Induction of photoresponse by the hydrolysis of polyphosphoinositides in the Hermissenda type B photoreceptor.
Direct evidence that the photoresponse of the Hermissenda type B photoreceptor cell is triggered directly by the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) was obtained. Neomycin and spermine, which inhibit PIP2 breakdown, suppressed light response, while injection of inositol 1,4,5-trisphosphate (IP3), guanosine 5'-(3-O-thio)triphosphate (GTP gamma S), guanosine 5'-(2-O-thio)diphosphate (GDP beta S), cAMP, cGMP did not alter the light-induced Na+ influx underlying the photoresponse. Suppression of the photoresponse was also observed with decrease of total amount of membraneous PIP2 induced by injection of the phosphoinositides (PI) turnover inhibitors, isobutylmethylxanthine (IBMX), LiCl and R 59022.
Sakakibara
M
M
Department of Biological Science and Technology, School of High Technology for Human Welfare, Tokai University, Numazu, Japan.
Alkon
D L
DL
Kouchi
T
T
Inoue
H
H
Yoshioka
T
T
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D000242:Cyclic AMP / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006868:Hydrolysis; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D007700:Kinetics; D018021:Lithium Chloride / Q000494:pharmacology; D008954:Models, Biological; D009355:Neomycin / Q000494:pharmacology; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D017956:Photoreceptor Cells, Invertebrate / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors; D011744:Pyrimidinones / Q000494:pharmacology; D012908:Snails; D013096:Spermine / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism
D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010972:Platelet Activating Factor; D011744:Pyrimidinones; D013844:Thiazoles; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D013096:Spermine; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C023427:guanosine 5'-O-(2-thiodiphosphate); D015544:Inositol 1,4,5-Trisphosphate; C047505:R 59022; D000242:Cyclic AMP; D010738:Type C Phospholipases; D018021:Lithium Chloride; D006152:Cyclic GMP; D009355:Neomycin; D015056:1-Methyl-3-isobutylxanthine