Acetylation of the C terminus of Ku70 by CBP and PCAF controls Bax-mediated apoptosis.

Journal article

Apoptosis is a key tumor suppression mechanism that can be initiated by activation of the proapoptotic factor Bax. The Ku70 DNA end-joining protein has recently been shown to suppress apoptosis by sequestering Bax from mitochondria. The mechanism by which Bax is regulated remains unknown. Here, we identify eight lysines in Ku70 that are targets for acetylation in vivo. Five of these, K539, K542, K544, K533, and K556, lie in the C-terminal linker domain of Ku70 adjacent to the Bax interaction domain. We show that CBP and PCAF efficiently acetylate K542 in vitro and associate with Ku70 in vivo. Mimicking acetylation of K539 or K542 or treating cells with deacetylase inhibitors abolishes the ability of Ku70 to suppress Bax-mediated apoptosis. We demonstrate that increased acetylation of Ku70 disrupts the Ku70-Bax interaction and coincides with cytoplasmic accumulation of CBP. These results shed light on the role of acetyltransferases as tumor suppressors.

Authors: Cohen, H; Lavu, S; Bitterman, K; Hekking, B; Imahiyerobo, T

• Publication status: Published
• Journal: Molecular cell
• Volume: 13
• Issue: 5
• Pages: 627-638
• Publication date: 2004-03-01
• DOI: 10.1016/s1097-2765(04)00094-2
• EISSN: 1097-4164
• ISSN: 1097-2765
• Language: English
• Keywords: Amino Acid Sequence; Animals; Binding Sites; Sequence Homology, Amino Acid; Trans-Activators; DNA Helicases; Mice; bcl-2-Associated X Protein; Proto-Oncogene Proteins c-bcl-2; Acetyltransferases; Antigens, Nuclear; Apoptosis; Models, Molecular; Histone Acetyltransferases; CREB-Binding Protein; Lysine; Tumor Suppressor Proteins; Acetylation; Molecular Sequence Data; Proto-Oncogene Proteins; Hela Cells; Cricetinae; DNA-Binding Proteins; Protein Structure, Tertiary; Nuclear Proteins; Enzyme Inhibitors; Humans