The mechanism of kinesin inhibition by kinesin-binding protein.

Joseph Atherton,Casper C Hoogenraad,Julia Locke,Jessica Ja Hummel,Carolyn A Moores,Michel O Steinmetz,Natacha Olieric,Steven S Rosenfeld,Alejandro Peña

doi:10.7554/elife.61481

Abstract

Subcellular compartmentalisation is necessary for eukaryotic cell function. Spatial and temporal regulation of kinesin activity is essential for building these local environments via control of intracellular cargo distribution. Kinesin-binding protein (KBP) interacts with a subset of kinesins via their motor domains, inhibits their microtubule (MT) attachment, and blocks their cellular function. However, its mechanisms of inhibition and selectivity have been unclear. Here we use cryo-electron microscopy to reveal the structure of KBP and of a KBP-kinesin motor domain complex. KBP is a tetratricopeptide repeat-containing, right-handed α-solenoid that sequesters the kinesin motor domain's tubulin-binding surface, structurally distorting the motor domain and sterically blocking its MT attachment. KBP uses its α-solenoid concave face and edge loops to bind the kinesin motor domain, and selected structure-guided mutations disrupt KBP inhibition of kinesin transport in cells. The KBP-interacting motor domain surface contains motifs exclusively conserved in KBP-interacting kinesins, suggesting a basis for kinesin selectivity.

Highlights

Kinesins are a superfamily of microtubule (MT)-based molecular motors that play important roles in cellular functions such as mitosis, cell motility, and intracellular transport (Vale, 2003; Hirokawa et al, 2009; Klinman and Holzbaur, 2018)
Kinesin-binding protein (KBP) was originally identified as a kinesin-3-binding partner that modulated its mitochondrial transport function (Wozniak et al, 2005); KBP has since been shown to interact with a subset of other kinesin family members to regulate diverse cellular processes including mitosis (Brouwers et al, 2017; Malaby et al, 2019), spermatogenesis (Lehti et al, 2015), and neuronal differentiation, growth, and cargo distribution (Alves et al, 2010; Lyons et al, 2008; Drevillon et al, 2013; Drerup et al, 2016; Chang et al, 2019; Hirst et al, 2017)
We present cryo-electron microscopy structures of KBP alone and of KBP bound to the motor domain of the human mitotic kinesin KIF15 (a 110 kDa complex)

Summary

Introduction

Kinesins are a superfamily of microtubule (MT)-based molecular motors that play important roles in cellular functions such as mitosis, cell motility, and intracellular transport (Vale, 2003; Hirokawa et al, 2009; Klinman and Holzbaur, 2018). KBP was originally identified as a kinesin-3-binding partner that modulated its mitochondrial transport function (Wozniak et al, 2005); KBP has since been shown to interact with a subset of other kinesin family members to regulate diverse cellular processes including mitosis (Brouwers et al, 2017; Malaby et al, 2019), spermatogenesis (Lehti et al, 2015), and neuronal differentiation, growth, and cargo distribution (Alves et al, 2010; Lyons et al, 2008; Drevillon et al, 2013; Drerup et al, 2016; Chang et al, 2019; Hirst et al, 2017). We show that KBPs kinesin selectivity is associated with specific kinesin sequences spread across the interaction surface

Results

Discussion

Materials and methods

Funding Funder Medical Research Council