SpeakerProf. Jing Xu, Physics, UC Merced, Host: Kevin Plaxco
Date and LocationWednesday January 13, 2016 11:00am to 12:00pm
Microtubules are protein polymers that form "molecular highways" for long-range transport within living cells. Molecular motors actively step along microtubules to shuttle cellular materials between the nucleus and the cell periphery; this transport is critical for the survival and health of all eukaryotic cells. Structural defects in microtubules exist, but whether these structural defects impact molecular-motor based transport remains unknown. Here we report a new approach that allowed us to directly investigate the impact of such structural defects. Using a modified optical-trapping method, we examined the group function of a major molecular motor, conventional kinesin, when transporting cargoes along individual microtubules in vitro. We found that structural defects in microtubules are a determining factor in kinesin-based transport. This impact depends on motor number: cargoes driven by two motors tended to dissociate prematurely from the microtubule, whereas cargoes driven by more motors tended to pause. Our study provides the first direct link between structural defects in microtubules and kinesin function, and suggests the potential of kinesins as non-invasive biomarkers of structural defects in microtubules.