#How to extract audio from video fission plus

The cause and the mechanism of reversals during transport are unknown, but are of obvious importance in understanding how this transport may be regulated.

#How to extract audio from video fission plus

This opposing motor activity appears to be regulated to bias motion in a net plus or minus direction and consequently deliver many cargos to desired spatiotemporal locations ( 2, 3).

Multiple motors of both kinds usually reside on a single cargo, and their opposing activity leads to bidirectional motion of cargos with frequent reversals. Most kinesins move to the MT-plus end (away from the nucleus) whereas dynein moves to MT-minus end (toward the nucleus) while carrying cargo such as lipid droplets, endosomes, mitochondria, vesicles, and virus. Motor proteins of the kinesin and dynein families ( 1) use energy from ATP hydrolysis to walk along microtubules (MTs). Our work may provide a platform to understand intracellular transport of a variety of organelles in terms of measurable quantities. To the best of our knowledge, this is a unique demonstration that dynein and kinesin function differently at the molecular level inside cells and of how this difference is used in a specific cellular process, namely endosome biogenesis. We elucidate how this clever choice of dissimilar motors and motor teams achieves net transport together with endosome fission, both of which are important in controlling the balance of endocytic sorting. Further, we use a combination of optical trap-based force measurements and Monte Carlo simulations to make the surprising discovery that endosome transport uses many (approximately four to eight) weak and detachment-prone dyneins in a tug-of-war against a single strong and tenacious kinesin. We show through precise motion analysis that reversals during endosome motion are caused by a tug-of-war between kinesin and dynein. Here we present measurements inside live Dictyostelium cells, in a cell extract and with purified motors to quantify such an ensemble function of motors. Unlike established single-motor biophysical assays, this problem requires understanding of the cooperative behavior of multiple interacting motors. The cause and the mechanism of reversals are unknown, but are a key to understanding how cargos are delivered in a regulated manner to specific cellular locations.

Intracellular transport is interspersed with frequent reversals in direction due to the presence of opposing kinesin and dynein motors on organelles that are carried as cargo.