Microtubule Motors

There are two families of microtubule motors:

                The Kinesin motors, which move towards the plus-ends of microtubules

and

            The Dynein motors, which move towards the minus-end of microtubules.

Much more is known about kinesin than dynein. A number of people have worked on understanding the details of the single molecule properties of kinesin, including Dr. Steven Block (now at Stanford), Dr. Jeff Gelles (at Brandeis), Dr. Ronald Vale (UCSF), to name a few scientists from the united states.  Drs. Hirokawa and Yanagida in Japan have also been instrumental in our current understanding of how kinesin functions, as has Dr. Joe Howard (Now at EMBL, in Heidelberg).  Many others have important contributions; this list is a short one only, to get interested neophytes started.  There is more information on the kinesin home page.

Dynein is much larger than kinesin, and requires a co-factor complex called dynactin.  While there are many different kinesin family members, most organisms have a few cytoplasmic dyneins at most. Drosophila has only one. Since dynein is used in many different processes, and can be simultaneously correctly regulated for each, the cofactor dynactin and other dynein cofactors are presumably very important in regulating dynein-based motility and function. Little is known about this regulation.  Many people have had important contributions to our understanding of dynein function. To start, perhaps look at papers by Dr. Erika Holzbaur (U. Penn), Dr. Trina Schroer (Johns Hopkins) and Dr. Richard Vallee (U. Mass. Medical School).