Ca2+-modulated ONE-GC odorant signal transduction

Edited by Ned Mantei

Received 11 February 2009; received in revised form 14 March 2009; accepted 17 March 2009. published online 23 March 2009.

Abstract

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, Ca2+-independent and Ca2+-dependent, sequential process. In step one, the odorant, uroguanylin, binds ONE-GC and primes it for stimulation. In step two, Ca2+-bound neurocalcin δ binds to the defined intracellular domain and saturates ONE-GC activity. A prototype model is proposed that depicts this signal transduction process.

Keywords: Cyclic GMP, ONE-GC membrane guanylate cyclase, Odorant signal transduction

Research Divisions of Biochemistry and Molecular Biology, The Unit of Regulatory and Molecular Biology, Salus University, Elkins Park, PA 19027, United States

Corresponding authors. Fax: +1 215 780 3125 (R.K. Sharma).

PII: S0014-5793(09)00222-1

doi:10.1016/j.febslet.2009.03.036

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