Forum 02/20/2003

“Structural transitions of unc104 on the microtubule: a unique mechanism for kinesin dimerization required in pre-synaptic vesicle transport”

Jawdat Al-Bassam, Graduate Student – Department of Cell Biology, The Scripps Research Institute, La Jolla, CA

Kinesins generate motility required for the transport of vesicles on microtubules.  In cells with elongated dimensions, like neurons, the vesicle transport becomes a crucial activity required for their survival.   A large number of studies on conventional kinesin provide the basis of our current understanding of how kinesins generate movement.  However, conventional kinesins represent only a small class of a large and diverse super-family.    We have addressed the structural transitions of the unc104/KIF1A class of kinesins, which are the primary pre-synaptic vesicle movers in neurons. Unc104 kinesins are unique in the kinesin super-family in that they are monomric in solution, whereas conventional kinesins are dimeric.  However, unc104 kinesin undergoes dimerization and generate a “walking” motility on microtubules similar to conventional kinesin. Thus, regulating unc104 dimerization on microtubules plays an important role in controlling pre-synaptic vesicle movement.