Robert O. Poyton, PhD
Department of Molecular, Cellular, and Developmental Biology
University of Colorado
Boulder, Colorado

Presentation Title
Mitochondrial Nitrite-dependent NO Production and Hypoxic Signaling in Eukaryotes (Summary of Presentation)

Professor Robert O. Poyton teaches and heads a research group in the Department of Molecular, Cellular, and Developmental Biology at the University of Colorado, Boulder.  He received his BA degree Magna cum Laude in Biology from Brown University, his PhD in Molecular Biology from the University of California, Berkeley, and his post-doctoral work in Biochemistry at Cornell University.  Dr Poyton has been recognized for his research on: oxygen sensing, and oxygen-regulated gene expression, cellular energy production: the structure, function, and assembly of cytochrome c oxidase, mitochondrial dysfunction in aging and degenerative disease; and signaling pathways between the mitochondrion and the nucleus. He has traveled and lectured widely on these topics.

Dr Poyton’s recent research focuses on hypoxic signaling pathways, which are crucial for the survival of mammals and nearly all other organisms. Recent studies have revealed that the mitochondrial respiratory chain and cytochrome c oxidase play key roles in oxygen sensing and the induction of nuclear gene expression under hypoxic conditions. They have also revealed a novel pathway for the production of nitric oxide by mitochondrial cytochrome c oxidase and have implicated reactive oxygen and nitrogen species as intermediaries in the hypoxic signaling pathway from the mitochondrion to the nucleus.  This pathway is functional only when oxygen is limiting, indicating that the mitochondrial respiratory chain has an alternative function under anoxic or hypoxic conditions.  Current experiments are aimed at examining mitochondrial-nuclear crosstalk in the context of hypoxic signaling. In particular, Dr Poyton is interested in how oxygen concentration is involved in switching cytochrome c oxidase from an oxidase to a nitrite reductase and in the role of specific protein nitration and oxidation in the hypoxic signal transduction pathway between the mitochondrion and the nucleus.