A change in the selective translocation of the Kinesin-1 motor domain marks the initial specification of the axon

Neuron. 2006 Mar 16;49(6):797-804. doi: 10.1016/j.neuron.2006.02.005.


We used the accumulation of constitutively active kinesin motor domains as a measure of where kinesins translocate in developing neurons. Throughout development, truncated Kinesin-3 accumulates at the tips of all neurites. In contrast, Kinesin-1 selectively accumulates in only a subset of neurites. Before neurons become polarized, truncated Kinesin-1 accumulates transiently in a single neurite. Coincident with axon specification, truncated Kinesin-1 accumulates only in the emerging axon and no longer appears in any other neurite. The translocation of Kinesin-1 along a biochemically distinct track leading to the nascent axon could ensure the selective delivery of Kinesin-1 cargoes to the axon and hence contribute to its molecular specification. Imaging YFP-tagged truncated Kinesin-1 provides the most precise definition to date of when neuronal polarity first emerges and allows visualization of the molecular differentiation of the axon in real time.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Axonal Transport / physiology*
  • Axons / metabolism*
  • Biomarkers / metabolism
  • Cells, Cultured
  • Embryo, Mammalian
  • Hippocampus / cytology
  • Kinesins / genetics
  • Kinesins / metabolism*
  • Luminescent Proteins
  • Molecular Motor Proteins / physiology*
  • Neurites / metabolism
  • Neurons / cytology
  • Protein Structure, Tertiary / physiology
  • Protein Transport / physiology
  • Rats
  • Time Factors
  • Transfection / methods


  • Biomarkers
  • Luminescent Proteins
  • Molecular Motor Proteins
  • Kinesins