title: Structural characterization of the caveolin scaffolding domain in association with cholesterol-rich membranes.
abstract: Members of the caveolin protein family are implicated in the formation of caveolae and play important roles in a number of signaling pathways and in the regulation of various proteins. We employ complementary spectroscopic methods to study the structure of the caveolin scaffolding domain (CSD) in caveolin-1 fragments, while bound to cholesterol-rich membranes. This key domain is thought to be involved in multiple critical functions that include protein recognition, oligomerization, and cholesterol binding. In our membrane-bound peptides, residues within the flanking intramembrane domain (IMD) are found to adopt an α-helical structure, consistent with its commonly believed helical hairpin conformation. Intriguingly, in these same peptides, we observe a β-stranded conformation for residues in the CSD, contrasting with earlier reports, which commonly do not reflect β-structure. Our experimental data based on solid-state NMR, CD, and FTIR are found to be consistent with computational analyses of the secondary structure preference of the primary sequence. We discuss how our structural data of membrane binding Cav fragments may match certain general features of cholesterol-binding domains and could be consistent with the role for CSD in protein recognition and homo-oligomerization.
authors.affiliation: Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260, United States.
authors.forename: Cody L
authors.initials: CL
authors.lastname: Hoop
authors.forename: V N
authors.initials: VN
authors.lastname: Sivanandam
authors.forename: Ravindra
authors.initials: R
authors.lastname: Kodali
authors.forename: Matthew N
authors.initials: MN
authors.lastname: Srnec
authors.forename: Patrick C A
authors.initials: PC
authors.lastname: van der Wel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051242:Caveolin 1 / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D002784:Cholesterol / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D011237:Predictive Value of Tests; D011485:Protein Binding / Q000502:physiology; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs / Q000502:physiology; D055503:Protein Multimerization / Q000502:physiology; D017433:Protein Structure, Secondary / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology
chemical_list: C495540:CAV1 protein, human; D051242:Caveolin 1; D008563:Membrane Lipids; D010446:Peptide Fragments; D002784:Cholesterol