Cholesterol modulates acetylcholine receptor diffusion by tuning confinement sojourns and nanocluster stability

Sci Rep. 2018 Aug 10;8(1):11974. doi: 10.1038/s41598-018-30384-y.

Abstract

Translational motion of neurotransmitter receptors is key for determining receptor number at the synapse and hence, synaptic efficacy. We combine live-cell STORM superresolution microscopy of nicotinic acetylcholine receptor (nAChR) with single-particle tracking, mean-squared displacement (MSD), turning angle, ergodicity, and clustering analyses to characterize the lateral motion of individual molecules and their collective behaviour. nAChR diffusion is highly heterogeneous: subdiffusive, Brownian and, less frequently, superdiffusive. At the single-track level, free walks are transiently interrupted by ms-long confinement sojourns occurring in nanodomains of ~36 nm radius. Cholesterol modulates the time and the area spent in confinement. Turning angle analysis reveals anticorrelated steps with time-lag dependence, in good agreement with the permeable fence model. At the ensemble level, nanocluster assembly occurs in second-long bursts separated by periods of cluster disassembly. Thus, millisecond-long confinement sojourns and second-long reversible nanoclustering with similar cholesterol sensitivities affect all trajectories; the proportion of the two regimes determines the resulting macroscopic motional mode and breadth of heterogeneity in the ensemble population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport
  • CHO Cells
  • Cholesterol / metabolism*
  • Cricetulus
  • Diffusion
  • Protein Binding
  • Receptors, Nicotinic / chemistry
  • Receptors, Nicotinic / metabolism*

Substances

  • Receptors, Nicotinic
  • Cholesterol