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Bonadonna M, Altamura S, Tybl E, Palais G, Qatato M, Polycarpou-Schwarz M, Schneider M, Kalk C, Rüdiger W, Ertl A, Anstee N, Bogeska R, Helm D, Milsom MD, Galy B. Iron regulatory protein (IRP)-mediated iron homeostasis is critical for neutrophil development and differentiation in the bone marrow. Sci Adv 2022; 8:eabq4469. [PMID: 36197975 PMCID: PMC9534496 DOI: 10.1126/sciadv.abq4469] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/18/2022] [Indexed: 06/01/2023]
Abstract
Iron is mostly devoted to the hemoglobinization of erythrocytes for oxygen transport. However, emerging evidence points to a broader role for the metal in hematopoiesis, including the formation of the immune system. Iron availability in mammalian cells is controlled by iron-regulatory protein 1 (IRP1) and IRP2. We report that global disruption of both IRP1 and IRP2 in adult mice impairs neutrophil development and differentiation in the bone marrow, yielding immature neutrophils with abnormally high glycolytic and autophagic activity, resulting in neutropenia. IRPs promote neutrophil differentiation in a cell intrinsic manner by securing cellular iron supply together with transcriptional control of neutropoiesis to facilitate differentiation to fully mature neutrophils. Unlike neutrophils, monocyte count was not affected by IRP and iron deficiency, suggesting a lineage-specific effect of iron on myeloid output. This study unveils the previously unrecognized importance of IRPs and iron metabolism in the formation of a major branch of the innate immune system.
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Affiliation(s)
- Michael Bonadonna
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Biosciences Faculty, University of Heidelberg, 69120 Heidelberg, Germany
| | - Sandro Altamura
- University of Heidelberg, Department of Pediatric Hematology, Oncology and Immunology, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
| | - Elisabeth Tybl
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- IB-Cancer Research Foundation, Science Park 2, 66123 Saarbrücken, Germany
| | - Gael Palais
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maria Qatato
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maria Polycarpou-Schwarz
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Martin Schneider
- German Cancer Research Center, Mass Spectrometry based Protein Analysis Unit, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Christina Kalk
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Wibke Rüdiger
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alina Ertl
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Natasha Anstee
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ruzhica Bogeska
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Dominic Helm
- German Cancer Research Center, Mass Spectrometry based Protein Analysis Unit, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Michael D. Milsom
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Bruno Galy
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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2
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Ludwig KU, Schmithausen RM, Li D, Jacobs ML, Hollstein R, Blumenstock K, Liebing J, Słabicki M, Ben-Shmuel A, Israeli O, Weiss S, Ebert TS, Paran N, Rüdiger W, Wilbring G, Feldman D, Lippke B, Ishorst N, Hochfeld LM, Beins EC, Kaltheuner IH, Schmitz M, Wöhler A, Döhla M, Sib E, Jentzsch M, Borrajo JD, Strecker J, Reinhardt J, Cleary B, Geyer M, Hölzel M, Macrae R, Nöthen MM, Hoffmann P, Exner M, Regev A, Zhang F, Schmid-Burgk JL. LAMP-Seq enables sensitive, multiplexed COVID-19 diagnostics using molecular barcoding. Nat Biotechnol 2021; 39:1556-1562. [PMID: 34188222 PMCID: PMC8678193 DOI: 10.1038/s41587-021-00966-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/26/2021] [Indexed: 02/06/2023]
Abstract
Frequent testing of large population groups combined with contact tracing and isolation measures will be crucial for containing Coronavirus Disease 2019 outbreaks. Here we present LAMP-Seq, a modified, highly scalable reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. Unpurified biosamples are barcoded and amplified in a single heat step, and pooled products are analyzed en masse by sequencing. Using commercial reagents, LAMP-Seq has a limit of detection of ~2.2 molecules per µl at 95% confidence and near-perfect specificity for severe acute respiratory syndrome coronavirus 2 given its sequence readout. Clinical validation of an open-source protocol with 676 swab samples, 98 of which were deemed positive by standard RT-qPCR, demonstrated 100% sensitivity in individuals with cycle threshold values of up to 33 and a specificity of 99.7%, at a very low material cost. With a time-to-result of fewer than 24 h, low cost and little new infrastructure requirement, LAMP-Seq can be readily deployed for frequent testing as part of an integrated public health surveillance program.
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Affiliation(s)
- Kerstin U. Ludwig
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Ricarda M. Schmithausen
- Institute of Hygiene and Public Health, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - David Li
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Max L. Jacobs
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany,Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Ronja Hollstein
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Katja Blumenstock
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Jana Liebing
- Institute of Experimental Oncology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Mikołaj Słabicki
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.,Division of Translational Medical Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Amir Ben-Shmuel
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shay Weiss
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Thomas S. Ebert
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Nir Paran
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness Ziona, Israel
| | - Wibke Rüdiger
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Gero Wilbring
- Institute of Hygiene and Public Health, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - David Feldman
- Department of Biochemistry and Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Bärbel Lippke
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Nina Ishorst
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany.,Institute of Anatomy, Division of Neuroanatomy, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Lara M. Hochfeld
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Eva C. Beins
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Ines H. Kaltheuner
- Institute of Structural Biology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Maximilian Schmitz
- Institute of Structural Biology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Aliona Wöhler
- Department of General, Visceral and Thoracic Surgery, Bundeswehr Central Hospital Koblenz, Koblenz, Germany
| | - Manuel Döhla
- Institute of Hygiene and Public Health, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany.,Department of Microbiology and Hospital Hygiene, Bundeswehr Central Hospital Koblenz, Koblenz, Germany
| | - Esther Sib
- Institute of Hygiene and Public Health, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Marius Jentzsch
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Jacob D. Borrajo
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jonathan Strecker
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Julia Reinhardt
- Institute of Experimental Oncology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Brian Cleary
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Michael Hölzel
- Institute of Experimental Oncology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Rhiannon Macrae
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Markus M. Nöthen
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Per Hoffmann
- Institute of Human Genetics, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany.,Genomics Research Group, Department of Biomedicine, University of Basel, Switzerland
| | - Martin Exner
- Institute of Hygiene and Public Health, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany
| | - Aviv Regev
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Klarman Cell Observatory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Howard Hughes Medical Institute, Cambridge, MA 02139, USA.,Current address: Genentech, 1 DNA Way, South San Francisco, CA, USA
| | - Feng Zhang
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Howard Hughes Medical Institute, Cambridge, MA 02139, USA
| | - Jonathan L. Schmid-Burgk
- Broad Institute of MIT and Harvard, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, 53127 Bonn, Germany,Correspondence to:
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3
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Tchiengue B, Neumann K, Rüdiger W. Early succession in the tropical forest in southern Cameroon, Central Africa. Trop Plant Res 2020. [DOI: 10.22271/tpr.2020.v7.i1.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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4
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López-Figueroa F, Lindemann P, Braslavsky SE, Schaffner K, Schneider-Poetsch HAW, Rüdiger W. Detection of a Phytochrome-like Protein in Macroalgae. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1989.tb00089.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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5
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Salomon M, Zacherl M, Rüdiger W. Phototropism and Protein Phosphorylation in Higher Plants: Unilateral Blue Light Irradiation Generates a Directional Gradient of Protein Phosphorylation Across the Oat Coleoptile. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1997.tb00631.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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6
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7
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8
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Rüdiger W, Thümmler F, Cmiel E, Schneider S. Chromophore structure of the physiologically active form (P(fr)) of phytochrome. Proc Natl Acad Sci U S A 2010; 80:6244-8. [PMID: 16593380 PMCID: PMC394272 DOI: 10.1073/pnas.80.20.6244] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chromopeptides were prepared by proteolytic digestion of phytochrome (far-red absorbing form, P(fr)) and of phycocyanin. The phycocyanobilin peptide, the chromophore of which is Z,Z,Z-configurated, was modified to the Z,Z,E isomeric chromophore. It has been demonstrated earlier that the P(fr) chromopeptide and the Z,Z,E-configurated phycocyanin chromopeptide behave similarly with regard to spectral and chromatographic properties and reactivity. We present evidence here, obtained by high-resolution (1)H NMR spectroscopy, that both the modified phycocyanobilin chromophore and the phytochrome chromophore obtained directly from P(fr) are 15E-configurated.
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Affiliation(s)
- W Rüdiger
- Botanisches Institut der Universität München, Menzinger Strasse 67, D-8000 München 19
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9
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Abstract
Recent progress in the knowledge of chlorophyll b biosynthesis from chlorophyllide a and reduction of chlorophyll b to chlorophyll a is described. The minireview includes a description of the enzymes involved in these reactions and, where appropriate, of the genes encoding these enzymes. The possible physiological role of the mutual transformation of chlorophylls a and b (chlorophyll cycle) and the evolution of chlorophyll b formation are discussed.
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Affiliation(s)
- W Rüdiger
- Botanisches Institut, Universität München, Menzingerstr. 67, 86038, München, Germany,
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10
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Salomon M, Eisenreich W, Dürr H, Schleicher E, Knieb E, Massey V, Rüdiger W, Müller F, Bacher A, Richter G. An optomechanical transducer in the blue light receptor phototropin from Avena sativa. Proc Natl Acad Sci U S A 2001; 98:12357-61. [PMID: 11606742 PMCID: PMC60058 DOI: 10.1073/pnas.221455298] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2001] [Indexed: 01/08/2023] Open
Abstract
The PHOT1 (NPH1) gene from Avena sativa specifies the blue light receptor for phototropism, phototropin, which comprises two FMN-binding LOV domains and a serine/threonine protein kinase domain. Light exposure is conducive to autophosphorylation of the protein kinase domain. We have reconstituted a recombinant LOV2 domain of A. sativa phototropin with various (13)C/(15)N-labeled isotopomers of the cofactor, FMN. The reconstituted protein samples were analyzed by NMR spectroscopy under dark and light conditions. Blue light irradiation is shown to result in the addition of a thiol group (cysteine 450) to the 4a position of the FMN chromophore. The adduct reverts spontaneously in the dark by elimination. The light-driven flavin adduct formation results in conformational modification, which was diagnosed by (1)H and (31)P NMR spectroscopy. This conformational change is proposed to initiate the transmission of the light signal via conformational modulation of the protein kinase domain conducive to autophosphorylation of NPH1.
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Affiliation(s)
- M Salomon
- Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany
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11
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Schroda M, Kropat J, Oster U, Rüdiger W, Vallon O, Wollman FA, Beck CF. Possible role for molecular chaperones in assembly and repair of photosystem II. Biochem Soc Trans 2001; 29:413-8. [PMID: 11497999 DOI: 10.1042/bst0290413] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Genes of the HSP70 chaperone family are induced by light. In Chlamydomonas reinhardtii, the induction of HSP70 (70 kDa heat shock protein) chaperones by light results in a partial protection of photosystem II against damage by photoinhibitory conditions. Underexpression of a chloroplast-localized HSP70 protein caused an increased sensitivity of photosystem II to light. Overexpression of this protein had a protective effect. Fluorescence measurements and studies of the turnover of photosystem II core components suggest that this HSP70 might function in both the protection and the regeneration of photosystem II. This concept is supported by fractionation studies in which the plastid HSP70 was found associated with chloroplast membranes. Because the light-induced elevation of HSP70 levels provides protection for photosystem II, we examined whether the chloroplast is involved in this regulation and found that mutants defective in plastid-localized chlorophyll synthesis, i.e. the insertion of Mg(2+) into protoporphyrin IX are impaired in the induction of HSP70 by light. Exogenous addition of Mg-protoporphyrin in the dark induced the genes. The combined results support a model in which chlorophyll precursors are essential in the signalling from chloroplast to nucleus that regulates the chaperone genes.
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Affiliation(s)
- M Schroda
- Institute of Biology III, University of Freiburg, Schaenzlestrasse 1, D-79104 Freiburg, Germany
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12
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Abstract
The chlorophyll synthase gene from oat (Avena sativa) was cloned and expressed in Escherichia coli. The deduced amino acid sequence consists of 378 amino acids including a presequence of 46 amino acids. Deletion mutants show that a core protein comprising amino acid residues 88 to 377 is enzymatically active. The sequence of the mature protein shows 85% identity with the chlorophyll synthase of Arabidopsis thaliana and 62% identity with the chlorophyll synthase of Synechocystis PCC 6803. The gene is constitutively expressed as the same transcript level is found in dark-grown and in light-grown seedlings. The enzyme requires magnesium ions for activity; manganese ions can reconstitute only part of the activity. Diacetyl and N-phenylmaleimide (NPM) inhibit the enzyme activity. Site-directed mutagenesis reveals that, out of the 4 Arg residues present in the active core protein, Arg-91 and Arg-161 are essential for the activity. Five cysteine residues are present in the core protein, of which only Cys-109 is essential for the enzyme activity. Since the wild-type and all other Cys-mutants with the exception of the mutant C304A are inhibited by N-phenylmaleimide, we conclude that the inhibitor binds to a non-essential Cys residue to abolish activity. The role of the various Arg and Cys residues is discussed.
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Affiliation(s)
- H C Schmid
- Botanisches Institut der Ludwig-Maximilians-Universität München, Germany
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13
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La Rocca N, Rascio N, Oster U, Rüdiger W. Amitrole treatment of etiolated barley seedlings leads to deregulation of tetrapyrrole synthesis and to reduced expression of Lhc and RbcS genes. Planta 2001; 213:101-8. [PMID: 11523645 DOI: 10.1007/s004250000477] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The effect of amitrole, known as an inhibitor of carotenoid biosynthesis, upon tetrapyrrole biosynthesis and its regulation has been studied. Etiolated barley (Hordeum vulgare L.) seedlings, grown in 125 microM amitrole, accumulated high levels of 5-aminolevulinate, Mg-protoporphyrin, Mg-protoporphyrin monomethyl ester, and protochlorophyllide. The amitrole-treated seedlings did not form paracrystalline prolamellar bodies, and the induction of Lhc and RbcS gene expression was reduced by non-photooxidative, low-intensity light. None of these events was observed upon treatment of the seedlings with 100 microM norflurazon, another inhibitor of carotenoid biosynthesis. The effect of amitrole cannot be explained solely by interaction with a presumed feedback inhibition of 5-aminolevulinate synthesis since incubation with amitrole and 5-aminolevulinate indicated that deregulation also occurs at later steps of tetrapyrrole biosynthesis. A possible relationship between this deregulation and ultrastructural changes is discussed. In connection with previously published data, we discuss Mg-protoporphyrin and its monomethyl ester as possible candidates for a "plastid signal" that operates as a negative factor, reducing the expression of Lhc and RbcS genes in this higher plant.
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Affiliation(s)
- N La Rocca
- Dipartimento di Biologia, Universitá degli Studi di Padova, Italy
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14
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Briggs WR, Beck CF, Cashmore AR, Christie JM, Hughes J, Jarillo JA, Kagawa T, Kanegae H, Liscum E, Nagatani A, Okada K, Salomon M, Rüdiger W, Sakai T, Takano M, Wada M, Watson JC. The phototropin family of photoreceptors. Plant Cell 2001; 13:993-7. [PMID: 11424903 PMCID: PMC1464709 DOI: 10.1105/tpc.13.5.993] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
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15
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Mijit G, Rahman E, Nikulina KV, Boladhan Z, Chunaev AS, Rüdiger W. [Genetic characterization of subcbnI genes of Chlamydomonas reinhardtii]. Yi Chuan Xue Bao 2001; 27:734-41. [PMID: 11055127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Fourteen different revertants of Chlamydomonas reinhardtii recovered with ability of biosynthesis chlorophyll b were hybridized with wile-type strain, and tetrad analysis with random sampling was performed. It appeared that sub genes resulting in cbnI gene to reverse mutation, and localize on the first chromosome. According to its linkage that differences, 5 strains carrying various mutant alleles of suppressor genes were determined. Forward hybridological analysis demonstrated that the sub genes were absent of allelic specificity and had a single genic character in response to suppression. Phenotypic analysis of the sub/Sub diplontic hybrid have verified the dominant character of mutant sub genes. The phenomenon of present various allelic sub genes and all its characters revealed that the possibility of several ways or various regulatory means exists in biosynthesis of chlorophyll b.
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Affiliation(s)
- G Mijit
- Department of Biology, Xinjiang University, Urumqi, China
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16
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Abstract
The kinetics of formation of esterified chlorophyll in etiolated barley (Hordeum vulgare L.) leaves after illumination with a single flash was studied. It was found that after partial (14-24%) and after full photoreduction of protochlorophyllide, the same quantity of esterified products appear during the first 5 s after the flash. The rest of formed chlorophyllide was esterified in a slow process during at least 30 min at 15 degrees C. The product of fast esterification can be correlated with 'short-wavelength' chlorophyll, characterized by a fluorescence emission peak at 673-675 nm. This is the only chlorophyll form detectable within 20 s after partial (14%) photoconversion, and it appears at the same time as the shoulder of the chlorophyll(ide) fluorescence after full photoconversion. The main product after full photoconversion shows a fluorescence at 689 nm shifting in darkness within 15 s to 693 nm and then within 30 min to 682 nm (Shibata shift). The slow esterification proceeds with similar kinetics as the Shibata shift. We propose that the fast esterification of only part of total chlorophyllide after full photoconversion of protochlorophyllide in etiolated leaves reflects the restricted capacity of the esterifying system. The slow esterification of the residual chlorophyllide may be time-limited by its release from protochlorophyllide oxidoreductase, by disaggregation of prolamellar bodies and by diffusion of tetraprenyl diphosphates towards chlorophyll synthase.
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Affiliation(s)
- V P Domanskii
- Institute of Photobiology of National Academy of Sciences of Belarus; Botanisches Institut der Universität München, 86038, München, Germany
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17
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Kropat J, Oster U, Rüdiger W, Beck CF. Chloroplast signalling in the light induction of nuclear HSP70 genes requires the accumulation of chlorophyll precursors and their accessibility to cytoplasm/nucleus. Plant J 2000; 24:523-531. [PMID: 11115133 DOI: 10.1111/j.1365-313x.2000.00898.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Chlorophyll precursors Mg-protoporphyrin IX and its monomethylester are candidates for plastid-derived molecules involved in light signalling from the chloroplast to the nucleus. The pool sizes of these two Mg2+-containing porphyrins and of protoporphyrin IX transiently increased upon a shift of Chlamydomonas cultures from dark to light. This increase coincided with the accumulation of mRNAs encoded by the nuclear genes HSP70A and HSP70B. Analysis of a mutant (brs-1), previously shown to be defective in the light induction of these genes, revealed high levels of protoporphyrin IX but no light-induced increase in the levels of Mg2+-containing porphyrins. Inhibitors of cytoplasmic protein synthesis prevented both the light-induced rise in pool levels and induction of the HSP70 genes. Similarly, pre-gametes, intermediates of sexual differentiation, lacked both responses to light. The block in light induction of the HSP70 genes in inhibitor-treated cells and in pre-gametes could be circumvented by the exogenous addition of Mg-protoporphyrin IX in the dark. This suggests an essential role for light-induced Mg-protoporphyrin IX accumulation in this chloroplast-to-nucleus signalling pathway. However, accumulation of this porphyrin in the dark - presumably in the chloroplast - did not result in induction. A second crucial role for light in this signalling pathway is postulated which makes this plastidic compound accessible to the cytoplasm/nucleus where the downstream signalling pathway may be activated.
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Affiliation(s)
- J Kropat
- Institut für Biologie III, Universität Freiburg, Schaenzlestrasse 1, D-79104 Freiburg, Germany
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18
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Kropat J, Oster U, Rüdiger W, Beck CF. Chloroplast signalling in the light induction of nuclear HSP70 genes requires the accumulation of chlorophyll precursors and their accessibility to cytoplasm/nucleus. Plant J 2000; 24:523-31. [PMID: 11115133 DOI: 10.1046/j.1365-313x.2000.00898.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Chlorophyll precursors Mg-protoporphyrin IX and its monomethylester are candidates for plastid-derived molecules involved in light signalling from the chloroplast to the nucleus. The pool sizes of these two Mg2+-containing porphyrins and of protoporphyrin IX transiently increased upon a shift of Chlamydomonas cultures from dark to light. This increase coincided with the accumulation of mRNAs encoded by the nuclear genes HSP70A and HSP70B. Analysis of a mutant (brs-1), previously shown to be defective in the light induction of these genes, revealed high levels of protoporphyrin IX but no light-induced increase in the levels of Mg2+-containing porphyrins. Inhibitors of cytoplasmic protein synthesis prevented both the light-induced rise in pool levels and induction of the HSP70 genes. Similarly, pre-gametes, intermediates of sexual differentiation, lacked both responses to light. The block in light induction of the HSP70 genes in inhibitor-treated cells and in pre-gametes could be circumvented by the exogenous addition of Mg-protoporphyrin IX in the dark. This suggests an essential role for light-induced Mg-protoporphyrin IX accumulation in this chloroplast-to-nucleus signalling pathway. However, accumulation of this porphyrin in the dark - presumably in the chloroplast - did not result in induction. A second crucial role for light in this signalling pathway is postulated which makes this plastidic compound accessible to the cytoplasm/nucleus where the downstream signalling pathway may be activated.
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Affiliation(s)
- J Kropat
- Institut für Biologie III, Universität Freiburg, Schaenzlestrasse 1, D-79104 Freiburg, Germany
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19
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Klement H, Oster U, Rüdiger W. The influence of glycerol and chloroplast lipids on the spectral shifts of pigments associated with NADPH: protochlorophyllide oxidoreductase from Avena sativa L. FEBS Lett 2000; 480:306-10. [PMID: 11034350 DOI: 10.1016/s0014-5793(00)01887-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Dark-grown angiosperm seedlings lack chlorophylls, but accumulate protochlorophyllide a complexed with the light-dependent enzyme NADPH:protochlorophyllide oxidoreductase. Previous investigators correlated spectral heterogeneity of in vivo protochlorophyllide forms and a shift of chlorophyllide forms from 680 to 672 nm (Shibata shift) occurring after irradiation, with intact membrane structures which are destroyed by solubilization. We demonstrate here that the various protochlorophyllide forms and the Shibata shift which disappear upon solubilization are restored if the reconstituted complex is treated with plastid lipids and 80% (w/v) glycerol. We hypothesize that the lipids can form a cubic phase and that this is the precondition in vitro and in vivo for the observed spectral properties before and after irradiation.
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Affiliation(s)
- H Klement
- Botanisches Institut der Ludwig-Maximilians-Universität München, Munich, Germany
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20
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Eichenberg K, Bäurle I, Paulo N, Sharrock RA, Rüdiger W, Schäfer E. Arabidopsis phytochromes C and E have different spectral characteristics from those of phytochromes A and B. FEBS Lett 2000; 470:107-12. [PMID: 10734217 DOI: 10.1016/s0014-5793(00)01301-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The red/far-red light absorbing phytochromes play a major role as sensor proteins in photomorphogenesis of plants. In Arabidopsis the phytochromes belong to a small gene family of five members, phytochrome A (phyA) to E (phyE). Knowledge of the dynamic properties of the phytochrome molecules is the basis of phytochrome signal transduction research. Beside photoconversion and destruction, dark reversion is a molecular property of some phytochromes. A possible role of dark reversion is the termination of signal transduction. Since Arabidopsis is a model plant for biological and genetic research, we focussed on spectroscopic characterization of Arabidopsis phytochromes, expressed in yeast. For the first time, we were able to determine the relative absorption maxima and minima for a phytochrome C (phyC) as 661/725 nm and for a phyE as 670/724 nm. The spectral characteristics of phyC and E are strictly different from those of phyA and B. Furthermore, we show that both phyC and phyE apoprotein chromophore adducts undergo a strong dark reversion. Difference spectra, monitored with phycocyanobilin and phytochromobilin as the apoprotein's chromophore, and in vivo dark reversion of the Arabidopsis phytochrome apoprotein phycocyanobilin adducts are discussed with respect to their physiological function.
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Affiliation(s)
- K Eichenberg
- Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Schänzlestrasse 1, D-79104, Freiburg, Germany
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21
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Oster U, Tanaka R, Tanaka A, Rüdiger W. Cloning and functional expression of the gene encoding the key enzyme for chlorophyll b biosynthesis (CAO) from Arabidopsis thaliana. Plant J 2000; 21:305-10. [PMID: 10758481 DOI: 10.1046/j.1365-313x.2000.00672.x] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Chlorophyll (Chl) biosynthesis and degradation are the only biochemical processes on Earth that can be directly observed from satellites or other planets. The bulk of the Chls is found in the light-harvesting antenna complexes of photosynthetic organisms. Surprisingly little is known about the biosynthesis of Chl b, which is the second most abundant Chl pigment after Chl a. We describe here the expression and properties of the chlorophyllide a oxygenase gene (CAO) from Arabidopsis thaliana, which is apparently the key enzyme in Chl b biosynthesis. The recombinant enzyme produced in Escherichia coli catalyses an unusual two-step oxygenase reaction that is the 'missing link' in the chlorophyll cycle of higher plants.
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Affiliation(s)
- U Oster
- Institute of Botany, University of Munich, Menzinger Str. 67, D-80638 Munich, Germany, andInstitute of Low Temperature Science, Hokkaido University, N19W8 Sapporo, Japan
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Abstract
Recent in vitro studies have led to speculation that a novel light-harvesting protochlorophyllide a/b-binding protein complex (LHPP) might exist in dark-grown angiosperms. Structurally, it has been suggested that LHPP consists of a 5:1 ratio of dark-stable ternary complexes of the light-dependent NADPH: protochlorophyllide oxidoreductases A and B containing nonphotoactive protochlorophyllide b and photoactive protochlorophyllide a, respectively. Functionally, LHPP has been hypothesized to play major roles in establishing the photosynthetic apparatus, in protecting against photo-oxidative damage during greening, and in determining etioplast inner membrane architecture. However, the LHPP model is not compatible with other studies of the pigments and the pigment-protein complexes of dark-grown angiosperms. Protochlorophyllide b, which is postulated to be the major light-harvesting pigment of LHPP, has, for example, never been detected in etiolated seedlings. This raises the question: does LHPP exist?
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Affiliation(s)
- G A Armstrong
- Institute for Plant Sciences, Plant Genetics, Swiss Federal Institute of Technology (ETH), Universitätstr. 2, CH-8092 Zürich, Switzerland.
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Klement H, Helfrich M, Oster U, Schoch S, Rüdiger W. Pigment-free NADPH:protochlorophyllide oxidoreductase from Avena sativa L. Purification and substrate specificity. Eur J Biochem 1999; 265:862-74. [PMID: 10518779 DOI: 10.1046/j.1432-1327.1999.00627.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The enzyme NADPH:protochlorophyllide oxidoreductase (POR) is the key enzyme for light-dependent chlorophyll biosynthesis. It accumulates in dark-grown plants as the ternary enzyme-substrate complex POR-protochlorophyllide a-NADPH. Here, we describe a simple procedure for purification of pigment-free POR from etioplasts of Avena sativa seedlings. The procedure implies differential solubilization with n-octyl-beta-D-glucoside and one chromatographic step with DEAE-cellulose. We show, using pigment and protein analysis, that etioplasts contain a one-to-one complex of POR and protochlorophyllide a. The preparation of 13 analogues of protochlorophyllide a is described. The analogues differ in the side chains of the macrocycle and in part contain zinc instead of the central magnesium. Six analogues with different side chains at rings A or B are active substrates, seven analogues with different side chains at rings D or E are not accepted as substrates by POR. The kinetics of the light-dependent reaction reveals three groups of substrate analogues with a fast, medium and slow reaction. To evaluate the kinetic data, the molar extinction coefficients in the reaction buffer had to be determined. At concentrations above 2 mole substrate/mole enzyme, inhibition was found for protochlorophyllide a and for the analogues.
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Affiliation(s)
- H Klement
- Botanisches Institut der Ludwig-Maximilians-Universität München, Munich, Germany
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24
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De Santis-MacIossek G, Kofer W, Bock A, Schoch S, Maier RM, Wanner G, Rüdiger W, Koop HU, Herrmann RG. Targeted disruption of the plastid RNA polymerase genes rpoA, B and C1: molecular biology, biochemistry and ultrastructure. Plant J 1999; 18:477-89. [PMID: 10417698 DOI: 10.1046/j.1365-313x.1999.00473.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The plastid encoded RNA polymerase subunit genes rpoA, B and C1 of tobacco were disrupted individually by PEG-mediated plastid transformation. The resulting off-white mutant phenotype is identical for inactivation of the different genes. The mutants pass through a normal ontogenetic cycle including flower formation and production of fertile seeds. Their plastids reveal a poorly developed internal membrane system consisting of large vesicles and, occasionally, flattened membranes, reminiscent of stacked thylakoids. The rpo- material is capable of synthesising pigments and lipids, similar in composition but at lower amounts than the wild-type. Western analysis demonstrates that plastids contain nuclear-coded stroma and thylakoid polypeptides including terminally processed lumenal components of the Sec but not of the DeltapH thylakoid translocation machineries. Components using the latter route accumulate as intermediates. In striking contrast, polypeptides involved in photosynthesis encoded by plastid genes could not be detected by Western analysis, although transcription of plastid genes, including the rrn operon, by the plastid RNA polymerase of nuclear origin is found as expected. Remarkably, ultrastructural, sedimentation and Northern analyses as well as pulse experiments suggest that rpo- plastids contain functional ribosomes. The detection of the plastid-encoded ribosomal protein Rpl2 is consistent with these results. The findings demonstrate that the consequences of rpo gene disruption, and implicitly the integration of the two plastid polymerase types into the entire cellular context, are considerably more complex than presently assumed.
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Abstract
Barley (Hordeum vulgare L.) etioplasts were isolated, and the pigments were extracted with acetone. The extract was analyzed by HPLC. Only protochlorophyllide a and no protochlorophyllide b was detected (limit of detection < 1% of protochlorophyllide a). Protochlorophyllide b was synthesized starting from chlorophyll b and incubated with etioplast membranes and NADPH. In the light, photoconversion to chlorophyllide b was observed, apparently catalyzed by NADPH :protochlorophyllide oxidoreductase. In darkness, reduction of the analogue zinc protopheophorbide b to zinc 7-hydroxy-protopheophorbide a was observed, apparently catalyzed by chlorophyll b reductase. We conclude that protochlorophyllide b does not occur in detectable amounts in etioplasts, and even traces of it as the free pigment are metabolically unstable. Thus the direct experimental evidence contradicts the idea by Reinbothe et al. (Nature 397 (1999) 80-84) of a protochlorophyllide b-containing light-harvesting complex in barley etioplasts.
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Affiliation(s)
- V Scheumann
- Botanisches Institut der Ludwig-Maximilians-Universität München, Germany
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26
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Abstract
The reduction of chlorophyllide b and its analogue zinc pheophorbide b in etioplasts of barley (Hordeum vulgare L.) was investigated in detail. In intact etioplasts, the reduction proceeds to chlorophyllide a and zinc pheophorbide a or, if incubated together with phytyldiphosphate, to chlorophyll a and zinc pheophytin a, respectively. In lysed etioplasts supplied with NADPH, the reduction stops at the intermediate step of 7(1)-OH-chlorophyll(ide) and Zn-7(1)-OH-pheophorbide or Zn-7(1)-OH-pheophytin. However, the final reduction is achieved when reduced ferredoxin is added to the lysed etioplasts, suggesting that ferredoxin is the natural cofactor for reduction of chlorophyll b to chlorophyll a. The reduction to chlorophyll a requires ATP in intact etioplasts but not in lysed etioplasts when reduced ferredoxin is supplied. The role of ATP and the significance of two cofactors for the two steps of reduction are discussed.
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Affiliation(s)
- V Scheumann
- Botanisches Institut der Ludwig-Maximilians-Universität München, Menzingerstrasse 67, 80638 München, Germany
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27
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Abstract
The insertion(I)/deletion(D) polymorphism of the angiotensin-converting-enzyme (ACE) gene has been associated with an increased risk of myocardial infarction, lacunar stroke, and with an increased intimal-medial thickness in several populations. The aim of this study was to evaluate whether the ACE I/D genotype is associated with stenosis of extracranial arteries and stroke in middle-aged and aged men and women. We studied 388 patients (247 male, 141 female) using Doppler and Duplex ultrasound of the extracranial arteries. Patients' history was obtained by standard questionnaire and by the hospital case records. Genomic DNA was analyzed by polymerase chain reaction (PCR) to identify the I/D polymorphism, with a second insertion specific PCR in samples classified as homozygous DD genotypes to prevent mistyping. The ACE genotype groups (DD 132, ID 164, II 92) were well matched for the basic characteristics. The DD genotype was more common in patients with extracranial artery stenosis > or = 50%, compared with patients without stenosis (59/147 versus 73/241, odds ratio 1.54, 95%-CI 1.01-2.37), but was not associated with a history of stroke (30/91 versus 102/297, odds ratio 0.94, 95%-CI 0.57-1.54). The association of the DD genotype with extracranial artery stenosis was also present in hypertensive subjects (n = 206, odds ratio 1.76, 95%-CI 0.99-3.17). In the whole group multiple logistic regression analysis revealed that the association of the DD genotype with extracranial artery stenosis was independent of age, gender, hypertension, hyperlipidemia, and diabetes. In conclusion, the ACE DD genotype is a weak risk factor for hemodynamically relevant stenosis of extracranial arteries, but not for stroke.
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Affiliation(s)
- M Pfohl
- Department of Medicine, University of Tübingen, Germany.
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Kropat J, Oster U, Rüdiger W, Beck CF. Chlorophyll precursors are signals of chloroplast origin involved in light induction of nuclear heat-shock genes. Proc Natl Acad Sci U S A 1997; 94:14168-72. [PMID: 9391171 PMCID: PMC28451 DOI: 10.1073/pnas.94.25.14168] [Citation(s) in RCA: 202] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Coordination between the activities of organelles and the nucleus requires the exchange of signals. Using Chlamydomonas, we provide evidence that plastid-derived chlorophyll precursors may replace light in the induction of two nuclear heat-shock genes (HSP70A and HSP70B) and thus qualify as plastidic signal. Mutants defective in the synthesis of Mg-protoporphyrin IX were no longer inducible by light. Feeding of Mg-protoporphyrin IX or its dimethyl ester to wild-type or mutant cells in the dark resulted in induction. The analysis of HSP70A promoter mutants that do or do not respond to light revealed that these chlorophyll precursors specifically activate the light signaling pathway. Activation of gene expression was not observed when protoporphyrin IX, protochlorophyllide, or chlorophyllide were added. A specific interaction of defined chlorophyll precursors with factor(s) that regulate nuclear gene expression is suggested.
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Affiliation(s)
- J Kropat
- Institut fur Biologie III, Universitat Freiburg, Schanzlestrasse 1, D-79104 Freiburg, Germany
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29
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Oster U, Bauer CE, Rüdiger W. Characterization of chlorophyll a and bacteriochlorophyll a synthases by heterologous expression in Escherichia coli. J Biol Chem 1997; 272:9671-6. [PMID: 9092496 DOI: 10.1074/jbc.272.15.9671] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genes coding for putative chlorophyll a synthase (chlG) from Synechocystis sp. PCC 6803 and bacteriochlorophyll a synthase (bchG) from Rhodobacter capsulatus were amplified by the polymerase chain reaction and cloned into T7 RNA polymerase-based expression plasmids. In vitro enzymatic assays indicated that heterologous expression of the chlG and bchG gene products in Escherichia coli conferred chlorophyll a and bacteriochlorophyll a synthase activity, respectively. Chlorophyll a synthase utilized chlorophyllide a, but not bacteriochlorophyllide a, as a substrate, whereas bacteriochlorophyll a synthase utilized bacteriochlorophyllide a, but not chlorophyllide a. Both enzymes were also observed to exhibit a marked preference for phytyl diphosphate over geranylgeranyl diphosphate.
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Affiliation(s)
- U Oster
- Botanisches Institut der Universität München, 86038 München, Federal Republic of Germany
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Eichacker LA, Helfrich M, Rüdiger W, Müller B. Stabilization of chlorophyll a-binding apoproteins P700, CP47, CP43, D2, and D1 by chlorophyll a or Zn-pheophytin a. J Biol Chem 1996; 271:32174-9. [PMID: 8943272 DOI: 10.1074/jbc.271.50.32174] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Stabilization of chlorophyll a-binding apoproteins P700, CP47, CP43, D2, and D1 against proteolytic degradation has been investigated through in vitro synthesis of chlorophyll a or Zn-pheophytin a in intact etioplasts from barley. Stabilization of the apoproteins was dependent on the concentration of chlorophyll a or Zn-pheophytin a. Zn-pheophytin a was superior to chlorophyll a with respect to the concentration of pigment required for an equal yield of the stabilized chlorophyll a protein CP47, CP43, and P700 and for the total yield of chlorophyll a proteins. Zn-pheophytin a was most efficient for stabilizing CP47 and, at an increased concentration, efficient for stabilizing CP43, P700, and D1. Stabilization of apoproteins was highest after de novo synthesis of 90-300 pmol of Zn-pheophytin a or of about 400-600 pmol of chlorophyll a/4.2 x 10(7) etioplasts. The yield of stabilized chlorophyll proteins decreased at higher concentrations of Zn-pheophytin a, but was unaffected by higher concentrations of chlorophyll a.
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Affiliation(s)
- L A Eichacker
- Department of Botany, University of Munich, 80638 München, Menzinger Strasse 67, Federal Republic of Germany.
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31
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Scheumann V, Ito H, Tanaka A, Schoch S, Rüdiger W. Substrate specificity of chlorophyll(ide) b reductase in etioplasts of barley (Hordeum vulgare L.). Eur J Biochem 1996; 242:163-70. [PMID: 8954166 DOI: 10.1111/j.1432-1033.1996.0163r.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Enzyme activity of chlorophyll(ide) b reductase is present in etioplasts. Recently the conversion of chlorophyllide b to chlorophyll a via 7(1)-hydroxychlorophyll a was demonstrated in barley etioplasts. We used zinc pheophorbide b for a detailed investigation of the reduction of the 7-formyl group to the 7(1)-hydroxy compound in intact barley etioplasts. The reaction proceeded likewise before esterification and after esterification with phytyl diphosphate. The metal-free pheophorbide b, that is not accepted by chlorophyll synthase for esterification, is reduced to 7(1)-hydroxypheophorbide a to a small extent. The zinc (13(2)S)-pheophorbide b is at least equally well accepted for reduction as the epimer with the 13(2)R configuration of natural chlorophyll b. The reaction requires NADPH or NADH, although the latter is less effective. ATP is not required for the first step to the 7(1)-hydroxy compound. The significance of chlorophyll b reduction for acclimation from shade to sun leaves and for chlorophyll degradation is discussed.
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Affiliation(s)
- V Scheumann
- Botanisches Institut der Universität München, Germany
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32
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Schoch S, Helfrich M, Wiktorsson B, Sundqvist C, Rüdiger W, Ryberg M. Photoreduction of zinc protopheophorbide b with NADPH-protochlorophyllide oxidoreductase from etiolated wheat (Triticum aestivum L.). Eur J Biochem 1995; 229:291-8. [PMID: 7744043 DOI: 10.1111/j.1432-1033.1995.tb20468.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A preparation of prolamellar bodies from wheat etioplasts was used as a source for NADPH-protochlorophyllide oxidoreductase (pchlide reductase). The enzyme was solubilized with Triton X-100 after reduction of the endogenous photoconvertible protochlorophyllide a to chlorophyllide a by saturating illumination. Protochlorophylls a and b, protochlorophyllide a and zinc protopheophorbide b were added to the soluble enzyme preparation to determine if they were reduced in the dark or in the light. None of the compounds were reduced (with NADPH) in the dark; however, light-dependent reduction was demonstrated with protochlorophyllide a and zinc protopheophorbide b. The yield was approximately 50% for both substrates. Photoreduction did not occur with the esterified protochlorophylls a and b. Photoreduction of zinc protopheophorbide b, the zinc analogue of protochlorophyllide b, is the first demonstration of the reduction of a chlorophyll-b-related compound by pchlide reductase.
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Affiliation(s)
- S Schoch
- Botanical Institute, University of Munich, Germany
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33
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Brunner H, Rüdiger W. On the expression of several Lhc genes in garden cress (Lepidium sativum L.). Z NATURFORSCH C 1994; 49:802-10. [PMID: 7865032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The polymerase chain reaction was used to prepare gene-specific probes for several Lhc genes coding for chlorophyll a/b-binding proteins of cress (Lepidium sativum L.). Due to the presence of about 150 basepairs of the coding region, the isolated clones could be attributed to Lhc a3 (1 clone), Lhc b1 (5 clones), Lhc b2 (1 clone) and Lhc b3 (1 clone) genes. Probes prepared from the 3'non-coding regions of the clones did not cross-hybridize; they were specific for 3 different Lhc b1 transcripts and one each of Lhc b2, Lhc b3 and Lhc a3 transcripts. The transcript levels were higher in leaves than in cotyledons of light-grown seedlings; they decreased significantly in cotyledons from week 1 to week 4. The levels of 2 Lhc b1 transcripts (detected with probes cd1 and cd2) changed from 1 week old cotyledons (30% cd1, 28% cd2) to 3 months old leaves (14% cd1), 44% cd2), stems (11% cd1, 56% cd2) and fruits (15% cd1, 62% cd2, all values percent of total transcripts), whereas transcript levels of another Lhc b1 gene (detected with probe cd3) and of a Lhc a3 gene remained nearly constant. The level of Lhc b2 and Lhc b3 transcripts were 1-2 orders of magnitude smaller than those of the other Lhc transcripts. The data obtained with cress plants are compared with published data from other plants.
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Affiliation(s)
- H Brunner
- Botanisches Institut der Universität München, Bundesrepublik Deutschland
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Hanfstingl U, Berry A, Kellogg EA, Costa JT, Rüdiger W, Ausubel FM. Haplotypic divergence coupled with lack of diversity at the Arabidopsis thaliana alcohol dehydrogenase locus: roles for both balancing and directional selection? Genetics 1994; 138:811-28. [PMID: 7851777 PMCID: PMC1206230 DOI: 10.1093/genetics/138.3.811] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We designate a region of the alcohol dehydrogenase locus (Adh) of the weedy crucifer, Arabidopsis thaliana, as "hypervariable" on the basis of a comparison of sequences from ecotypes Columbia and Landsberg. We found eight synonymous and two replacement mutations in the first 262 nucleotides of exon 4, and an additional two mutations in the contiguous region of intron 3. The rest of the sequence (2611 bp) has just three mutations, all of them confined to noncoding regions. Our survey of the hypervariable region among 37 ecotypes of A. thaliana revealed two predominant haplotypes, corresponding to the Columbia and Landsberg sequences. We identified five additional haplotypes and 4 additional segregating sites. The lack of haplotype diversity is presumably in part a function of low rates of recombination between haplotypes conferred by A. thaliana's tendency to self-fertilize. However, an analysis in 32 ecotypes of 12 genome-wide polymorphic markers distinguishing Columbia and Landsberg ecotypes indicated levels of outcrossing sufficient at least to erode linkage disequilibrium between dispersed markers. We discuss possible evolutionary explanations for the coupled observation of marked divergence within the hypervariable region and a lack of haplotype diversity among ecotypes. The sequence of the region for closely related species argues against the possibility that one allele is the product of introgression. We note (1) that several loss of function mutations (both naturally and chemically induced) map to the hypervariable region, and (2) the presence of two amino acid replacement polymorphisms, one of which causes the mobility difference between the two major classes of A. thaliana Adh electrophoretic alleles. We argue that protein polymorphism in such a functionally significant part of the molecule may be subject to balancing selection. The observed pattern of extensive divergence between the alleles is consistent with this explanation because balancing selection on a particular site maintains linked neutral polymorphisms at intermediate frequencies.
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Affiliation(s)
- U Hanfstingl
- Department of Genetics, Harvard Medical School, Boston, Massachusetts
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Gus-Mayer S, Brunner H, Schneider-Poetsch HA, Rüdiger W. Avenacosidase from oat: purification, sequence analysis and biochemical characterization of a new member of the BGA family of beta-glucosidases. Plant Mol Biol 1994; 26:909-21. [PMID: 8000004 DOI: 10.1007/bf00028858] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A protein consisting of 60 kDa subunits (As-P60) was isolated from etiolated oat seedlings (Avena sativa L.) and characterized as avenacosidase, a beta-glucosidase that belongs to a preformed defence system of oat against fungal infection. The enzyme is highly aggregated; it consists of 300-350 kDa aggregates and multimers thereof. Dissociation by freezing/thawing leads to complete loss of enzyme activity. The specificity of the enzyme was investigated with para-nitrophenyl derivatives which serve as substrates, in decreasing order beta-fucoside, beta-glucoside, beta-galactoside, beta-xyloside. The corresponding orthonitrophenyl glycosides are less well accepted. No hydrolysis was found with alpha-glycosides and beta-thioglucoside. An anti-As-P60 antiserum was prepared and used for isolation of a cDNA clone coding for As-P60. A presequence of 55 amino acid residues was deduced from comparison of the cDNA sequence with the N-terminal sequence determined by Edman degradation of the mature protein. The presequence has the characteristics of a stroma-directing signal peptide; localization of As-P60 in plastids of oat seedlings was confirmed by western blotting. The amino acid sequence revealed significant homology (> 39% sequence identity) to beta-glucosidases that are constituents of a defence mechanism in dicotyledonous plants. 34% sequence identity was even found with mammalian and bacterial beta-glucosidases of the BGA family. Avenacosidase extends the occurrence of this family of beta-glucosidases to monocotyledonous plants.
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Affiliation(s)
- S Gus-Mayer
- Botanisches Institut, Universität München, Germany
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36
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Gus-Mayer S, Brunner H, Schneider-Poetsch HA, Lottspeich F, Eckerskorn C, Grimm R, Rüdiger W. The amino acid sequence previously attributed to a protein kinase or a TCP1-related molecular chaperone and co-purified with phytochrome is a beta-glucosidase. FEBS Lett 1994; 347:51-4. [PMID: 8013661 DOI: 10.1016/0014-5793(94)00503-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A 60 kDa protein (P60) co-purified with phytochrome was identified as avenacosidase, a beta-glucosidase which is part of the defense system of Avena sativa. An antiserum raised against P60 was used to isolate a cDNA clone coding for the complete amino acid sequence of P60. The cDNA-derived amino acid sequence contained the partial sequences described before for a protein kinase [(1989) Planta 178, 199-206] and for a TCP1-related molecular chaperone [(1993) Nature 363, 644-647] co-purified with phytochrome. We conclude that these activities were related to minor contaminants and that only sequences of avenacosidase had been obtained.
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Affiliation(s)
- S Gus-Mayer
- Botanisches Institut, Universität München, Germany
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37
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Burghardt H, Brunner H, Oelmüller R, Lottspeich F, Oster U, Rüdiger W. Natural inhibitors of germination and growth, VII synthesis of ribulosebisphosphate carboxylase in darkness and its inhibition by coumarin. Z NATURFORSCH C 1994; 49:321-6. [PMID: 8060457 DOI: 10.1515/znc-1994-5-607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cress (Lepidium sativum) seeds were germinated in darkness. Seedlings were investigated for soluble proteins by SDS-PAGE. Two proteins were identified by microsequencing: the small subunit of ribulosebisphosphate carboxylase (SSU) and the alpha subunit of the storage protein cruciferin. Net synthesis of small and large subunits of ribulosebisphosphate carboxylase (SSU and LSU) was investigated by Western blot. Net synthesis of both subunits was inhibited by coumarin. To the contrary, net synthesis of cruciferin was increased by coumarin. With specific cDNA probes, we determined steady state levels of the corresponding mRNAs (rbcS mRNA for SSU, rbcL mRNA for LSU). Both mRNAs can be detected in dry seeds; their amount increases during germination in the dark. Incubation with coumarin inhibits this increase. Inhibition of development by coumarin on the level of transcription is discussed.
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Affiliation(s)
- H Burghardt
- Botanisches Institut, Universität München, Bundesrepublik Deutschland
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38
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Abstract
Chlorophyll synthetase catalyzes the last step of chlorophyll biosynthesis, namely prenylation (esterification) of chlorophyllide with phytyl diphosphate or geranylgeranyl diphosphate. During investigation of various chlorophyllide derivatives as potential substrates we observed lower esterification with increasing percentages of chlorophyllide a' in epimeric mixtures of chlorophyllides a and a'. To avoid epimerization during esterification, we studied the reaction in detail with model compounds [zinc-13(2)(R)-methoxy-pheophorbide a and zinc-13(2)(S)-methoxy-pheophorbide a, zinc-13(2)(R)-methoxy-pyropheophorbide a and zinc-chlorine6-13(1), 15(2)-dimethylester]. We conclude that compounds which have the 13(2)-carbomethoxy group at the same side of the macrocycle as the propionic side chain of ring D are neither substrates nor competitive inhibitors. Only compounds having the 13(2)-carbomethoxy group at the opposite site are substrates for the enzyme. Naturally occurring chlorophyll a' must be formed by epimerization after esterification.
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Affiliation(s)
- M Helfrich
- Botanisches Institut, Universität München, Germany
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Bonenberger J, Schendel R, Schneider-Poetsch HA, Rüdiger W. Structural studies on the photoreceptor phytochrome: reevaluation of the epitope for monoclonal antibody Z-3B1. Photochem Photobiol 1992; 56:717-23. [PMID: 1282262 DOI: 10.1111/j.1751-1097.1992.tb02226.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The photoreceptor phytochrome is widely distributed in the plant kingdom from angiosperms to ferns, mosses and algae. The epitope for the monoclonal antibody Z-3B1 which exhibits wide-ranging cross-reactivity with phytochromes from higher and lower plants was mapped by the combination of several methods: by Western blot with proteolytic fragments of known localization, by sequence comparison of phytochromes from various plants, and by production of overlapping fusion proteins. The only sequence which is common to all positively-reacting fusion proteins is the sequence A-830 to R-859. This sequence must contain the Z-3B1 epitope. The best candidate is suggested to be the T-cell antigenic sequence K-Y-V/I-E-A/C-L-L-T (= K-848 to T-855). The significance of the highly conserved epitope in all phytochromes is discussed.
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Affiliation(s)
- J Bonenberger
- Botanisches Institut der Universität München, Germany
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40
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Abstract
The photoconversion of Pr to Pfr has been investigated by a large number of investigators. We have previously demonstrated that Z, E isomerization of the tetrapyrrole chromophore is involved in the photoconversion. It is the best candidate for the primary photoreaction. Conformation and configuration of the Pr chromophore will be compared with that of chromophores in phycocyanin. The crystal structure of phycocyanin had been elucidated by x-ray analysis. Proton transfer and/or Z, E isomerization of the tetrapyrrole are probably involved in different steps of the photoconversion in phytochrome and in photoreversible phycobiliproteins. Fluorescence decay kinetics of irradiated Pr and intermediate formation show heterogeneity. Possible reasons for this heterogeneity will be discussed.
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Affiliation(s)
- W Rüdiger
- Botanisches Institut, Universität München, Germany
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Hess WR, Schendel R, Rüdiger W, Fieder B, Börner T. Components of chlorophyll biosynthesis in a barley albina mutant unable to synthesize δ-aminolevulinic acid by utilizing the transfer RNA for glutamic acid. Planta 1992; 188:19-27. [PMID: 24178195 DOI: 10.1007/bf00198935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/1991] [Accepted: 03/10/1992] [Indexed: 06/02/2023]
Abstract
Components of chlorophyll biosynthesis were investigated in the plastid-ribosome-deficient albostrians mutant of barley (Hordeum vulgare L.). Compared with green leaves, white leaves lacked chloroplast tRNA(Glu) and 16S ribosomal RNA, but contained a much higher level of the mRNA for glutamate 1-semialdehyde aminotransferase. Substantial amounts of protochlorophyllide were accumulated when the mutant was incubated in a solution of δ-aminolevulinic acid. The level of protochlorophyllide oxidoreductase mRNA (PCOR, EC 1.6.99.1.) in etiolated albostrians plants reached only about 50% of the level in wild-type plants. In addition the content of PCOR protein and the activity of chlorophyll synthetase were distinctly lower than in the wild-type. Mutant and wild-type barley seedlings which were grown under a daily light/dark regime and were therefore nonetiolated both possessed PCOR mRNA. The data presented may help explain the albino phenotype of this mutant. The results are discussed in relation to biosynthesis of tetrapyrrols in higher plants, regulation of chlorophyll biosynthesis and the action of a plastidderived signal involved in the expression of certain nuclear genes.
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Affiliation(s)
- W R Hess
- Humboldt-Universität zu Berlin, Institut für Genetik, Invalidenstrasse 43, 1040, Berlin, Federal Republic of Germany
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43
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Eichacker L, Paulsen H, Rüdiger W. Synthesis of chlorophyll a regulates translation of chlorophyll a apoproteins P700, CP47, CP43 and D2 in barley etioplasts. Eur J Biochem 1992; 205:17-24. [PMID: 1555577 DOI: 10.1111/j.1432-1033.1992.tb16747.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Accumulation of plastid-encoded chlorophyll apoproteins and chlorophyll synthesis are controlled by light in angiosperms. An in vitro system utilizing isolated and lysed barley (Hordeum vulgare L.) etioplasts revealed the specific accumulation of P700, CP47, CP43 and D2 triggered by de novo synthesis of chlorophyll. Accumulation rates of radiolabelled chlorophyll apoproteins were linear for about 30 min. Pulse/chase translation assays showed that synthesis of chlorophyll does not result in increased chlorophyll apoprotein stability. Instead turnover rates of chlorophyll apoproteins were higher in the presence than in the absence of chlorophyll. Chlorophyll-dependent accumulation of chlorophyll apoproteins must therefore be regulated on the level of translation. Translation of chlorophyll apoproteins was blocked to about 50% by addition of 30-50 microM aurintricarboxylic acid or 20 microM kasugamycin. The kinetics of chlorophyll-dependent translation indicated that the in vitro translation system is capable of translation initiation. The capability of translation initiation was lost in lysed etioplasts after preincubation for at least 5 min without chlorophyll synthesis. The results suggest that initiation is involved in chlorophyll-dependent regulation of translation.
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Affiliation(s)
- L Eichacker
- Botanisches Institut, Universität München, Federal Republic of Germany
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44
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Abstract
Fourier-transform infrared difference spectra between the red-absorbing and far-red-absorbing forms of oat phytochrome have been measured in H2O and 2H2O. The difference spectra are compared with infrared spectra of model compounds, i.e. the (5Z,10Z,15Z)- and (5Z,10Z,15E)-isomers of 2,3,7,8,12,13,17,18-octaethyl-bilindion (Et8-bilindion), 2,3-dihydro-2,3,7,8,12,13,17,18-octaethyl-bilindion (H2Et8-bilindion), and protonated H2Et8-bilindion in various solvents. The spectra of the model compounds show that only for the protonated forms can clear differences between the two isomers be detected. Since considerable differences are present between the spectra of Et8-bilindion and H2Et8-bilindion, it is concluded that only the latter compound can serve as a model system of phytochrome. The 2H2O effect on the difference spectrum of phytochrome supports the view that the chromophore in red-absorbing phytochrome is protonated and suggests, in addition, that it is also protonated in far-red-absorbing phytochrome. The spectra show that protonated carboxyl groups are influenced. The small amplitudes in the difference spectra exclude major changes of protein secondary structure.
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Affiliation(s)
- F Siebert
- Albert-Ludwigs-Universität, Institut für Biophysik und Strahlenbiologie, Freiburg, Federal Republic of Germany
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Thümmler F, Beetz A, Rüdiger W. Phytochrome in lower plants. Detection and partial sequence of a phytochrome gene in the moss Ceratodon purpureus using the polymerase chain reaction. FEBS Lett 1990; 275:125-9. [PMID: 2261981 DOI: 10.1016/0014-5793(90)81455-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The polymerase chain reaction was carried out with primers hybridizing to conserved regions of the phytochrome genes. With DNA from the moss Ceratodon purpureus 5 overlapping fragments were obtained resulting in a continuous nucleotide sequence of 1474 bp. The deduced amino acid sequence showed homology of around 60% with all known phytochrome sequences. The sequences contained a conserved chromophore attachment site. In light-grown Ceratodon protonemata the phytochrome mRNA with the size of about 4.5 kb was detected.
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Affiliation(s)
- F Thümmler
- Botanisches Institut, Universität München, FRG
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46
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Eichacker LA, Soll J, Lauterbach P, Rüdiger W, Klein RR, Mullet JE. In vitro synthesis of chlorophyll a in the dark triggers accumulation of chlorophyll a apoproteins in barley etioplasts. J Biol Chem 1990; 265:13566-71. [PMID: 2199441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
An in vitro translation system using lysed etioplasts was developed to test if the accumulation of plastid-encoded chlorophyll a apoproteins is dependent on the de novo synthesis of chlorophyll a. The P700 apoproteins, CP47 and CP43, were not radiolabeled in pulsechase translation assays employing lysed etioplasts in the absence of added chlorophyll precursors. When chlorophyllide a plus phytylpyrophosphate were added to lysed etioplast translation assays in the dark, chlorophyll a was synthesized and radiolabeled P700 apoproteins, CP47 and CP43, and a protein which comigrates with D1 accumulated. Chlorophyllide a or phytylpyrophosphate added separately to the translation assay in darkness did not induce chlorophyll a formation or chlorophyll a apoprotein accumulation. Chlorophyll a formation and chlorophyll a apoprotein accumulation were also induced in the lysed etioplast translation system by the photoreduction of protochlorophyllide to chlorophyllide a in the presence of exogenous phytylpyrophosphate. Accumulation of radiolabeled CP47 was detectable when very low levels of chlorophyll a were synthesized de novo (less than 0.01 nmol/10(7) plastids), and radiolabel increased linearly with increasing de novo chlorophyll a formation. Higher levels of de novo synthesized chlorophyll a were required prior to detection of radiolabel incorporation into the P700 apoproteins and CP43 (greater than 0.01 nmol/10(7) plastids). Radiolabel incorporation into the P700 apoproteins, CP47 and CP43, saturated at a chlorophyll a concentration which corresponds to 50% of the etioplast protochlorophyllide content (0.06 nmol of chlorophyll a/10(7) plastids).
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Affiliation(s)
- L A Eichacker
- Department of Botany, University of Munich, Federal Republic of Germany
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47
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López-Figueroa F, Rüdiger W. A POSSIBLE CONTROL BY PHYTOCHROME and OTHER PHOTORECEPTORS OF PROTEIN ACCUMULATION IN THE GREEN ALGA Ulva rigida. Photochem Photobiol 1990. [DOI: 10.1111/j.1751-1097.1990.tb01763.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Paulsen H, Rümler U, Rüdiger W. Reconstitution of pigment-containing complexes from light-harvesting chlorophyll a/b-binding protein overexpressed inEscherichia coli. Planta 1990; 181:204-211. [PMID: 24196737 DOI: 10.1007/bf02411539] [Citation(s) in RCA: 161] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/1989] [Accepted: 12/16/1989] [Indexed: 06/02/2023]
Abstract
A gene for a light-harvesting chlorophyll (Chl) a/b-binding protein (LHCP) from pea (Pisum sativum L.) has been cloned in a bacterial expression vector. Bacteria (Escherichia coli) transformed with this construct produced up to 20% of their protein as pLHCP, a derivative of the authentic precursor protein coded for by the pea gene with three amino-terminal amino acids added and-or exchanged, or as a truncated LHCP carrying a short amino-terminal deletion into the mature protein sequence. Following the procedure of Plumley and Schmidt (1987, Proc. Natl. Acad. Sci. USA84, 146-150), all bacteria-produced LHCP derivatives can be reconstituted with acetone extracts from pea thylakoids or with isolated pigments to yield pigment-protein complexes that are stable during partially denaturing polyacrylamide-gel electrophoresis. The spectroscopic properties of these complexes closely resemble those of the light-harvesting complex associated with photosystem II (LHCII) isolated from pea thylakoids. The pigment requirement for the reconstitution is highly specific for the pigments found in native LHCII: Chl a and b as well as at least two out of three xanthophylls are necessary. Varying the Chl a:Chl b ratios in the reconstitution mixtures changes the yields of complex formed but not the Chl a:Chl b ratio in the complex. We conclude that LHCP-pigment assembly in vitro is highly specific and that the complexes formed are structurally similar to LHCII. The N-terminal region of the protein can be varied without affecting complex formation and therefore does not seem to be involved in pigment binding.
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Affiliation(s)
- H Paulsen
- Botanisches Institut III der Universität, Menzinger Strasse 67, D-8000, München 19, Germany
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Singh BR, Song PS, Eilfeld P, Rüdiger W. Differential exposure of aromatic amino acids in the red-light-absorbing and far-red-light-absorbing forms of 124-kDa oat phytochrome. Eur J Biochem 1989; 184:715-21. [PMID: 2806252 DOI: 10.1111/j.1432-1033.1989.tb15071.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The surface topography of aromatic amino acid residues and/or other hydrophobic groups of phytochrome has been investigated by ultraviolet absorption spectra and ultraviolet circular dichroism using phytochrome-cyclodextrin inclusion complexation. Three different types of cyclodextrins (alpha, beta and gamma) with varying hydrophobic cavity sizes, were used. Complexation resulted in significant changes in the circular dichroic signals of both the red-light-absorbing (Pr) and far-red-light-absorbing (Pfr) forms of phytochrome in the ultraviolet region at 222 nm, mid-ultraviolet at 280 nm and 300 nm and in the near-ultraviolet and visible regions at 365 nm and 670 mm, respectively, alpha- and beta-Cyclodextrins were markedly (1.7-4.5-fold) more effective in reducing the mid-ultraviolet CD signal of Pr than that of Pfr, indicating a differential inclusion of the aromatic amino acid residues. gamma-Cyclodextrin did not exhibit any significant differentiation. Secondary structure analysis of the phytochrome-cyclodextrin complexes revealed a considerable increase in the alpha-helical contents of both Pr and Pfr forms. The increase in the Pfr form (17-25%) was about twice that in the Pr form (8-9%), indicating a differential effect of complexation on the conformation of the phytochrome protein. Although the photostationary-state equilibrium of the phytochrome was not affected by the cyclodextrin complexation, the Pr----Pfr phototransformation rate was significantly increased. However, the Pfr----Pr photoreversion was not affected significantly. The results suggest a differential complexation of cyclodextrins with the Pr and Pfr forms of phytochrome as a result of a difference in accessibility of aromatic amino acids in the two forms. A detailed analysis of absorption difference spectra and circular dichroic spectra around 280 nm also revealed evidence for a difference in the exposure of aromatic amino acids.
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Affiliation(s)
- B R Singh
- Department of Chemistry, School of Biological Sciences, University of Nebraska, Lincoln
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50
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Abstract
Phytochrome was isolated from etiolated rice seedlings (Oryza sativa L.) by slight modification of the procedure for oat phytochrome. Spectral data of rice phytochrome are comparable with those of oat and rye phytochrome. Controlled proteolysis with endoproteinases Lys-C and Glu-C yielded defined fragments some of which were different for Pr and Pfr. The fragments were identified by comparison with the corresponding fragments of oat phytochrome and by comparison of the amino acid sequences of rice and oat phytochrome. Regions of the peptide chain which are differently exposed in Pr and Pfr were identified. A highly conserved sequence around residues 740-750 is discussed as candidate for an "active center" of signal transduction.
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Affiliation(s)
- R Schendel
- Botanisches Institut der Universität München, Bundesrepublik Deutschland
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