SCNN1B [SEP] chromosome
organization of the human beta ENaC gene SCNN1B was determined by Saxena et al. by sequencing genomic DNA from three subjects from three different ethnic groups. This study also established that the exon-intron architecture of the three subunits of ENaC have remained highly conserved despite the divergence of their sequences.
Gene structure.
While the human gene SCNN1A is located in chromosome 12p, the human genes encoding SCNN1B and SCNN1G are located in juxtaposition in the short arm of chromosome 16 (16p12-p13). Sequencing of the human genomic DNA
indicated that the SCNN1B gene has 13 exons separated by 12 introns. The positions of introns are conserved in all three human ENaC genes, SCNN1A, SCNN1B and SCNN1G. The positions of the introns are also highly conserved across vertebrates. See: Ensembl GeneTree.
Analysis of transcripts of the SCNN1B gene in human kidney and lung showed several alternative transcription and translation initiation sites. However, only one of these transcripts (ENST00000343070) is highly expressed and other transcripts appear at low amounts.
Tissue-specific expression.
The three