The neuropeptide head activator induces activation and translocation of the growth-factor-regulated Ca(2+)-permeable channel GRC.
The neuropeptide head activator stimulates cell proliferation of neuronal precursor and neuroendocrine cells. The mitogenic signaling cascade requires Ca(2+) influx for which, as we show in this paper, the growth-factor-regulated Ca(2+)-permeable cation channel, GRC, is responsible. GRC is a member of the transient receptor potential channel family. In uninduced cells only low amounts of GRC are present on the plasma membrane but, upon stimulation with head activator, GRC translocates from an intracellular compartment to the cell surface. Head activator functions as an inducer of GRC translocation in neuronal and neuroendocrine cells, which express GRC endogenously, and also in COS-7 cells after transfection with GRC. Head activator is no direct ligand for GRC, but its action requires the presence of a receptor coupled to a pertussis-toxin inhibitable G-protein. Heterologously expressed GRC becomes activated by head activator, which results in opening of the channel and Ca(2+) influx. SK&F 96365, an inhibitor specific for TRP-like channels, blocks Ca(2+) entry and, consequently, translocation of GRC is prevented. Head activator-induced GRC activation and translocation are also inhibited by wortmannin and KN-93, blockers of the phosphatidylinositol 3-kinase and of the Ca(2+)/calmodulin-dependent kinase, respectively, which implies a role for both kinases in head-activator signaling to GRC.
Boels
K
K
Zentrum für Molekulare Neurobiologie, Universität Hamburg, Martinistrasse 52, 20246 Hamburg, Germany.
Glassmeier
G
G
Herrmann
D
D
Riedel
I B
IB
Hampe
W
W
Kojima
I
I
Schwarz
J R
JR
Schaller
H C
HC
D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D016466:CHO Cells; D019556:COS Cells; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane; D006224:Cricetinae; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D037342:Pertussis Toxin; D021381:Protein Transport; D011687:Purines / Q000494:pharmacology; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D000077546:Roscovitine; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology; D050916:TRPV Cation Channels; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D000077191:Wortmannin; D000096926:Benzenesulfonamides
D000730:Androstadienes; D001596:Benzylamines; D002118:Calcium; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004791:Enzyme Inhibitors; D007093:Imidazoles; D009479:Neuropeptides; D037342:Pertussis Toxin; D011687:Purines; D011761:Pyrrolidonecarboxylic Acid; D011993:Recombinant Fusion Proteins; D000077546:Roscovitine; D013449:Sulfonamides; D050916:TRPV Cation Channels; D010566:Virulence Factors, Bordetella; D000077191:Wortmannin; C400769:TRPV2 protein, human; C072105:KN 93; D000096926:Benzenesulfonamides; C032522:head activator peptide; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole