Showing papers on "Mitochondrial carrier published in 1991"
TL;DR: In this article, the authors showed that the import of in vitro synthesized precursors into isolated mitochondria was demonstrated for the three largest F1-ATPase subunits; as an operational measure of import, they checked whether any of the polypeptides added to the mitochondria became resistant to externally added proteases.
Abstract: The biogenesis of mitochondria involves a close interaction between the nucleocytoplasmic and the mitochondrial genetic system. The majority of the mitochondrial proteins are synthesized on cytoplasmic ribosomes and transported into the organelle (1). The mechanism of this protein import has been under debate for many years (e.g., (2,3)). Recent experiments with yeast cells have shown that several cytoplasmic- ally made mitochondrial proteins are initially made as larger precursors, both in vitro as well as in pulse-labeled yeast spheroplasts (4,5). So far, larger precursors have been detected for the following cytoplasmically made mitochondrial proteins: the three largest subunits of the mitochondrial F1-ATPase (i.e., the α, β, and γ subunit, see (4)) and two subunits of the mitochondrial cytochrome bc1 complex (cytochrome c1 and subunit V; (5) and C. Cote, unpublished). Import of in vitro synthesized precursors into isolated mitochondria was demonstrated for the three largest F1-ATPase subunits; as an operational measure of import, we checked whether any of the polypeptides added to the mitochondria became resistant to externally added proteases (4).
569 citations
TL;DR: The present study has shown that the appearance of these proteins occurs in a dose-responsive manner with both human chorionic gonadotropin and cyclic AMP analog and proposes that during this transfer contact sites form between the two mitochondrial membranes and may offer an ideal situation for the transfer of cholesterol from the outer membrane to the inner membrane by an as yet unknown mechanism.
257 citations
TL;DR: The multifaceted aspects of research on UCP make this protein interesting in areas of research as different as studies of ion translocating mechanisms, cellular specificity of gene transcription, control of gene expression by neuromediators, adipocyte differentiation, and the pharmacological treatment of obesity.
Abstract: The uncoupling protein (UCP) is a proton/anion transporter found in the inner mitochondrial membrane of brown adipocyte. Although UCP has not been detected in mitochondria from any other tissue, it shares structural and catalytic properties with several other mitochondrial carrier proteins. Although UCP was discovered only recently it is one of the most extensively studied mitochondrial carrier proteins. Many tools useful in research on UCP have been developed such as antibodies and cDNAs corresponding to UCP of several animal species. More recently, the mouse, rat, and human genes encoding for UCP have been isolated and sequenced. The availability of these various tools has led to several significant observations. UCP gene expression is strongly controlled at the level of transcription by signals that are activated after the stimulation of brown adipocytes by norepinephrine. The comparison of UCP gene with the genes encoding the adenine nucleotide translocator revealed the existence of structural and evo...
188 citations
TL;DR: It is concluded that the mitochondrial PPase encoded by PPA2 is essential for mitochondrial function and maintenance of the mitochondrial genome.
177 citations
TL;DR: Highly basic peptides, i.e. poly-L-lysines, were shown to strongly interact with membranes formed with lipid extracts of mitochondrial membranes: they both induced intermembrane binding and fusion, lower than that of octameric Mi-CK.
121 citations
TL;DR: The deduced amino acid sequence predicts that MOM19 is anchored in the outer membrane by an NH2-terminal hydrophobic sequence, while the rest of the protein forms a hydrophilic domain exposed to the cytosol.
Abstract: The targeting of proteins to mitochondria involves the recognition of the precursor proteins by receptors on the mitochondrial surface followed by insertion of the precursors into the outer membrane at the general insertion site GIP. Most mitochondrial proteins analyzed so far use a mitochondrial outer membrane protein of 19 kilodaltons (MOM19) as an import receptor. The gene encoding MOM19 has now been isolated. The deduced amino acid sequence predicts that MOM19 is anchored in the outer membrane by an NH2-terminal hydrophobic sequence, while the rest of the protein forms a hydrophilic domain exposed to the cytosol. MOM19 was targeted to the mitochondria via a pathway that is independent of protease-accessible surface receptors and controlled by direct assembly of the MOM19 precursor with GIP.
117 citations
TL;DR: The properties of this intermediate support the proposal that import into the matrix involves two distinct translocation systems in the outer and the inner mitochondrial membrane that are not permanently coupled to each other.
97 citations
TL;DR: Sequence comparisons indicate that MRS3 and MRS4 may be related to the family of mitochondrial carrier proteins, and structural analysis of these proteins shows a tripartite structure that is consistent with a mitochondrial function ofThese proteins.
93 citations
TL;DR: It is suggested that mitochondrial contact sites are not sealed structures, but that polypeptides pass (at least partly) through the intermembrane space on their route from the outer membrane to the inner membrane.
83 citations
TL;DR: The observation that membrane localization of SCO1 is affected in mitochondria of a rho0 strain, hints at the possible involvement of mitochondrially coded components in ensuring proper membrane insertion.
Abstract: The SCO1 gene of Saccharomyces cerevisiae encodes a 30 kDa protein which is specifically required for a post-translational step in the accumulation of subunits 1 and 2 of cytochrome c oxidase (COXI and COXII). Antibodies directed against a β-Gal::SCO1 fusion protein detect SCO1 in the mitochondrial fraction of yeast cells. The SCO1 protein is an integral membrane protein as shown by its resistance to alkaline extraction and by its solubilization properties upon treatment with detergents. Based on the results obtained by isopycnic sucrose gradient centrifugation and by digitonin treatment of mitochondria, SCO1 is a component of the inner mitochondrial membrane. Membrane localization is mediated by a stretch of 17 hydrophobic amino acids in the amino-terminal region of the protein. A truncated SCO1 derivative lacking this segment, is no longer bound to the membrane and simultaneously loses its biological function. The observation that membrane localization of SCO1 is affected in mitochondria of a rho
0 strain, hints at the possible involvement of mitochondrially coded components in ensuring proper membrane insertion.
81 citations
TL;DR: Evidence is presented that the rat liver mitochondrial phosphate transporter can be synthesized in vitro, imported into mitochondria, and processed to a protein of Mr 33,000, and that optimal import of the mitochondrial phosphorous transporter, unlike the ADP/ATP carrier and the brown fat uncoupling protein, is dependent on a presequence.
TL;DR: Fractionation of mitochondrial membrane vesicles into outer membranes, inner membranes and contact sites between outer and inner membranes showed that the GTP-binding activity was highly enriched in contact sites, the location at which preprotein import is believed to occur.
Book•
01 Feb 1991
TL;DR: This session discusses studies on the Function of the Mitochondrial Hinge Protein, and Theory and Applications of the Kinetics of Substrate Reaction during Irreversible Modification of Enzyme Activity.
Abstract: Opening Session.- Introductory Remarks.- Opening Lecture.- Special Session.- Memories of My Flavoprotein Research.- I. Biochemistry 1. Mitochondrial Electron Transfer.- An Overview of Ubiquinone Proteins.- Studies on the Mechanism of Action of the Mitochondrial Energy-Linked Nicotinamide Nucleotide Transhydrogenase.- Structures of Beef Mitochondrial Complex I Subunits.- Inhibition of the Mitochondrial Complex I Activity by Fatty Acid Derivatives of Vanillylamide.- New 4-Hydroxypyridine and 4-Hydroxyquinoline Derivatives as Inhibitors of NADH-Ubiquinone Oxidoreductase in the Respiratory Chain II.- Effects of Redox State for Ubiquinone-10 on the Membrane Fluidity of Cardiolipin-Containing Liposomes.- Features of Assembly and Mechanism of Yeast Mitochondrial Ubiquinol: Cytochrome c Oxidoreductase.- Structural Studies of Euglena Cytochrome c1.- How Well is Cytochrome c Engineered?.- Subunit I is the Catalytic Center of P. denitrificans Cytochrome c Oxidase.- The Separation between Cytochrome a and Cytochrome a3 in the Absolute Spectrum.- I. 2. Energy Coupling and Ion Transport.- Which Electron-Transferring Reactions in the Respiratory Chain Contribute to the Energy Conservation?.- Cytochrome Oxidase and Peroxide Metabolism.- Do Hydrogen Ions Serve as Bioenergetic Messengers in Yeast?.- Molecular Organization and Regulation of the Protonmotive System of Mammalian ATP Synthase.- Situation of Archaebacterial ATPase among Ion-Translocating ATPases.- Structure and Chemical Modification of Pig Gastric (H++K+)-ATPase.- Inhibition of the Uncoupler-Induced Mitochondrial ATP-Hydrolysis by the Cooperative Work of the ATPase Inhibitor, 9K Protein and 15K Protein.- Reconstitution of H+ATPase into Planar Phospholipid Bilayers and its Kinetic Analysis.- A Mitochondrial Carrier Family for Solute Transport.- The Calcium Pump of the Plasma Membrane: Structure/Function Relationships.- I.3. Other Related Topics.- The 9-kDa Polypeptide with Iron-Sulfur Centers A/B in Spinach Photosystem I with Special Reference to its Structure and Topographic Consideration in Thylakoid Membrane.- A Photo-Signal Transducing Photoreceptor (Stentorin) in Stentor coeruleus: A Brief Review.- Theory and Applications of the Kinetics of Substrate Reaction during Irreversible Modification of Enzyme Activity.- High Pressure Kinetic Studies on Certain Hemoproteins.- The Purification and Properties of Glycerol-3-Phosphate Dehydrogenase in the Mitochondrial Inner Membrane.- II. Molecular Biology.- Subunit 8 of Yeast Mitochondrial ATP Synthase: Biochemical Genetics and Membrane Assembly.- Gene Structure of Human ATP Synthase Beta Subunit.- Molecule and Gene of Sulfolobus acidocaldarius ATPase.- Nuclear Genes Encoding Two Subunits of Human Mitochondrial Cytochrome bc1 Complex, Cytochrome c1 and Ubiquinone-Binding Protein: Their Structural Organization of the 5?-Flanking Regions and Chromosomal Localization.- Studies on the Function of the Mitochondrial Hinge Protein: Molecular Genetic Approach Using Yeast as a Model System.- Molecular Evolution and Biology of Human Mitochondrial DNA.- III. Mitochondrial Pathology.- Stable and Unstable Bioenergetics in Vivo.- Regulation of Activity and Tissue-Specific Expression of Cytochrome c Oxidase Genes under Normal and Pathological Conditions.- Mitochondrial DNA Mutations as an Etiology of Human Degenerative Diseases.- Mitochondrial Myopathies: Morphological Approach to Molecular Abnormalities.- S1 Nuclease Analysis and Direct Sequencing of Deleted Mitochondrial DNA in Myopathic Patients: Role of Directly Repeated Sequences in Deletion.- Thirty Years of Mitochondrial Pathophysiology: From Luft's Disease to Oxygen Toxicity.- Participants.- Author Index.