Neuronal depolarization modifies motor protein mobility

Neuroscience. 2009 Apr 21;160(1):1-5. doi: 10.1016/j.neuroscience.2009.02.034. Epub 2009 Feb 27.

Abstract

Active neuronal transport along microtubules participates in the targeting of mRNAs, proteins and organelles to their sites of action. Cytoplasmic dynein represents a minus-end-directed microtubule-dependent motor protein. Due to the polarity of microtubules in axonal and distal dendritic compartments, with microtubule minus-ends pointing toward the inside of the cell, dyneins mainly mediate retrograde transport pathways in neurons. Since dyneins transport synaptic proteins, we asked whether changes in neuronal activity would in general influence dynein transport. KCl-induced depolarization, a condition that mimics the effects of neuronal activity, or pharmacological blockade of neuronal action potentials, respectively, was combined with neuronal live cell imaging, using an autofluorescent dynein intermediate chain fusion (monomeric red fluorescent protein [mRFP]-dynein intermediate chain [DIC]) as a model protein. Notably, we found that induced activity significantly reduced dynein particle mobility, as well as both the total distance and velocity of movements in mouse cultured hippocampal neurons. In contrast, blockade of neuronal action potentials through TTX did not alter any of the parameters analyzed. Neuronal depolarization processes therefore represent candidate mechanisms to regulate intracellular transport of neuronal cargoes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Animals
  • Biological Transport, Active / drug effects
  • Biological Transport, Active / physiology
  • Cells, Cultured
  • Dyneins / metabolism*
  • Hippocampus / drug effects
  • Hippocampus / physiology
  • Luminescent Proteins
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology*
  • Mice
  • Microtubules / metabolism
  • Neurons / drug effects
  • Neurons / physiology*
  • Neurotransmitter Agents / administration & dosage
  • Potassium Chloride / administration & dosage
  • Red Fluorescent Protein
  • Sodium Channel Blockers / administration & dosage
  • Tetrodotoxin / administration & dosage
  • Video Recording

Substances

  • Luminescent Proteins
  • Neurotransmitter Agents
  • Sodium Channel Blockers
  • Tetrodotoxin
  • Potassium Chloride
  • Dyneins