C. Harteneck et al., THE DROSOPHILA CATION CHANNEL TRPL EXPRESSED IN INSECT SF9 CELLS IS STIMULATED BY AGONISTS OF G-PROTEIN-COUPLED RECEPTORS, FEBS letters, 358(3), 1995, pp. 297-300
Structures and regulations of vertebrate channels responsible for sust
ained calcium elevations after hormone stimulation are largely unknown
. Therefore, the Drosophila photoreceptor channels, trp and trpl, whic
h are assumed to be involved in calcium influx, serve as model system.
trpl expressed in Sf9 cells showed spontanous activity. Hormonal stim
ulations of calcium influx (detected by fura-2) and of an outwardly re
ctifying current were observed in Sf9 cells coinfected with baculoviru
ses encoding trpl and various heptahelical receptors for histamine, th
rombin, and thromboxane A(2), all known to cause phospholipase C-beta
activation in mammalian cells. Although the identity of the G-proteins
and of possible second messengers involved need to be clarified, it i
s clear that trpl represents a receptor/G-protein regulated cation cha
nnel.