Cannabinoid receptor 1 splice variants (CB1R splice variants)

The Cannabinoid receptor 1 (CB1) splice variants, primarily CB1a and CB1b, are isoforms of the canonical CB1 receptor encoded by the CNR1 gene (UniProt P21554) [2]. These variants result from alternative splicing of the N-terminal region, leading to structural differences that influence ligand binding affinity and signaling efficiency (Ryberg et al., 2005) [1]. While the canonical CB1 receptor is one of the most abundant G protein-coupled receptors in the central nervous system, the splice variants exhibit distinct expression patterns (Shire et al., 1995) [4]. CB1a and CB1b show higher relative expression in peripheral tissues such as the liver, pancreas, and skeletal muscle compared to the brain (Gonzalez-Mariscal et al., 2016) [3]. These variants play significant roles in regulating energy balance, lipid metabolism, and neurotransmission (PubMed) [5]. Dysregulation of CB1 splice variants is implicated in metabolic disorders like obesity and type 2 diabetes, as well as psychiatric conditions (NIH) [6]. Pharmacological targeting of these receptors has focused on weight loss and metabolic improvement, though central nervous system side effects remain a major challenge (PubMed) [5]. Understanding the specific roles of CB1a and CB1b may allow for more tissue-specific therapeutic interventions with reduced adverse effects (Ryberg et al., 2005) [1]. Overall, these splice variants represent critical components of the endocannabinoid system with unique pharmacological profiles.

Other names

CB1aCB1bCNR1 splice variantsCannabinoid receptor 1 isoform aCannabinoid receptor 1 isoform bCNR1

Modulation of G protein-coupled receptor signaling through agonism, antagonism, or inverse agonism, primarily affecting the Gi/o pathway to inhibit adenylyl cyclase and regulate calcium and potassium channels.