TY - JOUR A1 - Neupert, W. A1 - Sebald, Walter A1 - Schwab, A. J. A1 - Pfaller, A. A1 - Bücher, T. T1 - Puromycin sensitivity of ribosomal label after incorporation of \(^{14}\)C-labelled amino acids into isolated mitochondria from Neurospora crassa N2 - Radioactive amino acids were incorporated into isolated mitochondria from Neurospora crassa. Then the mitochondrial ribosomes were isolated and submitted to density gradient centrifugation. A preferential labelling of polysomes was observed. However, when the mitochondrial suspension was treated with puromycin after amino acid incorporation, no radioactivity could be detected in either the monosomes or the polysomes. The conclusion is drawn that isolated mitochondria under these conditions do not incorporate significant amounts of amino acids into proteins of their ribosomes. KW - Biochemie Y1 - 1969 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62899 ER - TY - JOUR A1 - Kleene, R. A1 - Pfanner, N. A1 - Pfaller, R. A1 - Link, T. A. A1 - Sebald, Walter A1 - Neupert, W. A1 - Tropschug, M. T1 - Mitochondrial porin of Neurospora crassa: cDNA cloning, in vitro expression and import into mitochondria N2 - No abstract available KW - Biochemie Y1 - 1987 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62566 ER - TY - JOUR A1 - Schmidt, B. A1 - Wachter, E. A1 - Sebald, Walter A1 - Neupert, W. T1 - Processing peptidase of Neurospora mitochondria. Two-step cleavage of imported ATPase subunit 9 N2 - Subunit 9 (dicyclohexylcarbodümide binding protein, 'proteolipid') of the mitochondrial F 1F0-ATPase is a nuclearly coded protein in Neurospora crassa. lt is synthesized on free cytoplasmic ribosomes as a larger precursor with an NH2-terminal peptide extension. The peptide extension is cleaved ofT after transport of the protein into the mitochondria. A processing activity referred to as processing peptidase that cleaves the precursor to subunit 9 and other mitochondrial proteins is described and characterized using a cell-free system. Precursor synthesized in vitro was incubated with extracts of mitochondria. Processing peptidase required Mn2 + for its activity. Localization studies suggested that it is a soluble component of the mitochondrial matrix. The precursor was cleaved in two sequential steps via an intermediate-sized polypeptide. The intermediate form in the processing of subunit 9 was also seen in vivo and upon import of the precursor into isolated mitochondria in vitro. The two dcavage sites in the precursor molecule were determined. The data indicate that: {a) the correct NH2-terminus of the mature protein was generated, (b) the NH2-terminal amino acid of the intermediate-sized polypeptide is isoleueine in position -31. The cleavage sites show similarity ofprimary structure. It is concluded that processing peptidase removes the peptide extension from the precursor to subunit 9 (and probably other precursors) after translocation of these polypeptides (or the NHrterminal part of these polypeptides) into the matrix space of mitochondria. KW - Biochemie Y1 - 1984 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62674 ER - TY - JOUR A1 - Sebald, Walter A1 - Neupert, W. A1 - Birkmayer, G. D. T1 - Internal and external contributions to the biogenesis of mitochondrial proteins N2 - No abstract available KW - Biochemie Y1 - 1970 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62876 ER - TY - JOUR A1 - Neupert, W. A1 - Sebald, Walter A1 - Schwab, A. J. A1 - Massinger, P. A1 - Bücher, T. T1 - Incorporation in vivo of \(^{14}\)C-labelled amino acids into the proteins of mitochondrial ribosomes from Neurospora crassa sensitive to cycloheximide and insensitive to Chloramphenicol N2 - Radioactive amino acids were incorporated in vivo into N eurospora crassa cells, and the mitochondrial ribosomes were isolated. The incorporation of radioactivity into the proteins of these ribosomes was inhibited by cycloheximide, but not by chloramphenicol. It is therefore concluded that these proteins are synthesized on the cycloheximide sensitive and chloramphenicol insensitive cytoplasmic ribosomes. KW - Biochemie Y1 - 1969 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62884 ER - TY - JOUR A1 - Sebald, Walter A1 - Neupert, W. A1 - Weiss, H. T1 - Preparation of Neurospora crassa mitochondria N2 - The fungus Neurospora crassa represents a eukaryotic cell with high biosynthetic activities. Cell mass doubles in 2-4 hr during expone ntial growth , even in simple salt media with sucrose as the sole carbon source. The microorgani sm forms a mycelium of long hyphae durlng vegetative growth . The mitochondria can be isolated under relatively gentle condi tions since a few breaks in the threadlike hyphae are sufficient to cause the outflow of the organelles. This article describes two methods for the physical disruption of the hyphae : (I) The cell s are opened in a grind mill between two rotating corundum di sks. This is a continuous and fast procedure and allows large- and small-scale preparations of mitochondria. (2) Hyphae are ground with sand in a mortar and pestle. This procedure can be applied to microscale preparations of mitochondria starting with minute amounts of cells. Other procedures for the isolation of Neurospora mitochondria after the physical di sruption or the enzymatic degradation of the cell wall have been described elsewhere KW - Biochemie Y1 - 1979 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-82070 ER -