Life without myoglobin

Abstract.

Hemoproteins are widely distributed among prokaryotes, unicellular eukaryotes, plants and animals . Myoglobin, a cytoplasmic hemoprotein that is restricted to cardiomyocytes and oxidative skeletal myofibers in vertebrates, has been proposed to facilitate oxygen transport to the mitochondria . This cytoplasmic hemoprotein was the first protein to be subjected to definitive structural analysis and has been a subject of long-standing and ongoing interest to biologists . Recently, we utilized gene disruption technology to generate mice that are viable and fertile despite a complete absence of myoglobin . This unexpected result led us to reexamine existing paradigms regarding the function of myoglobin in striated muscle.