Caveolin-2

a protein about 20 kD

is a major component of the inner surface of caveolae

small invaginations of the plasma membrane. Similar with caveolin-1 and caveolin-3

it serves as a protein marker of caveolae. Caveolin-1 and -2 are located next to each other at 7q31.1 on human chromosome

the proteins encoded are co-localized and form a stable hetero-oligomeric complex

distributing similarly in tissue and cultured cells. Caveolin-3 is located on different chromosomes but confirmed to interact with caveolin-2. Caveolin-2 is similar to caveolin-1 in many respects but differs from the latter in functional domains

especially in G-protein binding domain and caveolin scaffolding domain. The mRNAs of both caveolin-1 and caveolin-2 are most abundantly expressed in white adipose tissue and are induced during differentiation of 3T3-L1 cells to adipocytes. Caveolin-2-deficinet mice demonstrate clear pulmonary defects

with little or no change in caveolin-1 expression and caveolae formation

suggesting that caveolin-2 plays a selective role in lung functions. Caveolin-2 is also involved in lipid metabolism and human cancers.