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closeother sirtuins involved?
Posted by RDarst on 01 May 2008 at 19:29 GMT
An interesting finding! When I saw the Chen et al. paper "Restriction of DNA replication to the reductive phase of the metabolic cycle protects genome integrity" in Science last year, I hypothesized that Sir2 might provide a link -- perhaps an abrupt change in NADH levels at the transition to anaerobic growth could relieve Sir2 inhibition of replication initiation. Sadly I did not do anything with my idea other than assay telomeric silencing in the absence of oxygen. The authors' discovery that Sir2 actually goes to the origins of replication is a breakthrough. While the results indicate that NADH levels still matter in the absence of Sir2, isn't it possible that other sirtuin family members could be mediating this?
RE: other sirtuins involved?
marybryk replied to RDarst on 09 May 2008 at 18:22 GMT
Are you referring to the rapid cell cycle progression observed in the 3XABF2 sir2D strains, which appears to be faster than that of 3XABF2 cells and sir2D cells? We have not looked at the HSTs specifically but they are interesting candidate factors because of their similarity to Sir2. There are likely to be several factors that transmit signals from the mt to chromatin regulators. We do not yet appreciate the breadth of the network. Did you see the recent paper in Cell from Michael Weinreich lab on Sir2 regulation of certain ARS elements?