Perilipin-2

Perilipin-2, also known as Adipophilin or ADPH, is a protein that in humans is encoded by the PLIN2 gene. It is a member of the perilipin family, a group of proteins associated with the surface of lipid droplets in adipocytes and other cells. Perilipin-2 plays a crucial role in the regulation of intracellular lipid storage and metabolism. It is involved in the formation and stabilization of lipid droplets and influences the access of lipases to the lipid esters contained within the droplets, thereby modulating the breakdown of stored fats.

Function

Perilipin-2 is predominantly found in adipose tissue, where it coats the surface of lipid droplets. By doing so, it serves as a protective barrier that regulates the access of enzymes responsible for lipid metabolism, such as hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL). This regulation is essential for the controlled mobilization of fatty acids from stored triglycerides, which are then used as an energy source by the body. Perilipin-2 also plays a role in lipid droplet formation and is involved in various cellular processes, including lipid storage diseases, obesity, and the metabolic syndrome.

Structure

The PLIN2 gene encodes the perilipin-2 protein, which is characterized by a series of conserved domains that are critical for its function in lipid droplet stabilization and interaction with other proteins. The protein's structure allows it to bind to the surface of lipid droplets, effectively shielding them from the aqueous cytosol and enabling the selective interaction with lipolytic enzymes.

Clinical Significance

Alterations in perilipin-2 expression levels have been associated with several metabolic disorders. Overexpression of perilipin-2 has been observed in obesity and is thought to contribute to the excessive accumulation of fat. Conversely, reduced perilipin-2 levels have been linked to lipodystrophy and other lipid storage diseases, where the capacity for normal lipid storage is compromised. Understanding the role of perilipin-2 in these conditions is crucial for developing potential therapeutic strategies targeting lipid metabolism.

Research Directions

Current research on perilipin-2 is focused on elucidating its precise mechanisms of action in lipid metabolism and its role in metabolic diseases. Studies are also exploring the potential of targeting perilipin-2 as a therapeutic approach for obesity and related metabolic disorders. Additionally, the role of perilipin-2 in other tissues and its involvement in diseases beyond metabolic syndrome are areas of active investigation.

See Also

• Lipid droplet
• Adipose tissue
• Lipid metabolism
• Obesity
• Metabolic syndrome