DOCSLIB.ORG

Temporal Control of Differentiation by the Cell Nucleus: Evidence for a Species-Specific Nuclear Suppression of Enzymes at the Early Generative Phase in Acetabularia

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Temporal Control of Differentiation by the Cell Nucleus: Evidence for a Species-Specific Nuclear Suppression of Enzymes at the Early Generative Phase in Acetabularia Temporal control of differentiation by the cell nucleus: evidence for a species-specific nuclear suppression of enzymes at the early generative phase in Acetabularia HORST BANNWARTH Institut fur Naturwissenschaften und ihre Didaktik, Abt. Biologie, Uniuersitat zu Koln, Gronewaldstr. 2, 5000 Koln 41, Germany and EGON J. DE GROOT* Max-Planck-Institut fiir Zellbiologie, Abt. Schweiger, Rosenhof, 6802 Ladenburg, Germany * Author for correspondence Summary The role of the cell nucleus in controling steps of nuclear action is species-specific, the nucleus of the differentiation has been revealed by comparing species Acetabularia acetabulum was replaced by a nucleate and anucleate cells of Acetabularia (Berger nucleus of the species Acetabularia crenulata. The et al. 1987; Bonotto, 1988). In all cases investigated so foreign nucleus did not suppress the increase in far, events related to the generative phase of the life dCMP deaminase (EC 3.5.4.12) enzyme activity. This cycle are expressed earlier in anucleate cells. Conse- result indicates that the suppression by the nucleus quently, the existence of a nuclear suppressor is species-specific. delaying the onset of generative functions in the intact cell has been postulated (Bannwarth and Key words: Acetabularia, enzyme acitivity, nuclear Schweiger, 1983). In order to determine whether this suppression. Introduction suppressed by implanting nuclei. This result excludes the possibility that the early onset is a non-specific reaction to The life cycle of the unicellular and uninucleate marine the surgery, and means that the cell nucleus influences the green alga Acetabularia can be subdivided into a vegetat- onset of gene expression. The exclusion of the cell nucleus ive and a generative phase (Bannwarth, 1988; Schweiger, by other means (ligation, Actinomycin D treatment) 1969). The genetic information is transferred from the always results in an earlier onset of generative events nucleus into the cytoplasm much earlier than needed for (Bannwarth and Schweiger, 1983). gene expression (Hammerling, 1934; Harris, 1970; In order to elucidate the molecular mechanism of the Schweiger, 1980). The duration of the interval between the nuclear control, it is necessary to answer first the question transcription of nuclear DNA and the appearance of the of whether the suppression is species-specific or not. corresponding morphological and physiological features Therefore the activity of dCMP deaminase, an enzyme can be weeks or even months. The genetic program is which is regulated in the early generative phase, has been suppressed until its realization by an as yet unknown investigated (Bannwarth et al. 1982; Schweiger et al. mechanism. 1984). It was discovered many years ago that removing the cell nucleus of an Acetabularia cell leads to an earlier formation of the cap (Beth, 1953; Hammerling and Materials and methods Zetsche, 1966; Werz, 1965). This indicates that the nuclear suppression is removed by enucleation (Rommelaere and Acetabularia was cultured in a synthetic medium as described Hiernaux, 1975; Zetsche, 1966). The rate of total protein before (Berger and Schweiger, 1980; Schweiger et al. 1977). synthesis is also different in nucleate and anucleate cells, Zygotes of a species Acetabularia acetabulum=mediterranea and being higher in enucleated cells (Brachet et al. 1955). Acetabularia crenulata were illuminated and the algae were These are some indications of the existence of nuclear grown for 60 days. Cells of a medium cap size (diameter: 3—4 mm) control by suppression of gene expression. In addition to were selected for the experiments. morphological characteristics, functional features, in Nucleate cells, anucleate cells and intraspecific grafts were particular enzyme regulation, can be used to characterize pretreated and prepared as previously described (Bannwarth and Schweiger, 1983). Interspecific grafts were made by replacing the distinct parts of the life cycle (Berger et al. 1987; nucleus-containing rhizoid of the species Acetabularia acetabu- Schweiger, 1982; Schweiger and Berger, 1979). lum by a rhizoid of the species Acetabularia crenulata. The early onset of deoxycytidine monophosphate The medium was changed after two weeks and the enzyme (dCMP) deaminase activity induced by enucleation can be activity was estimated every 3-5 days. Enzyme activities of Journal of Cell Science 100, 863-868 (1991) Printed in Great Britain © The Company of Biologists Limited 1991 863 dCMP deaminase (Bannwarth et al. 1982) were estimated in four cells. The incidence of cyst formation and the translocation of chloroplasts from the stalk into the cap were recorded over the 40-45 day duration of the experiments. Results Intraspecific grafts The activity of dCMP deaminase increased dramatically in nucleate cells of Acetabularia acetabulum after the growth of the cap ceased (Bannwarth et al. 1982; Bannwarth and Schweiger, 1983). The events that led to this regulation occurred some time before the enzyme activity started to increase. This conclusion can be drawn from the fact that enzyme activity also increased in cells which were enucleated two or three weeks earlier. In all the cases investigated so far, the regulation was achieved by de novo synthesis of enzyme proteins, independent of the site of synthesis, on 70 S or 80 S ribosomes (Schweiger et al. 1984). The enzyme activity was not regulated synchronously in nucleate and anucleate cells. Depending upon the stage of development, the increase in enzyme activity occurred suddenly or after a certain lag phase. In each case it was earlier in enucleated than in intact cells. The early increase in enzyme activity in the anucleate cell seemed not to be due to the surgery, but due to the 10 20 absence of the nucleus. In order to prove this assumption, Time (days) the nucleate cells were also subjected to surgery. The cells were subdivided into a larger anterior, anucleate part and Fig. 1. Suppression of dCMP deaminase activity in nucleate cells and in intraspecific grafts of Acetabularia acetabulum. a smaller, nucleate posterior rhizoid part, and sub- Homogenates taken from four cells were incubated at 37 °C for sequently recombined (Bannwarth and Schweiger, 1983). 1 h in the presence of dCTP and [14C]dCMP as described These cells exhibited a delayed increase in enzyme earlier (Bannwarth et al. 1982). Values are given as activity as is typical for nucleate cells. Cysts were also radioactivity in [uC]dUMP per cell. The experiment was formed at the same time in treated and untreated nucleate started with cells of 3 mm cap diameter and terminated with cells (Fig. 1). cells of 11 mm cap diameter. Approximately 50% cysts finally This was in accordance with the hypothesis that the were formed. •, nucleate untreated controls; •, nucleate retransplanted cells (%); A, cysts in the untreated cells (%); A, nucleus normally suppresses all the steps leading to the cysts in the retransplanted cells (%). onset of generative events until its disintegration. The cell nucleus, therefore, not only gave early instructions to the cell cytoplasm, but it also influenced the temporal control after the beginning of the experiment, the influence of the and the sequence of developmental steps. crenulata nucleus became apparent by a dramatic new increase in dCMP deaminase activity in the interspecific Interspecific grafts grafts, while it increased only slightly in the anucleate The next question concerned the species specificity of the controls. suppression described above. It could be answered by It seemed therefore that the foreign nucleus did not replacing the cell nucleus with a foreign nucleus from control the host-specific genetic program of Acetabularia another species. The cell nucleus of Acetabularia acetabu- acetabulum, but expressed its own species-specific regulat- lum cells was removed by cutting off the rhizoid and ory instructions of Acetabularia crenulata at a later time. replaced by the nucleus-containing rhizoid of Acetabularia The species-specific influence of the foreign nucleus on the crenulata. regulation of enzyme activity can be pointed out by The result of this experiment was that the foreign comparing heterologous grafts with the untreated cells of nucleus was not able to suppress the early increase of both species (Fig. 3). The activity of dCMP deaminase enzyme activity. It could not regulate the generative activity started to increase earlier in the Acetabularia functions as the homologous nucleus does. The enzyme crenulata cells than in Acetabularia acetabulum. Again, in activity increased after the exchange of the nuclei at least the hybrid grafts the enzyme activity behaved at first in a as fast as in enucleated cells (Fig. 2). This indicated that similar manner to that in the anucleate cell, showing the the suppression was species-specific. Heterologous nuclei immediate typical small increase, and in addition, 28 days obviously were unable to accomplish the temporal control after the nuclear exchange, the foreign nucleus of the of generative functions in a foreign cell. species Acetabularia crenulata provoked a new species- On the other hand this statement does not mean that the specific increase in enzyme activity. This increase was foreign nucleus has no influence on the regulation of the parallel to that of crenulata cells, but occurred with a delay enzyme activity in the hybrid cells. It took some time of about four days. This time was obviously needed for the before a significant difference between anucleate cells and change from the acetabulum to the crenulata type. cells with a foreign nucleus could be detected. Three weeks This means that a nucleus-dependent regulation in the 864 H. Bannwarth and E. J. de Groot 2.5 o o x CD 0) 0.5 10 20 30 20 30 LO Time (days) 10 Time (days) Fig. 2. Suspension of the suppression of dCMP deaminase activity increase in anucleate cells of Acetabularia acetabulum Fig. 3. Species-specific regulation of dCMP deaminase activity and in cells of this species with a foreign nucleus (interspecific in nucleate cells of Acetabularia acetabulum and Acetabularia grafts, creniXaceto). In the absence of the cell nucleus the crenulata as well as in interspecific grafts of both species.
Load more

Recommended publications
  • Syllabus of Msc Degree in Botany W.E.F. 2019-20
    UNIVERSITY OF KERALA THIRUVANANTHAPURAM M.Sc. Degree in Botany (Semester System) Revised Course Structure & Syllabus (w.e.f. 2019 Admissions) October 2018 PG BOARD OF STUDIES IN BOTANY UNIVERSITY OF KERALA M.Sc. Degree in Botany (Semester System) Revised Course structure Semes Paper Hours/ Hours / ESA Title of the Paper Maximum Marks ter Code semester week hours L P 3 CA ESA Total Phycology, Mycology, BO 211 108 6 2 3 25 75 100 Microbiology & Plant Pathology Bryophyta, Pteridophyta & I BO212 Gymnosperms 108 6 2 3 25 75 100 Histology, Reproductive Biology, BO213 Microtechnique & Histochemistry 108 6 3 3 25 75 100 BO214 Practical I 126 7 4 25♦ 75♦ Δ Total for Semester I 450 18 7 13 75 225 300 Taxonomy of Angiosperms, BO 221 Economic Botany & Ethnobotany 108 6 2.5 3 25 75 100 Environmental Biology, Forest BO 222 Botany, Phytogeography & 108 6 2 3 25 75 100 Conservation Biology II Cell Biology, Genetics & Evolution BO 223 108 6 2.5 3 25 75 100 Practical I 100♦ BO 224 Practical II 126 7 4 25 75 100 BO 225 Submission I* (I A+1B) 25+25 50 Total for Semester II 450 18 7 13 100 350 550 Plant Breeding, Horticulture & BO 231 108 6 1.5 3 25 75 100 Biostatistics Biochemistry, Plant Physiology BO 232 & Research Methodology 108 6 3 3 25 75 100 III Molecular Biology, Immunology & BO 233 108 6 2.5 3 25 75 100 Plant Biotechnology BO 234 Practical III 126 7 4 25♦♦ 75♦♦ Δ Δ Total for Semester III 450 18 7 13 75 225 300 Special Paper –I BO 241 Bioinformatics & Biophysics 144 8 2 3 25 75 100 BO 242 Special Paper –II Elective 144 8 5 3 25 75 100 Practical III 100♦♦ IV BO 243 Practical IV 126 7 4 25 75 100 BO 244 Dissertation 36 2 100 100 BO 245 Submissions II** 50 50 BO 246 Comprehensive Viva Voce 25 .
    [Show full text]
  • Plant Evolution Acetabularia Is a Genus of Green Algae
    Botany – Plant Evolution Acetabularia is a genus of green algae, specifically of the Polyphysaceae family. Typically found in subtropical waters, Acetabularia is a single- celled organism, but gigantic in size and complex in form, making it an excellent model organism for studying cell biology. The name, Acetabularia, derives from the Latin word acetabulum, a broad, shallow cup used for dipping bread; the upturned cap of Acetabularia resembles such a cup. For this reason, it is also sometimes called mermaid's wineglass.[6] Acetabularia was the first demonstration that genes are encoded by DNA in eukaryotes. Cladophora is a genus of reticulated filamentous Ulvophyceae (green algae). The genus Cladophora contains many species that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is affected by habitat, age and environmental conditions. Unlike Spirogyra the filaments of Cladophora branch and it doesn't undergo conjugation. They have swimming gametes instead. There are two multicellular stages in its life cycle - a haploid gametophyte and a diploid sporophyte - which look highly similar. The only way to tell the two stages apart is to either count their chromosomes, or examine their offspring. The haploid gametophyte produces haploid gametes by mitosis and the diploid sporophyte produces haploid spores by meiosis. The only visible difference between the gametes and spores of Cladophora is that the gametes have two flagella and the spores have four. Cladophora is an invahsive species damaging the fishing industry and shoreline property values along the Great Lakes in the United States Chara species are multicellular and superficially resemble land plants because of stem-like and leaf-like structures.
    [Show full text]
  • Plant Life Magill’S Encyclopedia of Science
    MAGILLS ENCYCLOPEDIA OF SCIENCE PLANT LIFE MAGILLS ENCYCLOPEDIA OF SCIENCE PLANT LIFE Volume 4 Sustainable Forestry–Zygomycetes Indexes Editor Bryan D. Ness, Ph.D. Pacific Union College, Department of Biology Project Editor Christina J. Moose Salem Press, Inc. Pasadena, California Hackensack, New Jersey Editor in Chief: Dawn P. Dawson Managing Editor: Christina J. Moose Photograph Editor: Philip Bader Manuscript Editor: Elizabeth Ferry Slocum Production Editor: Joyce I. Buchea Assistant Editor: Andrea E. Miller Page Design and Graphics: James Hutson Research Supervisor: Jeffry Jensen Layout: William Zimmerman Acquisitions Editor: Mark Rehn Illustrator: Kimberly L. Dawson Kurnizki Copyright © 2003, by Salem Press, Inc. All rights in this book are reserved. No part of this work may be used or reproduced in any manner what- soever or transmitted in any form or by any means, electronic or mechanical, including photocopy,recording, or any information storage and retrieval system, without written permission from the copyright owner except in the case of brief quotations embodied in critical articles and reviews. For information address the publisher, Salem Press, Inc., P.O. Box 50062, Pasadena, California 91115. Some of the updated and revised essays in this work originally appeared in Magill’s Survey of Science: Life Science (1991), Magill’s Survey of Science: Life Science, Supplement (1998), Natural Resources (1998), Encyclopedia of Genetics (1999), Encyclopedia of Environmental Issues (2000), World Geography (2001), and Earth Science (2001). ∞ The paper used in these volumes conforms to the American National Standard for Permanence of Paper for Printed Library Materials, Z39.48-1992 (R1997). Library of Congress Cataloging-in-Publication Data Magill’s encyclopedia of science : plant life / edited by Bryan D.
    [Show full text]
  • (Polyphysacea, Dasycladales, Chlorophyta), Mid
    Geologica Acta: an international earth science journal ISSN: 1695-6133 [email protected] Universitat de Barcelona España Granier, B.; Dias Brito, D.; Bucur, I. I. Clypeina tibanai, sp. nov. (Polyphysacea, Dasycladales, Chlorophyta), mid-Cretaceous green alga from the Potiguar Basin, Brazilian margin of the young South Atlantic Ocean Geologica Acta: an international earth science journal, vol. 12, núm. 3, julio-septiembre, 2014, pp. 227- 237 Universitat de Barcelona Barcelona, España Available in: http://www.redalyc.org/articulo.oa?id=50531655005 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Geologica Acta, Vol.12, Nº 3, September 2014, 227-237 DOI: 10.1344/GeologicaActa2014.12.3.5 Clypeina tibanai, sp. nov. (Polyphysacea, Dasycladales, Chlorophyta), mid-Cretaceous green alga from the Potiguar Basin, Brazilian margin of the young South Atlantic Ocean B. GRANIER1 D. DIAS-BRITO2 I.I. BUCUR3 1Department of Ecology and Evolutionary Biology, The University of Kansas 1200 Sunnyside Avenue, Lawrence, Kansas 66045 (USA). E-mail: [email protected] 2UNESP - Universidade Estadual Paulista, Center for Geosciences Applied to Petroleum (UNESPetro) and Departamento de Geologia Caixa Postal 178, Av. 24 A, n º 1515, Bela Vista, CEP13506-900 - Rio Claro -SP (Brazil) 3Babeş-Bolyai University, Department of Geology and Center for Integrated Geological Studies Str. M. Kogalniceanu nr.1, 400084 Cluj-Napoca (Romania) ABS TRACT The fossil genus Clypeina (Michelin, 1845) comprises some 40 species. We describe Clypeina tibanai, a new spe- cies from ? upper Albian–Cenomanian strata of the Potiguar Basin, Brazil, characterised by closely set verticils of tubular, bended laterals.
    [Show full text]
  • Coordination of Cellular Events That Precede Reproductive Onset in Acetabularia Acetabulum: Evidence for a ‘Loop’ in Development
    Development 122, 1187-1194 (1996) 1187 Printed in Great Britain © The Company of Biologists Limited 1996 DEV0050 Coordination of cellular events that precede reproductive onset in Acetabularia acetabulum: evidence for a ‘loop’ in development Linda L. Runft† and Dina F. Mandoli* Department of Botany 355325, University of Washington, Seattle, WA 98195-5325, USA *Author for correspondence †Present address: The University of Connecticut Health Center, Department of Physiology, Farmington, CT, USA SUMMARY Amputated apices from vegetative wildtype cells of the early in adult growth required more cell volume to make a uninucleate green alga Acetabularia acetabulum can differ- cap without the nucleus than did apices removed from cells entiate a reproductive structure or ‘cap’ in the absence of late in adult growth. To define the limits of the cell to reca- the nucleus (Hämmerling, J. (1932) Biologisches Zentral- pitulate development when reproduction falters, we blatt 52, 42-61). To define the limits of the ability of wild- analyzed development in cells whose caps either had been type cells to control reproductive differentiation, we deter- amputated or had spontaneously aborted. After loss of the mined when during development apices from wildtype cells first cap, cells repeated part of vegetative growth and then first acquired the ability to make a cap in the absence of made a second cap. The ability to make a second cap after the nucleus and, conversely, when cells with a nucleus lost amputation of the first one was lost 15-20 days after cap the ability to recover from the loss of their apices. To see initiation. Our data suggest that internal cues, cell age and when the apex acquired the ability to make a cap without size, are used to regulate reproductive onset in Acetabularia the nucleus, we removed apices from cells varying either acetabulum and add to our understanding of how repro- the developmental age of the cells or the cellular volume duction is coordinated in this giant cell.
    [Show full text]
  • Plate. Acetabularia Schenckii
    Training in Tropical Taxonomy 9-23 July, 2008 Tropical Field Phycology Workshop Field Guide to Common Marine Algae of the Bocas del Toro Area Margarita Rosa Albis Salas David Wilson Freshwater Jesse Alden Anna Fricke Olga Maria Camacho Hadad Kevin Miklasz Rachel Collin Andrea Eugenia Planas Orellana Martha Cecilia Díaz Ruiz Jimena Samper Villareal Amy Driskell Liz Sargent Cindy Fernández García Thomas Sauvage Ryan Fikes Samantha Schmitt Suzanne Fredericq Brian Wysor From July 9th-23rd, 2008, 11 graduate and 2 undergraduate students representing 6 countries (Colombia, Costa Rica, El Salvador, Germany, France and the US) participated in a 15-day Marine Science Network-sponsored workshop on Tropical Field Phycology. The students and instructors (Drs. Brian Wysor, Roger Williams University; Wilson Freshwater, University of North Carolina at Wilmington; Suzanne Fredericq, University of Louisiana at Lafayette) worked synergistically with the Smithsonian Institution's DNA Barcode initiative. As part of the Bocas Research Station's Training in Tropical Taxonomy program, lecture material included discussions of the current taxonomy of marine macroalgae; an overview and recent assessment of the diagnostic vegetative and reproductive morphological characters that differentiate orders, families, genera and species; and applications of molecular tools to pertinent questions in systematics. Instructors and students collected multiple samples of over 200 algal species by SCUBA diving, snorkeling and intertidal surveys. As part of the training in tropical taxonomy, many of these samples were used by the students to create a guide to the common seaweeds of the Bocas del Toro region. Herbarium specimens will be contributed to the Bocas station's reference collection and the University of Panama Herbarium.
    [Show full text]
  • Chloroplast Incorporation and Long-Term Photosynthetic Performance Through the Life Cycle in Laboratory Cultures of Elysia Timid
    Chloroplast incorporation and long-term photosynthetic performance through the life cycle in laboratory cultures of Elysia timida (Sacoglossa, Heterobranchia) Schmitt et al. Schmitt et al. Frontiers in Zoology 2014, 11:5 http://www.frontiersinzoology.com/content/11/1/5 Schmitt et al. Frontiers in Zoology 2014, 11:5 http://www.frontiersinzoology.com/content/11/1/5 RESEARCH Open Access Chloroplast incorporation and long-term photosynthetic performance through the life cycle in laboratory cultures of Elysia timida (Sacoglossa, Heterobranchia) Valerie Schmitt1,2, Katharina Händeler2, Susanne Gunkel2, Marie-Line Escande3, Diedrik Menzel4, Sven B Gould2, William F Martin2 and Heike Wägele1* Abstract Introduction: The Mediterranean sacoglossan Elysia timida is one of the few sea slug species with the ability to sequester chloroplasts from its food algae and to subsequently store them in a functional state in the digestive gland cells for more than a month, during which time the plastids retain high photosynthetic activity (= long-term retention). Adult E. timida have been described to feed on the unicellular alga Acetabularia acetabulum in their natural environment. The suitability of E. timida as a laboratory model culture system including its food source was studied. Results: In contrast to the literature reporting that juvenile E. timida feed on Cladophora dalmatica first, and later on switch to the adult diet A. acetabulum, the juveniles in this study fed directly on A. acetabulum (young, non-calcified stalks); they did not feed on the various Cladophora spp. (collected from the sea or laboratory culture) offered. This could possibly hint to cryptic speciation with no clear morphological differences, but incipient ecological differentiation.
    [Show full text]
  • The Umbrella Algae's Crazy Caps
    Flashback_Cell Biology The umbrella algae’s crazy caps Acetabularia is several centimeters long – and consists of a single cell. Joachim Hämmerling from the Kaiser Wilhelm Institute for Biology in Berlin-Dahlem and Hans-Georg Schweiger from the Max Planck Institute for Cell Biology in Ladenburg dedicated most of their research life to the umbrella algae. One of their goals was to find out about the role of the nucleus. TEXT ELKE MAIER Berlin-Dahlem in 1931. It was a rather is regenerated time and time again. peculiar little plant that the biolo- The nucleus can be isolated and gist Joachim Hämmerling was con- transferred into another Acetabu- templating. It did not really look like laria fragment, even a foreign one, a plant at all, but more like an um- without losing its functionality. The brella or a small mushroom. A thin little plant was the perfect model stalk the length of a finger was organism to tackle fundamental equipped with a flat, ribbed cap on questions of cell biology. one end, and a root-like holdfast on In order to find out more about the other end which the plant used the function of the nucleus, Häm- to anchor itself to the substrate in merling removed the nucleus of a the surf zone of the sea. young specimen that had not yet Hämmerling’s object of study formed a cap. And lo and behold: was a type of umbrella algae known against all expectations the plant as Acetabularia mediterranea. From a Pioneers of cell biology: Joachim Hämmerling (left) did not die – quite the contrary.
    [Show full text]
  • Neoproterozoic Origin and Multiple Transitions to Macroscopic Growth in Green Seaweeds
    bioRxiv preprint doi: https://doi.org/10.1101/668475; this version posted June 12, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Neoproterozoic origin and multiple transitions to macroscopic growth in green seaweeds Andrea Del Cortonaa,b,c,d,1, Christopher J. Jacksone, François Bucchinib,c, Michiel Van Belb,c, Sofie D’hondta, Pavel Škaloudf, Charles F. Delwicheg, Andrew H. Knollh, John A. Raveni,j,k, Heroen Verbruggene, Klaas Vandepoeleb,c,d,1,2, Olivier De Clercka,1,2 Frederik Leliaerta,l,1,2 aDepartment of Biology, Phycology Research Group, Ghent University, Krijgslaan 281, 9000 Ghent, Belgium bDepartment of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium cVIB Center for Plant Systems Biology, Technologiepark 71, 9052 Zwijnaarde, Belgium dBioinformatics Institute Ghent, Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium eSchool of Biosciences, University of Melbourne, Melbourne, Victoria, Australia fDepartment of Botany, Faculty of Science, Charles University, Benátská 2, CZ-12800 Prague 2, Czech Republic gDepartment of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA hDepartment of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, 02138, USA. iDivision of Plant Sciences, University of Dundee at the James Hutton Institute, Dundee, DD2 5DA, UK jSchool of Biological Sciences, University of Western Australia (M048), 35 Stirling Highway, WA 6009, Australia kClimate Change Cluster, University of Technology, Ultimo, NSW 2006, Australia lMeise Botanic Garden, Nieuwelaan 38, 1860 Meise, Belgium 1To whom correspondence may be addressed. Email [email protected], [email protected], [email protected] or [email protected].
    [Show full text]
  • H+-Pumping Rhodopsin from the Marine Alga Acetabularia
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Biophysical Journal Volume 91 August 2006 1471–1479 1471 H1-Pumping Rhodopsin from the Marine Alga Acetabularia Satoshi P. Tsunoda,* David Ewers,y Sabrina Gazzarrini,z Anna Moroni,z Dietrich Gradmann,y and Peter Hegemann* *Experimentelle Biophysik, Fachbereich fu¨r Biologie, Humboldt-Universita¨t zu Berlin, 10115 Berlin, Germany; yA.-v.-Haller-Institut der Universita¨t, 37073 Go¨ttingen, Germany; and zDipartimento di Biologia and Consiglio Nazionale delle Ricerche Istituto di Biofisica, Universita` degli Studi di Milano, 20133 Milan, Italy ABSTRACT An opsin-encoding cDNA was cloned from the marine alga Acetabularia acetabulum. The cDNA was expressed in Xenopus oocytes into functional Acetabularia rhodopsin (AR) mediating H1 carried outward photocurrents of up to 1.2 mA with an action spectrum maximum at 518 nm (AR518). AR is the first ion-pumping rhodopsin found in a plant organism. Steady- state photocurrents of AR are always positive and rise sigmoidally from negative to positive transmembrane voltages. Numerous kinetic details (amplitudes and time constants), including voltage-dependent recovery of the dark state after light-off, are documented with respect to their sensitivities to light, internal and external pH, and the transmembrane voltage. The results are analyzed by enzyme kinetic formalisms using a simplified version of the known photocycle of bacteriorhodopsin (BR). Blue- 1 light causes a shunt of the photocycle under H reuptake from the extracellular side. Similarities and differences of AR with BR are pointed out. This detailed electrophysiological characterization highlights voltage dependencies in catalytic membrane processes of this eukaryotic, H1-pumping rhodopsin and of microbial-type rhodopsins in general.
    [Show full text]
  • BMC Evolutionary Biology Biomed Central
    BMC Evolutionary Biology BioMed Central Research article Open Access Complex distribution of EFL and EF-1α proteins in the green algal lineage Geoffrey P Noble, Matthew B Rogers and Patrick J Keeling* Address: Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada Email: Geoffrey P Noble - [email protected]; Matthew B Rogers - [email protected]; Patrick J Keeling* - [email protected] * Corresponding author Published: 23 May 2007 Received: 5 February 2007 Accepted: 23 May 2007 BMC Evolutionary Biology 2007, 7:82 doi:10.1186/1471-2148-7-82 This article is available from: http://www.biomedcentral.com/1471-2148/7/82 © 2007 Noble et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: EFL (or elongation factor-like) is a member of the translation superfamily of GTPase proteins. It is restricted to eukaryotes, where it is found in a punctate distribution that is almost mutually exclusive with elongation factor-1 alpha (EF-1α). EF-1α is a core translation factor previously thought to be essential in eukaryotes, so its relationship to EFL has prompted the suggestion that EFL has spread by horizontal or lateral gene transfer (HGT or LGT) and replaced EF-1α multiple times. Among green algae, trebouxiophyceans and chlorophyceans have EFL, but the ulvophycean Acetabularia and the sister group to green algae, land plants, have EF-1α.
    [Show full text]
  • Acetabularia Acetabulum
    Plant Cell Physiol. 48(1): 122–133 (2007) doi:10.1093/pcp/pcl053, available online at www.pcp.oxfordjournals.org ß The Author 2006. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: [email protected] Spectroscopic and Biochemical Analysis of Regions of the Cell Wall of the Unicellular ‘Mannan Weed’, Acetabularia acetabulum Erin K. Dunn 1, 5, Douglas A. Shoue 2, 5, Xuemei Huang 3, Raymond E. Kline 4, Alex L. MacKay 3, Nicholas C. Carpita 2, Iain E.P. Taylor 4 and Dina F. Mandoli 1,Ã 1 Department of Biology, Center for Developmental Biology & Institute for Stem Cell and Regenerative Medicine, Box 35325, University of Washington, Seattle, WA 98195-5325, USA 2 Department of Botany and Plant Pathology, Purdue University, W. Lafayette, Indiana 47907-2054, USA 3 Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada V6T 1Z1 4 Department of Botany, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 Downloaded from https://academic.oup.com/pcp/article/48/1/122/2469303 by guest on 29 September 2021 Although the Dasycladalean alga Acetabularia acetabulum Introduction has long been known to contain mannan-rich walls, it is not known to what extent wall composition varies as a function of The Mediterranean coralline alga Acetabularia the elaborate cellular differentiation of this cell, nor has it acetabulum (previously classified as A. mediterranea)isa been determined what other polysaccharides
    [Show full text]