Novel Optical Trapping Methodology Reveals Cooperative Function of Kinesin Motors on Cellular Organelles

Cooperative protein transport in cellular organelles.

Compartmentalization into biochemically distinct organelles constantly exchanging material is one of the hallmarks of eukaryotic cells. In the most naive picture of interorganelle transport driven by concentration gradients, concentration differences between organelles should relax. We determine the conditions under which cooperative transport, i.e., based on molecular recognition, allows for t...

Modeling Spatial Distribution of Intracellular Organelles by Molecular Motors

Directionality of kinesin motors.

Kinesins are molecular motors that transport various cargoes along microtubule tracks using energy derived from ATP hydrolysis. Although the motor domains of kinesins are structurally similar, the family contains members that move on microtubules in opposite directions. Recent biochemical and biophysical studies of several kinesins make it possible to identify structural elements responsible fo...

Correction for “ In vivo optical trapping indicates kinesin ’ s stall

BIOPHYSICS AND COMPUTATIONAL BIOLOGY Correction for “In vivo optical trapping indicates kinesin’s stall force is reduced by dynein during intracellular transport,” by Benjamin H. Blehm, Trina A. Schroer, Kathleen M. Trybus, Yann R. Chemla, and Paul R. Selvin, which appeared in issue 9, February 26, 2013, of Proc Natl Acad Sci USA (110:3381–3386; first published February 12, 2013; 10.1073/pnas.1...

Cooperative kinesin

Cooperative kinesin rain travel might be more efficient if the tracks helped the train along. On page 691, Muto et al. show that, unlike trains, kinesin motors do get a boost from their tracks—in this case, microtubules. Muto and colleagues show that the binding of the plus end–directed motor kinesin to microtubules is cooperative. Like proverbial sheep, once one bead (or motor) bound to a fila...