Gene structure of the human amiloride-sensitive epithelial sodium channel beta subunit.
ENaC functions in the transport of sodium ions across epithelial cells and consequently regulates blood volume and pressure. ENaC complex includes at least three different subunits, alpha, beta, and gamma, which are developmentally regulated and differentially controlled by aldosterone. In this study, we determined the exon-intron organization of the beta ENaC subunit by sequencing genomic DNA from three subjects from three different ethnic groups. The results showed that the coding region of the human betaENaC gene (SCNN1B) extends from exon 2 to exon 13. No polymorphism was observed in the examined subjects, indicating strict conservation of the coding region sequence. The introns of beta subunit gene are located at exactly the same positions as in the alpha and gamma subunits, although these proteins share only 26-32% sequence identity. These results thus elucidate the gene structure of the beta subunit and indicate that exon-intron architecture of the three genes encoding the three subunits of ENaC have remained highly conserved despite the divergence of their sequences.
Saxena
A
A
E. Katzir Biotechnology Program, The Research Institute, College of Judea and Samaria, Ariel 44837, Israel.
Hanukoglu
I
I
Strautnieks
S S
SS
Thompson
R J
RJ
Gardiner
R M
RM
Hanukoglu
A
A
D000584:Amiloride / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers; D004847:Epithelial Cells / Q000378:metabolism*; D053503:Epithelial Sodium Channels; D005006:Ethnicity; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D044465:White People / Q000235:genetics
D017931:DNA Primers; D053503:Epithelial Sodium Channels; D011994:Recombinant Proteins; C507048:SCNN1B protein, human; D015222:Sodium Channels; D000584:Amiloride