Dissecting the genetic landscape of GPCR signaling through phenotypic profiling in C. elegans

Abstract

G protein-coupled receptors (GPCRs) mediate responses to various extracellular and intracellular cues. However, the large number of GPCR genes and their substantial functional redundancy make it challenging to systematically dissect GPCR functions in vivo. Here, we employ a CRISPR/Cas9-based approach, disrupting 1654 GPCR-encoding genes in 284 strains and mutating 152 neuropeptide-encoding genes in 38 strains in C. elegans. These two mutant libraries enable effective deorphanization of chemoreceptors, and characterization of receptors for neuropeptides in various cellular processes. Mutating a set of closely related GPCRs in a single strain permits the assignment of functions to GPCRs with functional redundancy. Our analyses identify a neuropeptide that interacts with three receptors in hypoxia-evoked locomotory responses, unveil a collection of regulators in pathogen-induced immune responses, and define receptors for the volatile food-related odorants. These results establish our GPCR and neuropeptide mutant libraries as valuable resources for the C. elegans community to expedite studies of GPCR signaling in multiple contexts.

Antagonism between neuropeptides and monoamines in a distributed circuit for pathogen avoidance

“… 22 AVK’s broadcasting function may orchestrate responses to other pathogens as well; an independent study showed that flp-1 and dmsr-7 , as well as several other neuropeptides, affect avoidance of pathogenic Vibrio cholerae . 56 At the same time, AVK is not solely a pathogen-detecting neuron because AVK and its component neuropeptides have locomotor functions in the absence of pathogens. 31 , 40 , 57 Instead, the aggregate results support a distributed and combinatorial logic for the action of FLP-1 neuropeptides in multiple behaviors.…”

Systematic creation and phenotyping of Mendelian disease models inC. elegans: towards large-scale drug repurposing

“…The large deletions we use here can delete regulatory elements or non-coding RNAs that could lead to phenotypes not related to the modelled disease. Alternative methods of creating loss-of-function alleles such as introducing premature stop codons can also be done at the scale of dozens of strains (Pu et al, 2023). Furthermore, to study loss of function in essential genes, balanced heterozygous strains can be created where this makes sense for a particular disease model.…”

Unraveling the Roles of Neuropeptides in the Chemosensation of the Root-Knot Nematode Meloidogyne javanica

“…Only 210 up-regulated and 54 down-regulated genes were shared between the 1 h and 6 h DEGs (Figure 1D,E). GPCRs mediate responses to various extracellular and intracellular cues and represent the largest family of cell surface proteins in metazoan [28,29]. However, the functional overlap among GPCRs poses a challenge for the dissection of their functions.…”