Marcia C. Haigis, Ph.D.

The Haigis lab studies a family of conserved proteins termed sirtuins (SIRT1-7). Sir2 and its homologs extend lifespan in model organisms. We are examining new roles for mammalian sirtuins in the regulation of mitochondrial metabolism. We are also investigating how sirtuins regulate signaling pathways stemming from the mitochondria. First, we have discovered that a mitochondrial sirtuin, SIRT4, regulates fatty acid oxidation. We have also discovered that another mitochondrial sirtuin, SIRT3, is required to achieve maximum metabolic flux in mitochondria. Moreover, we have discovered that SIRT3 loss results in HIF stabilization and increased expression of glycolytic enzymes.