title: Myoglobin and mitochondria: a relationship bound by oxygen and nitric oxide.
abstract: Since their initial discovery over a century ago, our knowledge of the functions of myoglobin and the mitochondrion has gradually evolved. The mitochondrion, once thought to be solely responsible for energy production, is now known to be an integral redox and apoptotic signal transducer within the cell. Likewise, myoglobin, traditionally thought of only as an oxygen store, has emerged as a physiological catalyst that can modulate reactive oxygen species levels, facilitate oxygen diffusion and scavenge or generate nitric oxide (NO) depending on oxygen tensions within the cell. By virtue of its unique ability to regulate O(2) and NO levels within the cell, myoglobin can modulate mitochondrial function in energy-demanding tissues such as the beating heart and exercising muscle. In this review, we present the conventional functions of myoglobin and mitochondria, and describe how these roles have been reassessed and advanced, particularly in the context of NO and nitrite signaling. We present the mechanisms by which mitochondria and myoglobin regulate one another within the cell through their interactions with NO and oxygen and discuss the implications of these interactions in terms of health and disease.
authors.affiliation: Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15261, United States.
authors.forename: Christelle
authors.initials: C
authors.lastname: Kamga
authors.forename: Suhas
authors.initials: S
authors.lastname: Krishnamurthy
authors.forename: Sruti
authors.initials: S
authors.lastname: Shiva
mesh_terms: D000818:Animals; D055459:Facilitated Diffusion; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D009572:Nitrite Reductases / Q000378:metabolism; D010085:Oxidative Phosphorylation; D010100:Oxygen / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism
chemical_list: D009211:Myoglobin; D009569:Nitric Oxide; D010105:Oxygenases; C114415:nitric oxide dioxygenase; D009572:Nitrite Reductases; D010100:Oxygen