The Sir2 (or sirtuin) protein family plays critical roles in aging, DMA repair, apoptosis, resistance to cell stress, and metabolism. However, the molecular basis for the varied phenotypes has remained elusive. The majority of sirtuins catalyze a reaction in which the cleavage of NAD+ and histone/protein deacetylation are coupled to the formation of O-acetyl-ADP-ribose (OAADPr), a novel metabolite. Several reports suggest that some sirtuins are mono-ADP-ribosyltransferases, while others have suggested that these enzymes harbor both activities. Detailed mechanistic studies have yet to validate these reports. The dependence on NAD+ and the generation of a potential second messenger offer clues toward understanding their cellular functions. Here, we will focus on answering questions of molecular mechanism, filling major gaps in our understanding of these unique proteins. To address their molecular and biological functions, this proposal outlines a multi-disciplinary approach, involving chemistry, enzymology and genetics.
In Aim 1, the catalytic pathways that yield protein deacetylation versus ADP-ribosylation will be elucidated.
Aim 2 focuses on understanding how sirtuins recognize specific protein targets. To explore the biological functions of OAADPr, Aim 3 will involve the synthesis of nonhydrolyzable OAADPr analogs, followed by an examination of their ability to act as ligands, substrates and inhibitors against reported protein targets. The experiments in Aim 4 directly probe the cellular function of OAADPr. An assay for the quantitation of cellular OAADPr levels will be coupled with cell- based assays of genetically modified cells. The ability of OAADPr to promote gene silencing in yeast will be assessed. In mammalian cells, the ability of sirtuins and OAADPr to modulate the gating of the TRPM2 ion channel will be determined. Resveratrol, plant polyphenol known to harbor a variety of cardiovascular and neurological health benefits, was reported to be an activator of Sir2 enzymes. Here several hypotheses for the ability of resveratrol to """"""""activate"""""""" SIRT1 will be examined in vivo and in vitro (Aim 2). Given the implications for cancer, aging and neurodegeneration, sirtuins have emerged as viable drug targets to treat these diseases. The knowledge gained from this study will provide the major steps towards the design and development of such small molecules.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM065386-08S1
Application #
8005210
Study Section
Macromolecular Structure and Function A Study Section (MSFA)
Program Officer
Gerratana, Barbara
Project Start
2010-01-14
Project End
2010-12-31
Budget Start
2010-01-14
Budget End
2010-12-31
Support Year
8
Fiscal Year
2010
Total Cost
$123,239
Indirect Cost
Name
University of Wisconsin Madison
Department
Biochemistry
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Ferrer, Christina M; Alders, Marielle; Postma, Alex V et al. (2018) An inactivating mutation in the histone deacetylase SIRT6 causes human perinatal lethality. Genes Dev 32:373-388
Latorre-Muro, Pedro; Baeza, Josue; Armstrong, Eric A et al. (2018) Dynamic Acetylation of Phosphoenolpyruvate Carboxykinase Toggles Enzyme Activity between Gluconeogenic and Anaplerotic Reactions. Mol Cell 71:718-732.e9
Damodaran, Shivashankar; Damaschke, Nathan; Gawdzik, Joseph et al. (2017) Dysregulation of Sirtuin 2 (SIRT2) and histone H3K18 acetylation pathways associates with adverse prostate cancer outcomes. BMC Cancer 17:874
Lee, Jin-Hee; Yang, Bing; Lindahl, Anastasia J et al. (2017) Identifying Dysregulated Epigenetic Enzyme Activity in Castrate-Resistant Prostate Cancer Development. ACS Chem Biol 12:2804-2814
Deota, Shaunak; Chattopadhyay, Tandrika; Ramachandran, Deepti et al. (2017) Identification of a Tissue-Restricted Isoform of SIRT1 Defines a Regulatory Domain that Encodes Specificity. Cell Rep 18:3069-3077
Sanders, Dean; Qian, Shuiming; Fieweger, Rachael et al. (2017) Histone Lysine-to-Methionine Mutations Reduce Histone Methylation and Cause Developmental Pleiotropy. Plant Physiol 173:2243-2252
Dhillon, Rashpal S; Denu, John M (2017) Using comparative biology to understand how aging affects mitochondrial metabolism. Mol Cell Endocrinol 455:54-61
Yu, Wei; Denu, Ryan A; Krautkramer, Kimberly A et al. (2016) Loss of SIRT3 Provides Growth Advantage for B Cell Malignancies. J Biol Chem 291:3268-79
Hullinger, Rikki; Li, Mi; Wang, Jingxin et al. (2016) Increased expression of AT-1/SLC33A1 causes an autistic-like phenotype in mice by affecting dendritic branching and spine formation. J Exp Med 213:1267-84
Gregg, Trillian; Poudel, Chetan; Schmidt, Brian A et al. (2016) Pancreatic ?-Cells From Mice Offset Age-Associated Mitochondrial Deficiency With Reduced KATP Channel Activity. Diabetes 65:2700-10

Showing the most recent 10 out of 62 publications