GPR81

HCAR1
Identifiers
Aliases	HCAR1 , GPR104, GPR81, HCA1, LACR1, TA-GPCR, TAGPCR, FKSG80, hydroxycarboxylic acid receptor 1
External IDs	MGI: 2441671 HomoloGene: 13060 GeneCards: HCAR1
Gene location (Human)
Chr.	Chromosome 12 (human) [1]
End	122,730,843 bp [1]
Gene location (Mouse)
Chr.	Chromosome 5 (mouse) [2]
End	123,880,020 bp [2]
RNA expression pattern
	More reference expression data
Gene ontology
Molecular function	• G-protein coupled receptor activity ; • signal transducer activity ;
Cellular component	• integral component of membrane ; • plasma membrane ; • membrane ;
Biological process	• signal transduction ; • G-protein coupled receptor signaling pathway ;
	Sources:Amigo / QuickGO
Orthologs
	27198
	243270
	ENSG00000196917
	ENSMUSG00000049241
	Q9BXC0
	Q8C131
	NM_032554
	NM_175520
	NP_115943
	NP_780729
	Wikidata
View/Edit Human	View/Edit Mouse

Last updated April 02, 2019

G protein-coupled receptor 81, also known as GPR81, is a protein that in humans is encoded by the GPR81 gene.^[5]^[6]

Protein biological molecule consisting of chains of amino acid residues

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific three-dimensional structure that determines its activity.

In biology, a gene is a sequence of nucleotides in DNA or RNA that codes for a molecule that has a function. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic trait. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes as well as gene–environment interactions. Some genetic traits are instantly visible, such as eye color or number of limbs, and some are not, such as blood type, risk for specific diseases, or the thousands of basic biochemical processes that constitute life.

G protein-coupled receptors (GPCRs, or GPRs), such as GPR81, contain 7 transmembrane domains and transduce extracellular signals through heterotrimeric G proteins.^[5]

G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their activity is regulated by factors that control their ability to bind to and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When they are bound to GTP, they are 'on', and, when they are bound to GDP, they are 'off'. G proteins belong to the larger group of enzymes called GTPases.

Lactate activates the GPR81 receptor which in turn inhibits lipolysis in fat cells.^[7]^[8]

Lactic acid is an organic acid. It has a molecular formula CH₃CH(OH)CO₂H. It is white in solid state and it is extremely soluble in water. Solubility is so high that 1 part of lactic acid can dissolve 12 parts of water. While in liquid state (dissolved state) it is a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of carboxyl group adjacent to the hydroxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate.

Lipolysis is the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and three fatty acids. It is used to mobilize stored energy during fasting or exercise, and usually occurs in fat adipocytes. Lipolysis is induced by several hormones, including glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol.

Adipocytes, also known as lipocytes and fat cells, are the cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes, osteoblasts, myocytes and other cell types through adipogenesis.

Related Research Articles

Butyric acid (from Ancient Greek: βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a carboxylic acid with the structural formula CH₃CH₂CH₂-COOH. Salts and esters of butyric acid are known as butyrates or butanoates. Butyric acid is found in animal fat and plant oils, bovine milk, breast milk, butter, parmesan cheese, and as a product of anaerobic fermentation (including in the colon and as body odor). Butyric acid has a taste somewhat like butter and an unpleasant odor. Mammals with good scent detection abilities, such as dogs, can detect it at 10 parts per billion, whereas humans can only detect it in concentrations above 10 parts per million. In food manufacturing, it is used as a flavoring agent.

β-Hydroxybutyric acid, also known as 3-hydroxybutyric acid, is an organic compound and a beta hydroxy acid with the chemical formula CH₃CH(OH)CH₂CO₂H; its conjugate base is β-hydroxybutyrate, also known as 3-hydroxybutyrate. β-Hydroxybutyric acid is a chiral compound with two enantiomers: D-β-hydroxybutyric acid and L-β-hydroxybutyric acid. Its oxidized and polymeric derivatives occur widely in nature. In humans, D-β-hydroxybutyric acid is one of two primary endogenous agonists of hydroxycarboxylic acid receptor 2 (HCA₂), a G_i/o-coupled G protein-coupled receptor (GPCR).

G protein-coupled receptor 35 also known as GPR35 is a G protein-coupled receptor which in humans is encoded by the GPR35 gene. Heightened expression of GPR35 is found in immune and gastrointestinal tissues, including the crypts of Lieberkühn.

N-Arachidonyl glycine receptor, also known as G protein-coupled receptor 18 (GPR18), is a protein that in humans is encoded by the GPR18 gene. Along with the other previously "orphan" receptors GPR55 and GPR119, GPR18 has been found to be a receptor for endogenous lipid neurotransmitters, several of which also bind to cannabinoid receptors.

Lysophosphatidic acid receptor 4 also known as LPA₄ is a protein that in humans is encoded by the LPAR4 gene. LPA₄ is a G protein-coupled receptor that binds the lipid signaling molecule lysophosphatidic acid (LPA).

Putative G-protein coupled receptor 42 is a protein that in humans is encoded by the GPR42P gene.

Hydroxycarboxylic acid receptor 3 (HCA₃), also known as niacin receptor 2 (NIACR2) and GPR109B, is a protein which in humans is encoded by the HCAR3 gene. HCA₃, like the other hydroxycarboxylic acid receptors HCA₁ and HCA₂, is a G_i/o-coupled G protein-coupled receptor (GPCR). The primary endogenous agonist of HCA₃ is 3-hydroxyoctanoic acid. HCA₃ is also a low-affinity biomolecular target for niacin (aka nicotinic acid).

Probable G-protein coupled receptor 75 is a protein that in humans is encoded by the GPR75 gene.

2-Oxoglutarate receptor 1 (OXGR1), also known as cysteinyl leukotriene receptor E (CysLT_E) and GPR99, is a protein that in humans is encoded by the OXGR1 gene. The Gene has recently been nominated as a receptor not only for 2-oxogluterate but also for the three cysteinyl leukotrienes (CysLTs), particularly leukotriene E4 (LTE4) and to far lesser extents LTC4 and LTE4. Recent studies implicate GPR99 as a cellular receptor which is activated by LTE4 thereby causing these cells to contribute to mediating various allergic and hypersensitivity responses.

Lysophosphatidic acid receptor 5 also known as LPA₅ is a protein that in humans is encoded by the LPAR5 gene. LPA₅ is a G protein-coupled receptor that binds the lipid signaling molecule lysophosphatidic acid (LPA).

Pyroglutamylated RFamide peptide receptor also known as orexigenic neuropeptide QRFP receptor or G-protein coupled receptor 103 (GPR103) is a protein that in humans is encoded by the QRFPR gene.

G protein-coupled receptor 128 is a protein encoded by the ADGRG7 gene. GPR128 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.

G protein-coupled receptor 112 is a protein encoded by the ADGRG4 gene. GPR112 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.

G protein-coupled receptor 119 also known as GPR119 is a G protein-coupled receptor that in humans is encoded by the GPR119 gene.

G protein-coupled receptor 114 is a protein encoded by the ADGRG5 gene. GPR114 is a member of the adhesion GPCR family. Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.

Hydroxycarboxylic acid receptor 2 (HCA₂), also known as niacin receptor 1 (NIACR1) and GPR109A, is a protein which in humans is encoded by the HCAR2 gene. HCA₂, like the other hydroxycarboxylic acid receptors HCA₁ and HCA₃, is a G_i/o-coupled G protein-coupled receptor (GPCR). The primary endogenous agonists of HCA₂ are D-β-hydroxybutyric acid and butyric acid (and their conjugate bases, β-hydroxybutyrate and butyrate). HCA₂ is also a high-affinity biomolecular target for niacin (aka nicotinic acid).

Relaxin/insulin-like family peptide receptor 4, also known as RXFP4, is a human G-protein coupled receptor.

Oxoeicosanoid receptor 1 (OXER1) also known as G-protein coupled receptor 170 (GPR170) is a protein that in humans is encoded by the OXER1 gene located on human chromosome 2p21; it is the principle receptor for the 5-Hydroxyicosatetraenoic acid family of carboxy fatty acid metabolites derived from arachidonic acid. The receptor has also been termed hGPCR48, HGPCR48, and R527 but OXER1 is now its preferred designation. OXER1 is a G protein-coupled receptor (GPCR) that is structurally related to the hydroxy-carboxylic acid (HCA) family of G protein-coupled receptors whose three members are HCA1 (GPR81), HCA2, and HCA3 ; OXER1 has 30.3%, 30.7%, and 30.7% amino acid sequence identity with these GPCRs, respectively. It is also related to the recently defined receptor, GPR31, for the hydroxyl-carboxy fatty acid 12-HETE.

3-Hydroxyoctanoic acid is a beta-hydroxy acid that is naturally produced in humans, other animals, and plants.

References

1 2 3 GRCh38: Ensembl release 89: ENSG00000196917 - Ensembl, May 2017
1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000049241 - Ensembl, May 2017
↑ "Human PubMed Reference:".
↑ "Mouse PubMed Reference:".
1 2 "Entrez Gene: GPR81 G protein-coupled receptor 81".
↑ Lee DK, Nguyen T, Lynch KR, Cheng R, Vanti WB, Arkhitko O, Lewis T, Evans JF, George SR, O'Dowd BF (September 2001). "Discovery and mapping of ten novel G protein-coupled receptor genes". Gene. 275 (1): 83–91. doi:10.1016/S0378-1119(01)00651-5. PMID 11574155.
↑ Liu C, Wu J, Zhu J, Kuei C, Yu J, Shelton J, Sutton SW, Li X, Yun SJ, Mirzadegan T, Mazur C, Kamme F, Lovenberg TW (January 2009). "Lactate inhibits lipolysis in fat cells through activation of an orphan G-protein-coupled receptor, GPR81". The Journal of Biological Chemistry. 284 (5): 2811–22. doi:10.1074/jbc.M806409200. PMID 19047060.
↑ Cai TQ, Ren N, Jin L, Cheng K, Kash S, Chen R, Wright SD, Taggart AK, Waters MG (December 2008). "Role of GPR81 in lactate-mediated reduction of adipose lipolysis". Biochemical and Biophysical Research Communications. 377 (3): 987–91. doi:10.1016/j.bbrc.2008.10.088. PMID 18952058.

GPR81

Related Research Articles

References

Further reading