GPBA receptors (GPBAR1, M-BAR, TGR5) are G protein-coupled receptors (GPCRs) that are activated by bile acids. They are primarily expressed in the gallbladder, ileum and colon, and are important in the regulation of glucose and lipid metabolism, and energy expenditure.
GPBA receptors are members of the class A (rhodopsin-like) subgroup of GPCRs and are present at varying levels in the liver, gallbladder, ileum, colon, heart, spleen, kidney, placenta, leukocytes, skeletal muscle, brown adipose tissue and central nervous system. Bile acids, which are the major constituent of bile, are endogenous ligands for the GBPA receptor. They are synthesized from cholesterol in the liver and are stored in the gallbladder. Bile acids are secreted into the duodenum where they promote the absorption of lipids and lipid-soluble vitamins.
The receptors are involved in a range of processes. Activation of GPBA receptors increases energy consumption in mouse brown adipose tissue and human skeletal muscle cells by promoting the conversion of inactive thyroxine (T4) to active 3,5,3'-tri-iodothyronine which, in turn, enhances mitochondrial oxidative phosphorylation. Another effect of GBPA activation is on glucose metabolism. Bile acids released into the gut following ingestion of a meal, activate GBPA receptors on enteroendocrine cells resulting in the release of glucagon-like peptide (GLP-1) into the blood, which in turn regulates insulin secretion from pancreatic β cells and glucose homeostasis. In addition, GBPA receptors are expressed on macrophages where their activation suppresses NF-κB signaling and inhibits production of pro-inflammatory cytokines, which has been proposed to attenuate the development of atherosclerosis.
To view external sources of pharmacological information for GPBA Receptors, please click here: IUPHAR Receptor CodeView all products for GPBA Receptors »
|Gene||Species||Gene Symbol||Gene Accession No.||Protein Accession No.|
|G protein-coupled bile acid receptor 1||Human||GPBAR1||NM_001077191||Q8TDU6|
Literature for GPBA Receptors
A collection of over 250 products for cardiovascular research, the guide includes research tools for the study of:
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A collection of over 450 products for G protein-coupled receptors, the listing includes research tools for the study of:
- Rhodopsin-like Receptors
- Secretin-like Receptors
- Glutamate Receptors
- Frizzled Receptors
- GPCR Signaling