (hARD1), the only described human enzyme in this class, complexes with N-acetyltransferase human (NATH) and cotranslationally transfers acetyl groups to the N-termini of nascent polypeptides. Here, we demonstrate that knockdown of NATH and/or hARD1 triggers apoptosis in human cell lines. Knockdown of hARD1 also sensitized cells to daunorubicin-induced apoptosis, potentially pointing at the NATH-hARD1 acetyltransferase complex as a novel target for chemotherapy. Our results argue for an essential role of the NATH-hARD1 complex in cell survival and underscore the importance of protein N-alpha-acetylation in mammalian cells.