title: Structural studies of apoptosis and ion transport regulatory proteins in membranes.
abstract: Solid-state NMR spectroscopy is being used to determine the structures of membrane proteins involved in the regulation of apoptosis and ion transport. The Bcl-2 family includes pro- and anti-apoptotic proteins that play a major regulatory role in mitochondrion-dependent apoptosis or programmed cell death. The NMR data obtained for (15)N-labeled anti-apoptotic Bcl-xL in lipid bilayers are consistent with membrane association through insertion of the two central hydrophobic alpha-helices that are also required for channel formation and cytoprotective activity. The FXYD family proteins regulate ion flux across membranes, through interaction with the Na(+), K(+)-ATPase, in tissues that perform fluid and solute transport or that are electrically excitable. We have expressed and purified three FXYD family members, Mat8 (mammary tumor protein), CHIF (channel-inducing factor) and PLM (phospholemman), for structure determination by NMR in lipids. The solid-state NMR spectra of Bcl-2 and FXYD proteins, in uniaxially oriented lipid bilayers, give the first view of their membrane-associated architectures.
authors.affiliation: The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Carla M
authors.initials: CM
authors.lastname: Franzin
authors.forename: Jungyuen
authors.initials: J
authors.lastname: Choi
authors.forename: Dayong
authors.initials: D
authors.lastname: Zhai
authors.forename: John C
authors.initials: JC
authors.lastname: Reed
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Marassi
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D006801:Humans; D008051:Lipid Bilayers; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D009363:Neoplasm Proteins; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification
chemical_list: C091777:FXYD3 protein, human; D008051:Lipid Bilayers; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins