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caveolin 1, caveolae protein, 22kDa
Identifiers
Symbol	CAV1
Alt. Symbols	CAV
Entrez	857
HUGO	1527
OMIM	601047
RefSeq	NM_001753
UniProt	Q03135
Other data
Locus	Chr. 7 q31

caveolin 2
Identifiers
Symbol	CAV2
Entrez	858
HUGO	1528
OMIM	601048
RefSeq	NM_001233
UniProt	P51636
Other data
Locus	Chr. 7 q31

caveolin 3
Identifiers
Symbol	CAV3
Entrez	859
HUGO	1529
OMIM	601253
RefSeq	NM_001234
UniProt	P56539
Other data
Locus	Chr. 3 p25

The caveolin gene family has three members in vertebrates: CAV1, CAV2, and CAV3, coding for the proteins caveolin-1, caveolin-2 and caveolin-3, respectively. All three members are membrane proteins with similar structure. Caveolin forms oligomers and associates with cholesterol and sphingolipids in certain areas of the cell membrane, leading to the formation of caveolae.

Contents 1 Structure and expression 2 Function 3 Role in disease 3.1 Cancer 3.2 Cardiovascular diseases 3.3 Muscular dystrophy 4 External links 5 References

The caveolins are similar in structure. They all form hairpin loops that are inserted into the cell membrane. Both the C-terminus and the N-terminus face the cytoplasmic side of the membrane. There are two isoforms of caveolin-1: caveolin-1α and caveolin-1β, the latter lacking a part of the N-terminus.

Caveolins are found in the majority of adherent, mammalian cells.

• Caveolin-1 is most prominently expressed in endothelial, fibrous and adipose tissue.
• The expression pattern of caveolin-2 is similar to that of caveolin-1; it seems to be co-expressed with caveolin-1.
• The expression of caveolin-3 is restricted to striated muscle.

The functions of caveolins are still under intensive investigation. They are best known for their role in the formation of 50 nanometer-sized invaginations of the plasma membrane, called caveolae. Oligomers of caveolin form the coat of these domains. Cells that lack caveolins also lack caveolae. Many functions are ascribed to these domains, ranging from endocytosis and transcytosis to signal transduction.

Caveolin-1 has also been shown to play a role in the integrin signaling. The tyrosine phosphorylated form of caveolin-1 colocalizes with focal adhesions, suggesting a role for caveolin-1 in migration. Indeed, downregulation of caveolin-1 leads to less efficient migration in vitro.

Genetically engineered mice that lack caveolin-1 and caveolin-2 are viable and fertile, showing that neither the caveolins, nor caveolae are essential in embryonic development or reproduction of these animals. However, knock-out animals do develop abnormal, hypertrophic lungs and cardiac myopathy, leading to a reduction in life span. Mice lacking caveolins also suffer from impaired angiogenic responses as well as abnormal responses to vasoconstrictive stimuli. In zebrafish, lack of caveolins leads to embryonic lethality, suggesting that higher vertebrates (as exemplified by mice) have developed compensation or redundancy for the functions of caveolins.

Caveolins have a paradoxical role in the development of this disease. They have been implicated in both tumor suppression and oncogenesis. High expression of caveolins leads to inhibition of cancer-related pathways, such as growth factor signaling pathways. However, certain cancer cells that express caveolins have been shown to be more aggressive and metastatic, because of a potential for anchorage-independent growth.

Caveolins are thought to be important in limiting vascular hypertrophic responses in endothelial cells. Furthermore, caveolin-3 has been associated with Long QT syndrome.

Caveolin-3 has been implicated in the development of certain muscular dystrophies.

• The Caveolin Protein
• MeSH Caveolins
• Caveolin-3 page

• Terence M Williams; Michael P Lisanti (2004). "The Caveolin proteins". Genome Biol. 5 (3): 214. PMID 15003112. 

v • d • e Cell signaling: carrier proteins: adaptor proteins
STAT	STAT1 - STAT2 - STAT3 - STAT4 - STAT5 - STAT6
Interferon regulatory factors	IRF1 - IRF2 - IRF3 - IRF6
Growth factor receptor-bound protein	GRB2 - GRB7 - GRB10
other	14-3-3 (YWHAE, YWHAZ) - Caveolin - Cortactin - Death Inducing Signaling Complex - Paxillin - Myd88 - PIAS - SMAD - SOCS - TRAF

v • d • e Membrane protein: vesicular transport proteins
Archain - Clathrin - Caveolin - Dynamin - Lysosomal trafficking regulator - SNARE (SNAP-25, Syntaxin, Synaptobrevin) - Synaptotagmin