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bioRxiv · 10.1101/058602

The mitotic kinesin-14 KlpA contains a context-dependent directionality switch

Andrew R Popchock·Kuo-Fu Tseng·Pan Wang·P. Andrew Karplus·Xin Xiang·Weihong Qiu
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Abstract

Kinesins are microtubule-based motor proteins that convert chemical energy from ATP hydrolysis into mechanical work for a variety of essential intracellular processes. Kinesin-14s (i.e. kinesins with a C-terminal motor domain) are commonly considered to be nonprocessive minus end-directed motors that mainly function for mitotic spindle assembly and maintenance. Here, we show that KlpA - a mitotic kinesin-14 motor from the filamentous fungus Aspergillus nidulans - contains a context-dependent directionality switch. KlpA exhibits canonical minus end-directed motility inside microtubule bundles, but on individual microtubules it unexpectedly moves processively toward the plus ends. Removal of the N-terminal nonmotor microtubule-binding domain renders KlpA diffusive on individual microtubules but does not abolish its minus end-directed motility to collectively glide microtubules, suggesting that the nonmotor microtubule-binding domain likely acts as a switch for controlling the direction of KlpA motility. Collectively, these findings provide important insights into the mechanism and regulation of KlpA functions inside the mitotic spindle.

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Andrew R Popchock, Kuo-Fu Tseng, Pan Wang, P. Andrew Karplus, Xin Xiang, Weihong Qiu. 2016-06-23. The mitotic kinesin-14 KlpA contains a context-dependent directionality switch. https://doi.org/10.1101/058602

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