Functional properties of channels formed by the neuronal gap junction protein connexin36

Midituru Srinivas, Renato Rozental, Takashi Kojima, Rolf Dermietzel, Mark Mehler, Daniele F. Condorelli, John A. Kessler, David C. Spray

Research output: Contribution to journalArticle

204 Scopus citations

Abstract

The expression and functional properties of connexin36 (Cx36) were examined in two communication-deficient cell lines (N2A-neuroblastoma and PC- 12 cells) transfected with Cx36 and in hippocampal neurons that express the connexin endogenously. Transfected cells expressed the expected 2.9 kb Cx36 transcript and Cx36 immunoreactivity, whereas nontransfected cells were devoid of Cx36. The relationship between steady-state junctional conductance (g(j)) and transjunctional voltage was well described by a two-state Boltzmann equation. The half-inactivation voltage (V0), the ratio of minimal to maximal g(j) (g(min)/g(max)), and the equivalent gating charge were ± 75 mV, 0.55, and 1.75, respectively, indicating that Cx36 exhibits very low voltage sensitivity. Conductance of single Cx36 channels measured with patch pipettes containing 130 mM CsCl was 10-15 pS (n = 15 cell pairs); despite this low unitary conductance, Cx36 channels were permeable to the dye Lucifer yellow. Hippocampal neurons expressed Cx36 both in vivo and in culture. The electrophysiological properties of channels in cultured hippocampal neurons were similar to those of the channels expressed by the transfected cell lines, and the neuronal channels were similarly permeable to Lucifer yellow. The unique combination of weak voltage sensitivity, small unitary conductance, and permeation by anions as large as second messenger molecules endows Cx36 gap junction channels with properties well suited for mediating flexible electrical and biochemical interactions between neurons.

Original languageEnglish (US)
Pages (from-to)9848-9855
Number of pages8
JournalJournal of Neuroscience
Volume19
Issue number22
StatePublished - Nov 15 1999

Keywords

  • Connexin
  • Cx36
  • Electrical coupling
  • Electrotonic synapse
  • Gap junction
  • Hippocampus
  • Single channels
  • Transfection
  • Voltage sensitivity

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Functional properties of channels formed by the neuronal gap junction protein connexin36'. Together they form a unique fingerprint.

  • Cite this

    Srinivas, M., Rozental, R., Kojima, T., Dermietzel, R., Mehler, M., Condorelli, D. F., Kessler, J. A., & Spray, D. C. (1999). Functional properties of channels formed by the neuronal gap junction protein connexin36. Journal of Neuroscience, 19(22), 9848-9855.