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Beyond Ca(2+) signalling: the role of TRPV3 in the transport of NH(4)
- Source :
- Pflugers Archiv
- Publication Year :
- 2021
- Publisher :
- Springer, 2021.
-
Abstract
- Mutations of TRPV3 lead to severe dermal hyperkeratosis in Olmsted syndrome, but whether the mutants are trafficked to the cell membrane or not is controversial. Even less is known about TRPV3 function in intestinal epithelia, although research on ruminants and pigs suggests an involvement in the uptake of NH4+. It was the purpose of this study to measure the permeability of the human homologue (hTRPV3) to NH4+, to localize hTRPV3 in human skin equivalents, and to investigate trafficking of the Olmsted mutant G573S. Immunoblotting and immunostaining verified the successful expression of hTRPV3 in HEK-293 cells and Xenopus oocytes with trafficking to the cell membrane. Human skin equivalents showed distinct staining of the apical membrane of the top layer of keratinocytes with cytosolic staining in the middle layers. Experiments with pH-sensitive microelectrodes on Xenopus oocytes demonstrated that acidification by NH4+ was significantly greater when hTRPV3 was expressed. Single-channel measurements showed larger conductances in overexpressing Xenopus oocytes than in controls. In whole-cell experiments on HEK-293 cells, both enantiomers of menthol stimulated influx of NH4+ in hTRPV3 expressing cells, but not in controls. Expression of the mutant G573S greatly reduced cell viability with partial rescue via ruthenium red. Immunofluorescence confirmed cytosolic expression, with membrane staining observed in a very small number of cells. We suggest that expression of TRPV3 by epithelia may have implications not just for Ca2+ signalling, but also for nitrogen metabolism. Models suggesting how influx of NH4+ via TRPV3 might stimulate skin cornification or intestinal NH4+ transport are discussed.
- Subjects :
- Keratinocytes
Ruthenium red
Cell Membrane Permeability
Patch-Clamp Techniques
Physiology
Colon
Clinical Biochemistry
Xenopus
TRPV Cation Channels
Human skin
NH4+
Epithelium
Cell Line
Cell membrane
chemistry.chemical_compound
Xenopus laevis
Ammonia
Physiology (medical)
medicine
Animals
Humans
Viability assay
Calcium Signaling
Olmsted syndrome
Skin
biology
Chemistry
Cell Membrane
Biological Transport
500 Naturwissenschaften und Mathematik::570 Biowissenschaften
Biologie::570 Biowissenschaften
Biologie
Apical membrane
Hydrogen-Ion Concentration
biology.organism_classification
Cell biology
Cytosol
medicine.anatomical_structure
HEK293 Cells
TRPV3
Mutation
Oocytes
Function and Dysfunction of the Nervous System
Immunostaining
Ion Channels, Receptors and Transporters
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Pflugers Archiv
- Accession number :
- edsair.doi.dedup.....17ff648ab0a5cde644263775cb32e5eb