Force studies of multiple kinesin-1 and EG5 molecular motors

Kinesin-1 and Eg5 are molecular motors that are essential for eukaryotic cell growth and development. Kinesin-1 motors transport intracellular cargo along the microtubule cytoskeleton through and against the dense viscoelastic cytoplasm. Eg5 motors mediate proper mitotic, microtubule spindle assembly during cell division, and then stabilize these spindle structures through a balance between plus-end directed and minus-end directed forces along the filaments. Therefore, it is impmiant to understand how multiple kinesin-1 and Eg5 motors withstand competing forces, their structural rigidity under such loads, and how quickly they are able to rebind ifloosed from microtubules. Using a unique type of analysis for our optical trapping experiments, we are able to get motor binding stoichiometry inaccessible by previous techniques. With this information we characterize both motors comparing them to one another. We find that the release forces for both types of motors add linearly with the number of motors bound and that Eg5 has a weaker binding than that of kinesin -1. The stiffuess for the motor domains is comparable, yet we find that the average time to rebind for Eg5 decreases at higher concentrations while it does not for kinesin-1. This may indicate that there exists some weak interaction between kinesin-1 and microtubules keeping them close while unbound.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Graves, Evan Taclibon

Contributors dc:contributor

• Ha, Taekjip
• Selvin, Paul R.
• Oono, Yoshitsugu
• Giannetta, Russell W.

• molecular motors

Statement dc:rights

• © Evan Taclibon Graves

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/27741

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/27741