A network of stimulatory and inhibitory G alpha-subunits regulates olfaction in Caenorhabditis elegans.
The two pairs of sensory neurons of C. elegans, AWA and AWC, that mediate odorant attraction, express six Galpha-subunits, suggesting that olfaction is regulated by a complex signaling network. Here, we describe the cellular localization and functions of the six olfactory Galpha-subunits: GPA-2, GPA-3, GPA-5, GPA-6, GPA-13, and ODR-3. All except GPA-6 localize to sensory cilia, suggesting a direct role in sensory transduction. GPA-2, GPA-3, GPA-5, and GPA-6 are also present in cell bodies and axons and GPA-5 specifically localizes to synaptic sites. Analysis of animals with single- to sixfold loss-of-function mutations shows that olfaction involves a balance between multiple stimulatory and inhibitory signals. ODR-3 constitutes the main stimulatory signal and is sufficient for the detection of odorants. GPA-3 forms a second stimulatory signal in the AWA and AWC neurons, also sufficient for odorant detection. In AWA, signaling is suppressed by GPA-5. In AWC, GPA-2 and GPA-13 negatively and positively regulate signaling, respectively. Finally, we show that only ODR-3 plays a role in cilia morphogenesis. Defects in this process are, however, independent of olfactory behavior. Our findings reveal the existence of a complex signaling network that controls odorant detection by C. elegans.
|Keywords||*Odors, Animals, Caenorhabditis elegans Proteins/*genetics, Caenorhabditis elegans/cytology/*genetics, GTP-Binding Protein alpha Subunits/*genetics, Gene Expression Regulation/*genetics, Plasmids/genetics, Research Support, Non-U.S. Gov't, Smell/*physiology|
|Persistent URL||dx.doi.org/10.1534/genetics.103.024786, hdl.handle.net/1765/13490|
Lans, W.J., Rademakers, S., & Jansen, G.. (2004). A network of stimulatory and inhibitory G alpha-subunits regulates olfaction in Caenorhabditis elegans.. Genetics (Print): a periodical record of investigations bearing on heredity and variation, 167(4), 1677–1687. doi:10.1534/genetics.103.024786