aThis paper is dedicated to the memory of our friend and colleague Dr. Guy Champigny, who has contributed in a major way to our current understanding of the properties of this ion channel family.
H+-Gated Cation Channelsa
Version of Record online: 6 FEB 2006
Annals of the New York Academy of Sciences
Volume 868, MOLECULAR AND FUNCTIONAL DIVERSITY OF ION CHANNELS AND RECEPTORS pages 67–76, April 1999
How to Cite
WALDMANN, R., CHAMPIGNY, G., LINGUEGLIA, E., DE WEILLE, J. R., HEURTEAUX, C. and LAZDUNSKI, M. (1999), H+-Gated Cation Channelsa. Annals of the New York Academy of Sciences, 868: 67–76. doi: 10.1111/j.1749-6632.1999.tb11274.x
- Issue online: 6 FEB 2006
- Version of Record online: 6 FEB 2006
ABSTRACT: H+-gated cation channels are members of a new family of ionic channels, which includes the epithelial Na+ channel and the FMRFamide-activated Na+ channel. ASIC, the first member of the H+-gated Na+ channel subfamily, is expressed in brain and dorsal root ganglion cells (DRGs). It is activated by pHe variations below pH 7. The presence of this channel throughout the brain suggests that the H+ might play an essential role as a neurotransmitter or neuromodulator. The ASIC channel is also present in dorsal root ganglion cells, as is its homolog DRASIC, which is specifically present in DRGs and absent in the brain. Since external acidification is a major factor in pain associated with inflammation, hematomas, cardiac or muscle ischemia, or cancer, these two channel proteins are potentially central players in pain perception. ASIC activates and inactivates rapidly, while DRASIC has both a fast and sustained component. Other members of this family such as MDEG1 and MDEG2 are either H+-gated Na+ channels by themselves (MDEG1) or modulators of H+-gated channels formed by ASIC and DRASIC. MDEG1 is of particular interest because the same mutations that produce selective neurodegeneration in C. elegans mechanosensitive neurons, when introduced in MDEG1, also produce neurodegeneration. MDEG2 is selectively expressed in DRGs, where it assembles with DRASIC to radically change its biophysical properties, making it similar to the native H+-gated channel, which is presently the best candidate for pain perception.