Amiloride-sensitive sodium channel subunit delta, also known as Delta-NaCH, is encoded by SCNN1D. The sequence of the SCNN1D gene is first revealed by the human genome project. SCNN1D is located in the short arm of chromosome 1 (Ensembl database code: ENSG00000162572). The Delta-NaCH shares a similar topology and 27–37% amino acid identity to the a-, b- and c-ENaC subunits. δ-ENaC is expressed as two splice isoforms with divergent NH2 termini in human and primates, but it is a pseudogene in rodents. It is able to form amiloride-sensitive, voltage-independent Na+ channels when expressed alone or in combination with β- and γ-subunits.
|Basic Information of SCNN1D|
|Protein Name||Amiloride-sensitive sodium channel subunit delta|
|Aliases||ENaCd, ENaCdelta, SCNED, dNaCh|
|Organism||Homo sapiens (Human)|
The a-, b- and c-ENaC subunits are highly expressed in kidney, colon, and lung. In contrast, the highest transcriptional expression levels of δ-ENaC are detected in nonepithelial tissues, such as brain, pancreas, heart, testis and ovary, whilst lung, kidney, colon and several other tissues showed only low expression. Additionally, the pharmacological and biophysical properties are clearly distinct between δ- and α-ENaC-generated currents. The role of δ-ENaC is uncertain, although its biophysical properties point toward several possibilities. First, being a voltage-independent, highly selective Na+ channel, it could serve as a leak Na+ conductance, contributing to the setting of resting membrane potential. In addition, δ-ENaC currents are enhanced by a drop in extracellular pH (pHe), suggesting that it could serve as a proton sensor and be involved in the transduction of ischemic signals that occur under conditions of tissue hypoxia or inflammation.
Fig.1 Phylogenetic and genomic analysis of SCNN1D. (Ji, 2012)
This article suggests that δ-ENaC may be involved in the controlling sodium reabsorption in the airways, which may provide evidence for ENaC as a therapeutic target for cystic fibrosis.
In this article, authors find that δ-ENaC expression is low in human airway epithelial cell lines (i.e. NCI-H441 and Calu-3) as well as human alveolar epithelial type I-like (ATI) cells in vitro, thus suggesting that δ-ENaC does not contribute to transepithelial sodium absorption.
This article systematically characterizes a new variant of δ2 ENaC in human lung epithelial cells. Heterologous δ2βγ ENaC exhibits a number of divergent features from the δ1βγ counterpart in biophysics and pharmacology, regulation, and the lifespan of proteins. Channels comprising of this novel splice variant may contribute to the diversities of native epithelial Na+ channels.
This article reveals that δ-ENaC undergoes dynamin-independent endocytosis as opposed to αβγ-channels.
This article suggests that COMMD1 controls dENaC cell surface population and thus regulates dENaC-mediated Na+ transport.
Membrane protein studies have advanced significantly over the past few years. Based on our versatile Magic™ membrane protein production platform, we could offer a series of membrane protein preparation services for worldwide customers in reconstitution forms as well as multiple active formats. Aided by our versatile Magic™ anti-membrane protein antibody discovery platform, we also provide customized anti-SCNN1D antibody development services.
During the past years, Creative Biolabs has successfully generated many functional membrane proteins for our global customers. We are happy to accelerate the development of our clients’ programs with our one-stop, custom-oriented service. For more detailed information, please feel free to contact us.