Enhancement of presynaptic calcium current by cysteine string protein

J Physiol. 2002 Jan 15;538(Pt 2):383-9. doi: 10.1113/jphysiol.2001.013397.


The isolated chick ciliary neuron calyx synapse preparation was used to test cysteine string protein (CSP) action on presynaptic N-type Ca(2+) channels. Endogenous CSP was localized primarily to secretory vesicle clusters in the presynaptic nerve terminal. Introduction of recombinant CSP into the voltage clamped terminal resulted in a prominent increase in Ca(2+) current amplitude. However, this increase could not be attributed to a change in Ca(2+) channel kinetics, voltage dependence, prepulse inactivation, or G protein inhibition but was attributed to the recruitment of dormant channels. Secretory vesicle associated endogenous CSP may play an important role in enhancing Ca(2+) channel activity at the transmitter release site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Channels / drug effects
  • Calcium Channels / physiology*
  • Chick Embryo
  • Electric Conductivity
  • HSP40 Heat-Shock Proteins
  • In Vitro Techniques
  • Membrane Proteins / pharmacology
  • Membrane Proteins / physiology*
  • Presynaptic Terminals / drug effects
  • Presynaptic Terminals / metabolism*
  • Recombinant Proteins / pharmacology
  • Tissue Distribution


  • Calcium Channels
  • HSP40 Heat-Shock Proteins
  • Membrane Proteins
  • Recombinant Proteins
  • cysteine string protein