Proposed structural elements of caveolins. (A–D) Structural elements include a N-terminal variable region (yellow), pin motif (red), hook region (blue), scaffolding domain (green), spoke region (gray), β-strand (cyan), and C-terminal variable region (purple). For illustration purposes, elements are mapped onto the structures of (A) two neighboring protomers from the cryo-EM–based secondary structure model of the human Cav1 8S complex (PDB: 7SC0), (B) two neighboring protomers from the 11-mer of human Cav1 (Q03135) predicted by AF2.2, and (C) two neighboring protomers from the 11-mer of C. elegans caveolin (Q94051) predicted by AF2.2. (D) Comparison between the previous domain designations and our proposed segmentation using structural elements can be observed in both panel (A) and sequence alignments of human Cav1 and C. elegans caveolin Q94051.