Research Paper|Volume 1, Issue 1|pp 38—48

dSir2 and Dmp53 interact to mediate aspects of CR-dependent life span extension in D. melanogaster

Johannes H. Bauer¹, Siti Nur Sarah Morris¹, Chengyi Chang¹, Thomas Flatt¹, Jason G. Wood¹, Stephen L. Helfand¹

¹Department of Molecular Biology, Cell Biology and Biochemistry, and *Department of Ecology and Evolutionary Biology, Division of Biology and Medicine, Brown University Providence, RI02912, USA

Received: October 3, 2008Accepted: November 2, 2008Published: November 6, 2008

Copyright: © 2008 Bauer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Calorie Restriction (CR) is a well established method of extending life span in a variety of organisms. In the fruit fly D. melanogaster, CR is mediated at least in part by activation of dSir2. In mammalian systems, one of the critical targets of Sir2 is the tumor suppressor p53. This deacetylation of p53 by Sir2 leads to inhibition of p53's transcriptional activity. We have recently shown that inhibition of Dmp53 activity in the fly brain through the use of dominant-negative (DN) constructs that inhibit DNA-binding can extend life span. This life span extension appears to be related to CR, as CR and DN-Dmp53 do not display additive effects on life span. Here we report that life span extension by DN-Dmp53 expression is highly dynamic and can be achieved even when DN-Dmp53 is expressed later in life. In addition, we demonstrate that life span extension by activation of dSir2 and DN-Dmp53 expression are not additive. Furthermore, we show that dSir2 physically interacts with Dmp53 and can deacetylate Dmp53-derived peptides. Taken together, our data demonstrate that Dmp53 is a down stream target of dSir2 enzymatic activity and mediates some aspects of the life span extending effects of CR.