title: Trp proteins form store-operated cation channels in human vascular endothelial cells.
abstract: Members of the Trp protein family have been suggested as the structural basis of store-operated cation conductances. With this study, we provide evidence for the expression of three isoforms of Trp (hTrp1, 3 and 4) in human umbilical vein endothelial cells (HUVEC). The role of Trp proteins in store regulation of endothelial membrane conductances was tested by expression of an N-terminal fragment of hTrp3 (N-TRP) which exerts a dominant negative effect on Trp channel function presumably due to suppression of channel assembly. Depletion of intracellular Ca2+ stores with IP3 (100 microM) or thapsigargin (100 nM) induced a substantial cation conductance in sham-transfected HUVEC as well as in HUVEC transfected with hTrp3. In contrast, HUVEC transfected with N-TRP failed to exhibit store-operated currents. Our results suggest the involvement of Trp related proteins in the store-operated cation conductance of human vascular endothelial cells.
authors.affiliation: Institut für Pharmakologie und Toxikologie, Karl-Franzens-Universität Graz, Austria. klaus.groschner@kfunigraz.ac.at
authors.forename: K
authors.initials: K
authors.lastname: Groschner
authors.forename: S
authors.initials: S
authors.lastname: Hingel
authors.forename: B
authors.initials: B
authors.lastname: Lintschinger
authors.forename: M
authors.initials: M
authors.lastname: Balzer
authors.forename: C
authors.initials: C
authors.lastname: Romanin
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: W
authors.initials: W
authors.lastname: Schreibmayer
mesh_terms: D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000378:metabolism*; D006801:Humans; D018408:Patch-Clamp Techniques; D050052:TRPC Cation Channels; D019284:Thapsigargin / Q000494:pharmacology; D014162:Transfection; D014471:Umbilical Veins
chemical_list: D015220:Calcium Channels; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D019284:Thapsigargin