We have studied the modulation of gating properties of the Ca2+-permeable, cation channel TRPV4 transiently expressed in HEK293 cells. The phorbol ester 4αPDD transiently activated a current through TRPV4 in the presence of extracellular Ca2+. Increasing the concentration of extracellular Ca2+ ([Ca2+]e) reduced the current amplitude and accelerated its decay. This decay was dramatically delayed in the absence of [Ca2+]e. It was also much slower in the presence of [Ca2+]e in a mutant channel, obtained by a point mutation in the 6th transmembrane domain, F707A. Mutant channels, containing a single mutation in the C-terminus of TRPV4 (E797 , were constitutively open. In conclusion, gating of the 4αPDD-activated TRPV4 channel depends on both extra- and intracellular Ca2+, and is modulated by mutations of single amino acid residues in the 6th transmembrane domain and the C-terminus of the TRPV4 protein.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-15240 |
| Date | 01 January 2003 |
| Creators | Watanabe, Hiroyuki, Vriens, Joris, Janssens, Annelies, Wondergem, Robert, Droogmans, Guy, Nilius, Bernd |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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