Referenced in: none

Automatically associated channels: Kv10.1

Title: Cell/cell channel formation involves disulfide exchange.

Authors: G Dahl, E Levine, C Rabadan-Diehl, R Werner

Journal, date & volume: Eur. J. Biochem., 1991 Apr 10 , 197, 141-4

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/1707811

Abstract
The oocyte cell/cell-channel assay was used to identify amino acids involved in the process of cell/cell-channel formation. The expression of the rat liver gap-junction protein, connexin 32, in single oocytes, results in the accumulation of a pool of channel precursors. Upon pairing of such oocytes, cell/cell channels form rapidly from this pool. The rate of formation is affected by thiol-specific reagents and the pH. This suggests the involvement of extracellular cysteine residues in the channel formation process. Two connexin-32 mutants were generated by site-directed mutagenesis in which cysteine residues were replaced by serine. Both mutant connexins were unable to form cell/cell channels. Thus, the cysteine residues appear to play an important role in the channel formation process.