Structural Basis of Kinesin-1 Autoinhibition and Its Control of Microtubule-Based Motility

ABSTRACT: Kinesin-1 is the first identified microtubule-based motor protein that drives anterograde intracellular transport of diverse cargoes in eukaryotic cells. Defects in kinesin-1 activity have been implicated in various human neurological disorders and intracellular pathogens such as bacteria and viruses hijack its activity. Despite its importance, the molecular mechanisms governing kinesin-1 activation remains poorly understood. Here, we report a 8.6-Å cryo-EM electron microscopy structure of the autoinhibited kinesin-1 heterotetramer. Our structure reveals a complex 36-nm head-to-tail assembly composed of two kinesin heavy chains (KHC) and two light chains (KLC), where the self-folded dimeric KHCs are stabilized by asymmetrically arranged KLCs tetratricopeptide repeat (TPR) domains. This state inhibits kinesin motility by constraining the dimeric motor domains in a configuration that is incompatible with motility. Notably, our structure also shows that the dimeric KLC TPR cargo-binding domains are occluded, providing a structural basis for the autoinhibition of both motor activity and cargo binding.In addition to functional studies, we also applied crosslinking mass spectrometry (XLMS) to validate the autoinhibitory model.

INSTRUMENT(S):

ORGANISM(S): Escherichia Coli

SUBMITTER: Yuqi Tang  

LAB HEAD: Stephen D. Fried

PROVIDER: PXD073177 | Pride | 2026-06-03

REPOSITORIES: Pride