PerilipinFamilie

PerilipinFamilie, commonly referred to as the perilipin family, is a group of cytosolic proteins that associate with lipid droplets in adipocytes and many other cell types. They form a protective coat around triglyceride-rich droplets and play a central role in controlling lipid storage and lipolysis. The family comprises several members, including PLIN1 (perilipin), PLIN2 (adipophilin or ADRP), PLIN3 (TIP47), PLIN4 (S3-12), and PLIN5 (OXPAT, LSDP5). Each member has distinct tissue distribution and regulatory properties, but all share a common function in managing lipid droplet dynamics.

In basal conditions, perilipins help stabilize lipid droplets and restrict lipase access, thereby preserving stored triglycerides. Upon hormonal stimulation that raises cyclic AMP levels, protein kinase A (PKA) phosphorylates perilipins, especially PLIN1, triggering structural changes. This phosphorylation promotes recruitment and activation of lipases such as adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) and enables the coactivator CGI-58 (ABHD5) to stimulate ATGL activity. The result is increased triglyceride hydrolysis and fatty acid release. PLIN2 and PLIN3 also participate in regulating droplet surface properties and lipid exchange, while PLIN5 is prominently expressed in oxidative tissues like heart and skeletal muscle, where it coordinates lipid storage with mitochondrial fatty acid oxidation.

Expression patterns vary by tissue, with PLIN1 predominating in adipose tissue and PLIN5 enriched in cardiac and skeletal muscle. The perilipin family is evolutionarily conserved across vertebrates and is a target of research due to its role in metabolic energy balance. Altered perilipin function or expression has been associated with metabolic disorders, making these proteins a focus for potential therapeutic strategies.