title: Interaction between myoglobin and mitochondria in rat skeletal muscle.
abstract: The mechanisms underlying subcellular oxygen transport mediated by myoglobin (Mb) remain unclear. Recent evidence suggests that, in the myocardium, transverse diffusion of Mb is too slow to effectively supply oxygen to meet the immediate mitochondrial oxygen demands at the onset of muscle contractions. The cell may accommodate the demand by maintaining the distribution of Mb to ensure a sufficient O(2) supply in the immediate vicinity of the mitochondria. The present study has verified the co-localization of Mb with mitochondria by using biochemical histological and electron microscopy analyses. Immunohistochemical and electron microscopy analysis indicates a co-localization of Mb with mitochondria. Western blotting confirms the presence of Mb colocalizes with the mitochondrial fraction and appears more prominently in slow-twitch oxidative than in fast-twitch glycolytic muscle. In particular, Mb interacts with cytochrome c oxidase-subunit IV. These results suggest that a direct Mb-mediated O2 delivery to the mitochondria, which may play a potentially significant role for respiration.
authors.affiliation: Faculty of Human Sciences, Kanazawa University, Kanazawa, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamada
authors.forename: Yasuro
authors.initials: Y
authors.lastname: Furuichi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Takakura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Hanai
authors.forename: Thomas
authors.initials: T
authors.lastname: Jue
authors.forename: Kazumi
authors.initials: K
authors.lastname: Masuda
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019069:Cell Respiration; D003576:Electron Transport Complex IV / Q000378:metabolism; D006019:Glycolysis; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D008297:Male; D046529:Microscopy, Electron, Transmission; D008931:Mitochondria, Muscle / Q000378:metabolism* / Q000648:ultrastructure; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism; D018657:Muscle Fibers, Slow-Twitch; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000648:ultrastructure; D009211:Myoglobin / Q000378:metabolism*; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009211:Myoglobin; D003576:Electron Transport Complex IV