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Principal Investigator: Doreen Matthies
Organization: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
Fiscal Year: 2024
Award: $3,299,641
Funding agency: Eunice Kennedy Shriver National Institute of Child Health and Human Development
(1) Structure and function of magnesium channel Mrs2
Mrs2 is the eukaryotic homolog of bacterial magnesium channel CorA. CorA forms a homo-pentameric channel which forms a symmetric closed state at normal to high concentrations of magnesium with magnesium binding sites between protomers as well as near the membrane pore. Under low magnesium concentrations the channel undergoes an asymmetric opening likely caused by the destabilization of protomer interactions when magnesium ions dissociate from their binding site. We expanded our research on magnesium channels by looking at eukaryotic magnesium channel Mrs2 which is located in the inner mitochondrial membrane. We have solved high-resolution cryo-EM structures of in detergent purified human Mrs2 in different conditions and found that it also forms a home-pentameric complex but it shows significant differences to its bacterial homolog CorA. A 70-amino acid long mitochondrial transit peptide is cleaved off of the N-terminal domain of human Mrs2 upon translocation into the mitochondrial membrane. Magnesium binding sites along the pore of the channel as well as in between subunits were identified, some of which may play a role in regulating channel activity. Two pore gates as well as an important inter-subunit salt bridge were identified, that when mutated lead to increased channel activity. Additional structural and functional studies of wild-type and mutant Mrs2 in synthetic as well as native nanodiscs as well as liposomes are planned to further investigate the structure, mechanism and regulation of this eukaryotic channel in its native lipid environment.
(2) Structural determination of full-length SARS-CoV-2 spike protein and drug development
COVID-19 caused by the SARS-CoV-2 virus has posed a global threat since it was first identified end of 2019. The rapid development of vaccines helped to counteract the rapid spread of COVID-19.
The SARS-Cov-2 spike protein is responsible for the initial binding of the virus to the receptor ACE2 on human cells. Better understanding of the function and structure of the spike protein is critical for development of both primary prevention such as vaccine, and therapeutic treatments to combat the COVID-19 pandemic. Structures of the spike proteins soluble ectodomain have been determined but the full-length spike including its membrane domain has not been well studied. We are working towards determining the structures of full-length spike protein and identify the key vaccine and drug binding interfaces in order to develop treatments that block viral entry into human cells with high efficiency and specificity which are also safe for children. We have successfully cloned and expressed the full-length spike protein, and we are working towards high-resolution structural determination of different variants and complexes.
(3) Structural investigation of inner mitochondrial membrane supercomplex II and III
As the powerhouses of cells, mitochondria provide energy in form of ATP for most of the cellular activities. There are five essential protein complexes located on the inner mitochondrial membrane which carry out one of the most important reaction in the cells oxidative phosphorylation, which generates ATP. Functions of these protein complexes have been extensively studied and crystal structures of individual complexes have been determined. It is proposed that protein complexes of the respiratory chain can associate and form of supercomplexes or respirasomes. Among these five protein complexes, cytochrome bc1, also known as complex III, is a central component of the cellular respiratory chain. It catalyzes electron transfer from quinol to cytochrome c and couples this electron transfer process to proton translocation across the membrane. Mitochondrial Complex II, also called succinate dehydrogenase, is another important protein complex within the mitochondrial electron transfer chain. It oxidizes succinate from the Krebs-cycle to fumarate and reduces ubiquinone to ubiquinol. Previous studies have proposed the formation of a supercomplex between complex II and complex III, which has been confirmed by biochemical analyses of scientist Dr. Fei Zhou. We are currently working towards solving the structure of this supercomplex by Single-Particle Cryo-EM. Together with biochemical data, the structure of supercompex II and III will reveal detailed information of electron transfer between the Krebs-cycle and the respiratory chain and could shed light on the biogenesis and treatment of many human diseases related to respiratory chain deficiency such as delayed child development, autism, tumorigenesis and aging.
(4) Collaborations
Collaborations involving structural and computational studies on a variety of membrane proteins including transporters, channels, and receptors as well as viral spike protein conformations in different cellular compartments, virus-like-particle (VLP), SARS-CoV-2 accessory membrane protein, extracellular vesicles and lipid transport across cells, as well as testing new detergents and polymers to gently extract membrane protein complexes from their native lipid environment for high-resolution structural studies.
Terms: <0-11 years old><2019 novel corona virus><2019 novel coronavirus><2019-nCoV><2019-nCoV S protein><2019-nCoV spike glycoprotein><2019-nCoV spike protein><ACE2><ASD><Aging><Amino Acids><Autism><Autistic Disorder><Binding><Binding Sites><Biochemical><Biochemistry><Biogenesis><Biological><Biological Chemistry><Body Tissues><COVID crisis><COVID epidemic><COVID pandemic><COVID-19><COVID-19 S protein><COVID-19 crisis><COVID-19 epidemic><COVID-19 era><COVID-19 global health crisis><COVID-19 global pandemic><COVID-19 health crisis><COVID-19 pandemic><COVID-19 period><COVID-19 public health crisis><COVID-19 spike><COVID-19 spike glycoprotein><COVID-19 spike protein><COVID-19 virus><COVID-19 years><COVID19 virus><CV-19><Cell Body><Cell Membrane Lipids><Cells><Child><Child Development><Child Youth><Children (0-21)><Citric Acid Cycle><CoV-2><CoV2><Coenzyme Q><Coenzyme Q-Cytochrome-c Reductase><Coenzyme QH2-Cytochrome-c Reductase><Collaborations><Combining Site><Complex><Complex III><Controlled Environment><Coronavirus Infectious Disease 2019><Couples><Cryo-electron Microscopy><Cryo-electron tomography><Cryoelectron Microscopy><Cytochrome b-c2 Oxidoreductase><Cytochrome bc1><Cytochrome bc1 Complex><DNA Molecular Biology><Data><Detergents><Development><Dihydroubiquinone-Cytochrome-c Reductase><Dissociation><Drugs><Early Infantile Autism><Electron Cryomicroscopy><Electron Microscopy><Electron Transport><Electron Transport Complex III><Environment><Ferricytochrome c><Ferrocytochrome c><Fumarate Reductase><Fumarates><GeneHomolog><Goals><H+ element><Home><Homolog><Homologous Gene><Homologue><Human><Hydrogen Ions><Hydroquinones><Individual><Infant and Child Development><Infantile Autism><Inner mitochondrial membrane><Investigation><Ions><Kanner's Syndrome><Krebs Cycle><Lead><Length><Lipid Trafficking><Lipids><Liposomal><Liposomes><Magnesium><Medication><Membrane><Membrane Lipids><Membrane Protein Gene><Membrane Proteins><Membrane Structure and Function><Membrane-Associated Proteins><Methods><Mg element><Mg++ element><Micelles><Microscopy><Mitochondria><Mitochondrial Respiratory Chain Deficiencies><Modern Man><Molecular Biology><Molecular Interaction><Molecular Transport><Morphology><Mutate><N-terminal><NH2-terminal><Oncogenesis><Origin of Life><Oxidative Phosphorylation><Oxidative Phosphorylation Pathway><Pb element><Peptides><Pharmaceutical Preparations><Polymers><Primary Prevention><Process><Protein Conformation><Proteins><Protomer><Protons><QH(2)-Cytochrome-c Reductase><QH(2)-Ferricytochrome-c Oxidoreductase><Quinols><Reaction><Reactive Site><Receptor Protein><Regulation><Research><Resolution><Respiratory Chain><Respiratory Chain Deficiency><SARS corona virus 2><SARS-CO-V2><SARS-COVID-2><SARS-CoV-2><SARS-CoV-2 S><SARS-CoV-2 S protein><SARS-CoV-2 epidemic><SARS-CoV-2 global health crisis><SARS-CoV-2 global pandemic><SARS-CoV-2 pandemic><SARS-CoV-2 spike><SARS-CoV-2 spike glycoprotein><SARS-CoV-2 spike protein><SARS-CoV2><SARS-associated corona virus 2><SARS-associated coronavirus 2><SARS-coronavirus-2><SARS-coronavirus-2 epidemic><SARS-coronavirus-2 pandemic><SARS-related corona virus 2><SARS-related coronavirus 2><SARSCoV2><Scanning Electron Microscopy><Scientist><Severe Acute Respiratory Coronavirus 2><Severe Acute Respiratory Distress Syndrome CoV 2><Severe Acute Respiratory Distress Syndrome Corona Virus 2><Severe Acute Respiratory Distress Syndrome Coronavirus 2><Severe Acute Respiratory Syndrome CoV 2><Severe Acute Respiratory Syndrome CoV 2 epidemic><Severe Acute Respiratory Syndrome CoV 2 pandemic><Severe Acute Respiratory Syndrome-associated coronavirus 2><Severe Acute Respiratory Syndrome-related coronavirus 2><Severe acute respiratory syndrome associated corona virus 2><Severe acute respiratory syndrome coronavirus 2><Severe acute respiratory syndrome coronavirus 2 S protein><Severe acute respiratory syndrome coronavirus 2 epidemic><Severe acute respiratory syndrome coronavirus 2 pandemic><Severe acute respiratory syndrome coronavirus 2 spike glycoprotein><Severe acute respiratory syndrome coronavirus 2 spike protein><Severe acute respiratory syndrome related corona virus 2><Shapes><Sodium Chloride><Specificity><Structure><Succinate Dehydrogenase><Succinates><Succinic Dehydrogenase><Succinic Oxidase><Surface Proteins><TCA cycle><Techniques><Testing><Therapeutic><Tissues><Transport Process><Tricarboxylic Acid Cycle><Ubihydroquinone-Cytochrome-c Reductase><Ubiquinol-Cytochrome-c Reductase><Ubiquinol-ferricytochrome-c oxidoreductase><Ubiquinone><Ubiquinone-Cytochrome b-c2 Oxidoreductase><Vaccines><Variant><Variation><Vesicle><Viral><Virus><Virus-like particle><Wuhan coronavirus><aminoacid><angiotensin converting enzyme 2><angiotensin converting enzyme II><artificial environment><autism spectral disorder><autism spectrum disorder><autistic spectrum disorder><biologic><biophysical approaches><biophysical methodology><biophysical methods><biophysical techniques><block viral entry><combat><computational studies><computer studies><coronavirus disease 2019><coronavirus disease 2019 S protein><coronavirus disease 2019 crisis><coronavirus disease 2019 epidemic><coronavirus disease 2019 global health crisis><coronavirus disease 2019 global pandemic><coronavirus disease 2019 health crisis><coronavirus disease 2019 pandemic><coronavirus disease 2019 public health crisis><coronavirus disease 2019 spike glycoprotein><coronavirus disease 2019 spike protein><coronavirus disease 2019 virus><coronavirus disease crisis><coronavirus disease epidemic><coronavirus disease pandemic><coronavirus disease-19><coronavirus disease-19 global pandemic><coronavirus disease-19 pandemic><coronavirus disease-19 virus><coronavirus infectious disease-19><cryo-EM><cryo-EM tomography><cryoEM><cryoEM tomography><cryoelectron tomography><cryogenic electron microscopy><cytochrome c><develop a vaccine><develop vaccines><development of a vaccine><developmental><drug development><drug/agent><electron cryo-tomography><electron transfer><extracellular vesicles><fumarate hydrogenase><hCoV19><heavy metal Pb><heavy metal lead><homes><human disease><inhibit viral entry><kids><light microscopy><lipid transport><magnesium ion><membrane structure><mitochondrial><mitochondrial membrane><mutant><nCoV2><nanodisk><p-Dihydroxybenzenes><para-Dihydroxybenzenes><particle><polymer><polymeric><programs><protein complex><protein function><protein structure><protein structures><proteins structure><receptor><resolutions><salt><severe acute respiratory syndrome coronavirus 2 global health crisis><severe acute respiratory syndrome coronavirus 2 global pandemic><spike proteins on SARS-CoV-2><structural biology><tumorigenesis><ubiquinol><vaccine development><vesicle transport><vesicular transport><viral entry blocker><viral entry inhibitor><virus-like nanoparticles><viruslike particle><youngster>