Patch-clamp electrophysiology of intracellular Ca2+ channels

Cold Spring Harb Protoc. 2013 Sep 1;2013(9):787-97. doi: 10.1101/pdb.top066217.

Abstract

The modulation of cytoplasmic free Ca(2+) concentration ([Ca(2+)]i) is a universal intracellular signaling pathway that regulates numerous cellular physiological processes. Ubiquitous intracellular Ca(2+)-release channels localized to the endoplasmic/sarcoplasmic reticulum-inositol 1,4,5-trisphosphate receptor (InsP3R) and ryanodine receptor (RyR) channels-play a central role in [Ca(2+)]i signaling in all animal cells. Despite their intracellular localization, electrophysiological studies of the single-channel permeation and gating properties of these Ca(2+)-release channels using the powerful patch-clamp approach have been possible by application of this technique to isolated nuclei because the channels are present in membranes of the nuclear envelope. Here we provide a concise description of how nuclear patch-clamp experiments have been used to study single-channel properties of different InsP3R channels in the outer nuclear membrane. We compare this with other methods for studying intracellular Ca(2+) release. We also briefly describe application of the technique to InsP3R channels in the inner nuclear membrane and to channels in the outer nuclear membrane of HEK293 cells expressing recombinant RyR.

MeSH terms

  • Calcium / metabolism*
  • Calcium Channels / physiology*
  • Cations, Divalent / metabolism
  • Cell Line
  • Cytological Techniques / methods*
  • Humans
  • Inositol 1,4,5-Trisphosphate Receptors / metabolism*
  • Nuclear Envelope / physiology*
  • Patch-Clamp Techniques / methods*

Substances

  • Calcium Channels
  • Cations, Divalent
  • Inositol 1,4,5-Trisphosphate Receptors
  • Calcium