Intracellular localization of mitochondria is important for their functions and depends on the cytoskeleton structures. It is known that mitochondria move over long distances using microtubules as tracks, while using actin filaments they move much slower and shorter distances. To investigate the role of actin filaments in the regulation of mitochondria transport along microtubules, we monitored movements of these organelles in CV-1 cells stably transfected by the fluorescent mitochondrial marker. To alter the concentration of F-actin in cells we used two distinct approaches: we either decreased its content by latrunculin B, or induced additional actin polymerization by expression of constitutively active mutants of N-WASP, which stimulates Arp2/3-dependent nucleation of branched actin meshwork, or by expression of mDial formin protein, known to activate polymerization via Arp2/3-independent mechanism. Disruption of F-actin by latrunculin B led to increased mitochondrial motility: the percentage of motile mitochondria increased two-fold; motile organelles spent more time in motion and their mean velocities were higher than in control cells. Enhanced polymerization of actin induced by overexpression of constitutively active mutant of mDial completely blocked fast movements of mitochondria. However, overexpression of the constitutively active mutant of N-WASP, which also increased F-actin concentration, had no effect on mitochondria motility. These data indicate that mitochondria transport along microtubules is regulated by F-actin induced by active mDial protein.
|Original language||English (US)|
|State||Published - Dec 14 2006|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology