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cyAbrB Transcriptional Regulators as Safety Devices To Inhibit Heterocyst Differentiation in Anabaena sp. Strain PCC 7120. J Bacteriol 2019; 201:JB.00244-19. [PMID: 31085690 DOI: 10.1128/jb.00244-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Cyanobacteria are monophyletic organisms that perform oxygenic photosynthesis. While they exhibit great diversity, they have a common set of genes. However, the essentiality of them for viability has hampered the elucidation of their functions. One example of these genes is cyabrB1 (also known as calA in Anabaena sp. strain PCC 7120), encoding a transcriptional regulator. In the present study, we investigated the function of calA/cyabrB1 in the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 through CRISPR interference, a method that we recently utilized for the photosynthetic production of a useful chemical in this strain. Conditional knockdown of calA/cyabrB1 in the presence of nitrate resulted in the formation of heterocysts. Two genes, hetP and hepA, which are required for heterocyst formation, were upregulated by calA/cyabrB1 knockdown in the presence of combined nitrogen sources. These genes are known to be induced by HetR, a master regulator of heterocyst formation. hetR was not induced by calA/cyabrB1 knockdown. hetP and hepA were repressed by direct binding of CalA/cyAbrB1 to their promoter regions in a HetR-independent manner. In addition, the overexpression of calA/cyabrB1 abolished heterocyst formation upon nitrogen depletion. Also, knockout of calB/cyabrB2 (a paralogue gene of calA/cyabrB1), in addition to knockdown of calA/cyabrB1, enhanced heterocyst formation in the presence of nitrate, suggesting functional redundancy of cyAbrB proteins. We propose that a balance between amounts of HetR and CalA/cyAbrB1 is a key factor influencing heterocyst differentiation during nitrogen stepdown. We concluded that cyAbrB proteins are essential safety devices that inhibit heterocyst differentiation.IMPORTANCE Spore formation in Bacillus subtilis and Streptomyces has been extensively studied as models of prokaryotic nonterminal cell differentiation. In these organisms, many cells/hyphae differentiate simultaneously, which is governed by a network in which one regulator stands at the top. Differentiation of heterocysts in Anabaena sp. strain PCC 7120 is unique because it is terminal, and only 5 to 10% of vegetative cells differentiate into heterocysts. In this study, we identified CalA/cyAbrB1 as a repressor of two genes that are essential for heterocyst formation independently of HetR, a master activator for heterocyst differentiation. This finding is reasonable for unique cell differentiation of Anabaena because CalA/cyAbrB1 could suppress heterocyst differentiation tightly in vegetative cells, while only cells in which HetR is overexpressed could differentiate into heterocysts.
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Higo A, Ehira S. Spatiotemporal Gene Repression System in the Heterocyst-Forming Multicellular Cyanobacterium Anabaena sp. PCC 7120. ACS Synth Biol 2019; 8:641-646. [PMID: 30865823 DOI: 10.1021/acssynbio.8b00496] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The heterocyst-forming multicellular cyanobacterium Anabaena sp. PCC 7120 is often used as a model organism for prokaryotic cell differentiation. We recently demonstrated that heterocysts are suitable for photosynthetic production of valuable chemicals, such as ethanol, due to their active catabolism and microoxic conditions. We have developed gene regulation systems, including cell type-specific gene induction systems, to broaden this cyanobacterium's use. In the present study, a heterocyst-specific conditional gene repression system was successfully created by combining a cell type-specific gene induction system with CRISPRi technology. We targeted the gln A gene that encodes glutamine synthetase, an essential enzyme for nitrogen assimilation, to reconstruct metabolism in the multicellular cyanobacterium. Heterocyst-specific repression of gln A enhanced ethanol production. We believe that heterocyst-specific gene repression systems are useful tools for basic research on cell differentiation as well as for metabolic engineering of heterocysts.
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Affiliation(s)
- Akiyoshi Higo
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Shigeki Ehira
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
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Agostoni M, Logan-Jackson AR, Heinz ER, Severin GB, Bruger EL, Waters CM, Montgomery BL. Homeostasis of Second Messenger Cyclic-di-AMP Is Critical for Cyanobacterial Fitness and Acclimation to Abiotic Stress. Front Microbiol 2018; 9:1121. [PMID: 29896182 PMCID: PMC5986932 DOI: 10.3389/fmicb.2018.01121] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/11/2018] [Indexed: 12/11/2022] Open
Abstract
Second messengers are intracellular molecules regulated by external stimuli known as first messengers that are used for rapid organismal responses to dynamic environmental changes. Cyclic di-AMP (c-di-AMP) is a relatively newly discovered second messenger implicated in cell wall homeostasis in many pathogenic bacteria. C-di-AMP is synthesized from ATP by diadenylyl cyclases (DAC) and degraded by specific c-di-AMP phosphodiesterases (PDE). C-di-AMP DACs and PDEs are present in all sequenced cyanobacteria, suggesting roles for c-di-AMP in the physiology and/or development of these organisms. Despite conservation of these genes across numerous cyanobacteria, the functional roles of c-di-AMP in cyanobacteria have not been well-investigated. In a unique feature of cyanobacteria, phylogenetic analysis indicated that the broadly conserved DAC, related to CdaA/DacA, is always co-associated in an operon with genes critical for controlling cell wall synthesis. To investigate phenotypes regulated by c-di-AMP in cyanobacteria, we overexpressed native DAC (sll0505) and c-di-AMP PDE (slr0104) genes in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter Synechocystis) to increase and decrease intracellular c-di-AMP levels, respectively. DAC- and PDE-overexpression strains, showed abnormal aggregation phenotypes, suggesting functional roles for regulating c-di-AMP homeostasis in vivo. As c-di-AMP may be implicated in osmotic responses in cyanobacteria, we tested whether sorbitol and NaCl stresses impacted expression of sll0505 and slr0104 or intracellular c-di-AMP levels in Synechocystis. Additionally, to determine the range of cyanobacteria in which c-di-AMP may function, we assessed c-di-AMP levels in two unicellular cyanobacteria, i.e., Synechocystis and Synechococcus elongatus PCC 7942, and two filamentous cyanobacteria, i.e., Fremyella diplosiphon and Anabaena sp. PCC 7120. C-di-AMP levels responded differently to abiotic stress signals in distinct cyanobacteria strains, whereas salt stress uniformly impacted another second messenger cyclic di-GMP in cyanobacteria. Together, these results suggest regulation of c-di-AMP homeostasis in cyanobacteria and implicate a role for the second messenger in maintaining cellular fitness in response to abiotic stress.
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Affiliation(s)
- Marco Agostoni
- Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI, United States.,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Alshaé R Logan-Jackson
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Emily R Heinz
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
| | - Geoffrey B Severin
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
| | - Eric L Bruger
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Christopher M Waters
- Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI, United States.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States
| | - Beronda L Montgomery
- Cell and Molecular Biology Graduate Program, Michigan State University, East Lansing, MI, United States.,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, United States.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, United States.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, United States
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4
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Bassler J, Schultz JE, Lupas AN. Adenylate cyclases: Receivers, transducers, and generators of signals. Cell Signal 2018; 46:135-144. [PMID: 29563061 DOI: 10.1016/j.cellsig.2018.03.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/09/2018] [Accepted: 03/12/2018] [Indexed: 11/18/2022]
Abstract
Class III adenylate cyclases (ACs) are widespread signaling proteins, which translate diverse intracellular and extracellular stimuli into a uniform intracellular signal. They are typically composed of an N-terminal array of input domains and transducers, followed C-terminally by a catalytic domain, which, as a dimer, generates the second messenger cAMP. The input domains, which receive stimuli, and the transducers, which propagate the signals, are often found in other signaling proteins. The nature of stimuli and the regulatory mechanisms of ACs have been studied experimentally in only a few cases, and even in these, important questions remain open, such as whether eukaryotic ACs regulated by G protein-coupled receptors can also receive stimuli through their own membrane domains. Here we survey the current knowledge on regulation and intramolecular signal propagation in ACs and draw comparisons to other signaling proteins. We highlight the pivotal role of a recently identified cyclase-specific transducer element located N-terminally of many AC catalytic domains, suggesting an intramolecular signaling capacity.
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Affiliation(s)
- Jens Bassler
- Max-Planck-Institut für Entwicklungsbiologie, Abt. Proteinevolution, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Joachim E Schultz
- Pharmazeutisches Institut der Universität Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany.
| | - Andrei N Lupas
- Max-Planck-Institut für Entwicklungsbiologie, Abt. Proteinevolution, Max-Planck-Ring 5, 72076 Tübingen, Germany.
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Higo A, Isu A, Fukaya Y, Ehira S, Hisabori T. Application of CRISPR Interference for Metabolic Engineering of the Heterocyst-Forming Multicellular Cyanobacterium Anabaena sp. PCC 7120. PLANT & CELL PHYSIOLOGY 2018; 59:119-127. [PMID: 29112727 DOI: 10.1093/pcp/pcx166] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Abstract
Anabaena sp. PCC 7120 (A. 7120) is a heterocyst-forming multicellular cyanobacterium that performs nitrogen fixation. This cyanobacterium has been extensively studied as a model for multicellularity in prokaryotic cells. We have been interested in photosynthetic production of nitrogenous compounds using A. 7120. However, the lack of efficient gene repression tools has limited its usefulness. We originally developed an artificial endogenous gene repression method in this cyanobacterium using small antisense RNA. However, the narrow dynamic range of repression of this method needs to be improved. Recently, clustered regularly interspaced short palindromic repeat (CRISPR) interference (CRISPRi) technology was developed and was successfully applied in some unicellular cyanobacteria. The technology requires expression of nuclease-deficient CRISPR-associated protein 9 (dCas9) and a single guide RNA (sgRNA) that is complementary to a target sequence, to repress expression of the target gene. In this study, we employed CRISPRi technology for photosynthetic production of ammonium through repression of glnA, the only gene encoding glutamine synthetase that is essential for nitrogen assimilation in A. 7120. By strictly regulating dCas9 expression using the TetR gene induction system, we succeeded in fine-tuning the GlnA protein in addition to the level of glnA transcripts. Expression of sgRNA by the heterocyst-specific nifB promoter led to efficient repression of GlnA in heterocysts, as well as in vegetative cells. Finally, we showed that ammonium is excreted into the medium only when inducers of expression of dCas9 were added. In conclusion, CRISPRi enables temporal control of desired products and will be a useful tool for basic science.
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Affiliation(s)
- Akiyoshi Higo
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-ku, Yokohama, 226-8503, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo, 192-0397 Japan
| | - Atsuko Isu
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-ku, Yokohama, 226-8503, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - Yuki Fukaya
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-ku, Yokohama, 226-8503, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
| | - Shigeki Ehira
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo, 192-0397 Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-ku, Yokohama, 226-8503, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
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Kashith M, Keerthana B, Sriram S, Ramamurthy V. Adenylate cyclase in Arthrospira platensis responds to light through transcription. Biochem Biophys Res Commun 2016; 477:297-301. [PMID: 27311855 DOI: 10.1016/j.bbrc.2016.06.061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 06/11/2016] [Indexed: 11/30/2022]
Abstract
Cyclic 3',5' adenosine monophosphate (cAMP) is a ubiquitous signaling molecule, but its role in higher plants was in doubt due to its very low concentration. In this study we wanted to look at the flux of cAMP in response to light in algae, considered to be the more primitive form of photosynthetic organisms. While it did not fluctuate very much in the tested green algae, in the cyanobacterium Arthrospira platensis its level was closely linked to exposure to light. The expression from cyaC, the major isoform of adenylate cyclase was strongly influenced by exposure of the cells to light. There was about 300 fold enhancement of cyaC transcripts in cells exposed to light compared to the transcripts in cells in the dark. Although post-translational regulation of adenylate cyclase activity has been widely known, our studies suggest that transcriptional control could also be an important aspect of its regulation in A. platensis.
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Affiliation(s)
- M Kashith
- Department of Biotechnology, PSG College of Technology, Coimbatore, 640 004, India.
| | - B Keerthana
- Department of Biotechnology, PSG College of Technology, Coimbatore, 640 004, India.
| | - S Sriram
- Department of Biotechnology, PSG College of Technology, Coimbatore, 640 004, India.
| | - V Ramamurthy
- Department of Biotechnology, PSG College of Technology, Coimbatore, 640 004, India.
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Kaushik MS, Singh P, Tiwari B, Mishra AK. Ferric Uptake Regulator (FUR) protein: properties and implications in cyanobacteria. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1134-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Kleigrewe K, Almaliti J, Tian IY, Kinnel RB, Korobeynikov A, Monroe EA, Duggan BM, Di Marzo V, Sherman DH, Dorrestein PC, Gerwick L, Gerwick WH. Combining Mass Spectrometric Metabolic Profiling with Genomic Analysis: A Powerful Approach for Discovering Natural Products from Cyanobacteria. JOURNAL OF NATURAL PRODUCTS 2015; 78:1671-82. [PMID: 26149623 PMCID: PMC4681511 DOI: 10.1021/acs.jnatprod.5b00301] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
An innovative approach was developed for the discovery of new natural products by combining mass spectrometric metabolic profiling with genomic analysis and resulted in the discovery of the columbamides, a new class of di- and trichlorinated acyl amides with cannabinomimetic activity. Three species of cultured marine cyanobacteria, Moorea producens 3L, Moorea producens JHB, and Moorea bouillonii PNG, were subjected to genome sequencing and analysis for their recognizable biosynthetic pathways, and this information was then compared with their respective metabolomes as detected by MS profiling. By genome analysis, a presumed regulatory domain was identified upstream of several previously described biosynthetic gene clusters in two of these cyanobacteria, M. producens 3L and M. producens JHB. A similar regulatory domain was identified in the M. bouillonii PNG genome, and a corresponding downstream biosynthetic gene cluster was located and carefully analyzed. Subsequently, MS-based molecular networking identified a series of candidate products, and these were isolated and their structures rigorously established. On the basis of their distinctive acyl amide structure, the most prevalent metabolite was evaluated for cannabinomimetic properties and found to be moderate affinity ligands for CB1.
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Affiliation(s)
- Karin Kleigrewe
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
| | - Jehad Almaliti
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
| | - Isaac Yuheng Tian
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
- University of California Berkeley, USA
| | | | - Anton Korobeynikov
- Faculty of Mathematics and Mechanics, Saint Petersburg State University, Russia
- Center for Algorithmic Biotechnology, Saint Petersburg State University, Russia
- Algorithmic Biology Laboratory, Saint Petersburg Academic University, Russia
| | - Emily A. Monroe
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
- Department of Biology, William Paterson University of New Jersey, USA
| | - Brendan M. Duggan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, USA
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - David H. Sherman
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan
| | - Pieter C. Dorrestein
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, USA
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
| | - William H. Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California San Diego, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, USA
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9
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González A, Angarica VE, Sancho J, Fillat MF. The FurA regulon in Anabaena sp. PCC 7120: in silico prediction and experimental validation of novel target genes. Nucleic Acids Res 2014; 42:4833-46. [PMID: 24503250 PMCID: PMC4005646 DOI: 10.1093/nar/gku123] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In the filamentous cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA functions as a global transcriptional regulator. Despite several analyses have focused on elucidating the FurA-regulatory network, the number of target genes described for this essential transcription factor is limited to a handful of examples. In this article, we combine an in silico genome-wide predictive approach with experimental determinations to better define the FurA regulon. Predicted FurA-binding sites were identified upstream of 215 genes belonging to diverse functional categories including iron homeostasis, photosynthesis and respiration, heterocyst differentiation, oxidative stress defence and light-dependent signal transduction mechanisms, among others. The probabilistic model proved to be effective at discerning FurA boxes from non-cognate sequences, while subsequent electrophoretic mobility shift assay experiments confirmed the in vitro specific binding of FurA to at least 20 selected predicted targets. Gene-expression analyses further supported the dual role of FurA as transcriptional modulator that can act both as repressor and as activator. In either role, the in vitro affinity of the protein to its target sequences is strongly dependent on metal co-regulator and reducing conditions, suggesting that FurA couples in vivo iron homeostasis and the response to oxidative stress to major physiological processes in cyanobacteria.
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Affiliation(s)
- Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009 Zaragoza, Spain, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Universidad de Zaragoza, 50018 Zaragoza, Spain and Unidad Asociada BIFI-IQFR (CSIC), 28006 Madrid, Spain
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Fujisawa T, Narikawa R, Okamoto S, Ehira S, Yoshimura H, Suzuki I, Masuda T, Mochimaru M, Takaichi S, Awai K, Sekine M, Horikawa H, Yashiro I, Omata S, Takarada H, Katano Y, Kosugi H, Tanikawa S, Ohmori K, Sato N, Ikeuchi M, Fujita N, Ohmori M. Genomic structure of an economically important cyanobacterium, Arthrospira (Spirulina) platensis NIES-39. DNA Res 2010; 17:85-103. [PMID: 20203057 PMCID: PMC2853384 DOI: 10.1093/dnares/dsq004] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A filamentous non-N2-fixing cyanobacterium, Arthrospira (Spirulina) platensis, is an important organism for industrial applications and as a food supply. Almost the complete genome of A. platensis NIES-39 was determined in this study. The genome structure of A. platensis is estimated to be a single, circular chromosome of 6.8 Mb, based on optical mapping. Annotation of this 6.7 Mb sequence yielded 6630 protein-coding genes as well as two sets of rRNA genes and 40 tRNA genes. Of the protein-coding genes, 78% are similar to those of other organisms; the remaining 22% are currently unknown. A total 612 kb of the genome comprise group II introns, insertion sequences and some repetitive elements. Group I introns are located in a protein-coding region. Abundant restriction-modification systems were determined. Unique features in the gene composition were noted, particularly in a large number of genes for adenylate cyclase and haemolysin-like Ca2+-binding proteins and in chemotaxis proteins. Filament-specific genes were highlighted by comparative genomic analysis.
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Affiliation(s)
- Takatomo Fujisawa
- Bioresource Information Center, Department of Biotechnology, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Shibuya-ku, Tokyo 151-0066, Japan
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Abstract
Production of cGMP in bacteria has been studied since the early 1970s. From the beginning on it proved to be a challenging topic. In Escherichia coli the cGMP levels were two orders of magnitude lower than the corresponding cAMP levels. Furthermore, no specific cGMP receptor protein was identified in the bacterium and a physiological role of cGMP in the bacterium was not substantiated. Consequently in 1977, compelling evidence was given that cGMP is a by-product of E. coli adenylate cyclase in vivo. This may be the reason why also work on cGMP in other bacteria like Bacillus licheniformis and Caulobacter crescentus was not pursued any further. However, recent study on cGMP and guanylate cyclase in the cyanobacterium Synechocysis PCC 6803 brought cGMP signaling in bacteria back to attention. In Synechocystis cGMP levels are of similar magnitude as those of cAMP and deletion of the cya2 gene markedly reduced the amount of cGMP without affecting cAMP. A few months ago the Cya2 gene product has been biochemically and structurally characterized. It behaves as a specific guanylate cyclase in vitro and a single amino acid substitution transforms the enzyme into a specific adenylate cyclase. These data point toward the existence of a true bacterial cGMP-signaling pathway, which needs to be explored and established by future experiments.
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The evolution of guanylyl cyclases as multidomain proteins: conserved features of kinase-cyclase domain fusions. J Mol Evol 2009; 68:587-602. [PMID: 19495554 DOI: 10.1007/s00239-009-9242-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Accepted: 04/21/2009] [Indexed: 12/30/2022]
Abstract
Guanylyl cyclases (GCs) are enzymes that generate cyclic GMP and regulate different physiologic and developmental processes in a number of organisms. GCs possess sequence similarity to class III adenylyl cyclases (ACs) and are present as either membrane-bound receptor GCs or cytosolic soluble GCs. We sought to determine the evolution of GCs using a large-scale bioinformatic analysis and found multiple lineage-specific expansions of GC genes in the genomes of many eukaryotes. Moreover, a few GC-like proteins were identified in prokaryotes, which come fused to a number of different domains, suggesting allosteric regulation of nucleotide cyclase activity. Eukaryotic receptor GCs are associated with a kinase homology domain (KHD), and phylogenetic analysis of these proteins suggest coevolution of the KHD and the associated cyclase domain as well as a conservation of the sequence and the size of the linker region between the KHD and the associated cyclase domain. Finally, we also report the existence of mimiviral proteins that contain putative active kinase domains associated with a cyclase domain, which could suggest early evolution of the fusion of these two important domains involved in signal transduction.
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14
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Higo A, Ikeuchi M, Ohmori M. cAMP regulates respiration and oxidative stress during rehydration in Anabaena sp. PCC 7120. FEBS Lett 2008; 582:1883-8. [PMID: 18498771 DOI: 10.1016/j.febslet.2008.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 04/30/2008] [Accepted: 05/06/2008] [Indexed: 10/22/2022]
Abstract
Cellular cAMP level increased dramatically upon rehydration following dehydration for 24h in Anabaena sp. PCC 7120, but not in disruptant of an adenylate cyclase gene, cyaC. Oxygen consumption in the cyaC disruptant upon rehydration was higher than that in wild-type strain. Determination of lipid peroxidation and protein carbonylation of the cells revealed greater oxidative stress in the cyaC disruptant than in the wild-type strain during rehydration. Addition of cAMP or KCN to the cyaC disruptant decreased cellular oxygen consumption upon rehydration and oxidative damage. These results suggest that respiration upon rehydration is regulated by cAMP and that the higher respiration activity results in more oxidative damage in cyaC disruptant.
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Affiliation(s)
- Akiyoshi Higo
- Department of Molecular Biology, Faculty of Science, Saitama University, 255 Shimo-Ohkubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan
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15
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Cho HY, Cho HJ, Kim YM, Oh JI, Kang BS. Crystallization and preliminary crystallographic analysis of the second GAF domain of DevS from Mycobacterium smegmatis. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:274-6. [PMID: 18391425 DOI: 10.1107/s1744309108005186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2007] [Accepted: 02/23/2008] [Indexed: 11/10/2022]
Abstract
Mycobacterium tuberculosis is known to transform into the nonreplicating persistence state under the influence of hypoxia or nitric oxide. DevS-DevR is a two-component regulatory system that mediates the genetic response for the transformation. DevS is a histidine kinase that contains two GAF domains for sensing hypoxia or nitric oxide. The second GAF from M. smegmatis DevS was crystallized using the sitting-drop vapour-diffusion method in the presence of sodium citrate and 2-propanol as precipitants. X-ray diffraction data were collected from crystals containing selenomethionine to a maximum resolution of 2.0 A on a synchrotron beamline. The crystals belong to the hexagonal space group P6(1). The asymmetric unit contains one molecule, corresponding to a packing density of 2.5 A(3) Da(-1). The selenium substructure was determined by the single anomalous dispersion method and structure refinement is in progress.
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Affiliation(s)
- Ha Yeon Cho
- School of Life Science and Biotechnology, Kyungpook National University, Daegu 702-701, Republic of Korea
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16
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Mutation at different sites in the Nostoc punctiforme cyaC gene, encoding the multiple-domain enzyme adenylate cyclase, results in different levels of infection of the host plant Blasia pusilla. J Bacteriol 2007; 190:1843-7. [PMID: 18156269 DOI: 10.1128/jb.01321-07] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The filamentous cyanobacterium Nostoc punctiforme forms symbioses with plants. Disruption of the catalytic domain of the N. punctiforme adenylate cyclase (CyaC) significantly increased symbiotic competence, whereas reduced infectivity was observed in a mutant with a disruption close to the N terminus of CyaC. The total cellular cyclic AMP levels were significantly reduced in both mutants.
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17
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Abstract
Most organisms maintain a transmembrane sodium gradient for cell function. Despite the importance of Na(+) in physiology, no directly Na(+)-responsive signalling molecules are known. The CyaB1 and CyaB2 adenylyl cyclases of the cyanobacterium Anabaena PCC 7120 are inhibited by Na(+). A D360A mutation in the GAF-B domain of CyaB1 ablated cAMP-mediated autoregulation and Na(+) inhibition. Na(+) bound the isolated GAF domains of CyaB2. cAMP blocked Na(+) binding to GAF domains but Na(+) had no effect on cAMP binding. Na(+) altered GAF domain structure indicating a mechanism of inhibition independent of cAMP binding. DeltacyaB1 and DeltacyaB2 mutant strains did not grow below 0.6 mM Na(+) and DeltacyaB1 cells possessed defects in Na(+)/H(+) antiporter function. Replacement of the CyaB1 GAF domains with those of rat phosphodiesterase type 2 revealed that Na(+) inhibition has been conserved since the eukaryotic/bacterial divergence. CyaB1 and CyaB2 are the first identified directly Na(+)-responsive signalling molecules that function in sodium homeostasis and we propose a subset of GAF domains underpin an evolutionarily conserved Na(+) signalling mechanism.
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Affiliation(s)
- Martin Cann
- School of Biological and Biomedical Sciences, Durham University, South Road, Durham, UK.
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18
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Ohmori M, Terauchi K, Okamoto S, Watanabe M. Regulation of cAMP-mediated Photosignaling by a Phytochrome in the Cyanobacterium Anabaena cylindrica¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2002)0750675rocmpb2.0.co2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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19
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Okamoto S, Kasahara M, Kamlya A, Nakahira Y, Ohmori M. A Phytochrome-like Protein AphC Triggers the cAMP Signaling Induced by Far-red Light in the Cyanobacterium Anabaena sp. Strain PCC7120¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2004.tb00109.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Suzuki T, Yoshimura H, Ehira S, Ikeuchi M, Ohmori M. AnCrpA, a cAMP receptor protein, regulates nif-related gene expression in the cyanobacterium Anabaena sp. strain PCC 7120 grown with nitrate. FEBS Lett 2006; 581:21-8. [PMID: 17173896 DOI: 10.1016/j.febslet.2006.11.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 11/08/2006] [Accepted: 11/23/2006] [Indexed: 10/23/2022]
Abstract
Target genes for a cAMP receptor protein, AnCrpA, were screened using an Anabaena oligonucleotide microarray and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. Several gene expressions, including some involved in nitrogen fixation, were downregulated in the ancrpA disruptant when cells were grown with nitrate. Electrophoretic mobility shift assays (EMSAs) revealed that AnCrpA bound to the 5' upstream region of nifB, all1439, hesA, all5347, hglE and coxBII in the presence of cAMP, and all of them are related with nitrogen fixation. A possible AnCrpA-binding site in the 5' upstream region of nifB was predicted using hidden Markov model (HMM) software based on the result of in vitro selection of AnCrpA-binding sequences, and the binding was confirmed by EMSA. Thus, AnCrpA regulates the expressions of gene clusters related to nitrogen fixation in the presence of nitrate.
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Affiliation(s)
- Takayuki Suzuki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan
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21
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Okamoto S, Kasahara M, Kamiya A, Nakahira Y, Ohmori M. A phytochrome-like protein AphC triggers the cAMP signaling induced by far-red light in the cyanobacterium Anabaena sp. strain PCC7120. Photochem Photobiol 2006; 80:429-33. [PMID: 15623325 DOI: 10.1562/0031-8655(2004)080<0429:appatt>2.0.co;2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the filamentous, nitrogen-fixing cyanobacterium Anabaena sp. PCC7120, red light (630 nm) decreased, whereas far-red light (720 nm) increased cellular adenosine 3',5'-cyclic monophosphate (cAMP) content. To find a red and far-red light photoreceptor that triggers the cAMP signal cascade, we disrupted 10 open reading frame having putative chromophore-binding GAF domains. The response of the cellular cAMP concentration to red and far-red light in each open reading frame disruptant was determined. It was found that only the mutant of the gene all2699 failed to respond to far-red light. The open reading frame named as aphC encoded a protein with 920 amino acids including GAF domains similar to those involved in Cph2, a photoreceptor of Synechocystis sp. PCC6803. To determine which adenylate cyclase (AC) is responsible for far-red light signal, we disrupted all AC genes and found that CyaC was the candidate. The enzymatic activity of CyaC might be controlled by a far-red light photoreceptor through the phosphotransfer reaction. The site-specific mutant of the Asp59 residue of the receiver (R1) domain of CyaC lost its light-response capability. It was suggested that the far-red light signal was received by AphC and then transferred to the N-terminal response regulator domain of CyaC. Then its catalytic activity was stimulated, which increased the cellular cAMP concentration and drove the subsequent signal transduction cascade.
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Affiliation(s)
- Shinobu Okamoto
- Department of Biology, Graduate School of Arts and Sciences, University of Tokyo, Tokyo, Japan
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22
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Ashby M, Houmard J. Cyanobacterial two-component proteins: structure, diversity, distribution, and evolution. Microbiol Mol Biol Rev 2006; 70:472-509. [PMID: 16760311 PMCID: PMC1489541 DOI: 10.1128/mmbr.00046-05] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A survey of the already characterized and potential two-component protein sequences that exist in the nine complete and seven partially annotated cyanobacterial genome sequences available (as of May 2005) showed that the cyanobacteria possess a much larger repertoire of such proteins than most other bacteria. By analysis of the domain structure of the 1,171 potential histidine kinases, response regulators, and hybrid kinases, many various arrangements of about thirty different modules could be distinguished. The number of two-component proteins is related in part to genome size but also to the variety of physiological properties and ecophysiologies of the different strains. Groups of orthologues were defined, only a few of which have representatives with known physiological functions. Based on comparisons with the proposed phylogenetic relationships between the strains, the orthology groups show that (i) a few genes, some of them clustered on the genome, have been conserved by all species, suggesting their very ancient origin and an essential role for the corresponding proteins, and (ii) duplications, fusions, gene losses, insertions, and deletions, as well as domain shuffling, occurred during evolution, leading to the extant repertoire. These mechanisms are put in perspective with the different genetic properties that cyanobacteria have to achieve genome plasticity. This review is designed to serve as a basis for orienting further research aimed at defining the most ancient regulatory mechanisms and understanding how evolution worked to select and keep the most appropriate systems for cyanobacteria to develop in the quite different environments that they have successfully colonized.
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Affiliation(s)
- Mark
K. Ashby
- Department
of Basic Medical Sciences, Biochemistry Section, University of the West
Indies, Mona Campus, Kingston 7,
Jamaica, Ecole Normale
Supérieure, CNRS UMR 8541, Génétique
Moléculaire, 46 rue d'Ulm, 75230 Paris Cedex 05,
France
| | - Jean Houmard
- Department
of Basic Medical Sciences, Biochemistry Section, University of the West
Indies, Mona Campus, Kingston 7,
Jamaica, Ecole Normale
Supérieure, CNRS UMR 8541, Génétique
Moléculaire, 46 rue d'Ulm, 75230 Paris Cedex 05,
France
- Corresponding
author. Mailing address: Ecole Normale Supérieure, CNRS UMR 8541,
Génétique Moléculaire, 46 rue d'Ulm, 75230 Paris
Cedex 05, France. Phone: 33 1 44 32 35 19. Fax: 33 1 44 96 53 60.
E-mail:
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23
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Imashimizu M, Yoshimura H, Katoh H, Ehira S, Ohmori M. NaCl enhances cellular cAMP and upregulates genes related to heterocyst development in the cyanobacterium, Anabaena sp. strain PCC 7120. FEMS Microbiol Lett 2005; 252:97-103. [PMID: 16182471 DOI: 10.1016/j.femsle.2005.08.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 08/23/2005] [Accepted: 08/24/2005] [Indexed: 11/30/2022] Open
Abstract
Cellular cAMP was rapidly increased in the nitrogen-fixing cyanobacterium, Anabaena sp. PCC 7120, by the addition of 200 mM NaCl to the culture medium. Other alkaline-metal chlorides such as KCl or LiCl caused a lesser increase. The increase in cellular cAMP was transient and diminished when an adenylate cyclase, CyaC, which contains the conserved domains of the bacterial two-component regulatory system, was disrupted. DNA microarray analysis showed that expression of a gene cluster containing all5347 and alr5351 (hglE) was upregulated by NaCl in the wild-type strain but not in the cyaC mutant. Primer extension analysis indicated that transcription levels of all5347 and hglE were rapidly increased in response to the NaCl addition, and that these genes have NaCl-dependent transcription start sites. It was concluded that NaCl induced expression of genes related to heterocyst envelope formation in this cyanobacterium, possibly via a CyaC-cAMP signal transduction system.
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Affiliation(s)
- Masahiko Imashimizu
- Department of Life Sciences, The University of Tokyo, 381 Komaba, Meguro, Tokyo 153-8902, Japan
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24
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Cadoret JC, Rousseau B, Perewoska I, Sicora C, Cheregi O, Vass I, Houmard J. Cyclic nucleotides, the photosynthetic apparatus and response to a UV-B stress in the Cyanobacterium Synechocystis sp. PCC 6803. J Biol Chem 2005; 280:33935-44. [PMID: 16096278 DOI: 10.1074/jbc.m503153200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclic nucleotides cAMP and cGMP are ubiquitous signaling molecules that mediate many adaptative responses in eukaryotic cells. Cyanobacteria present the peculiarity among the prokaryotes of having the two types of cyclic nucleotide. Cellular homeostasis requires both cyclases (adenylyl/guanylyl, for their synthesis) and phosphodiesterases (for their degradation). Fully segregated null mutants have been obtained for the two genes, sll1624 and slr2100, which encode putative cNMP phosphodiesterases. We present physiological evidence that the Synechocystis PCC 6803 open reading frame slr2100 could be a cGMP phosphodiesterase. In addition, we show that Slr2100, but not Sll1624, is required for the adaptation of the cells to a UV-B stress. UV-B radiation has deleterious effects for photosynthetic organisms, in particular on the photosystem II, through damaging the protein structure of the reaction center. Using biophysical and biochemical approaches, it was found that Slr2100 is involved in the signal transduction events which permit the repair of the UV-B-damaged photosystem II. This was confirmed by quantitative reverse transcriptase-PCR analyses. Altogether, the data point to an important role for cGMP in signal transduction and photoacclimation processes during a UV-B stress.
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Affiliation(s)
- Jean-Charles Cadoret
- Organismes Photosynthétiques et Environnement, CNRS FRE 2433, Département de Biologie, Ecole Normale Supérieure, 46 rue d'Ulm, 75230 Paris Cedex 05, France
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25
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Masuda S, Ono TA. Biochemical characterization of the major adenylyl cyclase, Cya1, in the cyanobacterium Synechocystis sp. PCC 6803. FEBS Lett 2005; 577:255-8. [PMID: 15527795 DOI: 10.1016/j.febslet.2004.09.086] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 09/26/2004] [Accepted: 09/27/2004] [Indexed: 10/26/2022]
Abstract
We report herein the biochemical properties of an adenylyl cyclase, Cya1, from the cyanobacterium Synechocystis sp. PCC 6803. Heterologously expressed Cya1 catalyzed cyclic AMP formation with a Km for ATP of approximately 2.2 microM at pH 7.5. Although cellular Cya1 activity is increased by blue light illumination [Terauchi and Ohmori, Mol. Microbiol. 52 (2004) 303], purified Cya1 did not contain any chromophores, and the activity was light-insensitive. This suggests that an unknown blue light-responsive factor interacts with the N-terminal regulatory domain of Cya1 to control its adenylyl cyclase activity. Finally, our results show that the sensor of blue light using FAD (BLUF) protein, Slr1694, does not appear to be involved in the regulation of Cya1-mediated cAMP signal transduction in this bacterium.
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Affiliation(s)
- Shinji Masuda
- Laboratory for Photo-Biology (1), RIKEN Photodynamics Research Center, The Institute of Physical and Chemical Research, 519-1399 Aramaki, Aoba, Sendai 980-0845, Japan.
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26
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Martinez SE, Bruder S, Schultz A, Zheng N, Schultz JE, Beavo JA, Linder JU. Crystal structure of the tandem GAF domains from a cyanobacterial adenylyl cyclase: modes of ligand binding and dimerization. Proc Natl Acad Sci U S A 2005; 102:3082-7. [PMID: 15708973 PMCID: PMC549502 DOI: 10.1073/pnas.0409913102] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In several species, GAF domains, which are widely expressed small-molecule-binding domains that regulate enzyme activity, are known to bind cyclic nucleotides. However, the molecular mechanism by which cyclic nucleotide binding affects enzyme activity is not known for any GAF domain. In the cyanobacterium, Anabaena, the cyaB1 and cyaB2 genes encode adenylyl cyclases that are stimulated by binding of cAMP to their N-terminal GAF domains. Replacement of the tandem GAF-A/B domains in cyaB1 with the mammalian phosphodiesterase 2A GAF-A/B tandem domains allows regulation of the chimeric protein by cGMP, suggesting a highly conserved mechanism of activation. Here, we describe the 1.9-A crystal structure of the tandem GAF-A/B domains of cyaB2 with bound cAMP and compare it to the previously reported structure of the PDE2A GAF-A/B. Unexpectedly, the cyaB2 GAF-A/B dimer is antiparallel, unlike the parallel dimer of PDE2A. Moreover, there is clear electron density for cAMP in both GAF-A and -B, whereas in PDE2A, cGMP is found only in GAF-B. Phosphate and ribose group contacts are similar to those in PDE2A. However, the purine-binding pockets appear very different from that in PDE2A GAF-B. Differences in the beta2-beta3 loop suggest that this loop confers much of the ligand specificity in this and perhaps in many other GAF domains. Finally, a conserved asparagine appears to be a new addition to the signature NKFDE motif, and a mechanism for this motif to stabilize the cNMP-binding pocket is proposed.
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Affiliation(s)
- Sergio E Martinez
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
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27
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Weber JH, Vishnyakov A, Hambach K, Schultz A, Schultz JE, Linder JU. Adenylyl cyclases from Plasmodium, Paramecium and Tetrahymena are novel ion channel/enzyme fusion proteins. Cell Signal 2004; 16:115-25. [PMID: 14607282 DOI: 10.1016/s0898-6568(03)00129-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In Paramecium, cAMP formation is stimulated by a potassium conductance, which is an intrinsic property of the adenylyl cyclase. We cloned a full-length cDNA and several gDNA fragments from Paramecium and Tetrahymena coding for adenylyl cyclases with a novel domain composition. A putative N-terminal ion channel domain contains a canonical S4 voltage-sensor and a canonical potassium pore-loop located C-terminally after the last transmembrane span on the cytoplasmic side. The adenylyl cyclase catalyst is C-terminally located. DNA microinjection of a green fluorescent protein (GFP)-tagged construct into the macronucleus of Paramecium resulted in ciliary localization of the expressed protein. An identical gene coding for an ion-channel adenylyl cyclase was cloned from the malaria parasite Plasmodium falciparum. Expression of the catalytic domain of the latter in Sf9 cells yielded an active homodimeric adenylyl cyclase. The occurrence of this highly unique subtype of adenylyl cyclase appears to be restricted to ciliates and apicomplexa.
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Affiliation(s)
- Jost H Weber
- Abteilung Pharmazeutische Biochemie, Fakultät für Chemie und Pharmazie, Universität Tübingen, Morgenstelle 8, 72076 Tübingen, Germany
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28
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Wu X, Liu D, Lee MH, Golden JW. patS minigenes inhibit heterocyst development of Anabaena sp. strain PCC 7120. J Bacteriol 2004; 186:6422-9. [PMID: 15375122 PMCID: PMC516582 DOI: 10.1128/jb.186.19.6422-6429.2004] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The patS gene encodes a small peptide that is required for normal heterocyst pattern formation in the cyanobacterium Anabaena sp. strain PCC 7120. PatS is proposed to control the heterocyst pattern by lateral inhibition. patS minigenes were constructed and expressed by different developmentally regulated promoters to gain further insight into PatS signaling. patS minigenes patS4 to patS8 encode PatS C-terminal 4 (GSGR) to 8 (CDERGSGR) oligopeptides. When expressed by P(petE), P(patS), or P(rbcL) promoters, patS5 to patS8 inhibited heterocyst formation but patS4 did not. In contrast to the full-length patS gene, P(hepA)-patS5 failed to restore a wild-type pattern in a patS null mutant, indicating that PatS-5 cannot function in cell-to-cell signaling if it is expressed in proheterocysts. To establish the location of the PatS receptor, PatS-5 was confined within the cytoplasm as a gfp-patS5 fusion. The green fluorescent protein GFP-PatS-5 fusion protein inhibited heterocyst formation. Similarly, full-length PatS with a C-terminal hexahistidine tag inhibited heterocyst formation. These data indicate that the PatS receptor is located in the cytoplasm, which is consistent with recently published data indicating that HetR is a PatS target. We speculated that overexpression of other Anabaena strain PCC 7120 RGSGR-encoding genes might show heterocyst inhibition activity. In addition to patS and hetN, open reading frame (ORF) all3290 and an unannotated ORF, orf77, encode an RGSGR motif. Overexpression of all3290 and orf77 under the control of the petE promoter inhibited heterocyst formation, indicating that the RGSGR motif can inhibit heterocyst development in a variety of contexts.
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Affiliation(s)
- Xiaoqiang Wu
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258, USA
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29
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Suzuki T, Yoshimura H, Hisabori T, Ohmori M. Two cAMP receptor proteins with different biochemical properties in the filamentous cyanobacterium Anabaena sp. PCC 7120. FEBS Lett 2004; 571:154-60. [PMID: 15280034 DOI: 10.1016/j.febslet.2004.06.074] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Revised: 06/24/2004] [Accepted: 06/28/2004] [Indexed: 10/26/2022]
Abstract
Two open reading frames (ORFs), alr0295 and alr2325, are found to encode putative cAMP receptor proteins (CRPs) in the genome of the filamentous cyanobacterium Anabaena sp. PCC 7120. These ORFs were named cAMP receptor protein-like gene A in Anabaena sp. PCC 7120 (ancrpA) and cAMP receptor protein-like gene B in Anabaena sp. PCC 7120 (ancrpB), respectively, and those translated products were investigated. The equilibrium dialysis measurements revealed that AnCrpA bound with cAMP specifically, while AnCrpB bound with both cAMP and cGMP, though the affinity for cGMP was weak. The binding affinity for cAMP of AnCrpA showed the lowest dissociation constant, approximately 0.8 microM, among bacterial CRPs. A gel mobility shift assay elucidated that AnCrpA and AnCrpB formed a complex with the consensus DNA sequence in the presence of cAMP, although AnCrpB did not have ordinary DNA-binding motifs.
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Affiliation(s)
- Takayuki Suzuki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan
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30
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Terauchi K, Ohmori M. Blue light stimulates cyanobacterial motility via a cAMP signal transduction system. Mol Microbiol 2004; 52:303-9. [PMID: 15049828 DOI: 10.1111/j.1365-2958.2003.03980.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The participation of cAMP in photosignal transduction in cyanobacteria was investigated. When cells of the cyanobacterium Synechocystis sp. PCC 6803 were exposed to light, cellular cAMP contents increased within a few minutes. Among incident monochromatic lights, blue light (450 nm) markedly increased cellular cAMP content, while red (630 nm) and far-red (720 nm) lights did not. Disruption of the cya1 gene encoding an adenylate cyclase caused the insensitivity of cellular cAMP level to blue light. Treatment of wild-type cells with the flavin antagonist phenylacetic acid inhibited this blue light effect. The motility of wild-type cells was enhanced by blue light, whereas that of cya1 mutant cells was not. Based on these results, we concluded that a blue light-cAMP signal transduction system stimulates the motility of Synechocystis sp. PCC 6803.
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Affiliation(s)
- Kazuki Terauchi
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan
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31
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Abstract
Bacterial signalling network includes an array of numerous interacting components that monitor environmental and intracellular parameters and effect cellular response to changes in these parameters. The complexity of bacterial signalling systems makes comparative genome analysis a particularly valuable tool for their studies. Comparative studies revealed certain general trends in the organization of diverse signalling systems. These include (i) modular structure of signalling proteins; (ii) common organization of signalling components with the flow of information from N-terminal sensory domains to the C-terminal transmitter or signal output domains (N-to-C flow); (iii) use of common conserved sensory domains by different membrane receptors; (iv) ability of some organisms to respond to one environmental signal by activating several regulatory circuits; (v) abundance of intracellular signalling proteins, typically consisting of a PAS or GAF sensor domains and various output domains; (vi) importance of secondary messengers, cAMP and cyclic diguanylate; and (vii) crosstalk between components of different signalling pathways. Experimental characterization of the novel domains and domain combinations would be needed for achieving a better understanding of the mechanisms of signalling response and the intracellular hierarchy of different signalling pathways.
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Affiliation(s)
- Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA.
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32
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Zhao J, Guo Y, Fujita K, Sakai K. Involvement of cAMP signaling in elicitor-induced phytoalexin accumulation in Cupressus lusitanica cell cultures. THE NEW PHYTOLOGIST 2004; 161:723-733. [PMID: 33873708 DOI: 10.1111/j.1469-8137.2004.00976.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
• An increasing body of evidence on plant electrophysiology, biochemistry, and molecular biology shows that cAMP exists in higher plants and plays a role in several physiological processes by affecting potassium (K+ ) or calcium (Ca2+ ) fluxes. Our study here reports that cAMP is involved in elicitor-induced accumulation of a phytoalexin, β-thujaplicin, in Cupressus lusitanica cell cultures. • Treatment of C. lusitanica cultured cells with cAMP or its analogues stimulated β-thujaplicin accumulation. Cholera toxin and forskolin, activators of adenylyl cyclase, also stimulated β-thujaplicin accumulation. Enzyme immunoassay showed that after elicitor treatment, cAMP level in the elicited cells quickly increased to about three- to five-fold over the control. Cholera toxin and forskolin also stimulated cAMP accumulation in the absence of elicitor. • However, K+ and Ca2+ channel blockers inhibited the β-thujaplicin accumulation induced by cAMP analogues, suggesting that the cAMP-stimulated β-thujaplicin accumulation may involve Ca2+ and K+ fluxes. Several ionophores mimicked cAMP induction of β-thujaplicin accumulation. • Cross-talk between cAMP treatment and the ethylene signaling pathway was also observed to work in the cell cultures via Ca2+ signaling. The study also indicates an involvement of protein kinase cascades in cAMP signaling processes, leading to both phytoalexin and ethylene production.
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Affiliation(s)
- Jian Zhao
- Laboratory of Forest Chemistry and Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 Japan
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050 China
| | - Yingqing Guo
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100050 China
| | - Koki Fujita
- Laboratory of Forest Chemistry and Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 Japan
| | - Kokki Sakai
- Laboratory of Forest Chemistry and Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581 Japan
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33
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Shenroy AR, Visweswariah SS. Class III nucleotide cyclases in bacteria and archaebacteria: lineage-specific expansion of adenylyl cyclases and a dearth of guanylyl cyclases. FEBS Lett 2004; 561:11-21. [PMID: 15043055 DOI: 10.1016/s0014-5793(04)00128-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Class III nucleotide cyclases are found in bacteria, eukaryotes and archaebacteria. Our survey of the bacterial and archaebacterial genome and plasmid sequences identified 193 Class III cyclase genes in only 29 species, of which we predict the majority to be adenylyl cyclases. Interestingly, several putative cyclase genes were found to have non-conserved substrate specifying residues. Ancestors of the eukaryotic C1-C2 domain containing soluble adenylyl cyclases as well as the protist guanylyl cyclases were found in bacteria. Diverse domains were fused to the cyclase domain and phylogenetic analysis indicated that most proteins within a single cluster have similar domain compositions, emphasising the ancient evolutionary origin and versatility of the cyclase domain.
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Affiliation(s)
- Avinash R Shenroy
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India.
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34
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Cann MJ, Hammer A, Zhou J, Kanacher T. A defined subset of adenylyl cyclases is regulated by bicarbonate ion. J Biol Chem 2003; 278:35033-8. [PMID: 12829712 DOI: 10.1074/jbc.m303025200] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular basis by which organisms detect and respond to fluctuations in inorganic carbon is not known. The cyaB1 gene of the cyanobacterium Anabaena sp. PCC7120 codes for a multidomain protein with a C-terminal class III adenylyl cyclase catalyst that was specifically stimulated by bicarbonate ion (EC50 9.6 mm). Bicarbonate lowered substrate affinity but increased reaction velocity. A point mutation in the active site (Lys-646) reduced activity by 95% and was refractory to bicarbonate activation. We propose that Lys-646 specifically coordinates bicarbonate in the active site in conjunction with an aspartate to threonine polymorphism (Thr-721) conserved in class III adenylyl cyclases from diverse eukaryotes and prokaryotes. Using recombinant proteins we demonstrated that adenylyl cyclases that contain the active site threonine (cyaB of Stigmatella aurantiaca and Rv1319c of Mycobacterium tuberculosis) are bicarbonate-responsive, whereas adenylyl cyclases with a corresponding aspartate (Rv1264 of Mycobacterium) are bicarbonate-insensitive. Large numbers of class III adenylyl cyclases may therefore be activated by bicarbonate. This represents a novel mechanism by which diverse organisms can detect bicarbonate ion.
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Affiliation(s)
- Martin J Cann
- Department of Biological and Biomedical Sciences, University of Durham, South Road, Durham, DH1 3LE, United Kingdom.
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35
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Muhia DK, Swales CA, Eckstein-Ludwig U, Saran S, Polley SD, Kelly JM, Schaap P, Krishna S, Baker DA. Multiple splice variants encode a novel adenylyl cyclase of possible plastid origin expressed in the sexual stage of the malaria parasite Plasmodium falciparum. J Biol Chem 2003; 278:22014-22. [PMID: 12668669 DOI: 10.1074/jbc.m301639200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report the characterization of an unusual adenylyl cyclase gene from Plasmodium falciparum, here designated PfACalpha. The level of mRNA expression is maximum during development of gametocytes (the sexual blood stage of the parasite life cycle). The gene is highly interrupted by 22 introns, and reverse transcriptase-PCR analysis revealed that there are multiple mRNA splice variants. One intron has three alternative 3'-splice sites that confer the potential to encode distinct forms of the enzyme using alternative start codons. Deduced amino acid sequences predict membrane-spanning regions, the number of which can vary between two and six depending on the splice variant. Expression of a synthetic form of two of these variants in Xenopus oocytes and in Dictyostelium adenylyl cyclase-deficient mutants, confirms that PfACalpha is a functional adenylyl cyclase. These results identify a novel mechanism in P. falciparum for the generation of multiple isoforms of a key, membrane-bound signaling molecule from a single genomic copy. Comparisons of the catalytic domains of PfACalpha and a second putative P. falciparum adenylyl cyclase (PfACbeta) with those from other species reveal an unexpected similarity with adenylyl cyclases from certain prokaryotes including the cyanobacteria (blue green algae). In addition, the presence of an unusual active site substitution in a position that determines substrate specificity, also characteristic of these prokaryotic forms of the enzyme, further suggests a plastid origin for the Plasmodium cyclases.
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Affiliation(s)
- David K Muhia
- Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
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36
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Zhulin IB, Nikolskaya AN, Galperin MY. Common extracellular sensory domains in transmembrane receptors for diverse signal transduction pathways in bacteria and archaea. J Bacteriol 2003; 185:285-94. [PMID: 12486065 PMCID: PMC141854 DOI: 10.1128/jb.185.1.285-294.2003] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Transmembrane receptors in microorganisms, such as sensory histidine kinases and methyl-accepting chemotaxis proteins, are molecular devices for monitoring environmental changes. We report here that sensory domain sharing is widespread among different classes of transmembrane receptors. We have identified two novel conserved extracellular sensory domains, named CHASE2 and CHASE3, that are found in at least four classes of transmembrane receptors: histidine kinases, adenylate cyclases, predicted diguanylate cyclases, and either serine/threonine protein kinases (CHASE2) or methyl-accepting chemotaxis proteins (CHASE3). Three other extracellular sensory domains were shared by at least two different classes of transmembrane receptors: histidine kinases and either diguanylate cyclases, adenylate cyclases, or phosphodiesterases. These observations suggest that microorganisms use similar conserved domains to sense similar environmental signals and transmit this information via different signal transduction pathways to different regulatory circuits: transcriptional regulation (histidine kinases), chemotaxis (methyl-accepting proteins), catabolite repression (adenylate cyclases), and modulation of enzyme activity (diguanylate cyclases and phosphodiesterases). The variety of signaling pathways using the CHASE-type domains indicates that these domains sense some critically important extracellular signals.
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Affiliation(s)
- Igor B Zhulin
- School of Biology, Georgia Institute of Technology, Atlanta, GA 30332-0230, USA.
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37
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Kanacher T, Schultz A, Linder JU, Schultz JE. A GAF-domain-regulated adenylyl cyclase from Anabaena is a self-activating cAMP switch. EMBO J 2002; 21:3672-80. [PMID: 12110580 PMCID: PMC126120 DOI: 10.1093/emboj/cdf375] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The gene cyaB1 from the cyanobacterium Anabaena sp. PCC 7120 codes for a protein consisting of two N-terminal GAF domains (GAF-A and GAF-B), a PAS domain and a class III adenylyl cyclase catalytic domain. The catalytic domain is active as a homodimer, as demonstrated by reconstitution from complementary inactive point mutants. The specific activity of the holoenyzme increased exponentially with time because the product cAMP activated dose dependently and nucleotide specifically (half-maximally at 1 microM), identifying cAMP as a novel GAF domain ligand. Using point mutants of either the GAF-A or GAF-B domain revealed that cAMP activated via the GAF-B domain. We replaced the cyanobacterial GAF domain ensemble in cyaB1 with the tandem GAF-A/GAF-B assemblage from the rat cGMP-stimulated phosphodiesterase type 2, and converted cyaB1 to a cGMP-stimulated adenylyl cyclase. This demonstrated the functional conservation of the GAF domain ensemble since the divergence of bacterial and eukaryotic lineages >2 billion years ago. In cyanobacteria, cyaB1 may act as a cAMP switch to stabilize committed developmental decisions.
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Affiliation(s)
| | | | - Jürgen U. Linder
- Pharmazeutische Biochemie, Pharmazeutisches Institut, Morgenstelle 8, D-72076 Tübingen, Germany
Corresponding authors e-mail: or
| | - Joachim E. Schultz
- Pharmazeutische Biochemie, Pharmazeutisches Institut, Morgenstelle 8, D-72076 Tübingen, Germany
Corresponding authors e-mail: or
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38
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Kimura Y, Mishima Y, Nakano H, Takegawa K. An adenylyl cyclase, CyaA, of Myxococcus xanthus functions in signal transduction during osmotic stress. J Bacteriol 2002; 184:3578-85. [PMID: 12057952 PMCID: PMC135126 DOI: 10.1128/jb.184.13.3578-3585.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2002] [Accepted: 04/08/2002] [Indexed: 11/20/2022] Open
Abstract
An adenylyl cyclase gene (cyaA) present upstream of an osmosensor protein gene (mokA) was isolated from Myxococcus xanthus. cyaA encoded a polypeptide of 843 amino acids with a predicted molecular mass of 91,187 Da. The predicted cyaA gene product had structural similarity to the receptor-type adenylyl cyclases that are composed of an amino-terminal sensor domain and a carboxy-terminal catalytic domain of adenylyl cyclase. In reverse transcriptase PCR experiments, the transcript of the cyaA gene was detected mainly during development and spore germination. A cyaA mutant, generated by gene disruption, showed normal growth, development, and germination. However, a cyaA mutant placed under conditions of ionic (NaCl) or nonionic (sucrose) osmostress exhibited a marked reduction in spore formation and spore germination. When wild-type and cyaA mutant cells at developmental stages were stimulated with 0.2 M NaCl or sucrose, the mutant cells increased cyclic AMP accumulation at levels similar to those of the wild-type cells. In contrast, the mutant cells during spore germination had mainly lost the ability to respond to high-ionic osmolarity. In vegetative cells, the cyaA mutant responded normally to osmotic stress. These results suggested that M. xanthus CyaA functions mainly as an ionic osmosensor during spore germination and that CyaA is also required for osmotic tolerance in fruiting formation and sporulation.
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Affiliation(s)
- Yoshio Kimura
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, Japan 761-0795.
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39
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Ohmori M, Terauchi K, Okamoto S, Watanabe M. Regulation of cAMP-mediated photosignaling by a phytochrome in the cyanobacterium Anabaena cylindrica. Photochem Photobiol 2002; 75:675-9. [PMID: 12081331 DOI: 10.1562/0031-8655(2002)075<0675:rocmpb>2.0.co;2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Changes in cellular adenosine 3',5'-cyclic monophosphate (cAMP) content induced by monochromatic light of various wavelengths were determined in the cyanobacterium Anabaena cylindrica. Irradiation with monochromatic red light caused a rapid decrease in cAMP content. In contrast, far-red light caused a rapid increase in its content. The effects of red and far-red light were reversible, suggesting the involvement of a prototype phytochrome as the photoreceptor for cAMP-mediated light-responsive signal transduction.
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Affiliation(s)
- Masayuki Ohmori
- Department of Biology, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Japan.
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40
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Shenoy AR, Srinivasan N, Visweswariah SS. The ascent of nucleotide cyclases: conservation and evolution of a theme. J Biosci 2002; 27:85-91. [PMID: 11937677 DOI: 10.1007/bf02703763] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Avinash R Shenoy
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India
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41
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Yoshimura H, Yanagisawa S, Kanehisa M, Ohmori M. Screening for the target gene of cyanobacterial cAMP receptor protein SYCRP1. Mol Microbiol 2002; 43:843-53. [PMID: 12085767 DOI: 10.1046/j.1365-2958.2002.02790.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The target genes for SYCRP1, a cyanobacterial cAMP receptor protein, were surveyed using a DNA microarray method. Total RNAs were extracted from a wild-type strain and a sycrp1 disruptant of Synechocystis sp. PCC 6803, and the respective gene expression levels were compared. The expression levels of six genes (slr1667, slr1168, slr2015, slr2016, slr2017 and slr2018) were clearly decreased by the disruption of the sycrp1 gene. The data suggest that slr1667 and slr1668 constitute one operon and the other four genes constitute another operon. Transcription start points for the first genes of these putative operons, which are slr1667 and slr2015, were determined by primer extension experiments. Gel mobility shift assays and DNase 1 footprint analyses were carried out to explore the binding of SYCRP1 to the putative promoter regions of slr1667 and slr2015. SYCRP1 bound to the specific site in the 5' upstream region of slr1667 from positions -170 to -155 relative to the transcription start point, while it did not bind to the 5' upstream region of slr2015. It was concluded that SYCRP1 regulates the expression of the slr1667 gene directly by binding to a specific site in its promoter.
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Affiliation(s)
- Hidehisa Yoshimura
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan
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42
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Segovia M, Gordillo FJ, Schaap P, Figueroa FL. Light regulation of cyclic-AMP levels in the red macroalga Porphyra leucosticta. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2001; 64:69-74. [PMID: 11705732 DOI: 10.1016/s1011-1344(01)00218-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Total cyclic-3'-5'-adenosine monophosphate (cAMP) levels were measured in the gametophyte of the red macroalga Porphyra leucosticta under different light conditions in order to study its regulation by phytochrome or photosynthesis. cAMP levels were relatively low when samples were incubated in darkness, or exposed to red or far-red light. Irradiation with red+far-red light induced a moderate increase in cAMP levels, while white light induced a pronounced increase in cAMP levels. When incubated under increasing white light irradiance, cAMP levels closely followed the increase in photosynthetic oxygen evolution rate, suggesting a direct relationship between photosynthesis and cAMP accumulation. cAMP levels were not dependent on cellular ATP concentration, as inhibitors of ATP synthesis did not significantly affect cAMP levels in light. We conclude that cAMP depends on photosynthetic activity regardless of ATP synthesis and concentration or phytochrome activity.
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Affiliation(s)
- M Segovia
- Departamento de Ecología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
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43
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Moutinho A, Hussey PJ, Trewavas AJ, Malhó R. cAMP acts as a second messenger in pollen tube growth and reorientation. Proc Natl Acad Sci U S A 2001; 98:10481-6. [PMID: 11517303 PMCID: PMC56986 DOI: 10.1073/pnas.171104598] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2001] [Indexed: 11/18/2022] Open
Abstract
Pollen tube growth and reorientation is a prerequisite for fertilization and seed formation. Here we report imaging of cAMP distribution in living pollen tubes microinjected with the protein kinase A-derived fluorosensor. Growing tubes revealed a uniform distribution of cAMP with a resting concentration of approximately 100-150 nM. Modulators of adenylyl cyclase (AC), forskolin, and dideoxyadenosine could alter these values. Transient elevations in the apical region could be correlated with changes in the tube-growth axis, suggesting a role for cAMP in polarized growth. Changes in cAMP arise through the activity of a putative AC identified in pollen. This signaling protein shows homology to functional motifs in fungal AC. Expression of the cDNA in Escherichia coli resulted in cAMP increase and complemented a catabolic defect in the fermentation of carbohydrates caused by the absence of cAMP in a cyaA mutant. Antisense assays performed with oligodeoxynucleotide probes directed against conserved motifs perturbed tip growth, suggesting that modulation of cAMP concentration is vital for tip growth.
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Affiliation(s)
- A Moutinho
- Department of Plant Biology, Faculdade de Ciências de Lisboa, University of Lisbon, Block C2, Lisboa, 1749-016 Lisbon, Portugal
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44
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Kasahara M, Unno T, Yashiro K, Ohmori M. CyaG, a novel cyanobacterial adenylyl cyclase and a possible ancestor of mammalian guanylyl cyclases. J Biol Chem 2001; 276:10564-9. [PMID: 11134014 DOI: 10.1074/jbc.m008006200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A novel gene encoding an adenylyl cyclase, designated cyaG, was identified in the filamentous cyanobacterium Spirulina platensis. The predicted amino acid sequence of the C-terminal region of cyaG was similar to the catalytic domains of Class III adenylyl and guanylyl cyclases. The N-terminal region next to the catalytic domain of CyaG was similar to the dimerization domain, which is highly conserved among guanylyl cyclases. As a whole, CyaG is more closely related to guanylyl cyclases than to adenylyl cyclases in its primary structure. The catalytic domain of CyaG was expressed in Escherichia coli and partially purified. CyaG showed adenylyl cyclase (but not guanylyl cyclase) activity. By site-directed mutagenesis of three amino acid residues (Lys(533), Ile(603), and Asp(605)) within the purine ring recognition site of CyaG to Glu, Arg, and Cys, respectively, CyaG was transformed to a guanylyl cyclase that produced cGMP instead of cAMP. Thus having properties of both cyclases, CyaG may therefore represent a critical position in the evolution of Class III adenylyl and guanylyl cyclases.
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Affiliation(s)
- M Kasahara
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153, Japan
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45
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Ochoa de Alda JAG, Houmard J. Genomic survey of cAMP and cGMP signalling components in the cyanobacterium Synechocystis PCC 6803. MICROBIOLOGY (READING, ENGLAND) 2000; 146 Pt 12:3183-3194. [PMID: 11101676 DOI: 10.1099/00221287-146-12-3183] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cyanobacteria modulate intracellular levels of cAMP and cGMP in response to environmental conditions (light, nutrients and pH). In an attempt to identify components of the cAMP and cGMP signalling pathways in Synechocystis PCC 6803, the authors screened its complete genome sequence by using bioinformatic tools and data from sequence-function studies performed on both eukaryotic and prokaryotic cAMP/cGMP-dependent proteins. Sll1624 and Slr2100 were tentatively assigned as being two putative cyclic nucleotide phosphodiesterases. Five proteins were identified as having all the determinants required to be cyclic nucleotide receptors, two of them being probably more specific for cGMP (an element of two-component regulatory systems - Slr2104 - and a putative cyclic-nucleotide-gated cation channel - Slr1575), the three others being probably more specific for cAMP: (i) a protein of unidentified function (Slr0842); (ii) a putative cyclic-nucleotide-modulated permease (Slr0593), previously annotated as a kinase A regulatory subunit; and (iii) a putative transcription factor (CRP-SYN: =Sll1371), which possesses cAMP- and DNA-binding determinants homologous to those of the cAMP receptor protein of Escherichia coli (CRP-EC:). This homology, together with the presence in Synechocystis of CRP-EC:-like binding sites upstream of crp, cya1, slr1575, and several genes encoding enzymes involved in transport and metabolism, strongly suggests that CRP-SYN: is a global regulator.
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Affiliation(s)
- Jesús A G Ochoa de Alda
- Dynamique des Membranes Végétales, Complexes Protéines-Pigments, CNRS UMR 8543, Ecole Normale Supérieure, 46 rue d'Ulm 75230 Paris Cedex 05, France1
| | - Jean Houmard
- Dynamique des Membranes Végétales, Complexes Protéines-Pigments, CNRS UMR 8543, Ecole Normale Supérieure, 46 rue d'Ulm 75230 Paris Cedex 05, France1
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46
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Thomason P, Kay R. Eukaryotic signal transduction via histidine-aspartate phosphorelay. J Cell Sci 2000; 113 ( Pt 18):3141-50. [PMID: 10954413 DOI: 10.1242/jcs.113.18.3141] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmembrane signal transduction is a feature common to all eukaryotic and prokaryotic cells. We now understand that a subset of the signalling mechanisms used by eukaryotes and prokaryotes are not just similar in principle, but actually use homologous proteins. These are the histidine-aspartate phosphorelays, signalling systems of eubacterial origin, now known to be widespread in eukaryotes outside the animal kingdom. Genome projects are revealing that His-Asp phosphorelays are present as multigene families in lower eukaryotes and in plants. A major challenge is to understand how these ‘novel’ signal transduction systems form integrated networks with the more familiar signalling mechanisms also present in eukaryotic cells. Already, phosphorelays have been characterised that regulate MAP kinase cascades and the cAMP/PKA pathway. The probable absence of His-Asp phosphorelays from animals has generated interest in their potential as targets for anti-microbial therapy, including antifungals. Recent findings suggest that this approach holds promise.
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Affiliation(s)
- P Thomason
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.
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47
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Ochoa De Alda JA, Ajlani G, Houmard J. Synechocystis strain PCC 6803 cya2, a prokaryotic gene that encodes a guanylyl cyclase. J Bacteriol 2000; 182:3839-42. [PMID: 10851002 PMCID: PMC94558 DOI: 10.1128/jb.182.13.3839-3842.2000] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Synechocystis strain PCC 6803 exhibits similar levels of cyclic AMP (cAMP) and cyclic GMP (cGMP). A thorough analysis of its genome showed that Cya2 (Sll0646) has all the sequence determinants required in terms of activity and purine specificity for being a guanylyl cyclase. Insertional mutagenesis of cya2 caused a marked reduction in cGMP content without altering the cAMP content. Thus, Cya2 represents the first example of a prokaryotic guanylyl cyclase.
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Affiliation(s)
- J A Ochoa De Alda
- Dynamique des Membranes Végétales, Complexes Protéines-Pigments, CNRS UMR8543, Ecole Normale Supérieure, 75230 Paris Cedex 05, France.
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48
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McCue LA, McDonough KA, Lawrence CE. Functional classification of cNMP-binding proteins and nucleotide cyclases with implications for novel regulatory pathways in Mycobacterium tuberculosis. Genome Res 2000; 10:204-19. [PMID: 10673278 DOI: 10.1101/gr.10.2.204] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We have analyzed the cyclic nucleotide (cNMP)-binding protein and nucleotide cyclase superfamilies using Bayesian computational methods of protein family identification and classification. In addition to the known cNMP-binding proteins (cNMP-dependent kinases, cNMP-gated channels, cAMP-guanine nucleotide exchange factors, and bacterial cAMP-dependent transcription factors), new functional groups of cNMP-binding proteins were identified, including putative ABC-transporter subunits, translocases, and esterases. Classification of the nucleotide cyclases revealed subtle differences in sequence conservation of the active site that distinguish the five classes of cyclases: the multicellular eukaryotic adenylyl cyclases, the eukaryotic receptor-type guanylyl cyclases, the eukaryotic soluble guanylyl cyclases, the unicellular eukaryotic and prokaryotic adenylyl cyclases, and the putative prokaryotic guanylyl cyclases. Phylogenetic distribution of the cNMP-binding proteins and cyclases was analyzed, with particular attention to the 22 complete archaeal and eubacterial genome sequences. Mycobacterium tuberculosis H37Rv and Synechocystis PCC6803 were each found to encode several more putative cNMP-binding proteins than other prokaryotes; many of these proteins are of unknown function. M. tuberculosis also encodes several more putative nucleotide cyclases than other prokaryotic species.
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Affiliation(s)
- L A McCue
- The Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany, New York 12201-0509 USA
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49
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Söderbom F, Anjard C, Iranfar N, Fuller D, Loomis WF. An adenylyl cyclase that functions during late development of Dictyostelium. Development 1999; 126:5463-71. [PMID: 10556070 DOI: 10.1242/dev.126.23.5463] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A variety of extracellular signals lead to the accumulation of cAMP which can act as a second message within cells by activating protein kinase A (PKA). Expression of many of the essential developmental genes in Dictyostelium discoideum are known to depend on PKA activity. Cells in which the receptor-coupled adenylyl cyclase gene, acaA, is genetically inactivated grow well but are unable to develop. Surprisingly, acaA(−) mutant cells can be rescued by developing them in mixtures with wild-type cells, suggesting that another adenylyl cyclase is present in developing cells that can provide the internal cAMP necessary to activate PKA. However, the only other known adenylyl cyclase gene in Dictyostelium, acgA, is only expressed during germination of spores and plays no role in the formation of fruiting bodies. By screening morphological mutants generated by Restriction Enzyme Mediated Integration (REMI) we discovered a novel adenylyl cyclase gene, acrA, that is expressed at low levels in growing cells and at more than 25-fold higher levels during development. Growth and development up to the slug stage are unaffected in acrA(−) mutant strains but the cells make almost no viable spores and produce unnaturally long stalks. Adenylyl cyclase activity increases during aggregation, plateaus during the slug stage and then increases considerably during terminal differentiation. The increase in activity following aggregation fails to occur in acrA(−) cells. As long as ACA is fully active, ACR is not required until culmination but then plays a critical role in sporulation and construction of the stalk.
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Affiliation(s)
- F Söderbom
- Center for Molecular Genetics, Department of Biology, University of California San Diego, La Jolla, CA 92093, USA
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50
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Abstract
The fruiting body development of Myxococcus xanthus consists of two separate but interacting pathways: one for aggregation of many cells to form raised mounds and the other for sporulation of individual cells into myxospores. Sporulation of individual cells normally occurs after mound formation, and is delayed at least 30 h after starvation under our laboratory conditions. This suggests that M. xanthus has a mechanism that monitors progress towards aggregation prior to triggering sporulation. A null mutation in a newly identified gene, espA (early sporulation), causes sporulation to occur much earlier compared with the wild type (16 h earlier). In contrast, a null mutation in an adjacent gene, espB, delays sporulation by about 16 h compared with the wild type. Interestingly, it appears that the espA mutant does not require raised mounds for sporulation. Many mutant cells sporulate outside the fruiting bodies. In addition, the mutant can sporulate, without aggregation into raised mounds, under some conditions in which cells normally do not form fruiting bodies. Based on these observations, it is hypothesized that EspA functions as an inhibitor of sporulation during early fruiting body development while cells are aggregating into raised mounds. The aggregation-independent sporulation of the espA mutant still requires starvation and high cell density. The espA and espB genes are expressed as an operon and their translations appear to be coupled. Expression occurs only under developmental conditions and does not occur during vegetative growth or during glycerol-induced sporulation. Sequence analysis of EspA indicates that it is a histidine protein kinase with a fork head-associated (FHA) domain at the N-terminus and a receiver domain at the C-terminus. This suggests that EspA is part of a two-component signal transduction system that regulates the timing of sporulation initiation.
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Affiliation(s)
- K Cho
- Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, CA 94720-3204, USA
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