The voltage-dependent anion channel (VDAC) mediates trafficking of small molecules and ions across the eukaryotic outer mitochondrial membrane. There are three isoforms that have distinct reported interactions with small molecules and proteins. These include pro- and anti-apoptotic members of the Bcl-2 family, and the different isoforms of VDAC have been implied to play roles in apoptosis, such as formation or inhibition of the mitochondrial exit channel. Recently, we obtained NMR assignments and determined the solution structure of human VDAC-1 in detergent micelles (Hiller et al., 2008). VDAC has been known for thirty years and numerous reports of interactions and functional aspects have been reported. With the recent NMR characterization of VDAC-1 we are now in a position to validate these reports and elucidate the function of the channel. The goal of the proposed research is to study the structure, interactions and function of VDAC isoforms. We will pursue the following specific aims: 1. Compare structure and interactions of VDAC-1 in LDAO micelles and phospholipids nanodiscs to assess differences between micelle and bilayer environments. 2. Determine the structure of VDAC-2, which contains an N-terminal extension and has reported functions distinct from VDAC-1. 3. Determine the membrane/micelle-bound structures of Bcl-2 type proteins and study VDAC complexes. 4. Characterize complexes of VDAC with the porin PorB from pathogenic bacteria.

Public Health Relevance

We will study the solution structure of the human voltage-dependent anion channel (VDAC) in the membrane mimicking phospholipids nanodiscs and compare it with our recent structure obtained in LDAO micelles. We will also determine the structure of the VDAC-2 isoform, which has been shown to stabilize an inactive form of the Bak protein and may play a crucial role in controlling the onset of apoptosis. We also will investigate interactions of VDAC with Bcl-2-type proteins, bacterial pathogens and small molecules.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM075879-09
Application #
8516522
Study Section
Biochemistry and Biophysics of Membranes Study Section (BBM)
Program Officer
Chin, Jean
Project Start
2005-09-23
Project End
2014-07-31
Budget Start
2013-08-01
Budget End
2014-07-31
Support Year
9
Fiscal Year
2013
Total Cost
$269,166
Indirect Cost
$110,366
Name
Harvard University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
Viegas, Aldino; Viennet, Thibault; Yu, Tsyr-Yan et al. (2016) UTOPIA NMR: activating unexploited magnetization using interleaved low-gamma detection. J Biomol NMR 64:9-15
Coote, Paul; Bermel, Wolfgang; Wagner, Gerhard et al. (2016) Analytical optimization of active bandwidth and quality factor for TOCSY experiments in NMR spectroscopy. J Biomol NMR 66:9-20
Raschle, Thomas; Lin, Chenxiang; Jungmann, Ralf et al. (2015) Controlled Co-reconstitution of Multiple Membrane Proteins in Lipid Bilayer Nanodiscs Using DNA as a Scaffold. ACS Chem Biol 10:2448-54
Eddy, Matthew T; Andreas, Loren; Teijido, Oscar et al. (2015) Magic angle spinning nuclear magnetic resonance characterization of voltage-dependent anion channel gating in two-dimensional lipid crystalline bilayers. Biochemistry 54:994-1005
Hagn, Franz; Wagner, Gerhard (2015) Structure refinement and membrane positioning of selectively labeled OmpX in phospholipid nanodiscs. J Biomol NMR 61:249-60
Kaptein, Rob; Wagner, Gerhard (2015) NMR studies of membrane proteins. J Biomol NMR 61:181-4
Elter, Shantha; Raschle, Thomas; Arens, Sabine et al. (2014) The use of amphipols for NMR structural characterization of 7-TM proteins. J Membr Biol 247:957-64
Coote, Paul; Leigh, Kendra E; Yu, Tsyr-Yan et al. (2014) A new broadband homonuclear mixing pulse for NMR with low applied power. J Chem Phys 141:024201
Hagn, Franz; Etzkorn, Manuel; Raschle, Thomas et al. (2013) Optimized phospholipid bilayer nanodiscs facilitate high-resolution structure determination of membrane proteins. J Am Chem Soc 135:1919-25
Coote, Paul; Arthanari, Haribabu; Yu, Tsyr-Yan et al. (2013) Pulse design for broadband correlation NMR spectroscopy by multi-rotating frames. J Biomol NMR 55:291-302

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