Identification and functional characterization of the promoter of the mouse sodium‐activated sodium channel Nax gene (Scn7a)
- 26 March 2009
- journal article
- research article
- Published by Wiley in Journal of Neuroscience Research
- Vol. 87 (11), 2509-2519
- https://doi.org/10.1002/jnr.22069
Abstract
Nax is a sodium channel, thought to be a descendant of the voltage-gated sodium channel family. Nevertheless, Nax is not activated by voltage but rather by augmentation of extracellular sodium over 150 mM. In the brain, it is localized to the circumventricular organs, important regions for salt and water homeostasis in mammals, where it operates as a sodium-level sensor of body fluid. Nax channel is expressed in lung, uterus, and heart, and it is also found in trigeminal and dorsal root ganglia and in nonmyelinating Schwann cells, where its physiological role remains unclarified. Here we identified the promoter and transcription start sites of Nax sodium channel in dorsal root ganglia neurons from mouse. We report a characterization of the basal TATA-less promoter and the sequence requirements for promoter activity in Neuro 2A neuroblastoma cells and in dorsal root ganglia neurons, where basal promoter activity seems to require NGFI-C and Ebox DNA elements. Finally, we provide evidence that a repression mechanism that inhibits Nax expression may be present in certain tissues. These findings provide the basis with which to understand tissue-specific regulation of Nax sodium channel gene (Scn7a) expression.Keywords
This publication has 40 references indexed in Scilit:
- Identification of the promoter region and the 5′‐untranslated exons of the human voltage‐gated sodium channel Nav1.1 gene (SCN1A) and enhancement of gene expression by the 5′‐untranslated exonsJournal of Neuroscience Research, 2008
- Genetic Variations Associated With Echocardiographic Left Ventricular Traits in Hypertensive BlacksHypertension, 2007
- Prevalence of the initiator over the TATA box in human and yeast genes and identification of DNA motifs enriched in human TATA-less core promotersGene, 2006
- Sodium Channel β2 Subunits Regulate Tetrodotoxin-Sensitive Sodium Channels in Small Dorsal Root Ganglion Neurons and Modulate the Response to PainJournal of Neuroscience, 2006
- Sodium-level-sensitive sodium channel Nax is expressed in glial laminate processes in the sensory circumventricular organsAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2006
- The Subfornical Organ, a Specialized Sodium Channel, and the Sensing of Sodium Levels in the BrainThe Neuroscientist, 2006
- Tandem Promoters and Developmentally Regulated 5′- and 3′-mRNA Untranslated Regions of the Mouse Scn5a Cardiac Sodium ChannelPublished by Elsevier BV ,2005
- The Subfornical Organ is the Primary Locus of Sodium-Level Sensing by NaxSodium Channels for the Control of Salt-Intake BehaviorJournal of Neuroscience, 2004
- NeuroD1/E47 Regulates the E-box Element of a Novel Zinc Finger Transcription Factor, IA-1, in Developing Nervous SystemJournal of Biological Chemistry, 2003
- Nax channel involved in CNS sodium-level sensingNature Neuroscience, 2002