2M3O633720276ENSG00000111319ENSMUSG00000030340P37088Q61180NM_001159576NM_001038NM_001159575NM_011324NP_001029NP_001153047NP_001153048NP_035454NP_001392957NP_001392960The SCNN1A gene encodes for the α subunit of the epithelial sodium channel ENaC in vertebrates.

ENaC is expressed in epithelial cells[5] and is different from the voltage-gated sodium channel that is involved in the generation of action potentials in neurons.

[6] ENaC allows transfer of sodium ions across the epithelial cell membrane in so-called "tight-epithelia" that have low permeability.

Thus, ENaC plays a central role in the regulation of body fluid and electrolyte homeostasis and consequently affects blood pressure.

The first mRNA encoding the alpha subunit of ENaC was isolated by two independent groups by screening a rat colon cDNA library.

Analysis of α subunit mRNA from human lung and kidney showed that during transcription of SCNN1A gene different mRNAs are produced as a result of alternative translation initiation and splicing sites.

The major organs where ENaC is expressed include parts of the kidney tubular epithelia,[5][7][17] the respiratory airway,[18] the female reproductive tract,[18] male reproductive tract, including testis, spermatogonia in the seminiferous tubules, Sertoli cells, and spermatozoa,[19] epididymis,[20] colon and salivary glands.

[17] In the skin, SCNN1A is expressed in the keratinocytes in the epidermal layer, in the sebaceous sweat glands, and the smooth muscle cells mostly within the cytoplasm.

[17] The expression of ENaC subunit genes is regulated mainly by the mineralocorticoid hormone aldosterone that is activated by the renin-angiotensin system.