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Left of dashed line the major part of caveolins brown

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Hypothetical model of the principal actions of caveolae and caveolins in signaling. Left of dashed line: The major part of caveolins (brown) is present as oligomers in structurally defined caveolae. Filamin (turquoise)– caveolin interactions link some caveolae to actin filaments (tan). Caveolin molecules with a ligand-binding site (scaffolding domain) not involved in oligomer formation can instead sequester and inhibit signaling proteins such as H-Ras (yellow). Activated growth factor receptors (blue-gray) in caveolae recruit adaptor proteins (red-white) like Grb2 and mSOS and can activate caveola-resident H-Ras. Outside of caveolae a fraction of caveolin-1 associates with integrins (gold) and keeps Src-family kinases like Fyn (orange) in an inactive conformation. Upon cell–matrix adhesion (integrin ligation) caveolin-1 and Fyn are coclustered with the integrins, and in the presence of GPI-linked uPAR (red) glycolipid rafts are recruited to the adhesion site. Fyn is activated and the inhibitory action of caveolin-1 is relieved. Fyn signals, via adapter molecules (Shc, Grb2/mSOS), to H-Ras. The activation of H-Ras (in rafts or caveolae)
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Left of dashed line The major part of caveolins brown is...

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