The study identifies peptide and protein ligands that bind to the caveolin-scaffolding domain, a 20-amino acid region of caveolin's cytosolic amino-terminal domain. This domain is crucial for organizing and concentrating caveolin-interacting proteins within caveolae membranes. Using phage display libraries, researchers selected random peptide ligands that interact with the caveolin-scaffolding domain. These ligands are rich in aromatic amino acids and exhibit specific spacing patterns. A known caveolin-interacting protein, Gαi2α, was used to further investigate the interaction. The study shows that a short peptide sequence derived from Gαi2α interacts directly with the caveolin-scaffolding domain and competitively inhibits its interaction with Gαi2α. This interaction is strictly dependent on the presence of aromatic residues within the peptide ligand. The study also identifies that the scaffolding domains of caveolins 1 and 3 recognize the same peptide ligands, whereas the corresponding domain in caveolin-2 does not. These findings highlight the specificity of the caveolin-scaffolding domain in recognizing its ligands. The study also explores the implications of these interactions for other caveolin- and caveolae-associated proteins. The caveolin-scaffolding domain is shown to interact with various lipid-modified signaling molecules, including G-proteins, Src-like kinases, and Ha-Ras. The study provides insights into the molecular recognition mechanisms and the role of the caveolin-scaffolding domain in organizing signaling molecules within caveolae membranes. The results suggest that the caveolin-scaffolding domain plays a critical role in signal transduction and cellular processes by interacting with specific proteins and lipids. The study also highlights the importance of aromatic residues in the interaction between the caveolin-scaffolding domain and its ligands. The findings contribute to the understanding of caveolin's role in cellular signaling and the organization of signaling molecules within caveolae membranes.The study identifies peptide and protein ligands that bind to the caveolin-scaffolding domain, a 20-amino acid region of caveolin's cytosolic amino-terminal domain. This domain is crucial for organizing and concentrating caveolin-interacting proteins within caveolae membranes. Using phage display libraries, researchers selected random peptide ligands that interact with the caveolin-scaffolding domain. These ligands are rich in aromatic amino acids and exhibit specific spacing patterns. A known caveolin-interacting protein, Gαi2α, was used to further investigate the interaction. The study shows that a short peptide sequence derived from Gαi2α interacts directly with the caveolin-scaffolding domain and competitively inhibits its interaction with Gαi2α. This interaction is strictly dependent on the presence of aromatic residues within the peptide ligand. The study also identifies that the scaffolding domains of caveolins 1 and 3 recognize the same peptide ligands, whereas the corresponding domain in caveolin-2 does not. These findings highlight the specificity of the caveolin-scaffolding domain in recognizing its ligands. The study also explores the implications of these interactions for other caveolin- and caveolae-associated proteins. The caveolin-scaffolding domain is shown to interact with various lipid-modified signaling molecules, including G-proteins, Src-like kinases, and Ha-Ras. The study provides insights into the molecular recognition mechanisms and the role of the caveolin-scaffolding domain in organizing signaling molecules within caveolae membranes. The results suggest that the caveolin-scaffolding domain plays a critical role in signal transduction and cellular processes by interacting with specific proteins and lipids. The study also highlights the importance of aromatic residues in the interaction between the caveolin-scaffolding domain and its ligands. The findings contribute to the understanding of caveolin's role in cellular signaling and the organization of signaling molecules within caveolae membranes.