Kinesin heavy chain isoform 5A

KIF5A (Kinesin heavy chain isoform 5A) is a microtubule-dependent motor protein essential for slow axonal transport of neurofilament proteins and anterograde axonal trafficking of cargo including MAPK8IP3/JIP3 (UniProt: Q12840). It participates in the ZFYVE27-KIF5A complex to mediate vesicular transport of multiple proteins in neurons. The protein is 1,032 amino acids long with a molecular mass of 117 kDa.

KIF5A is predominantly expressed in neuronal tissues where it functions in axonal maintenance and protein trafficking. Mutations in KIF5A are associated with several neurodegenerative disorders including spastic paraplegia 10 (SPG10), intractable neonatal myoclonic seizures, and amyotrophic lateral sclerosis 25 (ALS25) (UniProt: Q12840).

KIF5A is downregulated in Alzheimer's disease, with a mean log2 fold-change of −0.55 in post-mortem AD brain compared to age-matched controls (Chaparral AD proteomics). This reduction in a key axonal transport protein may contribute to disrupted neuronal trafficking and axonal dysfunction observed in AD pathology.