CAVIN

Cavin is a family of cytoplasmic proteins that associate with caveolae, small plasmalemmal invaginations found in many vertebrate cell types. Along with caveolins, cavins form the caveolar coat that influences caveolae formation, stability, endocytosis, and signaling. The vertebrate cavin family includes four members: Cavin-1, Cavin-2, Cavin-3, and Cavin-4.

Cavin-1 is encoded by the PTRF gene and is essential for the biogenesis of caveolae; cells lacking PTRF/cavin-1 typically lack caveolae. Cavin-2 is encoded by SDPR and modulates caveolae density, often interacting with caveolin-1. Cavin-3, encoded by PRKCDBP, is involved in signaling pathways related to protein kinase C and has distinct tissue distributions. Cavin-4, encoded by MURC, is enriched in skeletal and cardiac muscle and has been studied in models of muscle and heart disease.

Functionally, cavins form heteromeric complexes with caveolins at the plasma membrane to regulate the formation, maintenance, and turnover of caveolae. They contribute to lipid regulation, mechanotransduction, and signal transduction by modulating the structure of caveolae and the accessibility of signaling molecules.

Clinical and research relevance can include the effects of cavin disruption on caveolae numbers and cellular signaling. Mutations in PTRF/cavin-1 have been associated with congenital generalized lipodystrophy type 4, illustrating the role of caveolae in adipocyte lipid storage. Beyond human disease, cavin proteins are studied in model organisms to understand caveolae biology and responses to mechanical stress.

In addition to its primary scientific usage, cavin may appear as a surname or given name, but the term is chiefly recognized in biology as a protein family involved in caveolar biology.