HCAR2
Developmental stage
Expression in neutrophils occurs in the late terminal differentiation phase.
Function
Acts as a high affinity receptor for both nicotinic acid (also known as niacin) and (D)-beta-hydroxybutyrate and mediates increased adiponectin secretion and decreased lipolysis through G(i)-protein-mediated inhibition of adenylyl cyclase. This pharmacological effect requires nicotinic acid doses that are much higher than those provided by a normal diet. Mediates nicotinic acid-induced apoptosis in mature neutrophils. Receptor activation by nicotinic acid results in reduced cAMP levels which may affect activity of cAMP-dependent protein kinase A and phosphorylation of target proteins, leading to neutrophil apoptosis. The rank order of potency for the displacement of nicotinic acid binding is 5-methyl pyrazole-3-carboxylic acid = pyridine-3-acetic acid > acifran > 5-methyl nicotinic acid = acipimox >> nicotinuric acid = nicotinamide.
Sequence Similarities
Belongs to the G-protein coupled receptor 1 family.
Tissue Specificity
Expression largely restricted to adipose tissue and spleen. Expressed on mature neutrophils but not on immature neutrophils or eosinophils.
Cellular localization
- Cell membrane
- Multi-pass membrane protein
Alternative names
GPR109A, HCA2, HM74A, NIACR1, HCAR2, Hydroxycarboxylic acid receptor 2, G-protein coupled receptor 109A, G-protein coupled receptor HM74A, Niacin receptor 1, Nicotinic acid receptor