Structure of a gap junction gene: rat connexin-32.

A genomic clone for the rat liver gap junction protein (connexin-32) was isolated and characterized by restriction enzyme mapping and sequence analysis. While the complete coding sequence is contained within one uninterrupted block, the 5'-untranslated region of the transcript contains a 6.1 kb intron. Both S1 nuclease protection and primer extension assays indicate multiple transcription start sites. Sequences homologous to cAMP response elements are found near the transcription start sites and within the 3'-end of the intron.