You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Developmental Defects and p53 Hyperacetylation in Sir2 Homolog (SIRT1)-Deficient Mice
Hwei-Ling Cheng, Raul Mostoslavsky, Shin'ichi Saito, John P. Manis, Yansong Gu, Parin Patel, Roderick Bronson, Ettore Appella, Frederick W. Alt and Katrin F. Chua
Proceedings of the National Academy of Sciences of the United States of America
Vol. 100, No. 19 (Sep. 16, 2003), pp. 10794-10799
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/3147384
Page Count: 6
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
SIRT1 is a mammalian homolog of the Saccharomyces cerevisiae chromatin silencing factor Sir2. Dominant-negative and overexpression studies have implicated a role for SIRT1 in deacetylating the p53 tumor suppressor protein to dampen apoptotic and cellular senescence pathways. To elucidate SIRT1 function in normal cells, we used gene-targeted mutation to generate mice that express either a mutant SIRT1 protein that lacks part of the catalytic domain or has no detectable SIRT1 protein at all. Both types of SIRT1 mutant mice and cells had essentially the same phenotypes. SIRT1 mutant mice were small, and exhibited notable developmental defects of the retina and heart, and only infrequently survived postnatally. Moreover, SIRT1-deficient cells exhibited p53 hyperacetylation after DNA damage and increased ionizing radiation-induced thymocyte apoptosis. In SIRT1-deficient embryonic fibroblasts, however, p53 hyperacetylation after DNA damage was not accompanied by increased p21 protein induction or DNA damage sensitivity. Together, our observations provide direct evidence that endogenous SIRT1 protein regulates p53 acetylation and p53-dependent apoptosis, and show that the function of this enzyme is required for specific developmental processes.
Proceedings of the National Academy of Sciences of the United States of America © 2003 National Academy of Sciences