1
|
Aspects of the Neurospora crassa Sulfur Starvation Response Are Revealed by Transcriptional Profiling and DNA Affinity Purification Sequencing. mSphere 2021; 6:e0056421. [PMID: 34523983 PMCID: PMC8550094 DOI: 10.1128/msphere.00564-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Accurate nutrient sensing is important for rapid fungal growth and exploitation of available resources. Sulfur is an important nutrient source found in a number of biological macromolecules, including proteins and lipids. The model filamentous fungus Neurospora crassa is capable of utilizing sulfur found in a variety of sources from amino acids to sulfate. During sulfur starvation, the transcription factor CYS-3 is responsible for upregulation of genes involved in sulfur uptake and assimilation. Using a combination of RNA sequencing and DNA affinity purification sequencing, we performed a global survey of the N. crassa sulfur starvation response and the role of CYS-3 in regulating sulfur-responsive genes. The CYS-3 transcription factor bound the promoters and regulated genes involved in sulfur metabolism. Additionally, CYS-3 directly activated the expression of a number of uncharacterized transporter genes, suggesting that regulation of sulfur import is an important aspect of regulation by CYS-3. CYS-3 also directly regulated the expression of genes involved in mitochondrial electron transfer. During sulfur starvation, genes involved in nitrogen metabolism, such as amino acid and nucleic acid metabolic pathways, along with genes encoding proteases and nucleases that are necessary for scavenging nitrogen, were activated. Sulfur starvation also caused changes in the expression of genes involved in carbohydrate metabolism, such as those encoding glycosyl hydrolases. Thus, our data suggest a connection between sulfur metabolism and other aspects of cellular metabolism. IMPORTANCE Identification of nutrients present in the environment is a challenge common to all organisms. Sulfur is an important nutrient source found in proteins, lipids, and electron carriers that are required for the survival of filamentous fungi such as Neurospora crassa. Here, we transcriptionally profiled the response of N. crassa to characterize the global response to sulfur starvation. We also used DNA affinity purification sequencing to identify the direct downstream targets of the transcription factor responsible for regulating genes involved in sulfur uptake and assimilation. Along with genes involved in sulfur metabolism, this transcription factor regulated a number of uncharacterized transporter genes and genes involved in mitochondrial electron transfer. Our data also suggest a connection between sulfur, nitrogen, and carbon metabolism, indicating that the regulation of a number of metabolic pathways is intertwined.
Collapse
|
2
|
Heavy-metal resistance mechanisms developed by bacteria from Lerma-Chapala basin. Arch Microbiol 2021; 203:1807-1823. [PMID: 33491161 DOI: 10.1007/s00203-020-02140-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 11/08/2020] [Accepted: 12/03/2020] [Indexed: 10/22/2022]
Abstract
Heavy-metal (HM) contamination is a huge environmental problem in many countries including Mexico. Currently, microorganisms with multiple heavy-metal resistance and/or plant-promoting characteristics have been widely used for bioremediation of HM-contaminated soils. The aim of the study was isolated bacteria with multiple heavy-metal resistance and to determinate the resistance mechanism developed by these organisms. A total of 138 aerobic bacteria were isolated from soil and sediments surrounding the Lerma-Chapala basin located in the boundary of the States of Michoacán and Jalisco states of Mexico. One hundred and eight strains showed at least 1 plant growth-promoting features. The Lerma-Chapala basin bacteria were also resistant to high concentrations of HMs including the metalloid arsenic. Sequence analysis of 16S RNA genes reveled that these bacteria were mainly affiliated to the phyla Proteobacteria (38%), Firmicutes (31%) and Actinobacteria (25%), covering 21 genera with Bacillus as the most abundant one. Among them, at least 27 putative novel species were detected in the genera Acinetobacter, Arthrobacter, Bacillus, Agrobacterium, Dyadobacter, Enterobacter, Exiguobacterium, Kluyvera, Micrococcus, Microbacterium and Psychrobacter. In addition, these bacteria developed various heavy-metal-resistance mechanisms, such as biosorption/bioaccumulation, immobilization and detoxification. Therefore, the bacteria isolated from soils and sediments of Lerma-Chapala basin could be used in bioremediation strategies.
Collapse
|
3
|
Marieschi M, Gorbi G, Zanni C, Sardella A, Torelli A. Increase of chromium tolerance in Scenedesmus acutus after sulfur starvation: Chromium uptake and compartmentalization in two strains with different sensitivities to Cr(VI). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 167:124-133. [PMID: 26281774 DOI: 10.1016/j.aquatox.2015.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 07/16/2015] [Accepted: 08/04/2015] [Indexed: 06/04/2023]
Abstract
In photosynthetic organisms sulfate constitutes the main sulfur source for the biosynthesis of GSH and its precursor Cys. Hence, sulfur availability can modulate the capacity to cope with environmental stresses, a phenomenon known as SIR/SED (Sulfur Induced Resistance or Sulfur Enhanced Defence). Since chromate may compete for sulfate transport into the cells, in this study chromium accumulation and tolerance were investigated in relation to sulfur availability in two strains of the unicellular green alga Scenedesmus acutus with different Cr-sensitivities. Paradoxically, sulfur deprivation has been demonstrated to induce a transient increase of Cr-tolerance in both strains. Sulfur deprivation is known to enhance the sulfate uptake/assimilation pathway leading to important consequences on Cr-tolerance: (i) reduced chromate uptake due to the induction of high affinity sulfate transporters (ii) higher production of cysteine and GSH which can play a role both through the formation of unsoluble complexes and their sequestration in inert compartments. To investigate the role of the above mentioned mechanisms, Cr accumulation in total cells and in different cell compartments (cell wall, membranes, soluble and miscellaneous fractions) was analyzed in both sulfur-starved and unstarved cells. Both strains mainly accumulated chromium in the soluble fraction, but the uptake was higher in the wild-type. In this type a short period of sulfur starvation before Cr(VI) treatment lowered chromium accumulation to the level observed in the unstarved Cr-tolerant strain, in which Cr uptake seems instead less influenced by S-starvation, since no significant decrease was observed. The increase in Cr-tolerance following S-starvation seems thus to rely on different mechanisms in the two strains, suggesting the induction of a mechanism constitutively active in the Cr-tolerant strain, maybe a high affinity sulfate transporter also in the wild-type. Changes observed in the cell wall and membrane fractions suggest a strong involvement of these compartments in Cr-tolerance increase following S-starvation.
Collapse
Affiliation(s)
- M Marieschi
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy
| | - G Gorbi
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy
| | - C Zanni
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy
| | - A Sardella
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy
| | - A Torelli
- Department of Life Sciences, University of Parma, Parco Area delle Scienze 11/A, I-43124 Parma, Italy.
| |
Collapse
|
4
|
Viti C, Marchi E, Decorosi F, Giovannetti L. Molecular mechanisms of Cr(VI) resistance in bacteria and fungi. FEMS Microbiol Rev 2013; 38:633-59. [PMID: 24188101 DOI: 10.1111/1574-6976.12051] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/13/2013] [Accepted: 10/28/2013] [Indexed: 11/28/2022] Open
Abstract
Hexavalent chromium [Cr(VI)] contamination is one of the main problems of environmental protection because the Cr(VI) is a hazard to human health. The Cr(VI) form is highly toxic, mutagenic, and carcinogenic, and it spreads widely beyond the site of initial contamination because of its mobility. Cr(VI), crossing the cellular membrane via the sulfate uptake pathway, generates active intermediates Cr(V) and/or Cr(IV), free radicals, and Cr(III) as the final product. Cr(III) affects DNA replication, causes mutagenesis, and alters the structure and activity of enzymes, reacting with their carboxyl and thiol groups. To persist in Cr(VI)-contaminated environments, microorganisms must have efficient systems to neutralize the negative effects of this form of chromium. The systems involve detoxification or repair strategies such as Cr(VI) efflux pumps, Cr(VI) reduction to Cr(III), and activation of enzymes involved in the ROS detoxifying processes, repair of DNA lesions, sulfur metabolism, and iron homeostasis. This review provides an overview of the processes involved in bacterial and fungal Cr(VI) resistance that have been identified through 'omics' studies. A comparative analysis of the described molecular mechanisms is offered and compared with the cellular evidences obtained using classical microbiological approaches.
Collapse
Affiliation(s)
- Carlo Viti
- Dipartimento di Scienze delle Produzioni Agroalimentari e dell'Ambiente - sezione di Microbiologia, Università degli Studi di Firenze, Florence, Italy
| | | | | | | |
Collapse
|
5
|
Flores-Alvarez LJ, Corrales-Escobosa AR, Cortés-Penagos C, Martínez-Pacheco M, Wrobel-Zasada K, Wrobel-Kaczmarczyk K, Cervantes C, Gutiérrez-Corona F. The Neurospora crassa chr-1 gene is up-regulated by chromate and its encoded CHR-1 protein causes chromate sensitivity and chromium accumulation. Curr Genet 2012; 58:281-90. [PMID: 23085746 DOI: 10.1007/s00294-012-0383-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 09/18/2012] [Accepted: 10/05/2012] [Indexed: 10/27/2022]
Abstract
The ChrA membrane protein belongs to the CHR superfamily of chromate ion transporters, which includes homologues from bacteria, archaea and eukaryotes. Bacterial ChrA homologues confer chromate resistance by exporting chromate ions from the cell's cytoplasm. The Neurospora crassa strain 74-A chr-1 gene encodes a putative CHR-1 protein of 507 amino acid residues, which belongs to the CHR superfamily. RT-PCR assays showed that expression of the chr-1 gene was up-regulated by chromate exposure of N. crassa cultures. Introduction in N. crassa of sense and antisense fragments of the chr-1 gene, as part of a silencing module within the pSilent-1 vector, produced transformants with a phenotype of resistance to chromate and diminished accumulation of chromium, as compared with the control strain containing only the vector. A chromate-resistance phenotype was also observed in N crassa strains deleted in the genomic chr-1 gene, thus confirming that the absence of CHR-1 protein confers chromate resistance to the fungus. The cDNA from N. crassa chr-1 gene (Ncchr-1) was cloned into the pYES2 vector under the control of a GAL promoter and the resulting recombinant plasmid was transferred to the yeast Saccharomyces cerevisiae. Galactose-induced S. cerevisiae transformants expressing Ncchr-1 were more sensitive to chromate and accumulated 2.5 times more chromium than the induced strain containing only the vector. Excess sulfate, a chromate analog, was unable to protect S. cerevisiae chr-1 transformants from chromate toxicity. These data indicate that the N. crassa CHR-1 protein functions as a transporter that takes up chromate; it also appears that this transport occurs in a sulfate-independent fashion. This is the first report assigning a role as a chromate transporter to a nonbacterial CHR protein.
Collapse
Affiliation(s)
- Luis J Flores-Alvarez
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana, Morelia, MICH, Mexico
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Jennings ML, Cui J. Inactivation of Saccharomyces cerevisiae sulfate transporter Sul2p: use it and lose it. Biophys J 2012; 102:768-76. [PMID: 22385847 DOI: 10.1016/j.bpj.2012.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 12/09/2011] [Accepted: 01/03/2012] [Indexed: 12/12/2022] Open
Abstract
Saccharomyces cerevisiae SO(4)(=) transport is regulated over a wide dynamic range. Sulfur starvation causes ∼10,000-fold increase in the (35)SO(4)(=) influx mediated by transporters Sul1p and Sul2p; >80% of the influx is via Sul2p. Adding methionine to S-starved cells causes a 50-fold decline (t(1/2) ∼5 min) in SUL1 and SUL2 mRNA but a slower decline (t(1/2) ∼1 h) in transport. In contrast, SO(4)(=) addition does not affect mRNA but causes a rapid (t(1/2) = 2-4 min) decrease in transport. In met3Δ cells (unable to metabolize SO(4)(=)), addition of SO(4)(=) to S-starved cells causes inactivation of (35)SO(4)(=) influx over times in which cellular SO(4)(=) contents are nearly constant. The relationship between cellular SO(4)(=) and transport inactivation shows that cellular SO(4)(=) is not the signal for Sul2p inactivation. Instead, the transport inactivation rate has the same dependence on extracellular SO(4)(=) as (35)SO(4)(=) influx, indicating that Sul2p exhibits use-dependent inactivation; the transport process itself increases the probability of Sul2p inactivation and degradation. In addition, there is a transient efflux of SO(4)(=) shortly after adding >0.02 mM SO(4)(=) to S-starved met3Δ cells. This transient efflux provides further protection against excessive SO(4)(=) influx and may represent an alternate transport mode of Sul2p.
Collapse
Affiliation(s)
- Michael L Jennings
- Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
| | | |
Collapse
|
7
|
|
8
|
Poljsak B, Pócsi I, Raspor P, Pesti M. Interference of chromium with biological systems in yeasts and fungi: a review. J Basic Microbiol 2010; 50:21-36. [PMID: 19810050 DOI: 10.1002/jobm.200900170] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This paper deals with the interactions of chromium (Cr) with biological systems, focusing in particular on yeasts and fungi. These interactions are analysed with primarily regard to biochemical functions, but higher levels of organization are also considered. Thus, the morphological and cytological characteristics of selected microorganisms in response to exposure to chromium ions are evaluated. The different oxidation states of chromium and reactive oxygen species (ROS) generated in redox reactions with chromium ions are presented and characterized. The interactions of the most exposed subcellular structures, including the cell wall, plasma membrane and nuclei, have been deeply investigated in recent years, for two major reasons. The first is the toxicity of chromium ions and their strong impact on the metabolism of many species, ranging from microbes to humans. The second is the still disputed usefulness of chromium ions, and in particular trivalent chromium, in the glucose and fat metabolisms. Chromium pollution is still an important issue in many regions of the world, and various solutions have been proposed for the bioremediation of soil and water with selected microbial species. Yeasts and especially moulds have been most widely investigated from this aspect, and the biosorption and bioaccumulation of chromium for bioremediation purposes have been demonstrated. Accordingly, the mechanisms of chromium tolerance or resistance of selected microbes are of particular importance in both bioremediation and waste water treatment technologies. The mechanisms of chromium toxicity and detoxification have been studied extensively in yeasts and fungi, and some promising results have emerged in this area.
Collapse
Affiliation(s)
- Borut Poljsak
- Chair of Environmental Health, Faculty of Health Studies, University of Ljubljana, Slovenia
| | | | | | | |
Collapse
|
9
|
Abstract
SUMMARYMutants ofAspergillus nidulansunable to use either the choline moiety or the sulphate moiety of exogenous choline-0-sulphate have been selected. Choline-0-sulphate non-utilizing (csu) mutations have no other apparent pleiotropic effects, but it has not yet been established whether they lead to loss of choline sulphatase (and thus of the ability to utilize endogenously produced choline-0-sulphate) or to loss of a specific transport system for choline-0-sulphate or to loss of both.
Collapse
|
10
|
Chromium uptake, retention and reduction in photosynthetic Euglena gracilis. Arch Microbiol 2009; 191:431-40. [DOI: 10.1007/s00203-009-0469-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 01/14/2009] [Accepted: 02/25/2009] [Indexed: 10/21/2022]
|
11
|
Gremel G, Dorrer M, Schmoll M. Sulphur metabolism and cellulase gene expression are connected processes in the filamentous fungus Hypocrea jecorina (anamorph Trichoderma reesei). BMC Microbiol 2008; 8:174. [PMID: 18842142 PMCID: PMC2584116 DOI: 10.1186/1471-2180-8-174] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Accepted: 10/08/2008] [Indexed: 02/02/2023] Open
Abstract
Background Sulphur compounds like cysteine, methionine and S-adenosylmethionine are essential for the viability of most cells. Thus many organisms have developed a complex regulatory circuit that governs the expression of enzymes involved in sulphur assimilation and metabolism. In the filamentous fungus Hypocrea jecorina (anamorph Trichoderma reesei) little is known about the participants in this circuit. Results Analyses of proteins binding to the cellulase activating element (CAE) within the promotor of the cellobiohydrolase cbh2 gene led to the identification of a putative E3 ubiquitin ligase protein named LIMPET (LIM1), which is an orthologue of the sulphur regulators SCON-2 of Neurospora crassa and Met30p of Saccharomyces cerevisiae. Transcription of lim1 is specifically up-regulated upon sulphur limitation and responds to cellulase inducing conditions. In addition, light dependent stimulation/shut down of cellulase gene transcription by methionine in the presence of sulphate was observed. Further, lim1 transcriptionally reacts to a switch from constant darkness to constant light and is subject to regulation by the light regulatory protein ENVOY. Thus lim1, despite its function in sulphur metabolite repression, responds both to light as well as sulphur- and carbon source. Upon growth on cellulose, the uptake of sulphate is dependent on the light status and essential for growth in light. Unlike other fungi, growth of H. jecorina is not inhibited by selenate under low sulphur conditions, suggesting altered regulation of sulphur metabolism. Phylogenetic analysis of the five sulphate permeases found in the genome of H. jecorina revealed that the predominantly mycelial sulphate permease is lacking, thus supporting this hypothesis. Conclusion Our data indicate that the significance of the sulphate/methionine-related signal with respect to cellulase gene expression is dependent on the light status and reaches beyond detection of sulphur availability.
Collapse
Affiliation(s)
- Gabriela Gremel
- Research Area of Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/1665, A-1060 Wien, Austria.
| | | | | |
Collapse
|
12
|
Korolev N, Katan T, Elad Y. Use of Selenate-Resistant Strains as Markers for the Spread and Survival of Botrytis cinerea Under Greenhouse Conditions. PHYTOPATHOLOGY 2006; 96:1195-1203. [PMID: 18943956 DOI: 10.1094/phyto-96-1195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Botrytis cinerea marked strains combining traits of fungicide resistance or sensitivity (carbendazim, iprodione) with resistance to selenate were created and assessed for use in studying the dispersal of B. cinerea and its survival inside plant tissue under greenhouse conditions. Marked strains differed in their ability to cause lesions and to disperse in the greenhouse. A strain that was the most aggressive in infecting plants was also the most successful in spreading across the greenhouse. Following 7 to 14 days of exposure to marked inoculum, about 90% of plants showed quiescent B. cinerea infection with no significant difference between hosts or seasons. However, in a warm season, most of the plants were infected with wild-type B. cinerea, whereas most of the winter-recovered B. cinerea strains were of the marked phenotype, showing the importance of local inoculum from within the glasshouse in winter. The air of the greenhouse contained the same population of marked B. cinerea in warm and in cold periods, whereas the total population was significantly higher in summer. In the warm season, mycelium of B. cinerea inside plant debris lost viability within 3 to 4 months, whereas it stayed viable for 4 months in the winter (December to March) and started to lose viability in April.
Collapse
|
13
|
Melis A, Chen HC. Chloroplast sulfate transport in green algae--genes, proteins and effects. PHOTOSYNTHESIS RESEARCH 2005; 86:299-307. [PMID: 16307303 DOI: 10.1007/s11120-005-7382-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Accepted: 05/13/2005] [Indexed: 05/03/2023]
Abstract
This review summarizes evidence at the molecular genetic, protein and regulatory levels concerning the existence and function of a putative ABC-type chloroplast envelope-localized sulfate transporter in the model unicellular green alga Chlamydomonas reinhardtii. From the four nuclear genes encoding this sulfate permease holocomplex, two are coding for chloroplast envelope-targeted transmembrane proteins (SulP and SulP2), a chloroplast stroma-targeted ATP-binding protein (Sabc) and a substrate (sulfate)-binding protein (Sbp) that is localized on the cytosolic side of the chloroplast envelope. The sulfate permease holocomplex is postulated to consist of a SulP-SulP2 chloroplast envelope transmembrane heterodimer, flanked by the Sabc and the Sbp proteins on the stroma side and the cytosolic side of the inner envelope, respectively. The mature SulP and SulP2 proteins contain seven transmembrane domains and one or two large hydrophilic loops, which are oriented toward the cytosol. The corresponding prokaryotic-origin genes (SulP and SulP2) probably migrated from the chloroplast to the nuclear genome during the evolution of Chlamydomonas reinhardtii. These genes, or any of its homologues, have not been retained in vascular plants, e.g. Arabidopsis thaliana, although they are encountered in the chloroplast genome of a liverwort (Marchantia polymorpha). The function of the SulP protein was probed in antisense transformants of C. reinhardtii having lower expression levels of the SulP gene. Results showed that cellular sulfate uptake capacity was lowered as a consequence of attenuated SulP gene expression in the cell, directly affecting rates of de novo protein biosynthesis in the chloroplast. The antisense transformants exhibited phenotypes of sulfate-deprived cells, displaying slow rates of light-saturated oxygen evolution, low levels of Rubisco in the chloroplast and low steady-state levels of the Photosystem II D1 reaction center protein. The role of the chloroplast sulfate transport in the uptake and assimilation of sulfate in Chlamydomonas reinhardtii is discussed along with its impact on the repair of Photosystem II from a frequently occurring photo-oxidative damage and H2-evolution related metabolism in this green alga.
Collapse
Affiliation(s)
- Anastasios Melis
- Department of Plant & Microbial Biology, University of California , Berkeley, CA 94720-3102, USA.
| | | |
Collapse
|
14
|
Babyak LY, Ksheminskaya GP, Gonchar MV, Yanovich DV, Fedorovich DV. Selection and properties of mutant yeast Pichia guilliermondii strains resistant to chromium (VI). APPL BIOCHEM MICRO+ 2005. [DOI: 10.1007/s10438-005-0031-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
15
|
|
16
|
Borkovich KA, Alex LA, Yarden O, Freitag M, Turner GE, Read ND, Seiler S, Bell-Pedersen D, Paietta J, Plesofsky N, Plamann M, Goodrich-Tanrikulu M, Schulte U, Mannhaupt G, Nargang FE, Radford A, Selitrennikoff C, Galagan JE, Dunlap JC, Loros JJ, Catcheside D, Inoue H, Aramayo R, Polymenis M, Selker EU, Sachs MS, Marzluf GA, Paulsen I, Davis R, Ebbole DJ, Zelter A, Kalkman ER, O'Rourke R, Bowring F, Yeadon J, Ishii C, Suzuki K, Sakai W, Pratt R. Lessons from the genome sequence of Neurospora crassa: tracing the path from genomic blueprint to multicellular organism. Microbiol Mol Biol Rev 2004; 68:1-108. [PMID: 15007097 PMCID: PMC362109 DOI: 10.1128/mmbr.68.1.1-108.2004] [Citation(s) in RCA: 434] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We present an analysis of over 1,100 of the approximately 10,000 predicted proteins encoded by the genome sequence of the filamentous fungus Neurospora crassa. Seven major areas of Neurospora genomics and biology are covered. First, the basic features of the genome, including the automated assembly, gene calls, and global gene analyses are summarized. The second section covers components of the centromere and kinetochore complexes, chromatin assembly and modification, and transcription and translation initiation factors. The third area discusses genome defense mechanisms, including repeat induced point mutation, quelling and meiotic silencing, and DNA repair and recombination. In the fourth section, topics relevant to metabolism and transport include extracellular digestion; membrane transporters; aspects of carbon, sulfur, nitrogen, and lipid metabolism; the mitochondrion and energy metabolism; the proteasome; and protein glycosylation, secretion, and endocytosis. Environmental sensing is the focus of the fifth section with a treatment of two-component systems; GTP-binding proteins; mitogen-activated protein, p21-activated, and germinal center kinases; calcium signaling; protein phosphatases; photobiology; circadian rhythms; and heat shock and stress responses. The sixth area of analysis is growth and development; it encompasses cell wall synthesis, proteins important for hyphal polarity, cytoskeletal components, the cyclin/cyclin-dependent kinase machinery, macroconidiation, meiosis, and the sexual cycle. The seventh section covers topics relevant to animal and plant pathogenesis and human disease. The results demonstrate that a large proportion of Neurospora genes do not have homologues in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. The group of unshared genes includes potential new targets for antifungals as well as loci implicated in human and plant physiology and disease.
Collapse
Affiliation(s)
- Katherine A Borkovich
- Department of Plant Pathology, University of California, Riverside, California 92521, USA. Katherine/
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Chen HC, Yokthongwattana K, Newton AJ, Melis A. SulP, a nuclear gene encoding a putative chloroplast-targeted sulfate permease in Chlamydomonas reinhardtii. PLANTA 2003; 218:98-106. [PMID: 12883888 DOI: 10.1007/s00425-003-1076-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2003] [Accepted: 06/11/2003] [Indexed: 05/22/2023]
Abstract
Genomic, proteomic, phylogenetic and evolutionary aspects of a novel gene encoding a putative chloroplast-targeted sulfate permease of prokaryotic origin in the green alga Chlamydomonas reinhardtii are described. This nuclear-encoded sulfate permease gene (SulP) contains four introns, whereas all other known chloroplast sulfate permease genes lack introns and are encoded by the chloroplast genome. The deduced amino acid sequence of the protein showed an extended N-terminus, which includes a putative chloroplast transit peptide. The mature protein contains seven transmembrane domains and two large hydrophilic loops. This novel prokaryotic-origin gene probably migrated from the chloroplast to the nuclear genome during evolution of C. reinhardtii. The SulP gene, or any of its homologues, has not been retained in vascular plants, e.g. Arabidopsis thaliana, although it is encountered in the chloroplast genome of a liverwort (Marchantia polymorpha). A comparative structural analysis and phylogenetic origin of chloroplast sulfate permeases in a variety of species is presented.
Collapse
Affiliation(s)
- Hsu-Ching Chen
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | | | | | | |
Collapse
|
18
|
Shibagaki N, Rose A, McDermott JP, Fujiwara T, Hayashi H, Yoneyama T, Davies JP. Selenate-resistant mutants of Arabidopsis thaliana identify Sultr1;2, a sulfate transporter required for efficient transport of sulfate into roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 29:475-86. [PMID: 11846880 DOI: 10.1046/j.0960-7412.2001.01232.x] [Citation(s) in RCA: 212] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
To investigate how plants acquire and assimilate sulfur from their environment, we isolated and characterized two mutants of Arabidopsis thaliana deficient in sulfate transport. The mutants are resistant to selenate, a toxic analogue of sulfate. They are allelic to each other and to the previously isolated sel1 (selenate-resistant) mutants, and have been designated sel1-8 and sel1-9. Root elongation in these mutants is less sensitive to selenate than in wild-type plants. Sulfate uptake into the roots is impaired in the mutants under both sulfur-sufficient and sulfur-deficient conditions, but transport of sulfate to the shoot is not affected. The sel1 mutants contain lesions in the sulfate transporter gene Sultr1;2 located on the lower arm of chromosome 1. The sel1-1, sel1-3 and sel1-8 mutants contain point mutations in the coding sequences of Sultr1;2, while the sel1-9 mutant has a T-DNA insertion in the Sultr1;2 promoter. The Sultr1;2 cDNA derived from wild-type plants is able to complement Saccharomyces cerevisiae mutants defective in sulfate transport, but the Sultr1;2 cDNA from sel1-8 is not. The Sultr1;2 gene is expressed mainly in roots, and accumulation of transcripts increases during sulfate deprivation. Examination of transgenic plants containing the Sultr1;2 promoter fused to the GUS-reporter gene indicates that Sultr1;2 is expressed mainly in the root cortex, the root tip and lateral roots. Weaker expression of the reporter gene was observed in hydathodes, guard cells and auxiliary buds of leaves, and in anthers and the basal parts of flowers. The results indicate that Sultr1;2 is primarily involved in importing sulfate from the environment into the root.
Collapse
Affiliation(s)
- Nakako Shibagaki
- Department of Botany, Iowa State University, Ames, Iowa 50011, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
Cervantes C, Campos-García J, Devars S, Gutiérrez-Corona F, Loza-Tavera H, Torres-Guzmán JC, Moreno-Sánchez R. Interactions of chromium with microorganisms and plants. FEMS Microbiol Rev 2001; 25:335-47. [PMID: 11348688 DOI: 10.1111/j.1574-6976.2001.tb00581.x] [Citation(s) in RCA: 522] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.
Collapse
Affiliation(s)
- C Cervantes
- Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana, Edificio B-3, Ciudad Universitaris, 58030 Morelia, Michoacán, Mexico.
| | | | | | | | | | | | | |
Collapse
|
20
|
Czakó-Vér K, Batiè M, Raspor P, Sipiczki M, Pesti M. Hexavalent chromium uptake by sensitive and tolerant mutants of Schizosaccharomyces pombe. FEMS Microbiol Lett 1999; 178:109-15. [PMID: 10483729 DOI: 10.1111/j.1574-6968.1999.tb13765.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Lysine and leucine auxotrophic, heterothallic (h+, h-) strains of Schizosaccharomyces pombe were used to obtain chromium (VI)-sensitive and -tolerant mutants by ultraviolet radiation-induced and nitrosoguanidine-induced mutagenesis. The minimal inhibitory concentrations of K2Cr2O7 on YEA media were 225 microM for the wild-type strain CW-6, 125 microM for the sensitive mutant CS-6.51 and 275 microM for the tolerant mutant CT-6.66. The mutants exhibited cross-sensitivity of various patterns to Cd2+, Cu2+, Ni2+, Zn2+ and VO3-(4). Cr(VI) was added to the actively growing cultures and the total chromium (TOCr) content of the cells was determined. The sensitive mutant exhibited a high bioaccumulation ability, with a dry biomass of 810 micrograms g-1 after 30 min, while the tolerant mutant had a significantly lower ability than the wild-type strain. In PIPES buffer, washed, lysine-starved biomasses were treated with 75 microM Cr(VI) and after 2 h, the TOCr and the organically bound chromium (OBCr) were determined. Under these conditions, the sensitive and tolerant mutants had the same TOCr content, 50% of which was OBCr. The wild-type strain exhibited a lower TOCr content than that of its mutants and only 35% of this was OBCr. The Cr(VI)-sensitivity was due to a significantly increased uptake of Cr(VI).
Collapse
Affiliation(s)
- K Czakó-Vér
- Department of Genetics and Microbiology, Janus Pannonius University, Pécs, Hungary
| | | | | | | | | |
Collapse
|
21
|
Davies JP, Yildiz FH, Grossman AR. Sac3, an Snf1-like serine/threonine kinase that positively and negatively regulates the responses of Chlamydomonas to sulfur limitation. THE PLANT CELL 1999; 11:1179-90. [PMID: 10368187 PMCID: PMC144238 DOI: 10.1105/tpc.11.6.1179] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The Sac3 gene product of Chlamydomonas positively and negatively regulates the responses of the cell to sulfur limitation. In wild-type cells, arylsulfatase activity is detected only during sulfur limitation. The sac3 mutant expresses arylsulfatase activity even when grown in nutrient-replete medium, which suggests that the Sac3 protein has a negative effect on the induction of arylsulfatase activity. In contrast to its effect on arylsulfatase activity, Sac3 positively regulates the high-affinity sulfate transport system-the sac3 mutant is unable to fully induce high-affinity sulfate transport during sulfur limitation. We have complemented the sac3 mutant and cloned a cDNA copy of the Sac3 gene. The deduced amino acid sequence of the Sac3 gene product is similar to the catalytic domain of the yeast Snf1 family of serine/threonine kinases and is therefore classified as a Snf1-related kinase (SnRK). Specifically, Sac3 falls within the SnRK2 subfamily of kinases from vascular plants. In addition to the 11 subdomains common to Snf1-like serine/threonine kinases, Sac3 and the plant kinases have two additional subdomains and a highly acidic C-terminal region. The role of Sac3 in the signal transduction system that regulates the responses of Chlamydomonas to sulfur limitation is discussed.
Collapse
Affiliation(s)
- J P Davies
- Department of Botany, 353 Bessey Hall, Iowa State University, Ames, Iowa 50011-1020, USA.
| | | | | |
Collapse
|
22
|
|
23
|
Li Q, Zhou L, Marzluf GA. Functional in vivo studies of the Neurospora crassa cys-14 gene upstream region: importance of CYS3-binding sites for regulated expression. Mol Microbiol 1996; 22:109-17. [PMID: 8899713 DOI: 10.1111/j.1365-2958.1996.tb02660.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sulphate transport in Neurospora crassa is achieved by two distinct sulphate permeases, I and II, encoded by the cys-13 and cys-14 genes, respectively. The synthesis of both sulphate permeases is subject to sulphur repression and requires the global positive-acting regulatory protein CYS3, CYS3, a bZIP DNA binding protein, regulates cys-14 expression at the transcriptional level and binds in vitro specifically to three DNA-recognition sites, A, B, and C, in the cys-14 upstream region. In vivo functional analysis of the cys-14 promoter was carried out with 5' deletions and by deletions or mutations of CYS3 DNA-binding sites. The most distal CYS3-binding site, C, located 1.4kb upstream of the transcriptional start site, is necessary and sufficient to mediate strong transcriptional activation by CYS3; moreover, site C was able to function equally well when it was located at variable distances upstream of the cys-14 gene. Site B, located 1 kb upstream, alone is able to support a moderate degree of cys-14 expression. Site A is not required and does not appear to play any functional role in cys-14 expression, even though it is in close proximity to the transcriptional start site. The presence of multiple copies of CYS3-binding elements A or B in the cys-14 promoter results in a parallel increase of regulated gene expression. When a transforming cys-14 gene becomes integrated at ectopic locations in the host genome, it can be expressed in an unregulated fashion, presumably by coming under the control of other promoter elements. Our results also suggested that at least one enzyme in the sulphate catabolic pathway requires a functional CYS3 protein for expression.
Collapse
Affiliation(s)
- Q Li
- Department of Biochemistry, Ohio State University, Columbus 43210, Ohio, USA
| | | | | |
Collapse
|
24
|
Davies JP, Yildiz FH, Grossman A. Sac1, a putative regulator that is critical for survival of Chlamydomonas reinhardtii during sulfur deprivation. EMBO J 1996; 15:2150-9. [PMID: 8641280 PMCID: PMC450137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The sac1 mutant of Chlamydomonas reinhardtii is aberrant in most of the normal responses to sulfur limitation; it cannot synthesize arylsulfatase, does not take up sulfate as rapidly as wild-type cells, and does not synthesize periplasmic proteins that normally accumulate during sulfur-limited growth. Here, we show that the sac1 mutant dies much more rapidly than wild-type cells during sulfur deprivation; this emphasizes the vital role of the acclimation process. The loss of viability of the sac1 mutant during sulfur deprivation is only observed in the light and is mostly inhibited by DCMU. During sulfur-stress, wild-type cells, but not the sac1 mutant, downregulate photosynthesis. Thus, death of the sac1 mutant during sulfur deprivation is probably a consequence of its inability to downregulate photosynthesis. Furthermore, since SAC1 is necessary for the downregulation of photosynthesis, the process must be highly controlled and not simply the result of a general decrease in protein synthesis due to sulfur limitation. Genomic and cDNA copies of the SAC1 gene have been cloned. The deduced amino acid sequence of Sac1 is similar to an Escherichia coli gene that may involved in the response of E.coli to nutrient deprivation.
Collapse
Affiliation(s)
- J P Davies
- Carnegie Institution of Washington, Department of Plant Biology, Stanford, CA 94305, USA
| | | | | |
Collapse
|
25
|
Abstract
A comparative study has been made on the mechanisms of toxicities of trivalent and hexavalent forms of chromium in Neurospora crassa. Of the two forms, Cr6+ is more toxic than Cr3+. The toxicity of Cr3+ was found to be due to its specific antagonism with iron uptake. Fe3+ was found to be very effective in reversing the toxicity of Cr3+ by concomitantly suppressing its uptake. That the Cr3+ toxicity caused a conditional intracellular iron deficiency was indicated by the decrease in the activities of catalase and uricase and a progressive increase in the excretion of iron binding compound into the medium. The toxicity of Cr6+ (as Cr2O7(2-)) was found to be due to its specific antagonism of sulfate uptake. Methionine was found to be more effective in reversing dichromate toxicity than sulfate, probably by repressing the synthesis of sulfate permeases responsible for dichromate (Cr6+) uptake. Maximal uptake of Cr6+ was nearly tenfold lower and Vmax much higher than that of Cr3+. Evidence has been adduced to show that Cr6+ and Cr3+ were toxic by themselves and that interconversion between the tri- and hexavalent forms of chromium did not occur to any detectable extent.
Collapse
Affiliation(s)
- V V Ramana
- Department of Biochemistry, Osmania University, Hydrabad, India
| | | |
Collapse
|
26
|
Natorff R, Balińska M, Paszewski A. At least four regulatory genes control sulphur metabolite repression in Aspergillus nidulans. MOLECULAR & GENERAL GENETICS : MGG 1993; 238:185-92. [PMID: 8479426 DOI: 10.1007/bf00279546] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mutations in four genes: sconA (formerly suA25meth, mapA25), sconB (formerly mapB1), sconC and sconD, the last two identified in this work, relieve a group of sulphur amino acid biosynthetic enzymes from methionine-mediated sulphur metabolite repression. Exogenous methionine has no effect on sulphate assimilation in the mutant strains, whereas in the wild type it causes almost complete elimination of sulphate incorporation. In both mutant and wild-type strains methionine is efficiently taken up and metabolized to S-adenosylmethionine, homocysteine and other compounds, scon mutants also show elevated levels of folate-metabolizing enzymes which results from the large pool of homocysteine found in these strains. The folate enzymes appear to be inducible by homocysteine and repressible by methionine (or S-adenosylmethionine).
Collapse
Affiliation(s)
- R Natorff
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw
| | | | | |
Collapse
|
27
|
Production of the CYS3 regulator, a bZIP DNA-binding protein, is sufficient to induce sulfur gene expression in Neurospora crassa. Mol Cell Biol 1992. [PMID: 1532230 DOI: 10.1128/mcb.12.4.1568] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cys-3+ gene of Neurospora crassa encodes a bZIP (basic region-leucine zipper) regulatory protein that is essential for sulfur structural gene expression (e.g., ars-1+). Nuclear transcription assays confirmed that cys-3+ was under sulfur-regulated transcriptional control and that cys-3+ transcription was constitutive in sulfur controller (scon)-negative regulator mutants. Given these results, I have tested whether expression of cys-3+ under high-sulfur (repressing) conditions was sufficient to induce sulfur gene expression. The N. crassa beta-tubulin (tub) promoter was fused to the cys-3+ coding segment and used to transform a cys-3 deletion mutant. Function of the tub::cys-3 fusion in homokaryotic transformants grown under high-sulfur conditions was confirmed by Northern (RNA) and Western immunoblot analysis. The tub::cys-3 transformants showed arylsulfatase gene expression under normally repressing high-sulfur conditions. A tub::cys-3ts fusion encoding a temperature-sensitive CYS3 protein was used to confirm that the induced structural gene expression was due to CYS3 protein function. Constitutive CYS3 production did not induce scon-2+ expression under repressing conditions. In addition, a cys-3 promoter fusion to lacZ showed that CYS3 production was sufficient to induce its own expression and provides in vivo evidence for autoregulation. Finally, an apparent inhibitory effect observed with a strain carrying a point mutation at the cys-3 locus was examined by in vitro heterodimerization studies. These results support an interpretation of CYS3 as a transcriptional activator whose regulation is a crucial control point in the signal response pathway triggered by sulfur limitation.
Collapse
|
28
|
Paietta JV. Production of the CYS3 regulator, a bZIP DNA-binding protein, is sufficient to induce sulfur gene expression in Neurospora crassa. Mol Cell Biol 1992; 12:1568-77. [PMID: 1532230 PMCID: PMC369599 DOI: 10.1128/mcb.12.4.1568-1577.1992] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The cys-3+ gene of Neurospora crassa encodes a bZIP (basic region-leucine zipper) regulatory protein that is essential for sulfur structural gene expression (e.g., ars-1+). Nuclear transcription assays confirmed that cys-3+ was under sulfur-regulated transcriptional control and that cys-3+ transcription was constitutive in sulfur controller (scon)-negative regulator mutants. Given these results, I have tested whether expression of cys-3+ under high-sulfur (repressing) conditions was sufficient to induce sulfur gene expression. The N. crassa beta-tubulin (tub) promoter was fused to the cys-3+ coding segment and used to transform a cys-3 deletion mutant. Function of the tub::cys-3 fusion in homokaryotic transformants grown under high-sulfur conditions was confirmed by Northern (RNA) and Western immunoblot analysis. The tub::cys-3 transformants showed arylsulfatase gene expression under normally repressing high-sulfur conditions. A tub::cys-3ts fusion encoding a temperature-sensitive CYS3 protein was used to confirm that the induced structural gene expression was due to CYS3 protein function. Constitutive CYS3 production did not induce scon-2+ expression under repressing conditions. In addition, a cys-3 promoter fusion to lacZ showed that CYS3 production was sufficient to induce its own expression and provides in vivo evidence for autoregulation. Finally, an apparent inhibitory effect observed with a strain carrying a point mutation at the cys-3 locus was examined by in vitro heterodimerization studies. These results support an interpretation of CYS3 as a transcriptional activator whose regulation is a crucial control point in the signal response pathway triggered by sulfur limitation.
Collapse
Affiliation(s)
- J V Paietta
- Department of Biochemistry, Wright State University, Dayton, Ohio 45435
| |
Collapse
|
29
|
Pepi M, Baldi F. Modulation of chromium(VI) toxicity by organic and inorganic sulfur species in yeasts from industrial wastes. Biometals 1992; 5:179-85. [PMID: 1421967 DOI: 10.1007/bf01061326] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two chromium(VI) resistant yeast strains (Candida sp. and Rhodosporidium sp.) were isolated from industrial wastes. Four different yeasts, three from the Industrial Yeast Collection and one of pharmaceutical origin, were also studied in relation to chromate toxicity and its alleviation by sulfur species. The growth of yeasts from industrial wastes was inhibited by 50% by high concentrations of Cr(VI): Candida sp. by 4 mM Cr(VI) and Rhodosporidium sp. by 10 mM Cr(VI) in Sabouraud Broth medium. The other Cr(VI)-sensitive yeasts were inhibited by 0.1 mM Cr(VI). The general mechanism of chromium resistance in Candida sp. and Rhodosporidium sp. was due to reduced uptake of chromium, but not to biological reduction from Cr(VI) to Cr(III). In Cr(VI)-sensitive yeasts, chromium was accumulated as much as 10-fold, as in Saccharomyces cerevisiae. Cr(VI) toxicity in Candida sp. was modulated from Cr(VI)-resistance to Cr(VI)-hypersensitivity depending on the addition of methionine, cysteine, sulfate and djenkolic acid. If Candida sp. was grown in the presence of S-amino acids, especially methionine, it was more resistant than if the sulfur source was sulfate. When sulfate transport was enhanced by addition of djenkolic acid, Candida sp. became hypersensitive. Rhosporidium sp. was always resistant to Cr(VI) because sulfate transport was inefficient and it assimilated sulfur as S-amino acids. Cr(VI)-sensitive yeasts required larger amounts of S-amino acids, especially methionine, to tolerate Cr(VI) toxicity. Cysteine was toxic for C.famata 6016 above 50 microM.
Collapse
Affiliation(s)
- M Pepi
- Università di Siena, Dipartimento di Biologia Ambientale, Italy
| | | |
Collapse
|
30
|
Molecular cloning and analysis of the scon-2 negative regulatory gene of Neurospora crassa. Mol Cell Biol 1990. [PMID: 1975945 DOI: 10.1128/mcb.10.10.5207] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The sulfur regulatory system of Neurospora crassa is composed of a group of highly regulated structural genes (e.g., the gene encoding arylsulfatase) that are under coordinate control of scon+ (sulfur controller) negative and cys-3+ positive regulatory genes. In scon-1 (previously designated sconC) and scon-2 mutants, there is constitutive expression of sulfur structural genes regardless of the sulfur level available to the cells. The scon-2+ gene was cloned by sib selection screening of a cosmid-based gene library. The screening was based on the use of chromate, a toxic sulfate analog, which is transported into scon-2 cells grown on high sulfur but is not transported into cells that have regained normal sulfur regulation. Restriction fragment length polymorphism analysis was used to confirm that the cloned segment mapped to the proper chromosomal location. In wild-type cells, Northern (RNA) blot analysis showed that a 2.6-kilobase scon-2+ transcript was present at a substantial level only under sulfur-derepressing conditions. Kinetic analysis showed that scon-2+ mRNA content increased as the cells became sulfur starved. Further, scon-2+ RNA was detectable in a nuclear transcription assay only under derepressing conditions. In scon-1, the levels of scon-2+ mRNA were found to be constitutive. In the cys-3 regulatory mutant, there was a reduced level of scon-2+ transcript. cys-3+ and ars-1+ mRNAs were present under both derepressing and repressing conditions in the scon-2 mutant. Repeat-induced point mutation-generated scon-2 mutants were identical in phenotype to the known mutant.
Collapse
|
31
|
Molecular cloning and analysis of the scon-2 negative regulatory gene of Neurospora crassa. Mol Cell Biol 1990; 10:5207-14. [PMID: 1975945 PMCID: PMC361201 DOI: 10.1128/mcb.10.10.5207-5214.1990] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The sulfur regulatory system of Neurospora crassa is composed of a group of highly regulated structural genes (e.g., the gene encoding arylsulfatase) that are under coordinate control of scon+ (sulfur controller) negative and cys-3+ positive regulatory genes. In scon-1 (previously designated sconC) and scon-2 mutants, there is constitutive expression of sulfur structural genes regardless of the sulfur level available to the cells. The scon-2+ gene was cloned by sib selection screening of a cosmid-based gene library. The screening was based on the use of chromate, a toxic sulfate analog, which is transported into scon-2 cells grown on high sulfur but is not transported into cells that have regained normal sulfur regulation. Restriction fragment length polymorphism analysis was used to confirm that the cloned segment mapped to the proper chromosomal location. In wild-type cells, Northern (RNA) blot analysis showed that a 2.6-kilobase scon-2+ transcript was present at a substantial level only under sulfur-derepressing conditions. Kinetic analysis showed that scon-2+ mRNA content increased as the cells became sulfur starved. Further, scon-2+ RNA was detectable in a nuclear transcription assay only under derepressing conditions. In scon-1, the levels of scon-2+ mRNA were found to be constitutive. In the cys-3 regulatory mutant, there was a reduced level of scon-2+ transcript. cys-3+ and ars-1+ mRNAs were present under both derepressing and repressing conditions in the scon-2 mutant. Repeat-induced point mutation-generated scon-2 mutants were identical in phenotype to the known mutant.
Collapse
|
32
|
Molecular cloning and analysis of the regulation of cys-14+, a structural gene of the sulfur regulatory circuit of Neurospora crassa. Mol Cell Biol 1988. [PMID: 2898097 DOI: 10.1128/mcb.8.4.1504] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cys-14+ gene encodes sulfate permease II, which is primarily expressed in mycelia. cys-14+ is one of a set of sulfur-related structural genes under the control of cys-3+ and scon+, the regulatory genes of the sulfur control circuit. We have cloned cys-14+ from a cosmid library of Neurospora crassa DNA. A restriction fragment length polymorphism analysis showed that this clone maps to the region of chromosome IV corresponding to the cys-14+ locus. Northern blot analyses were used to examine the regulated expression of the cys-14+ gene. In the wild type, a 3-kilobase cys-14+ transcript was highly expressed under sulfur-derepressing conditions but completely absent during sulfur repression. A cys-3 mutant, which cannot synthesize any of the sulfur-controlled enzymes, including sulfate permease II, did not possess any cys-14+ transcript under either condition. A cys-3 temperature-sensitive revertant completely lacked any cys-14+ mRNA at the conditional temperature but expressed the cys-14+ transcript upon derepression at the permissive temperature. Mutation of a second sulfur regulatory gene, scon(c), causes the expression of sulfur-related enzymes in a constitutive fashion; the scon(c) mutant showed a corresponding constitutive expression of cys-14+ mRNA, such that it was present even in cells subjected to sulfur repression conditions. These results show that the cys-14+ gene is regulated through the modulation of message content by the cys-3+ and scon(c) control genes in response to the sulfur levels of the cells.
Collapse
|
33
|
Ketter JS, Marzluf GA. Molecular cloning and analysis of the regulation of cys-14+, a structural gene of the sulfur regulatory circuit of Neurospora crassa. Mol Cell Biol 1988; 8:1504-8. [PMID: 2898097 PMCID: PMC363309 DOI: 10.1128/mcb.8.4.1504-1508.1988] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The cys-14+ gene encodes sulfate permease II, which is primarily expressed in mycelia. cys-14+ is one of a set of sulfur-related structural genes under the control of cys-3+ and scon+, the regulatory genes of the sulfur control circuit. We have cloned cys-14+ from a cosmid library of Neurospora crassa DNA. A restriction fragment length polymorphism analysis showed that this clone maps to the region of chromosome IV corresponding to the cys-14+ locus. Northern blot analyses were used to examine the regulated expression of the cys-14+ gene. In the wild type, a 3-kilobase cys-14+ transcript was highly expressed under sulfur-derepressing conditions but completely absent during sulfur repression. A cys-3 mutant, which cannot synthesize any of the sulfur-controlled enzymes, including sulfate permease II, did not possess any cys-14+ transcript under either condition. A cys-3 temperature-sensitive revertant completely lacked any cys-14+ mRNA at the conditional temperature but expressed the cys-14+ transcript upon derepression at the permissive temperature. Mutation of a second sulfur regulatory gene, scon(c), causes the expression of sulfur-related enzymes in a constitutive fashion; the scon(c) mutant showed a corresponding constitutive expression of cys-14+ mRNA, such that it was present even in cells subjected to sulfur repression conditions. These results show that the cys-14+ gene is regulated through the modulation of message content by the cys-3+ and scon(c) control genes in response to the sulfur levels of the cells.
Collapse
Affiliation(s)
- J S Ketter
- Department of Biochemistry, Ohio State University, Columbus 43210
| | | |
Collapse
|
34
|
Lydiate DJ, Mendez C, Kieser HM, Hopwood DA. Mutation and cloning of clustered Streptomyces genes essential for sulphate metabolism. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf00425694] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
35
|
Molecular cloning and characterization of the cys-3 regulatory gene of Neurospora crassa. Mol Cell Biol 1987. [PMID: 2886908 DOI: 10.1128/mcb.7.7.2506] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The regulatory gene cys-3+ controls the synthesis of a number of enzymes involved in sulfur metabolism. cys-3 mutants show a multiple loss of enzymes in different pathways of sulfur metabolism. The cys-3+ gene was isolated by transformation of an aro-9 qa-2 cys-3 inl strain with a clone bank followed by screening with the "sib selection" method. The library used (pRAL1) contained inserts of Sau3a partial digest fragments of about 9 kilobases as well as the Neurospora qa-2+ gene. Double selection for qa-2+ and cys-3+ function was carried out. The transformants obtained with the isolated cys-3+ clone show recovery of the enzyme activities associated with the cys-3 mutation (e.g., arylsulfatase and sulfate permease). Restriction fragment length polymorphism experiments confirmed the identity of the clone, mRNA studies with Northern blots show that the expression of the cys-3+ gene is inducible. In contrast to cys-3+, the cys-3 (P22) mutant gene was not expressed at a higher level under sulfur-derepressed conditions.
Collapse
|
36
|
Cypionka H. Uptake of sulfate, sulfite and thiosulfate by proton-anion symport in Desulfovibrio desulfuricans. Arch Microbiol 1987. [DOI: 10.1007/bf00425363] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
37
|
Paietta JV, Akins RA, Lambowitz AM, Marzluf GA. Molecular cloning and characterization of the cys-3 regulatory gene of Neurospora crassa. Mol Cell Biol 1987; 7:2506-11. [PMID: 2886908 PMCID: PMC365384 DOI: 10.1128/mcb.7.7.2506-2511.1987] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The regulatory gene cys-3+ controls the synthesis of a number of enzymes involved in sulfur metabolism. cys-3 mutants show a multiple loss of enzymes in different pathways of sulfur metabolism. The cys-3+ gene was isolated by transformation of an aro-9 qa-2 cys-3 inl strain with a clone bank followed by screening with the "sib selection" method. The library used (pRAL1) contained inserts of Sau3a partial digest fragments of about 9 kilobases as well as the Neurospora qa-2+ gene. Double selection for qa-2+ and cys-3+ function was carried out. The transformants obtained with the isolated cys-3+ clone show recovery of the enzyme activities associated with the cys-3 mutation (e.g., arylsulfatase and sulfate permease). Restriction fragment length polymorphism experiments confirmed the identity of the clone, mRNA studies with Northern blots show that the expression of the cys-3+ gene is inducible. In contrast to cys-3+, the cys-3 (P22) mutant gene was not expressed at a higher level under sulfur-derepressed conditions.
Collapse
|
38
|
Elander RP. Strain Improvement and Preservation of β-Lactam-Producing Microorganisms. Antibiotics (Basel) 1983. [DOI: 10.1007/978-3-642-81966-7_3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023] Open
|
39
|
|
40
|
Breton A, Surdin-Kerjan Y. Sulfate uptake in Saccharomyces cerevisiae: biochemical and genetic study. J Bacteriol 1977; 132:224-32. [PMID: 199574 PMCID: PMC221848 DOI: 10.1128/jb.132.1.224-232.1977] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Sulfate uptake is the first step of the sulfate assimilation pathway, which has been shown in our laboratory to be part of the methionine biosynthetic pathway. Kinetic study of sulfate uptake has shown a biphasic curve in a Lineweaver-Burk plot. The analysis of this plot indicates that two enzymes participate in sulfate uptake. One (permease I) has a high affinity for the substrate (K(m) = 0.005 mM); the other (permease II) shows a much lower affinity for sulfate (K(m) = 0.35 mM). Regulation of the synthesis of both permeases is under the control of exogenous methionine or S-adenosylmethionine. It was shown, moreover, that synthesis of sulfate permeases is coordinated with the synthesis of the other methionine biosynthetic enzymes thus far studied in our laboratory. An additional specific regulation of sulfate permeases by inhibition of their activity by endogenous sulfate and adenosyl phosphosulfate (an intermediate metabolite in sulfate assimilation) has been shown. A mutant unable to concentrate sulfate has been selected. This strain carried mutations in two independent genes. These two mutations, separated in two different strains, lead to modified kinetics of sulfate uptake. The study of these strains leads us to postulate that there is an interaction in situ between the products of these two genes.
Collapse
|
41
|
Jeanjean R, Broda E. Dependence of sulphate uptake by Anacystis nidulans on energy, on osmotic shock and on sulphate stravation. Arch Microbiol 1977; 114:19-23. [PMID: 20862 DOI: 10.1007/bf00429625] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sulphate uptake by Anacystis nidulans under aerobic conditions in the light was found to be sensitive to metabolic poisons, such as N,N'-dicyclohexylcarbodiimide and carbonyl cyanide m-chlorophenyl hydrazone. It was also depressed by darkness. The sulphate absorption is an energy-dependent process. Sulphate uptake was also inhibited by chromate and selenate. Osmotic shock strongly affected sulphate uptake. This effect could be interpreted by a loss of a binding protein involved in the absorption of sulphate. Osmotic shock also depressed oxygen production in light and oxygen consumption in darkness; however, shocked cells were able to grow normally. Sulphate uptake was strongly enhanced by sulphate starvation, but this enhancement was partly prevented by chloramphenicol. Apparently sulphate starvation depressed the synthesis of a carrier involved in the transport of sulphate. During sulphate starvation the membrane potential, measured by the uptake of triphenylmethylphosphonium, increases. This may be due to changes in the membrane.
Collapse
|
42
|
Abstract
Sulfate transport by tobacco (Nicotiana tabacum L. var. Xanthi) cells cultured on either l-cysteine or sulfate as a sole sulfur source was measured. The transport rate on either sulfur source was low during pre-exponential growth, increased during exponential growth, and was maximal in late exponential cells. The initial increase in transport rate was correlated with a decline in the intracellular sulfate, but was not correlated with the amino acid content of the cells which remained relatively constant before the depletion of the endogenous sulfate pool. The previously reported inhibition of sulfate transport by l-cysteine was shown to be caused by an elevation in intracellular sulfate resulting from the degradation of cysteine to sulfate. It is proposed that the intracellular sulfate pool is the major factor regulating the entry of sulfate into tobacco cells.
Collapse
Affiliation(s)
- I K Smith
- Department of Botany, Ohio University, Athens, Ohio 45701
| |
Collapse
|
43
|
Marzluf GA. Uptake and efflux of sulfate in Neurospora crassa. BIOCHIMICA ET BIOPHYSICA ACTA 1974; 339:374-81. [PMID: 4276129 DOI: 10.1016/0005-2736(74)90164-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
44
|
Niss HF, Nash CH. Synthesis of cephalosporin C from sulfate by mutants of Cephalosporium acremonium. Antimicrob Agents Chemother 1973; 4:474-8. [PMID: 4799669 PMCID: PMC444579 DOI: 10.1128/aac.4.4.474] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The innate ability of Cephalosporium acremonium to use methionine preferentially over sulfate for synthesis of cephalosporin C can be influenced through mutation. Mutants of C. acremonium with altered capacity to utilize sulfate for synthesis of antibiotic were isolated and partially characterized with respect to the uptake of sulfate and the regulation of arylsulfatase.
Collapse
|
45
|
Marzluf GA. Regulation of sulfate transport in neurospora by transinhibition and by inositol depletion. Arch Biochem Biophys 1973; 156:244-54. [PMID: 4730472 DOI: 10.1016/0003-9861(73)90362-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
46
|
Dietrich PS, Metzenberg RL. Metabolic suppressors of a regulatory mutant in Neurospora. Biochem Genet 1973; 8:73-84. [PMID: 4266372 DOI: 10.1007/bf00485558] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
47
|
|
48
|
Marzluf GA. Genetic and metabolic control of sulfate metabolism in Neurospora crassa: a specific permease for choline-O-sulfate. Biochem Genet 1972; 7:219-33. [PMID: 4265021 DOI: 10.1007/bf00484820] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
49
|
Marzluf GA. Control of the synthesis, activity, and turnover of enzymes of sulfur metabolism in Neurospora crassa. Arch Biochem Biophys 1972; 150:714-24. [PMID: 4261415 DOI: 10.1016/0003-9861(72)90090-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
50
|
Roberts KR, Marzluf GA. The specific interaction of chromate with the dual sulfate permease systems of Neurospora crassa. Arch Biochem Biophys 1971; 142:651-9. [PMID: 5550165 DOI: 10.1016/0003-9861(71)90531-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|