Moving mitochondria: establishing distribution of an essential organelle.
Mitochondria form a dynamic network responsible for energy production, calcium homeostasis and cell signaling. Appropriate distribution of the mitochondrial network contributes to organelle function and is essential for cell survival. Highly polarized cells, including neurons and budding yeast, are particularly sensitive to defects in mitochondrial movement and have emerged as model systems for studying mechanisms that regulate organelle distribution. Mitochondria in multicellular eukaryotes move along microtubule tracks. Actin, the primary cytoskeletal component used for transport in yeast, has more subtle functions in other organisms. Kinesin, dynein and myosin isoforms drive motor-based movement along cytoskeletal tracks. Milton and syntabulin have recently been identified as potential organelle-specific adaptor molecules for microtubule-based motors. Miro, a conserved GTPase, may function with Milton to regulate transport. In yeast, Mmr1p and Ypt11p, a Rab GTPase, are implicated in myosin V-based mitochondrial movement. These potential adaptors could regulate motor activity and therefore determine individual organelle movements. Anchoring of stationary mitochondria also contributes to organelle retention at specific sites in the cell. Together, movement and anchoring ultimately determine mitochondrial distribution throughout the cell.
Frederick
Rebecca L
RL
Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA.|Current address: Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21218, USA.
Shaw
Janet M
JM
Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA.
D000818:Animals; D001369:Axons / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004398:Dyneins / Q000737:chemistry; D020558:GTP Phosphohydrolases / Q000737:chemistry; D006801:Humans; D016547:Kinesins / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D009218:Myosins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D015388:Organelles / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
D020558:GTP Phosphohydrolases; D009218:Myosins; D004398:Dyneins; D016547:Kinesins