Kinesin processivity is gated by phosphate release.

ABSTRACT: Kinesin-1 is a dimeric motor protein, central to intracellular transport, that steps hand-over-hand toward the microtubule (MT) plus-end, hydrolyzing one ATP molecule per step. Its remarkable processivity is critical for ferrying cargo within the cell: over 100 successive steps are taken, on average, before dissociation from the MT. Despite considerable work, it is not understood which features coordinate, or "gate," the mechanochemical cycles of the two motor heads. Here, we show that kinesin dissociation occurs subsequent to, or concomitant with, phosphate (P(i)) release following ATP hydrolysis. In optical trapping experiments, we found that increasing the steady-state population of the posthydrolysis ADP · P(i) state (by adding free P(i)) nearly doubled the kinesin run length, whereas

SUBMITTER: Milic B 

PROVIDER: S-EPMC4191751 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature