A neuropathy-associated kinesin KIF1A mutation hyper-stabilizes the motor-neck interaction during the ATPase cycle.
Morikawa, M., Jerath, N.U., Ogawa, T., Morikawa, M., Tanaka, Y., Shy, M.E., Zuchner, S., Hirokawa, N.(2022) EMBO J 41: e108899-e108899
- PubMed: 35132656 
- DOI: https://doi.org/10.15252/embj.2021108899
- Primary Citation of Related Structures:  
7EO9, 7EOB - PubMed Abstract: 
The mechanochemical coupling of ATPase hydrolysis and conformational dynamics in kinesin motors facilitates intramolecular interaction cycles between the kinesin motor and neck domains, which are essential for microtubule-based motility. Here, we characterized a charge-inverting KIF1A-E239K mutant that we identified in a family with axonal-type Charcot-Marie-Tooth disease and also in 24 cases in human neuropathies including spastic paraplegia and hereditary sensory and autonomic neuropathy. We show that Glu239 in the β7 strand is a key residue of the motor domain that regulates the motor-neck interaction. Expression of the KIF1A-E239K mutation has decreased ability to complement Kif1a +/- neurons, and significantly decreases ATPase activity and microtubule gliding velocity. X-ray crystallography shows that this mutation causes an excess positive charge on β7, which may electrostatically interact with a negative charge on the neck. Quantitative mass spectrometric analysis supports that the mutation hyper-stabilizes the motor-neck interaction at the late ATP hydrolysis stage. Thus, the negative charge of Glu239 dynamically regulates the kinesin motor-neck interaction, promoting release of the neck from the motor domain upon ATP hydrolysis.
Organizational Affiliation: 
Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.