Hydroxycarboxylic acid receptor 3

Hydroxycarboxylic acid receptor 3 (HCA3) is a G protein-coupled receptor that in humans is encoded by the HCAR3 gene. It is a member of the hydroxycarboxylic acid receptor family and plays a significant role in the regulation of energy metabolism and immune responses. HCA3 is primarily found in adipose tissue and immune cells, where it responds to various ligands, including hydroxycarboxylic acids derived from dietary sources or metabolic processes.

Function

HCA3 functions as a sensor for hydroxycarboxylic acids, substances that are produced during the metabolism of fats and carbohydrates. By binding to these ligands, HCA3 activates intracellular signaling pathways through G proteins, leading to various physiological responses. In adipose tissue, HCA3 activation can influence lipolysis and adipogenesis, thereby affecting energy homeostasis and metabolic regulation. In immune cells, HCA3 signaling can modulate inflammatory responses, making it a potential target for treating inflammatory and metabolic diseases.

Ligands

The primary ligands for HCA3 are hydroxycarboxylic acids, including β-hydroxybutyric acid, a ketone body produced during prolonged fasting or ketogenic diets. Other ligands include lactate and 3-hydroxyoctanoic acid, indicating the receptor's role in sensing metabolic states and dietary components.

Clinical Significance

Given its role in metabolism and inflammation, HCA3 has been studied for its potential therapeutic applications. Modulating HCA3 activity could offer new approaches for managing obesity, type 2 diabetes, and inflammatory conditions. However, research is still in the early stages, and more studies are needed to fully understand the receptor's functions and therapeutic potential.

See Also

• G protein-coupled receptor
• Metabolism
• Adipose tissue
• Inflammation
• Ketone bodies