Related Experiment Video
Updated: Dec 7, 2025

Demonstration of the Sequence Alignment to Predict Across Species Susceptibility Tool for Rapid Assessment of Protein Conservation
Published on: February 10, 2023
Alternative Splicing of Opioid Receptor Genes Shows a Conserved Pattern for 6TM Receptor Variants
Marjo Piltonen1,2,3, Andrey Krokhotin4, Marc Parisien1,2,3
1School of Dentistry, McGill University, Genome Building, Room 2201, 740 Dr. Penfield Avenue, Montreal, Quebec, H3A 0G1, Canada.
Abstract:
The opioid receptor (OPR) family comprises the mu-, delta-, and kappa-opioid, and nociceptin receptors that belong to the superfamily of 7-transmembrane spanning G protein-coupled receptors (GPCRs). The mu-opioid receptor is the main target for clinically used opioid analgesics, and its biology has been extensively studied. The N-terminally truncated 6TM receptors isoform produced through alternative splicing of the OPRM1 gene displays unique signaling and analgesic properties, but it is unclear if other OPRs have the same ability. In this study, we have built a comprehensive map of alternative splicing events that produce 6TM receptor variants in all the OPRs and demonstrated their evolutionary conservation. We then obtained evidence for their translation through ribosomal footprint analysis. We discovered that N-terminally truncated 6TM GPCRs are rare in the human genome and OPRs are overrepresented in this group. Finally, we also observed a significant enrichment of 6TM GPCR genes among genes associated with pain, psychiatric disorders, and addiction. Understanding the biology of 6TM receptors and leveraging this knowledge for drug development should pave the way for novel therapies.
Related Concept Videos
Opioid Receptors: Overview
Alternative RNA Splicing
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Alternative RNA Splicing
RNA Splicing
Spare Receptors
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon...

