A Seven-Transmembrane Receptor That Mediates Avoidance Response to Dihydrocaffeic Acid, a Water-Soluble Repellent inCaenorhabditis elegans

Abstract

The ability to detect harmful chemicals rapidly is essential for the survival of all animals. In Caenorhabditis elegans (C. elegans), repellents trigger an avoidance response, causing animals to move away from repellents. Dihydrocaffeic acid (DHCA) is a water-soluble repellent and nonflavonoid catecholic compound that can be found in plant products. Using a Xenopus laevis (X. laevis) oocyte expression system, we identified a candidate dihydrocaffeic acid receptor (DCAR), DCAR-1. DCAR-1 is a novel seven-transmembrane protein that is expressed in the ASH avoidance sensory neurons of C. elegans. dcar-1 mutant animals are defective in avoidance response to DHCA, and cell-specific expression of dcar-1 in the ASH neurons of dcar-1 mutant animals rescued the defect in avoidance response to DHCA. Our findings identify DCAR-1 as the first seven-transmembrane receptor required for avoidance of a water-soluble repellent, DHCA, in C. elegans.

Odour concentration-dependent olfactory preference change in C. elegans

“…The cause of difference between the rescue and knockdown experiments is discussed later. These behavioural-genetic analyses of odr-3 suggest that ODR-3 functions mainly in ASH sensory neurons to regulate avoidance of higher concentrations of isoamyl alcohol, supported by previous studies of the avoidance of water-soluble repellents 23,24 . It was previously suggested that ODR-3 mediates attraction to diluted isoamyl alcohol in AWC olfactory neurons 19 .…”

Evolutionary plasticity in the innate immune function of Akirin

“…HPLA acts via DCAR-1 to activate a p38 MAPK signalling cascade (Zugasti et al, 2014). This GPCR can also be activated by the HPLA tautomer DHCA (Aoki, Yagami et al, 2011), a non-physiological ligand, which we use routinely as it is somewhat more potent and less toxic for worms than HPLA (Zugasti et al, 2014). The induction of nlp-29p::gfp expression upon exposure to DHCA was greatly reduced upon akir-1(RNAi), to a degree that was comparable to dcar-1(RNAi) (Fig 1A).…”

The C. elegans cGMP-Dependent Protein Kinase EGL-4 Regulates Nociceptive Behavioral Sensitivity

“…Once dissociated, the Gα-GTP and Gβγ subunits can activate distinct signaling cascades within the cell [13]. Although the C. elegans genome encodes >500 predicted functional chemosensory GPCRs [14], only one aversive chemical stimulus, dihydrocaffeic acid, has been functionally coupled to a receptor, DCAR-1 [15]. However, the C. elegans stimulatory Gα subunits ODR-3 and GPA-3 (both most similar to Gα i/o ) are used by ASH to mediate avoidance of a variety of stimuli [7], [8], [16]–[18].…”