Hydroxycarboxylic acid receptor

Hydroxycarboxylic acid receptor (HCA) is a group of G protein-coupled receptors that are activated by hydroxycarboxylic acids. These receptors are involved in a variety of physiological processes, including lipid metabolism, glucose homeostasis, and immune responses.

Structure and Function

Hydroxycarboxylic acid receptors are integral membrane proteins that are characterized by seven transmembrane domains. They are coupled to G proteins, which are intracellular signaling molecules that mediate the effects of receptor activation.

Upon binding to their ligands, hydroxycarboxylic acid receptors undergo a conformational change that activates the associated G protein. This leads to the initiation of a series of intracellular signaling events that ultimately result in a physiological response.

Types

There are three known types of hydroxycarboxylic acid receptors: HCA1, HCA2, and HCA3. Each of these receptors is activated by a different set of hydroxycarboxylic acids and has a distinct physiological role.

• HCA1 is activated by lactic acid and is involved in the regulation of lipid metabolism.
• HCA2 is activated by butyric acid and is involved in the regulation of immune responses and inflammation.
• HCA3 is activated by 3-hydroxyoctanoic acid and is involved in the regulation of energy homeostasis.

Clinical Significance

Hydroxycarboxylic acid receptors are potential therapeutic targets for a variety of diseases, including metabolic disorders, inflammatory diseases, and cancer. For example, agonists of HCA2 have been shown to have anti-inflammatory effects and may be useful in the treatment of conditions such as atherosclerosis and multiple sclerosis.

See Also

• G protein-coupled receptor
• Lipid metabolism
• Glucose homeostasis
• Immune response