Suppression of TRPC3 leads to disappearance of store-operated channels and formation of a new type of store-independent channels in A431 cells.
In most non-excitable cells, calcium (Ca(2+)) release from the inositol 1,4,5-trisphosphate (InsP(3))-sensitive intracellular Ca(2+) stores is coupled to Ca(2+) influx through the plasma membrane Ca(2+) channels whose molecular composition is poorly understood. Several members of mammalian TRP-related protein family have been implicated to both receptor- and store-operated Ca(2+) influx. Here we investigated the role of the native transient receptor potential 3 (TRPC3) homologue in mediating the store- and receptor-operated calcium entry in A431 cells. We show that suppression of TRPC3 protein levels by small interfering RNA (siRNA) leads to a significant reduction in store-operated calcium influx without affecting the receptor-operated calcium influx. With single-channel analysis, we further demonstrate that reduction of TRPC3 levels results in suppression of specific subtype of store-operated calcium channels and activation of store-independent channels. Our data suggest that TRPC3 is required for the formation of functional store-operated channels in A431 cells.
Kaznacheyeva
Elena
E
Institute of Cytology RAS, 4 Tikhoretsky Ave., 194064 St. Petersburg, Russia.
Glushankova
Lyuba
L
Bugaj
Vladislav
V
Zimina
Olga
O
Skopin
Anton
A
Alexeenko
Vadim
V
Tsiokas
Leonidas
L
Bezprozvanny
Ilya
I
Mozhayeva
Galina N
GN
D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling; D045744:Cell Line, Tumor; D003600:Cytosol / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D008954:Models, Biological; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D050052:TRPC Cation Channels / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D034741:RNA, Small Interfering; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; D002118:Calcium