Director’s guest: Matthieu Benoit, Albert Einstein College of Medicine, NY – “Mechanochemical cycles diversity in the kinesin superfamily revealed by cryo-EM”

Abstract

Kinesins form a superfamily of motor proteins that play crucial roles in diverse eukaryotic cellular processes, including organelle transport, morphogenesis, cell division and cilia function. Kinesins couple the binding and hydrolysis of ATP to mechanical movements in their motor domain. The forces produced through this mechanochemical coupling are used for two basic kinesin activities that underpin their cellular functions: stepping on the microtubule and/or modulation of microtubule dynamics. While most kinesins – like members of the kinesin-3 family – are purely motile, members of the kinesin-13 family are microtubule depolymerase. Members of the kinesin-8 family specifically combine both motility and microtubule depolymerization activities. Recent developments in cryo-EM have enabled the observation of kinesins at high resolution on microtubules throughout their ATP cycles. The presentation will compare our studies by cryo-EM and complementary single molecule experiments addressing long-standing questions regarding the mechanism of the kinesin-3, kinesin-13 and kinesin-8 families, as well as differences between a slow kinesin-3 and a fast superprocessive counterpart.