Kinesin-2 is a heterotrimer with two different motor subunits and an accessory protein that is believed to interact with the cargo, or possibly regulate motor activity (Marszalek & Goldstein 2002). The motor domain interacts with microtubules and contains the ATPase used to translocate the holoenzyme along the microtubule. The coiled-coil stalk is where the two motor subunits interact with each other to form a stable heterodimer. The tail domains interact with the KAP3 non-motor accessory subunit. Kinesin-2 is a plus-end directed kinesin involved in photoreceptor cell function (Jimeno et al. 2006) and normal steady-state localization of late endosomes/lysosomes (Brown et al. 2005).