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Updated: Jun 13, 2026
08:33
Measuring Nucleotide Binding to Intact, Functional Membrane Proteins in Real Time
Published on: March 11, 2021
Beyond Binding Affinity: How a Conformation-Specific Salt Bridge Tunes KIF1A Mechanochemistry
Abhipsa Shatarupa1, Lu Rao1, Arne Gennerich1
1Department of Biochemistry and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York, USA.
Cytoskeleton (Hoboken, N.J.)
|June 12, 2026
Summary
Mutations in KIF1A cause hereditary spastic paraplegia type 30 (SPG30). A specific salt bridge disruption alters KIF1A motor function, revealing a new mechanism contributing to KAND.
Area of Science:
- Molecular Biology
- Neuroscience
- Biochemistry
Background:
- Mutations in KIF1A are associated with KIF1A-associated neurological disorders (KAND), including hereditary spastic paraplegia type 30 (SPG30).
- The KIF1A motor protein plays a critical role in intracellular transport.
Purpose of the Study:
- To investigate the structural and functional consequences of KIF1A mutations at residue R350.
- To elucidate the role of a specific salt bridge in KIF1A motor regulation and its link to KAND.
Main Methods:
- High-resolution cryo-electron microscopy (cryo-EM) to determine structures of KIF1A mutants.
- Single-molecule motility assays to assess motor function.
Main Results:
- KIF1A R350 mutations abolish a conformation-dependent salt bridge with α-tubulin E415.
- Disruption of this salt bridge increases KIF1A motor velocity but reduces processivity and microtubule affinity.
- These changes were observed in the apo state of the motor.
Conclusions:
- A novel mechanism involving a conformation-dependent electrostatic interaction regulates KIF1A motility.
- Alterations in KIF1A motor mechanochemistry due to R350 mutations contribute to the pathology of KAND.
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