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Published on: October 29, 2011
Ca2+-modulated ONE-GC odorant signal transduction.
Teresa Duda1, Rameshwar K Sharma
1Research Divisions of Biochemistry and Molecular Biology, The Unit of Regulatory and Molecular Biology, Salus University, Elkins Park, PA 19027, USA. tduda@salus.edu
FEBS Letters
|March 25, 2009
Summary
Odorant receptor guanylate cyclase (ONE-GC) initiates a two-step signaling process. First, uroguanylin primes ONE-GC, then calcium-bound neurocalcin delta saturates its activity, elucidating olfactory signal transduction.
Area of Science:
- Olfactory neurobiology
- Molecular signaling pathways
- Biochemistry
Background:
- The olfactory epithelium contains odorant receptor guanylate cyclase (ONE-GC), a key component in cyclic GMP (cGMP) signaling.
- Odorant binding to ONE-GC's extracellular domain activates its intracellular catalytic domain, producing cGMP.
Purpose of the Study:
- To elucidate the sequential mechanism of ONE-GC activation.
- To characterize the roles of uroguanylin and calcium-bound neurocalcin delta in olfactory signal transduction.
Main Methods:
- Investigated the two-step activation process of ONE-GC.
- Examined the Ca(2+)-independent and Ca(2+)-dependent steps in the signaling pathway.
- Utilized a prototype model to depict the signal transduction mechanism.
Main Results:
- Demonstrated a two-step activation process for ONE-GC.
- Identified uroguanylin as the priming agent in the first Ca(2+)-independent step.
- Showed that Ca(2+)-bound neurocalcin delta saturates ONE-GC activity in the second Ca(2+)-dependent step.
Conclusions:
- ONE-GC activation is a sequential, two-step process involving both Ca(2+)-independent and Ca(2+)-dependent phases.
- Uroguanylin primes ONE-GC, while neurocalcin delta modulates its activity via calcium binding.
- A model for this olfactory signal transduction pathway has been proposed.
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