Ca2+-modulated ONE-GC odorant signal transduction.
In a subset of olfactory epithelium the odorant receptor guanylate cyclase, ONE-GC, is a central transduction component of the cyclic GMP signaling pathway. The odorant binds to the extracellular domain and activates its intracellular catalytic domain to generate the odorant second messenger, cyclic GMP. The present study demonstrates that it is a two-step, Ca(2+)-independent and Ca(2+)-dependent, sequential process. In step one, the odorant, uroguanylin, binds ONE-GC and primes it for stimulation. In step two, Ca(2+)-bound neurocalcin delta binds to the defined intracellular domain and saturates ONE-GC activity. A prototype model is proposed that depicts this signal transduction process.
Duda
Teresa
T
Research Divisions of Biochemistry and Molecular Biology, The Unit of Regulatory and Molecular Biology, Salus University, Elkins Park, PA 19027, USA. tduda@salus.edu
Sharma
Rameshwar K
RK
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020134:Catalytic Domain; D006152:Cyclic GMP / Q000378:metabolism; D045265:Natriuretic Peptides / Q000378:metabolism; D009812:Odorants; D051381:Rats; D015290:Second Messenger Systems; D015398:Signal Transduction
D045265:Natriuretic Peptides; C084362:uroguanylin; D006152:Cyclic GMP; D002118:Calcium