Caveolae are highly-curved invaginated micro-domains located in the plasma membrane that play a central role in a variety of cellular processes. Caveolins (1, 2, and 3) are the most important proteins found in caveolae, and are responsible for giving caveolae their unusual "flask-like" shape. Recent evidence has shown that improper regulation and mutant forms of caveolin can result in a variety of diseases including Alzheimer's, muscular dystrophy, cancer, and heart disease. Caveolin adopts an unusual intra-membrane "horseshoe" conformation where both its N- and C-termini face the cytoplasm, and this conformation is thought to promote membrane curvature. In addition, via high-order oligomerization, caveolin forms a structural backbone which stabilizes the membrane curvature. Using biophysical techniques such as nuclear magnetic resonance (NMR), fluorescence spectroscopy, and analytical ultracentrifugation, our objective is to characterize caveolin-1 on a fundamental level. This will be achieved by pursuing the following two specific aims: 1. Investigation of the membrane topology and three-dimensional structure of caveolin-1. 2. Investigation of caveolin-1 oligomerization.
Specific aim 1 will determine the high-resolution three-dimensional solution structure of caveolin-1 as well as examine the solvent accessibility of tryptophan residues to assess the topology of caveolin-1 in a bilayer. Next, the role that two conserved proline residues play in the creation and/or stabilization of the intra-membrane "horseshoe" conformation will be probed using site-directed mutagenesis.
Specific aim 2 will characterize both the size and distribution of oligomers formed by caveolin-1 in the presence and absence of cholesterol. Additionally, the role that a proline to leucine mutant plays in the oligomerization process will be probed. A fundamental understanding of caveolin-1 structure and oligomerization will undoubtedly open the door to possible therapeutic interventions that could address diseases linked to caveolin misfunction.

Public Health Relevance

Caveolins are proteins that play an important role in a variety of events that happen within the cell. Alterations in the behavior of caveolins have been implicated in a variety of diseases including Alzheimer's, muscular dystrophy, cancer, and heart disease. Therefore, a more complete understanding of caveolins is necessary.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM093258-03S1
Application #
8847846
Study Section
Biochemistry and Biophysics of Membranes Study Section (BBM)
Program Officer
Chin, Jean
Project Start
2012-01-01
Project End
2016-11-30
Budget Start
2013-12-01
Budget End
2014-11-30
Support Year
3
Fiscal Year
2014
Total Cost
$65,250
Indirect Cost
$15,250
Name
Lehigh University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
808264444
City
Bethlehem
State
PA
Country
United States
Zip Code
18015
Rui, Huan; Root, Kyle T; Lee, Jinwoo et al. (2014) Probing the U-shaped conformation of caveolin-1 in a bilayer. Biophys J 106:1371-80
Rieth, Monica D; Lee, Jinwoo; Glover, Kerney Jebrell (2012) Probing the caveolin-1 P132L mutant: critical insights into its oligomeric behavior and structure. Biochemistry 51:3911-8