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Shi X, Yan H, Yuan F, Li G, Liu J, Li C, Yu X, Li Z, Zhu Y, Wang W. LexA, an SOS response repressor, activates TGase synthesis in Streptomyces mobaraensis. Front Microbiol 2024; 15:1397314. [PMID: 38855760 PMCID: PMC11157053 DOI: 10.3389/fmicb.2024.1397314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/13/2024] [Indexed: 06/11/2024] Open
Abstract
Transglutaminase (EC 2.3.2.13, TGase), an enzyme that catalyzes the formation of covalent cross-links between protein or peptide molecules, plays a critical role in commercial food processing, medicine, and textiles. TGase from Streptomyces is the sole commercial enzyme preparation for cross-linking proteins. In this study, we revealed that the SOS response repressor protein LexA in Streptomyces mobaraensis not only triggers morphological development but also enhances TGase synthesis. The absence of lexA significantly diminished TGase production and sporulation. Although LexA does not bind directly to the promoter region of the TGase gene, it indirectly stimulates transcription of the tga gene, which encodes TGase. Furthermore, LexA directly enhances the expression of genes associated with protein synthesis and transcription factors, thus favorably influencing TGase synthesis at both the transcriptional and posttranscriptional levels. Moreover, LexA activates four crucial genes involved in morphological differentiation, promoting spore maturation. Overall, our findings suggest that LexA plays a dual role as a master regulator of the SOS response and a significant contributor to TGase regulation and certain aspects of secondary metabolism, offering insights into the cellular functions of LexA and facilitating the strategic engineering of TGase overproducers.
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Affiliation(s)
- Xinyu Shi
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China
| | - Hao Yan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Fang Yuan
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
- Jiangsu Yiming Biological Technology Co., Ltd., Taixing, China
| | - Guoying Li
- Jiangsu Yiming Biological Technology Co., Ltd., Taixing, China
| | - Jingfang Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chunli Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaobin Yu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zilong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yunping Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China
| | - Weishan Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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2
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Martinez M, Petit J, Leyva A, Sogues A, Megrian D, Rodriguez A, Gaday Q, Ben Assaya M, Portela MM, Haouz A, Ducret A, Grangeasse C, Alzari PM, Durán R, Wehenkel AM. Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation. Nat Microbiol 2023; 8:1896-1910. [PMID: 37679597 PMCID: PMC10522489 DOI: 10.1038/s41564-023-01473-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 08/11/2023] [Indexed: 09/09/2023]
Abstract
The order Corynebacteriales includes major industrial and pathogenic Actinobacteria such as Corynebacterium glutamicum or Mycobacterium tuberculosis. These bacteria have multi-layered cell walls composed of the mycolyl-arabinogalactan-peptidoglycan complex and a polar growth mode, thus requiring tight coordination between the septal divisome, organized around the tubulin-like protein FtsZ, and the polar elongasome, assembled around the coiled-coil protein Wag31. Here, using C. glutamicum, we report the discovery of two divisome members: a gephyrin-like repurposed molybdotransferase (Glp) and its membrane receptor (GlpR). Our results show how cell cycle progression requires interplay between Glp/GlpR, FtsZ and Wag31, showcasing a crucial crosstalk between the divisome and elongasome machineries that might be targeted for anti-mycobacterial drug discovery. Further, our work reveals that Corynebacteriales have evolved a protein scaffold to control cell division and morphogenesis, similar to the gephyrin/GlyR system that mediates synaptic signalling in higher eukaryotes through network organization of membrane receptors and the microtubule cytoskeleton.
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Affiliation(s)
- Mariano Martinez
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Julienne Petit
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Alejandro Leyva
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Adrià Sogues
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
- Structural and Molecular Microbiology, VIB-VUB Center for Structural Biology, VIB, Vrije Universiteit Brussel, Brussels, Belgium
| | - Daniela Megrian
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Azalia Rodriguez
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Quentin Gaday
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Mathildeb Ben Assaya
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Maria Magdalena Portela
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Ahmed Haouz
- Plate-forme de cristallographie, C2RT-Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Adrien Ducret
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université de Lyon, Lyon, France
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université de Lyon, Lyon, France
| | - Pedro M Alzari
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France
| | - Rosario Durán
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
| | - Anne Marie Wehenkel
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, Paris, France.
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3
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Zhang L, Willemse J, Yagüe P, de Waal E, Claessen D, van Wezel GP. The SepF-like proteins SflA and SflB prevent ectopic localization of FtsZ and DivIVA during sporulation of Streptomyces coelicolor. Biochem Biophys Res Commun 2023; 645:79-87. [PMID: 36680940 DOI: 10.1016/j.bbrc.2023.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Bacterial cytokinesis starts with the polymerization of the tubulin-like FtsZ, which forms the cell division scaffold. SepF aligns FtsZ polymers and also acts as a membrane anchor for the Z-ring. While in most bacteria cell division takes place at midcell, during sporulation of Streptomyces many septa are laid down almost simultaneously in multinucleoid aerial hyphae. The genomes of streptomycetes encode two additional SepF paralogs, SflA and SflB, which can interact with SepF. Here we show that the sporogenic aerial hyphae of sflA and sflB mutants of Streptomyces coelicolor frequently branch, a phenomenon never seen in the wild-type strain. The branching coincided with ectopic localization of DivIVA along the lateral wall of sporulating aerial hyphae. Constitutive expression of SflA and SflB largely inhibited hyphal growth, further correlating SflAB activity to that of DivIVA. SflAB localized in foci prior to and after the time of sporulation-specific cell division, while SepF co-localized with active septum synthesis. Foci of FtsZ and DivIVA frequently persisted between adjacent spores in spore chains of sflA and sflB mutants, at sites occupied by SflAB in wild-type cells. Taken together, our data show that SflA and SflB play an important role in the control of growth and cell division during Streptomyces development.
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Affiliation(s)
- Le Zhang
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Joost Willemse
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Paula Yagüe
- Departamento de Biología Funcional e IUOPA, Área de Microbiología, Facultad de Medicina, Universidad de Oviedo, Oviedo, 33006, Spain
| | - Ellen de Waal
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Dennis Claessen
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands
| | - Gilles P van Wezel
- Department of Molecular Biotechnology, Institute of Biology Leiden, Leiden University, PO Box 9505, Leiden, 2300, AB, the Netherlands.
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4
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Freeman AH, Tembiwa K, Brenner JR, Chase MR, Fortune SM, Morita YS, Boutte CC. Arginine methylation sites on SepIVA help balance elongation and septation in Mycobacterium smegmatis. Mol Microbiol 2023; 119:208-223. [PMID: 36416406 PMCID: PMC10023300 DOI: 10.1111/mmi.15006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022]
Abstract
The growth of mycobacterial cells requires successful coordination between elongation and septation. However, it is not clear which factors mediate this coordination. Here, we studied the function and post-translational modification of an essential division factor, SepIVA, in Mycobacterium smegmatis. We find that SepIVA is arginine methylated, and that alteration of its methylation sites affects both septation and polar elongation of Msmeg. Furthermore, we show that SepIVA regulates the localization of MurG and that this regulation may impact polar elongation. Finally, we map SepIVA's two regulatory functions to different ends of the protein: the N-terminus regulates elongation while the C-terminus regulates division. These results establish SepIVA as a regulator of both elongation and division and characterize a physiological role for protein arginine methylation sites for the first time in mycobacteria.
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Affiliation(s)
- Angela H Freeman
- Department of Biology, University of Texas at Arlington,
Arlington, Texas, USA
| | - Karen Tembiwa
- Department of Biology, University of Texas at Arlington,
Arlington, Texas, USA
| | - James R Brenner
- Department of Microbiology, University of Massachusetts,
Amherst, Massachusetts, USA
| | - Michael R Chase
- Department of Immunology and Infectious Disease, Harvard TH
Chan School of Public Health, Boston, Massachusetts, USA
| | - Sarah M Fortune
- Department of Immunology and Infectious Disease, Harvard TH
Chan School of Public Health, Boston, Massachusetts, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts,
Amherst, Massachusetts, USA
| | - Cara C Boutte
- Department of Biology, University of Texas at Arlington,
Arlington, Texas, USA
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5
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Martinez M, Petit J, Leyva A, Sogues A, Megrian D, Rodriguez A, Gaday Q, Ben Assaya M, Portela M, Haouz A, Ducret A, Grangeasse C, Alzari PM, Durán R, Wehenkel A. Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526586. [PMID: 36778425 PMCID: PMC9915583 DOI: 10.1101/2023.02.01.526586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The order Corynebacteriales includes major industrial and pathogenic actinobacteria such as Corynebacterium glutamicum or Mycobacterium tuberculosis . Their elaborate multi-layered cell wall, composed primarily of the mycolyl-arabinogalactan-peptidoglycan complex, and their polar growth mode impose a stringent coordination between the septal divisome, organized around the tubulin-like protein FtsZ, and the polar elongasome, assembled around the tropomyosin-like protein Wag31. Here, we report the identification of two new divisome members, a gephyrin-like repurposed molybdotransferase (GLP) and its membrane receptor (GLPR). We show that the interplay between the GLPR/GLP module, FtsZ and Wag31 is crucial for orchestrating cell cycle progression. Our results provide a detailed molecular understanding of the crosstalk between two essential machineries, the divisome and elongasome, and reveal that Corynebacteriales have evolved a protein scaffold to control cell division and morphogenesis similar to the gephyrin/GlyR system that in higher eukaryotes mediates synaptic signaling through network organization of membrane receptors and the microtubule cytoskeleton.
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Affiliation(s)
- M. Martinez
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - J. Petit
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - A. Leyva
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - A. Sogues
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - D. Megrian
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - A. Rodriguez
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Q. Gaday
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - M. Ben Assaya
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - M. Portela
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - A. Haouz
- Plate-forme de cristallographie, C2RT-Institut Pasteur, CNRS, UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - A. Ducret
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - C. Grangeasse
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université de Lyon, 7 passage du Vercors, 69367 Lyon, France
| | - P. M. Alzari
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
| | - R. Durán
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - A. Wehenkel
- Structural Microbiology Unit, Institut Pasteur, CNRS UMR 3528, Université Paris Cité, F-75015 Paris, France
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6
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Habibi Arejan N, Ensinck D, Diacovich L, Patel PB, Quintanilla SY, Emami Saleh A, Gramajo H, Boutte CC. Polar protein Wag31 both activates and inhibits cell wall metabolism at the poles and septum. Front Microbiol 2023; 13:1085918. [PMID: 36713172 PMCID: PMC9878328 DOI: 10.3389/fmicb.2022.1085918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/20/2022] [Indexed: 01/15/2023] Open
Abstract
Mycobacterial cell elongation occurs at the cell poles; however, it is not clear how cell wall insertion is restricted to the pole or how it is organized. Wag31 is a pole-localized cytoplasmic protein that is essential for polar growth, but its molecular function has not been described. In this study we used alanine scanning mutagenesis to identify Wag31 residues involved in cell morphogenesis. Our data show that Wag31 helps to control proper septation as well as new and old pole elongation. We have identified key amino acid residues involved in these essential functions. Enzyme assays revealed that Wag31 interacts with lipid metabolism by modulating acyl-CoA carboxylase (ACCase) activity. We show that Wag31 does not control polar growth by regulating the localization of cell wall precursor enzymes to the Intracellular Membrane Domain, and we also demonstrate that phosphorylation of Wag31 does not substantively regulate peptidoglycan metabolism. This work establishes new regulatory functions of Wag31 in the mycobacterial cell cycle and clarifies the need for new molecular models of Wag31 function.
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Affiliation(s)
- Neda Habibi Arejan
- Department of Biology, University of Texas at Arlington, Arlington, TX, United States
| | - Delfina Ensinck
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Lautaro Diacovich
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | | | | | - Arash Emami Saleh
- Department of Civil Engineering, University of Texas at Arlington, Arlington, TX, United States
| | - Hugo Gramajo
- Laboratory of Physiology and Genetics of Actinomycetes, Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Cara C. Boutte
- Department of Biology, University of Texas at Arlington, Arlington, TX, United States,*Correspondence: Cara C. Boutte,
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7
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Quintanilla SY, Arejan NH, Patel PB, Boutte CC. PlrA (MSMEG_5223) is an essential polar growth regulator in Mycobacterium smegmatis. PLoS One 2023; 18:e0280336. [PMID: 36634117 PMCID: PMC9836265 DOI: 10.1371/journal.pone.0280336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/27/2022] [Indexed: 01/13/2023] Open
Abstract
Mycobacteria expand their cell walls at the cell poles in a manner that is not well described at the molecular level. In this study, we identify a new polar factor, PlrA, that is involved in restricting peptidoglycan metabolism to the cell poles in Mycobacterium smegmatis. We establish that only the N-terminal membrane domain of PlrA is essential. We show that depletion of plrA pheno-copies depletion of polar growth factor Wag31, and that PlrA is involved in regulating the Wag31 polar foci.
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Affiliation(s)
- Samantha Y. Quintanilla
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Neda Habibi Arejan
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Parthvi B. Patel
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
| | - Cara C. Boutte
- Department of Biology, University of Texas Arlington, Arlington, TX, United States of America
- * E-mail:
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8
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Mishra D, Srinivasan R. Catching a Walker in the Act-DNA Partitioning by ParA Family of Proteins. Front Microbiol 2022; 13:856547. [PMID: 35694299 PMCID: PMC9178275 DOI: 10.3389/fmicb.2022.856547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/28/2022] [Indexed: 12/01/2022] Open
Abstract
Partitioning the replicated genetic material is a crucial process in the cell cycle program of any life form. In bacteria, many plasmids utilize cytoskeletal proteins that include ParM and TubZ, the ancestors of the eukaryotic actin and tubulin, respectively, to segregate the plasmids into the daughter cells. Another distinct class of cytoskeletal proteins, known as the Walker A type Cytoskeletal ATPases (WACA), is unique to Bacteria and Archaea. ParA, a WACA family protein, is involved in DNA partitioning and is more widespread. A centromere-like sequence parS, in the DNA is bound by ParB, an adaptor protein with CTPase activity to form the segregation complex. The ParA ATPase, interacts with the segregation complex and partitions the DNA into the daughter cells. Furthermore, the Walker A motif-containing ParA superfamily of proteins is associated with a diverse set of functions ranging from DNA segregation to cell division, cell polarity, chemotaxis cluster assembly, cellulose biosynthesis and carboxysome maintenance. Unifying principles underlying the varied range of cellular roles in which the ParA superfamily of proteins function are outlined. Here, we provide an overview of the recent findings on the structure and function of the ParB adaptor protein and review the current models and mechanisms by which the ParA family of proteins function in the partitioning of the replicated DNA into the newly born daughter cells.
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Affiliation(s)
- Dipika Mishra
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India
- Homi Bhabha National Institutes, Mumbai, India
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar, India
- Homi Bhabha National Institutes, Mumbai, India
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9
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Zhang L, Wang Y, Dong Y, Pant A, Liu Y, Masserman L, Xu Y, McLaughlin RN, Bai J. The endophilin curvature-sensitive motif requires electrostatic guidance to recycle synaptic vesicles in vivo. Dev Cell 2022; 57:750-766.e5. [PMID: 35303431 PMCID: PMC8969179 DOI: 10.1016/j.devcel.2022.02.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/21/2022] [Accepted: 02/22/2022] [Indexed: 12/29/2022]
Abstract
Curvature-sensing mechanisms assist proteins in executing particular actions on various membrane organelles. Here, we investigate the functional specificity of curvature-sensing amphipathic motifs in Caenorhabditis elegans through the study of endophilin, an endocytic protein for synaptic vesicle recycling. We generate chimeric endophilin proteins by replacing the endophilin amphipathic motif H0 with other curvature-sensing amphipathic motifs. We find that the role of amphipathic motifs cannot simply be extrapolated from the identity of their parental proteins. For example, the amphipathic motif of the nuclear pore complex protein NUP133 functionally replaces the synaptic role of endophilin H0. Interestingly, non-functional endophilin chimeras have similar defects-producing fewer synaptic vesicles but more endosomes-and this indicates that the curvature-sensing motifs in these chimeras have a common deficiency for reforming synaptic vesicles. Finally, we convert non-functional endophilin chimeras into functional proteins by changing the cationic property of amphipathic motifs, successfully reprogramming the functional specificity of curvature-sensing motifs in vivo.
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Affiliation(s)
- Lin Zhang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yu Wang
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, P.R. China; Fudan University, Shanghai 200433, P.R. China
| | - Yongming Dong
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Aaradhya Pant
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Yan Liu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Laura Masserman
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Ye Xu
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | | | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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10
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Zambri MP, Williams MA, Elliot MA. How Streptomyces thrive: Advancing our understanding of classical development and uncovering new behaviors. Adv Microb Physiol 2022; 80:203-236. [PMID: 35489792 DOI: 10.1016/bs.ampbs.2022.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Streptomyces are soil- and marine-dwelling microbes that need to survive dramatic fluctuations in nutrient levels and environmental conditions. Here, we explore the advances made in understanding how Streptomyces bacteria can thrive in their natural environments. We examine their classical developmental cycle, and the intricate regulatory cascades that govern it. We discuss alternative growth strategies and behaviors, like the rapid expansion and colonization properties associated with exploratory growth, the release of membrane vesicles and S-cells from hyphal tips, and the acquisition of exogenous DNA along the lateral walls. We further investigate Streptomyces interactions with other organisms through the release of volatile compounds that impact nutrient levels, microbial growth, and insect behavior. Finally, we explore the increasingly diverse strategies employed by Streptomyces species in escaping and thwarting phage infections.
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Affiliation(s)
- Matthew P Zambri
- Department of Biology, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Michelle A Williams
- Department of Biology, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Marie A Elliot
- Department of Biology, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada.
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11
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Passot FM, Cantlay S, Flärdh K. Protein phosphatase SppA regulates apical growth and dephosphorylates cell polarity determinant DivIVA in Streptomyces coelicolor. Mol Microbiol 2021; 117:411-428. [PMID: 34862689 DOI: 10.1111/mmi.14856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/23/2021] [Accepted: 12/02/2021] [Indexed: 11/27/2022]
Abstract
Members of the Actinobacteria, including mycobacteria and streptomycetes, exhibit a distinctive mode of polar growth, with cell wall synthesis occurring in zones at cell poles and directed by the essential cell polarity determinant DivIVA. Streptomyces coelicolor modulates polar growth via the Ser/Thr protein kinase AfsK, which phosphorylates DivIVA. Here, we show that the phosphoprotein phosphatase SppA has strong effects on polar growth and cell shape and that it reverses the AfsK-mediated phosphorylation of DivIVA. SppA affects hyphal branching and the rate of tip extension. The sppA mutant hyphae also exhibit a high frequency of spontaneous growth arrests, indicating problems with maintenance of tip extension. The phenotypic effects are partially suppressed in an afsK sppA double mutant, indicating that AfsK and SppA to some extent share target proteins. Strains with a nonphosphorylatable mutant DivIVA confirm that the effect of afsK on hyphal branching during normal growth is mediated by DivIVA phosphorylation. However, the phenotypic effects of sppA deletion are independent of DivIVA phosphorylation and must be mediated via other substrates. This study adds a PPP-family protein phosphatase to the proteins involved in the control of polar growth and cell shape determination in S. coelicolor.
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Affiliation(s)
| | | | - Klas Flärdh
- Department of Biology, Lund University, Lund, Sweden
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12
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Sher JW, Lim HC, Bernhardt TG. Polar Growth in Corynebacterium glutamicum Has a Flexible Cell Wall Synthase Requirement. mBio 2021; 12:e0068221. [PMID: 34098735 PMCID: PMC8262863 DOI: 10.1128/mbio.00682-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/03/2021] [Indexed: 12/30/2022] Open
Abstract
Members of the Corynebacterineae suborder of bacteria, including major pathogens such as Mycobacterium tuberculosis, grow via the insertion of new cell wall peptidoglycan (PG) material at their poles. This mode of elongation differs from that used by Escherichia coli and other more well-studied model organisms that grow by inserting new PG at dispersed sites along their cell body. Dispersed cell elongation is known to strictly require the SEDS-type PG synthase called RodA, whereas the other major class of PG synthases called class A penicillin-binding proteins (aPBPs) are not required for this mode of growth. Instead, they are thought to be important for maintaining the integrity of the PG matrix in organisms growing by dispersed elongation. In contrast, based on prior genetic studies in M. tuberculosis and related members of the Corynebacterineae suborder, the aPBPs are widely believed to be essential for polar growth, with RodA being dispensable. However, polar growth has not been directly assessed in mycobacterial or corynebacterial mutants lacking aPBP-type PG synthases. We therefore investigated the relative roles of aPBPs and RodA in polar growth using Corynebacterium glutamicum as a model member of Corynebacterineae. Notably, we discovered that the aPBPs are dispensable for polar growth and that this growth mode can be mediated by either an aPBP-type or a SEDS-type enzyme functioning as the sole elongation PG synthase. Thus, our results reveal that the mechanism of polar elongation is fundamentally flexible and, unlike dispersed elongation, can be effectively mediated in C. glutamicum by either a SEDS-bPBP or an aPBP-type synthase. IMPORTANCE The Corynebacterineae suborder includes a number of major bacterial pathogens. These organisms grow by polar extension unlike most well-studied model bacteria, which grow by inserting wall material at dispersed sites along their length. A better understanding of polar growth promises to uncover new avenues for targeting mycobacterial and corynebacterial infections. Here, we investigated the roles of the different classes of cell wall synthases for polar growth using Corynebacterium glutamicum as a model. We discovered that the polar growth mechanism is surprisingly flexible in this organism and, unlike dispersed synthesis, can function using either of the two known types of cell wall synthase enzymes.
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Affiliation(s)
- Joel W. Sher
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Hoong Chuin Lim
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas G. Bernhardt
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, USA
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13
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Szafran MJ, Jakimowicz D, Elliot MA. Compaction and control-the role of chromosome-organizing proteins in Streptomyces. FEMS Microbiol Rev 2021; 44:725-739. [PMID: 32658291 DOI: 10.1093/femsre/fuaa028] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/09/2020] [Indexed: 12/17/2022] Open
Abstract
Chromosomes are dynamic entities, whose organization and structure depend on the concerted activity of DNA-binding proteins and DNA-processing enzymes. In bacteria, chromosome replication, segregation, compaction and transcription are all occurring simultaneously, and to ensure that these processes are appropriately coordinated, all bacteria employ a mix of well-conserved and species-specific proteins. Unusually, Streptomyces bacteria have large, linear chromosomes and life cycle stages that include multigenomic filamentous hyphae and unigenomic spores. Moreover, their prolific secondary metabolism yields a wealth of bioactive natural products. These different life cycle stages are associated with profound changes in nucleoid structure and chromosome compaction, and require distinct repertoires of architectural-and regulatory-proteins. To date, chromosome organization is best understood during Streptomyces sporulation, when chromosome segregation and condensation are most evident, and these processes are coordinated with synchronous rounds of cell division. Advances are, however, now being made in understanding how chromosome organization is achieved in multigenomic hyphal compartments, in defining the functional and regulatory interplay between different architectural elements, and in appreciating the transcriptional control exerted by these 'structural' proteins.
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Affiliation(s)
- Marcin J Szafran
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland
| | - Dagmara Jakimowicz
- Laboratory of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland
| | - Marie A Elliot
- Department of Biology, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, L8S 4K1, Canada
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14
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Stable inheritance of Sinorhizobium meliloti cell growth polarity requires an FtsN-like protein and an amidase. Nat Commun 2021; 12:545. [PMID: 33483499 PMCID: PMC7822825 DOI: 10.1038/s41467-020-20739-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022] Open
Abstract
In Rhizobiales bacteria, such as Sinorhizobium meliloti, cell elongation takes place only at new cell poles, generated by cell division. Here, we show that the role of the FtsN-like protein RgsS in S. meliloti extends beyond cell division. RgsS contains a conserved SPOR domain known to bind amidase-processed peptidoglycan. This part of RgsS and peptidoglycan amidase AmiC are crucial for reliable selection of the new cell pole as cell elongation zone. Absence of these components increases mobility of RgsS molecules, as well as abnormal RgsS accumulation and positioning of the growth zone at the old cell pole in about one third of the cells. These cells with inverted growth polarity are able to complete the cell cycle but show partially impaired chromosome segregation. We propose that amidase-processed peptidoglycan provides a landmark for RgsS to generate cell polarity in unipolarly growing Rhizobiales. In Sinorhizobium bacteria, cell elongation takes place only at new cell poles, generated by cell division. Here, Krol et al. show that an FtsN-like protein and a peptidoglycan amidase are crucial for reliable selection of the new cell pole as cell elongation zone.
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15
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Ultee E, Zhong X, Shitut S, Briegel A, Claessen D. Formation of wall-less cells in Kitasatospora viridifaciens requires cytoskeletal protein FilP in oxygen-limiting conditions. Mol Microbiol 2020; 115:1181-1190. [PMID: 33278050 PMCID: PMC8359286 DOI: 10.1111/mmi.14662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023]
Abstract
The cell wall is considered an essential component for bacterial survival, providing structural support, and protection from environmental insults. Under normal growth conditions, filamentous actinobacteria insert new cell wall material at the hyphal tips regulated by the coordinated activity of cytoskeletal proteins and cell wall biosynthetic enzymes. Despite the importance of the cell wall, some filamentous actinobacteria can produce wall‐deficient S‐cells upon prolonged exposure to hyperosmotic stress. Here, we performed cryo‐electron tomography and live cell imaging to further characterize S‐cell extrusion in Kitasatospora viridifaciens. We show that exposure to hyperosmotic stress leads to DNA compaction, membrane and S‐cell extrusion, and thinning of the cell wall at hyphal tips. Additionally, we find that the extrusion of S‐cells is abolished in a cytoskeletal mutant strain that lacks the intermediate filament‐like protein FilP. Furthermore, micro‐aerobic culturing promotes the formation of S‐cells in the wild type, but the limited oxygen still impedes S‐cell formation in the ΔfilP mutant. These results demonstrate that S‐cell formation is stimulated by oxygen‐limiting conditions and dependent on functional cytoskeleton remodeling.
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Affiliation(s)
- Eveline Ultee
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Xiaobo Zhong
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Shraddha Shitut
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Ariane Briegel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Dennis Claessen
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
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16
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Sexton DL, Tocheva EI. Ultrastructure of Exospore Formation in Streptomyces Revealed by Cryo-Electron Tomography. Front Microbiol 2020; 11:581135. [PMID: 33072052 PMCID: PMC7541840 DOI: 10.3389/fmicb.2020.581135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/04/2020] [Indexed: 02/02/2023] Open
Abstract
Many bacteria form spores in response to adverse environmental conditions. Several sporulation pathways have evolved independently and occur through distinctive mechanisms. Here, using cryo-electron tomography (cryo-ET), we examine all stages of growth and exospore formation in the model organism Streptomyces albus. Our data reveal the native ultrastructure of vegetative hyphae, including the likely structures of the polarisome and cytoskeletal filaments. In addition, we observed septal junctions in vegetative septa, predicted to be involved in protein and DNA translocation between neighboring cells. During sporulation, the cell envelope undergoes dramatic remodeling, including the formation of a spore wall and two protective proteinaceous layers. Mature spores reveal the presence of a continuous spore coat and an irregular rodlet sheet. Together, these results provide an unprecedented examination of the ultrastructure in Streptomyces and further our understanding of the structural complexity of exospore formation.
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Affiliation(s)
- Danielle L Sexton
- Department of Microbiology & Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Elitza I Tocheva
- Department of Microbiology & Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada
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17
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Tol-Pal System and Rgs Proteins Interact to Promote Unipolar Growth and Cell Division in Sinorhizobium meliloti. mBio 2020; 11:mBio.00306-20. [PMID: 32605980 PMCID: PMC7327166 DOI: 10.1128/mbio.00306-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Bacterial cell proliferation involves cell growth and septum formation followed by cell division. For cell growth, bacteria have evolved different complex mechanisms. The most prevalent growth mode of rod-shaped bacteria is cell elongation by incorporating new peptidoglycans in a dispersed manner along the sidewall. A small share of rod-shaped bacteria, including the alphaproteobacterial Rhizobiales, grow unipolarly. Here, we identified and initially characterized a set of Rgs (rhizobial growth and septation) proteins, which are involved in cell division and unipolar growth of Sinorhizobium meliloti and highly conserved in Rhizobiales. Our data expand the knowledge of components of the polarly localized machinery driving cell wall growth and suggest a complex of Rgs proteins with components of the divisome, differing in composition between the polar cell elongation zone and the septum. Sinorhizobium meliloti is an alphaproteobacterium belonging to the Rhizobiales. Bacteria from this order elongate their cell wall at the new cell pole, generated by cell division. Screening for protein interaction partners of the previously characterized polar growth factors RgsP and RgsM, we identified the inner membrane components of the Tol-Pal system (TolQ and TolR) and novel Rgs (rhizobial growth and septation) proteins with unknown functions. TolQ, Pal, and all Rgs proteins, except for RgsE, were indispensable for S. meliloti cell growth. Six of the Rgs proteins, TolQ, and Pal localized to the growing cell pole in the cell elongation phase and to the septum in predivisional cells, and three Rgs proteins localized to the growing cell pole only. The putative FtsN-like protein RgsS contains a conserved SPOR domain and is indispensable at the early stages of cell division. The components of the Tol-Pal system were required at the late stages of cell division. RgsE, a homolog of the Agrobacterium tumefaciens growth pole ring protein GPR, has an important role in maintaining the normal growth rate and rod cell shape. RgsD is a periplasmic protein with the ability to bind peptidoglycan. Analysis of the phylogenetic distribution of the Rgs proteins showed that they are conserved in Rhizobiales and mostly absent from other alphaproteobacterial orders, suggesting a conserved role of these proteins in polar growth.
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18
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Milner DS, Ray LJ, Saxon EB, Lambert C, Till R, Fenton AK, Sockett RE. DivIVA Controls Progeny Morphology and Diverse ParA Proteins Regulate Cell Division or Gliding Motility in Bdellovibrio bacteriovorus. Front Microbiol 2020; 11:542. [PMID: 32373080 PMCID: PMC7186360 DOI: 10.3389/fmicb.2020.00542] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/12/2020] [Indexed: 01/12/2023] Open
Abstract
The predatory bacterium B. bacteriovorus grows and divides inside the periplasm of Gram-negative bacteria, forming a structure known as a bdelloplast. Cell division of predators inside the dead prey cell is not by binary fission but instead by synchronous division of a single elongated filamentous cell into odd or even numbers of progeny cells. Bdellovibrio replication and cell division processes are dependent on the finite level of nutrients available from inside the prey bacterium. The filamentous growth and division process of the predator maximizes the number of progeny produced by the finite nutrients in a way that binary fission could not. To learn more about such an unusual growth profile, we studied the role of DivIVA in the growing Bdellovibrio cell. This protein is well known for its link to polar cell growth and spore formation in Gram-positive bacteria, but little is known about its function in a predatory growth context. We show that DivIVA is expressed in the growing B. bacteriovorus cell and controls cell morphology during filamentous cell division, but not the number of progeny produced. Bacterial Two Hybrid (BTH) analysis shows DivIVA may interact with proteins that respond to metabolic indicators of amino-acid biosynthesis or changes in redox state. Such changes may be relevant signals to the predator, indicating the consumption of prey nutrients within the sealed bdelloplast environment. ParA, a chromosome segregation protein, also contributes to bacterial septation in many species. The B. bacteriovorus genome contains three ParA homologs; we identify a canonical ParAB pair required for predatory cell division and show a BTH interaction between a gene product encoded from the same operon as DivIVA with the canonical ParA. The remaining ParA proteins are both expressed in Bdellovibrio but are not required for predator cell division. Instead, one of these ParA proteins coordinates gliding motility, changing the frequency at which the cells reverse direction. Our work will prime further studies into how one bacterium can co-ordinate its cell division with the destruction of another bacterium that it dwells within.
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Affiliation(s)
- David S Milner
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Luke J Ray
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Emma B Saxon
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Carey Lambert
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Rob Till
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andrew K Fenton
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Renee Elizabeth Sockett
- Laboratory C15, Division of Infections, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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19
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Laloux G. Shedding Light on the Cell Biology of the Predatory Bacterium Bdellovibrio bacteriovorus. Front Microbiol 2020; 10:3136. [PMID: 32038570 PMCID: PMC6985089 DOI: 10.3389/fmicb.2019.03136] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/26/2019] [Indexed: 12/25/2022] Open
Abstract
Bdellovibrio bacteriovorus is a predatory bacterium that feeds upon and proliferates inside other Gram-negative bacteria. Upon entry into the periplasmic space of the prey envelope, B. bacteriovorus initiates an exquisite developmental program in which it digests the host resources and grows as a filament, which eventually divides in a non-binary manner, releasing a variable number of daughter cells. The progeny then escape from the prey ghost to encounter new victims and resume the predation cycle. Owing to its unique biology, B. bacteriovorus undoubtedly represents an attractive model to unravel novel mechanisms of bacterial cell cycle control and cellular organization. Yet, the molecular factors behind the sophisticated lifestyle of this micro-predator are still mysterious. In particular, the spatiotemporal dynamics of proteins that control key cellular processes such as transmission of the genetic information, cell growth and division remain largely unexplored. In this Perspective article, I highlight outstanding fundamental questions related to these aspects and arising from the original biology of this bacterium. I also discuss available insights and potential cell biology approaches based on quantitative live imaging techniques, in combination with bacterial genetics and biochemistry, to shed light on the intracellular organization of B. bacteriovorus in space and time.
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Affiliation(s)
- Géraldine Laloux
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
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20
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Jurásek M, Flärdh K, Vácha R. Effect of membrane composition on DivIVA-membrane interaction. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183144. [PMID: 31821790 DOI: 10.1016/j.bbamem.2019.183144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 12/31/2022]
Abstract
DivIVA is a crucial membrane-binding protein that helps to localize other proteins to negatively curved membranes at cellular poles and division septa in Gram-positive bacteria. The N-terminal domain of DivIVA is responsible for membrane binding. However, to which lipids the domain binds or how it recognizes the membrane negative curvature remains elusive. Using computer simulations, we demonstrate that the N-terminal domain of Streptomyces coelicolor DivIVA adsorbs to membranes with affinity and orientation dependent on the lipid composition. The domain interacts non-specifically with lipid phosphates via its arginine-rich tip and the strongest interaction is with cardiolipin. Moreover, we observed a specific attraction between a negatively charged side patch of the domain and ethanolamine lipids, which addition caused the change of the domain orientation from perpendicular to parallel alignment to the membrane plane. Similar but less electrostatically dependent behavior was observed for the N-terminal domain of Bacillus subtilis. The domain propensity for lipids which prefer negatively curved membranes could be a mechanism for the cellular localization of DivIVA protein.
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Affiliation(s)
- Miroslav Jurásek
- Faculty of Science, Masaryk University,Kamenice 753/5, Brno 625 00, Czech Republic
| | - Klas Flärdh
- Department of Biology, Lund University, Sölvegatan 35, Lund 223 62, Sweden
| | - Robert Vácha
- Faculty of Science, Masaryk University,Kamenice 753/5, Brno 625 00, Czech Republic; CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, Brno 625 00, Czech Republic.
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21
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Fröjd MJ, Flärdh K. Extrusion of extracellular membrane vesicles from hyphal tips of Streptomyces venezuelae coupled to cell-wall stress. Microbiology (Reading) 2019; 165:1295-1305. [DOI: 10.1099/mic.0.000836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Markus J. Fröjd
- Department of Biology, Lund University, Sölvegatan 35, 22362 Lund, Sweden
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22
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Choukate K, Gupta A, Basu B, Virk K, Ganguli M, Chaudhuri B. Higher order assembling of the mycobacterial polar growth factor DivIVA/Wag31. J Struct Biol 2019; 209:107429. [PMID: 31778770 DOI: 10.1016/j.jsb.2019.107429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/04/2019] [Accepted: 11/21/2019] [Indexed: 12/26/2022]
Abstract
DivIVA or Wag31, which is an essential pole organizing protein in mycobacteria, can self-assemble at the negatively curved side of the membrane at the growing pole to form a higher order structural scaffold for maintaining cellular morphology and localizing various target proteins for cell-wall biogenesis. The structural organization of polar scaffold formed by polymerization of coiled-coil rich Wag31, which is implicated in the anti-tubercular activities of amino-pyrimidine sulfonamides, remains to be determined. A single-site phosphorylation in Wag31 regulates peptidoglycan biosynthesis in mycobacteria. We report biophysical characterizations of filaments formed by mycobacterial Wag31 using circular dichroism, atomic force microscopy and small angle solution X-ray scattering. Atomic force microscopic images of the wild-type, a phospho-mimetic (T73E) and a phospho-ablative (T73A) form of Wag31 show mostly linear filament formation with occasional curving, kinking and apparent branching. Solution X-ray scattering data indicates that the phospho-mimetic forms of the Wag31 polymers are on average more compact than their phospho-ablative counterparts, which is likely due to the extent of bending/branching. Observed structural features in this first view of Wag31 filaments suggest a basis for higher order Wag31 scaffold formation at the pole.
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Affiliation(s)
- Komal Choukate
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Aanchal Gupta
- CSIR Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Brohmomoy Basu
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Karman Virk
- CSIR Institute of Microbial Technology, Chandigarh, India
| | - Munia Ganguli
- CSIR Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Barnali Chaudhuri
- CSIR Institute of Microbial Technology, Chandigarh, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India.
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23
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Abstract
Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.
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24
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Javadi A, Söderholm N, Olofsson A, Flärdh K, Sandblad L. Assembly mechanisms of the bacterial cytoskeletal protein FilP. Life Sci Alliance 2019; 2:2/3/e201800290. [PMID: 31243049 PMCID: PMC6599971 DOI: 10.26508/lsa.201800290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 11/29/2022] Open
Abstract
FilP is a coiled-coil protein that self-assembles into striated filaments and meshwork that shares structural and biochemical characteristics with metazoan intermediate filaments. Despite low-sequence homology, the intermediate filament (IF)–like protein FilP from Streptomyces coelicolor displays structural and biochemical similarities to the metazoan nuclear IF lamin. FilP, like IF proteins, is composed of central coiled-coil domains interrupted by short linkers and flanked by head and tail domains. FilP polymerizes into repetitive filament bundles with paracrystalline properties. However, the cations Na+ and K+ are found to induce the formation of a FilP hexagonal meshwork with the same 60-nm repetitive unit as the filaments. Studies of polymerization kinetics, in combination with EM techniques, enabled visualization of the basic building block—a transiently soluble rod-shaped FilP molecule—and its assembly into protofilaments and filament bundles. Cryoelectron tomography provided a 3D view of the FilP bundle structure and an original assembly model of an IF-like protein of prokaryotic origin, thereby enabling a comparison with the assembly of metazoan IF.
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Affiliation(s)
- Ala Javadi
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | | | | | - Klas Flärdh
- Department of Biology, Lund University, Lund, Sweden
| | - Linda Sandblad
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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25
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Fröjd MJ, Flärdh K. Apical assemblies of intermediate filament-like protein FilP are highly dynamic and affect polar growth determinant DivIVA in Streptomyces venezuelae. Mol Microbiol 2019; 112:47-61. [PMID: 30929261 DOI: 10.1111/mmi.14253] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2019] [Indexed: 01/10/2023]
Abstract
Streptomyces spp. grow as branching hyphae, building the cell wall in restricted zones at hyphal tips. The organization of this mode of polar growth involves three coiled-coil proteins: DivIVA and Scy, which form apical protein complexes referred to as polarisomes; and the intermediate filament-like protein FilP, which influences cell shape and interacts with both Scy and DivIVA. Here, we use live cell imaging of Streptomyces venezuelae to clarify the subcellular localization and dynamics of FilP and its effect on hyphal morphology. By monitoring a FilP-mCherry fusion protein, we show that FilP accumulates in gradient-like zones behind the hyphal tips. The apical gradient pattern of FilP localization is dependent on hyphal tip extension and immediately dissipates upon growth arrest. Fluorescence recovery after photobleaching experiments show that FilP gradients are dynamic and subject to subunit exchange during vegetative growth. Further, the localization of FilP at hyphal tips is not directly dependent on scy, even though the strongly perturbed morphology of most scy mutant hyphae is associated with mislocalization of FilP. Finally, we find that filP has an effect on the size and position of the foci of key polar growth determinant DivIVA. This effect likely contributes to the phenotype of filP mutants.
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Affiliation(s)
- Markus J Fröjd
- Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden
| | - Klas Flärdh
- Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden
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26
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Cleverley RM, Rutter ZJ, Rismondo J, Corona F, Tsui HCT, Alatawi FA, Daniel RA, Halbedel S, Massidda O, Winkler ME, Lewis RJ. The cell cycle regulator GpsB functions as cytosolic adaptor for multiple cell wall enzymes. Nat Commun 2019; 10:261. [PMID: 30651563 PMCID: PMC6335420 DOI: 10.1038/s41467-018-08056-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 12/07/2018] [Indexed: 01/01/2023] Open
Abstract
Bacterial growth and cell division requires precise spatiotemporal regulation of the synthesis and remodelling of the peptidoglycan layer that surrounds the cytoplasmic membrane. GpsB is a cytosolic protein that affects cell wall synthesis by binding cytoplasmic mini-domains of peptidoglycan synthases to ensure their correct subcellular localisation. Here, we describe critical structural features for the interaction of GpsB with peptidoglycan synthases from three bacterial species (Bacillus subtilis, Listeria monocytogenes and Streptococcus pneumoniae) and suggest their importance for cell wall growth and viability in L. monocytogenes and S. pneumoniae. We use these structural motifs to identify novel partners of GpsB in B. subtilis and extend the members of the GpsB interactome in all three bacterial species. Our results support that GpsB functions as an adaptor protein that mediates the interaction between membrane proteins, scaffolding proteins, signalling proteins and enzymes to generate larger protein complexes at specific sites in a bacterial cell cycle-dependent manner.
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Affiliation(s)
- Robert M Cleverley
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Zoe J Rutter
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK
| | - Jeanine Rismondo
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstrasse 37, 38855, Wernigerode, Germany
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, SW7 2DD, UK
| | - Federico Corona
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | | | - Fuad A Alatawi
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | - Richard A Daniel
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4AX, UK
| | - Sven Halbedel
- FG11 Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Burgstrasse 37, 38855, Wernigerode, Germany
| | - Orietta Massidda
- Dipartimento di Scienze Chirurgiche, Università di Cagliari, Cagliari, 09100, Italy
- Department CIBIO, University of Trento, via Sommarive 9, 38123, Povo, Italy
| | - Malcolm E Winkler
- Department of Biology, Indiana University Bloomington, Bloomington, IN, 47405, USA
| | - Richard J Lewis
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, NE2 4HH, UK.
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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Melzer ES, Sein CE, Chambers JJ, Siegrist MS. DivIVA concentrates mycobacterial cell envelope assembly for initiation and stabilization of polar growth. Cytoskeleton (Hoboken) 2018; 75:498-507. [PMID: 30160378 PMCID: PMC6644302 DOI: 10.1002/cm.21490] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/07/2018] [Accepted: 06/27/2018] [Indexed: 12/31/2022]
Abstract
In many model organisms, diffuse patterning of cell wall peptidoglycan synthesis by the actin homolog MreB enables the bacteria to maintain their characteristic rod shape. In Caulobacter crescentus and Escherichia coli, MreB is also required to sculpt this morphology de novo. Mycobacteria are rod-shaped but expand their cell wall from discrete polar or subpolar zones. In this genus, the tropomyosin-like protein DivIVA is required for the maintenance of cell morphology. DivIVA has also been proposed to direct peptidoglycan synthesis to the tips of the mycobacterial cell. The precise nature of this regulation is unclear, as is its role in creating rod shape from scratch. We find that DivIVA localizes nascent cell wall and covalently associated mycomembrane but is dispensable for the assembly process itself. Mycobacterium smegmatis rendered spherical by peptidoglycan digestion or by DivIVA depletion are able to regain rod shape at the population level in the presence of DivIVA. At the single cell level, there is a close spatiotemporal correlation between DivIVA foci, rod extrusion and concentrated cell wall synthesis. Thus, although the precise mechanistic details differ from other organisms, M. smegmatis also establish and propagate rod shape by cytoskeleton-controlled patterning of peptidoglycan. Our data further support the emerging notion that morphology is a hardwired trait of bacterial cells.
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Affiliation(s)
- Emily S Melzer
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - Caralyn E Sein
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
| | - James J Chambers
- Institute for Applied Life Sciences, University of Massachusetts, Amherst, Massachusetts
| | - M Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts.,Molecular and Cellular Biology, University of Massachusetts, Amherst, Massachusetts
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29
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Koepff J, Sachs CC, Wiechert W, Kohlheyer D, Nöh K, Oldiges M, Grünberger A. Germination and Growth Analysis of Streptomyces lividans at the Single-Cell Level Under Varying Medium Compositions. Front Microbiol 2018; 9:2680. [PMID: 30524383 PMCID: PMC6262040 DOI: 10.3389/fmicb.2018.02680] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/19/2018] [Indexed: 01/27/2023] Open
Abstract
Quantitative single-cell cultivation has provided fundamental contributions to our understanding of heterogeneity among industrially used microorganisms. Filamentous growing Streptomyces species are emerging platform organisms for industrial production processes, but their exploitation is still limited due to often reported high batch-to-batch variations and unexpected growth and production differences. Population heterogeneity is suspected to be one responsible factor, which is so far not systematically investigated at the single-cell level. Novel microfluidic single-cell cultivation devices offer promising solutions to investigate these phenomena. In this study, we investigated the germination and growth behavior of Streptomyces lividans TK24 under varying medium compositions on different complexity levels (i.e., mycelial growth, hyphal growth and tip elongation) on single-cell level. Our analysis reveals a remarkable stability within growth and germination of spores and early mycelium development when exposed to constant and defined environments. We show that spores undergo long metabolic adaptation processes of up to > 30 h to adjust to new medium conditions, rather than using a "persister" strategy as a possibility to cope with rapidly changing environments. Due to this uniform behavior, we conclude that S. lividans can be cultivated quite robustly under constant environmental conditions as provided by microfluidic cultivation approaches. Failure and non-reproducible cultivations are thus most likely to be found in less controllable larger-scale cultivation workflows and as a result of environmental gradients within large-scale cultivations.
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Affiliation(s)
- Joachim Koepff
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Christian Carsten Sachs
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Wolfgang Wiechert
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Computational Systems Biotechnology, RWTH Aachen University – Aachener Verfahrenstechnik, Aachen, Germany
| | - Dietrich Kohlheyer
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Microscale Bioengineering, RWTH Aachen University – Aachener Verfahrenstechnik, Aachen, Germany
| | - Katharina Nöh
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Marco Oldiges
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Alexander Grünberger
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Multiscale Bioengineering, Bielefeld University, Bielefeld, Germany
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30
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Characterization of Conserved and Novel Septal Factors in Mycobacterium smegmatis. J Bacteriol 2018; 200:JB.00649-17. [PMID: 29311277 DOI: 10.1128/jb.00649-17] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/14/2017] [Indexed: 11/20/2022] Open
Abstract
Septation in bacteria requires coordinated regulation of cell wall biosynthesis and hydrolysis enzymes so that new septal cross-wall can be appropriately constructed without compromising the integrity of the existing cell wall. Bacteria with different modes of growth and different types of cell wall require different regulators to mediate cell growth and division processes. Mycobacteria have both a cell wall structure and a mode of growth that are distinct from well-studied model organisms and use several different regulatory mechanisms. Here, using Mycobacterium smegmatis, we identify and characterize homologs of the conserved cell division regulators FtsL and FtsB, and show that they appear to function similarly to their homologs in Escherichia coli We identify a number of previously undescribed septally localized factors which could be involved in cell wall regulation. One of these, SepIVA, has a DivIVA domain, is required for mycobacterial septation, and is localized to the septum and the intracellular membrane domain. We propose that SepIVA is a regulator of cell wall precursor enzymes that contribute to construction of the septal cross-wall, similar to the putative elongation function of the other mycobacterial DivIVA homolog, Wag31.IMPORTANCE The enzymes that build bacterial cell walls are essential for cell survival but can cause cell lysis if misregulated; thus, their regulators are also essential. The number and nature of these regulators is likely to vary in bacteria that grow in different ways. The mycobacteria are a genus that have a cell wall whose composition and construction vary greatly from those of well-studied model organisms. In this work, we identify and characterize some of the proteins that regulate the mycobacterial cell wall. We find that some of these regulators appear to be functionally conserved with their structural homologs in evolutionarily distant species such as Escherichia coli, but other proteins have critical regulatory functions that may be unique to the actinomycetes.
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31
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Figueroa-Cuilan WM, Brown PJB. Cell Wall Biogenesis During Elongation and Division in the Plant Pathogen Agrobacterium tumefaciens. Curr Top Microbiol Immunol 2018; 418:87-110. [PMID: 29808336 DOI: 10.1007/82_2018_92] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A great diversity of bacterial cell shapes can be found in nature, suggesting that cell wall biogenesis is regulated both spatially and temporally. Although Agrobacterium tumefaciens has a rod-shaped morphology, the mechanisms underlying cell growth are strikingly different than other well-studied rod-shaped bacteria including Escherichia coli. Technological advances, such as the ability to deplete essential genes and the development of fluorescent D-amino acids, have enabled recent advances in our understanding of cell wall biogenesis during cell elongation and division of A. tumefaciens. In this review, we address how the field has evolved over the years by providing a historical overview of cell elongation and division in rod-shaped bacteria. Next, we summarize the current understanding of cell growth and cell division processes in A. tumefaciens. Finally, we highlight the need for further research to answer key questions related to the regulation of cell wall biogenesis in A. tumefaciens.
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Affiliation(s)
| | - Pamela J B Brown
- Division of Biological Sciences, University of Missouri, Columbia, MO, USA.
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32
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Bactofilin-mediated organization of the ParABS chromosome segregation system in Myxococcus xanthus. Nat Commun 2017; 8:1817. [PMID: 29180656 PMCID: PMC5703909 DOI: 10.1038/s41467-017-02015-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/01/2017] [Indexed: 12/02/2022] Open
Abstract
In bacteria, homologs of actin, tubulin, and intermediate filament proteins often act in concert with bacteria-specific scaffolding proteins to ensure the proper arrangement of cellular components. Among the bacteria-specific factors are the bactofilins, a widespread family of polymer-forming proteins whose biology is poorly investigated. Here, we study the three bactofilins BacNOP in the rod-shaped bacterium Myxococcus xanthus. We show that BacNOP co-assemble into elongated scaffolds that restrain the ParABS chromosome segregation machinery to the subpolar regions of the cell. The centromere (parS)-binding protein ParB associates with the pole-distal ends of these structures, whereas the DNA partitioning ATPase ParA binds along their entire length, using the newly identified protein PadC (MXAN_4634) as an adapter. The integrity of these complexes is critical for proper nucleoid morphology and chromosome segregation. BacNOP thus mediate a previously unknown mechanism of subcellular organization that recruits proteins to defined sites within the cytoplasm, far off the cell poles. The roles played by bactofilins, a widespread type of bacterial cytoskeletal elements, are unclear. Here, the authors show that the bactofilins BacNOP facilitate proper subcellular localization of the ParABS chromosome segregation system in the model organism Myxococcus xanthus.
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33
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Santos-Beneit F, Roberts DM, Cantlay S, McCormick JR, Errington J. A mechanism for FtsZ-independent proliferation in Streptomyces. Nat Commun 2017; 8:1378. [PMID: 29123127 PMCID: PMC5680176 DOI: 10.1038/s41467-017-01596-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 10/02/2017] [Indexed: 11/17/2022] Open
Abstract
The central player in bacterial cell division, FtsZ, is essential in almost all organisms in which it has been tested, with the most notable exception being Streptomyces. Streptomycetes differ from many bacteria in growing from the cell tip and undergoing branching, similar to filamentous fungi. Here we show that limited cell damage, either mechanical or enzymatic, leads to near complete destruction of mycelial microcolonies of a Streptomyces venezuelae ftsZ mutant. This result is consistent with a lack of ftsZ-dependent cross-walls and may be inconsistent with a recently proposed role for membrane structures in the proliferation of ftsZ mutants in other Streptomyces species. Rare surviving fragments of mycelium, usually around branches, appear to be the preferred sites of resealing. Restoration of growth in hyphal fragments of both wild-type and ftsZ mutant hyphae can occur at multiple sites, via branch-like outgrowths containing DivIVA protein at their tips. Thus, our results highlight branching as a means of FtsZ-independent cell proliferation. Protein FtsZ plays key roles in cell division and is essential in most bacterial species; exceptions include streptomycetes, which grow from the cell tip and form branched hyphae. Here, Santos-Beneit et al. show that branching allows FtsZ-independent proliferation in Streptomyces venezuelae.
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Affiliation(s)
- Fernando Santos-Beneit
- Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle Upon Tyne, NE2 4AX, UK
| | - David M Roberts
- Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle Upon Tyne, NE2 4AX, UK
| | - Stuart Cantlay
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, 15282, USA
| | - Joseph R McCormick
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA, 15282, USA
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle Upon Tyne, NE2 4AX, UK.
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34
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Caccamo PD, Brun YV. The Molecular Basis of Noncanonical Bacterial Morphology. Trends Microbiol 2017; 26:191-208. [PMID: 29056293 DOI: 10.1016/j.tim.2017.09.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 09/08/2017] [Accepted: 09/28/2017] [Indexed: 01/04/2023]
Abstract
Bacteria come in a wide variety of shapes and sizes. The true picture of bacterial morphological diversity is likely skewed due to an experimental focus on pathogens and industrially relevant organisms. Indeed, most of the work elucidating the genes and molecular processes involved in maintaining bacterial morphology has been limited to rod- or coccal-shaped model systems. The mechanisms of shape evolution, the molecular processes underlying diverse shapes and growth modes, and how individual cells can dynamically modulate their shape are just beginning to be revealed. Here we discuss recent work aimed at advancing our knowledge of shape diversity and uncovering the molecular basis for shape generation in noncanonical and morphologically complex bacteria.
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Affiliation(s)
- Paul D Caccamo
- Department of Biology, Indiana University, 1001 E. 3rd St, Bloomington, IN 47405, USA
| | - Yves V Brun
- Department of Biology, Indiana University, 1001 E. 3rd St, Bloomington, IN 47405, USA.
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35
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Jones SE, Elliot MA. 'Exploring' the regulation of Streptomyces growth and development. Curr Opin Microbiol 2017; 42:25-30. [PMID: 29024914 DOI: 10.1016/j.mib.2017.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 09/06/2017] [Accepted: 09/14/2017] [Indexed: 12/14/2022]
Abstract
The Streptomyces life cycle encompasses three well-established developmental stages: vegetative hyphae, aerial hyphae and spores. Many regulators governing the transitions between these life cycle stages have been identified, and recent work is shedding light on their specific functions. A new discovery has shown Streptomyces can deviate from this classic life cycle through a process termed 'exploration', where cells rapidly traverse solid surfaces. Exploration does not require any of the traditional developmental regulators, and therefore provides an exciting new context in which to uncover novel developmental pathways. Here, we summarize our understanding of how Streptomyces exploration is controlled, and we speculate on how insight into classical regulation and stress response systems can inform future research into the regulation of exploratory growth.
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Affiliation(s)
- Stephanie E Jones
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1; Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
| | - Marie A Elliot
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1; Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1.
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36
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Absence of the Polar Organizing Protein PopZ Results in Reduced and Asymmetric Cell Division in Agrobacterium tumefaciens. J Bacteriol 2017. [PMID: 28630123 DOI: 10.1128/jb.00101-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Agrobacterium tumefaciens is a rod-shaped bacterium that grows by polar insertion of new peptidoglycan during cell elongation. As the cell cycle progresses, peptidoglycan synthesis at the pole ceases prior to insertion of new peptidoglycan at midcell to enable cell division. The A. tumefaciens homolog of the Caulobacter crescentus polar organelle development protein PopZ has been identified as a growth pole marker and a candidate polar growth-promoting factor. Here, we characterize the function of PopZ in cell growth and division of A. tumefaciens Consistent with previous observations, we observe that PopZ localizes specifically to the growth pole in wild-type cells. Despite the striking localization pattern of PopZ, we find the absence of the protein does not impair polar elongation or cause major changes in the peptidoglycan composition. Instead, we observe an atypical cell length distribution, including minicells, elongated cells, and cells with ectopic poles. Most minicells lack DNA, suggesting a defect in chromosome segregation. Furthermore, the canonical cell division proteins FtsZ and FtsA are misplaced, leading to asymmetric sites of cell constriction. Together, these data suggest that PopZ plays an important role in the regulation of chromosome segregation and cell division.IMPORTANCEA. tumefaciens is a bacterial plant pathogen and a natural genetic engineer. However, very little is known about the spatial and temporal regulation of cell wall biogenesis that leads to polar growth in this bacterium. Understanding the molecular basis of A. tumefaciens growth may allow for the development of innovations to prevent disease or to promote growth during biotechnology applications. Finally, since many closely related plant and animal pathogens exhibit polar growth, discoveries in A. tumefaciens may be broadly applicable for devising antimicrobial strategies.
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37
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Jones SE, Elliot MA. Streptomyces Exploration: Competition, Volatile Communication and New Bacterial Behaviours. Trends Microbiol 2017; 25:522-531. [DOI: 10.1016/j.tim.2017.02.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 10/20/2022]
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38
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Abstract
Signaling hubs at bacterial cell poles establish cell polarity in the absence of membrane-bound compartments. In the asymmetrically dividing bacterium Caulobacter crescentus, cell polarity stems from the cell cycle-regulated localization and turnover of signaling protein complexes in these hubs, and yet the mechanisms that establish the identity of the two cell poles have not been established. Here, we recapitulate the tripartite assembly of a cell fate signaling complex that forms during the G1-S transition. Using in vivo and in vitro analyses of dynamic polar protein complex formation, we show that a polymeric cell polarity protein, SpmX, serves as a direct bridge between the PopZ polymeric network and the cell fate-directing DivJ histidine kinase. We demonstrate the direct binding between these three proteins and show that a polar microdomain spontaneously assembles when the three proteins are coexpressed heterologously in an Escherichia coli test system. The relative copy numbers of these proteins are essential for complex formation, as overexpression of SpmX in Caulobacter reorganizes the polarity of the cell, generating ectopic cell poles containing PopZ and DivJ. Hierarchical formation of higher-order SpmX oligomers nucleates new PopZ microdomain assemblies at the incipient lateral cell poles, driving localized outgrowth. By comparison to self-assembling protein networks and polar cell growth mechanisms in other bacterial species, we suggest that the cooligomeric PopZ-SpmX protein complex in Caulobacter illustrates a paradigm for coupling cell cycle progression to the controlled geometry of cell pole establishment.IMPORTANCE Lacking internal membrane-bound compartments, bacteria achieve subcellular organization by establishing self-assembling protein-based microdomains. The asymmetrically dividing bacterium Caulobacter crescentus uses one such microdomain to link cell cycle progression to morphogenesis, but the mechanism for the generation of this microdomain has remained unclear. Here, we demonstrate that the ordered assembly of this microdomain occurs via the polymeric network protein PopZ directly recruiting the polarity factor SpmX, which then recruits the histidine kinase DivJ to the developing cell pole. Further, we find that overexpression of the bridge protein SpmX in Caulobacter disrupts this ordered assembly, generating ectopic cell poles containing both PopZ and DivJ. Together, PopZ and SpmX assemble into a cooligomeric network that forms the basis for a polar microdomain that coordinates bacterial cell polarity.
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39
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Abstract
For years intermediate filaments (IF), belonging to the third class of filamentous cytoskeletal proteins alongside microtubules and actin filaments, were thought to be exclusive to metazoan cells. Structurally these eukaryote IFs are very well defined, consisting of globular head and tail domains, which flank the central rod-domain. This central domain is dominated by an α-helical secondary structure predisposed to form the characteristic coiled-coil, parallel homo-dimer. These elementary dimers can further associate, both laterally and longitudinally, generating a variety of filament-networks built from filaments in the range of 10 nm in diameter. The general role of these filaments with their characteristic mechano-elastic properties both in the cytoplasm and in the nucleus of eukaryote cells is to provide mechanical strength and a scaffold supporting diverse shapes and cellular functions.Since 2003, after the first bacterial IF-like protein, crescentin was identified, it has been evident that bacteria also employ filamentous networks, other than those built from bacterial tubulin or actin homologues, in order to support their cell shape, growth and, in some cases, division. Intriguingly, compared to their eukaryote counterparts, the group of bacterial IF-like proteins shows much wider structural diversity. The sizes of both the head and tail domains are markedly reduced and there is great variation in the length of the central rod-domain. Furthermore, bacterial rod-domains often lack the sub-domain organisation of eukaryote IFs that is the defining feature of the IF-family. However, the fascinating display of filamentous assemblies, including rope, striated cables and hexagonal laces together with the conditions required for their formation both in vitro and in vivo strongly resemble that of eukaryote IFs suggesting that these bacterial proteins are deservedly classified as part of the IF-family and that the current definition should be relaxed slightly to allow their inclusion. The lack of extensive head and tail domains may well make the bacterial proteins more amenable for structural characterisation, which will be essential for establishing the mechanism for their association into filaments. What is more, the well-developed tools for bacterial manipulations provide an excellent opportunity of studying the bacterial systems with the prospect of making significant progress in our understanding of the general underlying principles of intermediate filament assemblies.
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Affiliation(s)
- Gabriella H Kelemen
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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40
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Kois-Ostrowska A, Strzałka A, Lipietta N, Tilley E, Zakrzewska-Czerwińska J, Herron P, Jakimowicz D. Unique Function of the Bacterial Chromosome Segregation Machinery in Apically Growing Streptomyces - Targeting the Chromosome to New Hyphal Tubes and its Anchorage at the Tips. PLoS Genet 2016; 12:e1006488. [PMID: 27977672 PMCID: PMC5157956 DOI: 10.1371/journal.pgen.1006488] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/16/2016] [Indexed: 01/26/2023] Open
Abstract
The coordination of chromosome segregation with cell growth is fundamental to the proliferation of any organism. In most unicellular bacteria, chromosome segregation is strictly coordinated with cell division and involves ParA that moves the ParB nucleoprotein complexes bi- or unidirectionally toward the cell pole(s). However, the chromosome organization in multiploid, apically extending and branching Streptomyces hyphae challenges the known mechanisms of bacterial chromosome segregation. The complex Streptomyces life cycle involves two stages: vegetative growth and sporulation. In the latter stage, multiple cell divisions accompanied by chromosome compaction and ParAB assisted segregation turn multigenomic hyphal cell into a chain of unigenomic spores. However, the requirement for active chromosome segregation is unclear in the absence of canonical cell division during vegetative growth except in the process of branch formation. The mechanism by which chromosomes are targeted to new hyphae in streptomycete vegetative growth has remained unknown until now. Here, we address the question of whether active chromosome segregation occurs at this stage. Applied for the first time in Streptomyces, labelling of the chromosomal replication initiation region (oriC) and time-lapse microscopy, revealed that in vegetative hyphae every copy of the chromosome is complexed with ParB, whereas ParA, through interaction with the apical protein complex (polarisome), tightly anchors only one chromosome at the hyphal tip. The anchor is maintained during replication, when ParA captures one of the daughter oriCs. During spore germination and branching, ParA targets one of the multiple chromosomal copies to the new hyphal tip, enabling efficient elongation of hyphal tube. Thus, our studies reveal a novel role for ParAB proteins during hyphal tip establishment and extension. To proliferate, cells synchronize growth and division with chromosome segregation. In unicellular bacteria, chromosomes segregate during replication by active movement of nucleoprotein complexes toward the cell pole(s). Here, we asked the question how active chromosome segregation occurs in the absence of cell division, during hyphal growth and branching of the filamentous bacterium, Streptomyces coelicolor. We show that in multigenomic Streptomyces hyphae, the bacterial segregation machinery anchors a single chromosome at the hyphal tip. Through chromosomal anchorage, segregation proteins facilitate chromosome targeting to the newly formed germ tubes or branches. Thus, being adapted for apical growth, in Streptomyces hyphae the bacterial segregation machinery imposes a chromosome distribution that is reminiscent of nuclear distribution in apically growing eukaryotic cells such as filamentous fungi.
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Affiliation(s)
| | | | | | - Emma Tilley
- Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Jolanta Zakrzewska-Czerwińska
- Faculty of Biotechnology, University of Wroclaw, Poland
- Institute of Immunology and Experimental Therapy, Wroclaw, Poland
| | - Paul Herron
- Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Dagmara Jakimowicz
- Faculty of Biotechnology, University of Wroclaw, Poland
- Institute of Immunology and Experimental Therapy, Wroclaw, Poland
- * E-mail:
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41
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Cell-Biological Studies of Osmotic Shock Response in Streptomyces spp. J Bacteriol 2016; 199:JB.00465-16. [PMID: 27795320 DOI: 10.1128/jb.00465-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/05/2016] [Indexed: 02/03/2023] Open
Abstract
Most bacteria are likely to face osmotic challenges, but there is yet much to learn about how such environmental changes affect the architecture of bacterial cells. Here, we report a cell-biological study in model organisms of the genus Streptomyces, which are actinobacteria that grow in a highly polarized fashion to form branching hyphae. The characteristic apical growth of Streptomyces hyphae is orchestrated by protein assemblies, called polarisomes, which contain coiled-coil proteins DivIVA and Scy, and recruit cell wall synthesis complexes and the stress-bearing cytoskeleton of FilP to the tip regions of the hyphae. We monitored cell growth and cell-architectural changes by time-lapse microscopy in osmotic upshift experiments. Hyperosmotic shock caused arrest of growth, loss of turgor, and hypercondensation of chromosomes. The recovery period was protracted, presumably due to the dehydrated state of the cytoplasm, before hyphae could restore their turgor and start to grow again. In most hyphae, this regrowth did not take place at the original hyphal tips. Instead, cell polarity was reprogrammed, and polarisomes were redistributed to new sites, leading to the emergence of multiple lateral branches from which growth occurred. Factors known to regulate the branching pattern of Streptomyces hyphae, such as the serine/threonine kinase AfsK and Scy, were not involved in reprogramming of cell polarity, indicating that different mechanisms may act under different environmental conditions to control hyphal branching. Our observations of hyphal morphology during the stress response indicate that turgor and sufficient hydration of cytoplasm are required for Streptomyces tip growth. IMPORTANCE Polar growth is an intricate manner of growth for accomplishing a complicated morphology, employed by a wide range of organisms across the kingdoms of life. The tip extension of Streptomyces hyphae is one of the most pronounced examples of polar growth among bacteria. The expansion of the cell wall by tip extension is thought to be facilitated by the turgor pressure, but it was unknown how external osmotic change influences Streptomyces tip growth. We report here that severe hyperosmotic stress causes cessation of growth, followed by reprogramming of cell polarity and rearrangement of growth zones to promote lateral hyphal branching. This phenomenon may represent a strategy of hyphal organisms to avoid osmotic stress encountered by the growing hyphal tip.
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42
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Kysela DT, Randich AM, Caccamo PD, Brun YV. Diversity Takes Shape: Understanding the Mechanistic and Adaptive Basis of Bacterial Morphology. PLoS Biol 2016; 14:e1002565. [PMID: 27695035 PMCID: PMC5047622 DOI: 10.1371/journal.pbio.1002565] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The modern age of metagenomics has delivered unprecedented volumes of data describing the genetic and metabolic diversity of bacterial communities, but it has failed to provide information about coincident cellular morphologies. Much like metabolic and biosynthetic capabilities, morphology comprises a critical component of bacterial fitness, molded by natural selection into the many elaborate shapes observed across the bacterial domain. In this essay, we discuss the diversity of bacterial morphology and its implications for understanding both the mechanistic and the adaptive basis of morphogenesis. We consider how best to leverage genomic data and recent experimental developments in order to advance our understanding of bacterial shape and its functional importance.
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Affiliation(s)
- David T. Kysela
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Amelia M. Randich
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Paul D. Caccamo
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Yves V. Brun
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
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Polydiglycosylphosphate Transferase PdtA (SCO2578) of Streptomyces coelicolor A3(2) Is Crucial for Proper Sporulation and Apical Tip Extension under Stress Conditions. Appl Environ Microbiol 2016; 82:5661-72. [PMID: 27422828 DOI: 10.1128/aem.01425-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/06/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Although anionic glycopolymers are crucial components of the Gram-positive cell envelope, the relevance of anionic glycopolymers for vegetative growth and morphological differentiation of Streptomyces coelicolor A3(2) is unknown. Here, we show that the LytR-CpsA-Psr (LCP) protein PdtA (SCO2578), a TagV-like glycopolymer transferase, has a dual function in the S. coelicolor A3(2) life cycle. Despite the presence of 10 additional LCP homologs, PdtA is crucial for proper sporulation. The integrity of the spore envelope was severely affected in a pdtA deletion mutant, resulting in 34% nonviable spores. pdtA deletion caused a significant reduction in the polydiglycosylphosphate content of the spore envelope. Beyond that, apical tip extension and normal branching of vegetative mycelium were severely impaired on high-salt medium. This growth defect coincided with the mislocalization of peptidoglycan synthesis. Thus, PdtA itself or the polydiglycosylphosphate attached to the peptidoglycan by the glycopolymer transferase PdtA also has a crucial function in apical tip extension of vegetative hyphae under stress conditions. IMPORTANCE Anionic glycopolymers are underappreciated components of the Gram-positive cell envelope. They provide rigidity to the cell wall and position extracellular enzymes involved in peptidoglycan remodeling. Although Streptomyces coelicolor A3(2), the model organism for bacterial antibiotic production, is known to produce two distinct cell wall-linked glycopolymers, teichulosonic acid and polydiglycosylphosphate, the role of these glycopolymers in the S. coelicolor A3(2) life cycle has not been addressed so far. This study reveals a crucial function of the anionic glycopolymer polydiglycosylphosphate for the growth and morphological differentiation of S. coelicolor A3(2). Polydiglycosylphosphate is attached to the spore wall by the LytR-CpsA-Psr protein PdtA (SCO2578), a component of the Streptomyces spore wall-synthesizing complex (SSSC), to ensure the integrity of the spore envelope. Surprisingly, PdtA also has a crucial role in vegetative growth under stress conditions and is required for proper peptidoglycan incorporation during apical tip extension.
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44
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Howell M, Brown PJ. Building the bacterial cell wall at the pole. Curr Opin Microbiol 2016; 34:53-59. [PMID: 27504539 DOI: 10.1016/j.mib.2016.07.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 01/06/2023]
Abstract
Polar growth is the predominant mode of cell wall extension in the Actinobacteria and the alphaproteobacterial clade Rhizobiales. The observation of polar elongation in taxonomically diverse bacteria suggests that polar growth may have evolved independently. Indeed, the regulatory mechanisms governing the assembly of cell wall biosynthesis machinery at the pole are distinct in the Actinobacteria and Rhizobiales. Here we highlight recent advances in our understanding of polar growth mechanisms in bacteria, with an emphasis on Streptomyces and Agrobacterium. This review illustrates that common themes are emerging in the regulation of polar growth in diverse bacteria. Emerging themes include the use of landmark proteins to direct growth to the pole and coordination of polar growth with cell-cycle progression.
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Affiliation(s)
- Matthew Howell
- Division of Biological Sciences, 423 Tucker Hall, 612 Hitt St., University of Missouri, Columbia, MO 65211, USA
| | - Pamela Jb Brown
- Division of Biological Sciences, 423 Tucker Hall, 612 Hitt St., University of Missouri, Columbia, MO 65211, USA.
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45
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Kloosterman TG, Lenarcic R, Willis CR, Roberts DM, Hamoen LW, Errington J, Wu LJ. Complex polar machinery required for proper chromosome segregation in vegetative and sporulating cells of Bacillus subtilis. Mol Microbiol 2016; 101:333-50. [PMID: 27059541 PMCID: PMC4949633 DOI: 10.1111/mmi.13393] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 04/04/2016] [Accepted: 04/04/2016] [Indexed: 01/16/2023]
Abstract
Chromosome segregation is an essential process of cell multiplication. In prokaryotes, segregation starts with the newly replicated sister origins of replication, oriCs, which move apart to defined positions in the cell. We have developed a genetic screen to identify mutants defective in placement of oriC during spore development in the Gram‐positive bacterium Bacillus subtilis. In addition to the previously identified proteins Soj and DivIVA, our screen identified several new factors involved in polar recruitment of oriC: a reported regulator of competence ComN, and the regulators of division site selection MinD and MinJ. Previous work implicated Soj as an important regulator of oriC positioning in the cell. Our results suggest a model in which the DivIVA‐interacting proteins ComN and MinJ recruit MinD to the cell pole, and that these proteins work upstream of Soj to enable oriC placement. We show that these proteins form a polar complex, which acts in parallel with but distinct from the sporulation‐specific RacA pathway of oriC placement, and also functions during vegetative growth. Our study further shows that MinD has two distinct cell cycle roles, in cell division and chromosome segregation, and highlights that cell probably use multiple parallel mechanisms to ensure accurate chromosome segregation.
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Affiliation(s)
- Tomas G Kloosterman
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.,Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Rok Lenarcic
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.,Lek Pharmaceuticals d.d., Menges, Slovenia
| | - Clare R Willis
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - David M Roberts
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Leendert W Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK.,Department of Cell Biology & Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Jeff Errington
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Ling J Wu
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, UK
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46
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Donczew M, Mackiewicz P, Wróbel A, Flärdh K, Zakrzewska-Czerwińska J, Jakimowicz D. ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation. Open Biol 2016; 6:150263. [PMID: 27248800 PMCID: PMC4852455 DOI: 10.1098/rsob.150263] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/01/2016] [Indexed: 12/22/2022] Open
Abstract
In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins.
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Affiliation(s)
- Magdalena Donczew
- Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14A, Wrocław 50-383, Poland
| | - Paweł Mackiewicz
- Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14A, Wrocław 50-383, Poland
| | - Agnieszka Wróbel
- Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14A, Wrocław 50-383, Poland
| | - Klas Flärdh
- Department of Biology, Lund University, Sölvegatan 35, Lund 22362, Sweden
| | - Jolanta Zakrzewska-Czerwińska
- Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14A, Wrocław 50-383, Poland Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, Wrocław 53-114, Poland
| | - Dagmara Jakimowicz
- Faculty of Biotechnology, University of Wrocław, Joliot-Curie 14A, Wrocław 50-383, Poland Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Weigla 12, Wrocław 53-114, Poland
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47
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Schlimpert S, Flärdh K, Buttner M. Fluorescence Time-lapse Imaging of the Complete S. venezuelae Life Cycle Using a Microfluidic Device. J Vis Exp 2016:53863. [PMID: 26967231 PMCID: PMC4828195 DOI: 10.3791/53863] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Live-cell imaging of biological processes at the single cell level has been instrumental to our current understanding of the subcellular organization of bacterial cells. However, the application of time-lapse microscopy to study the cell biological processes underpinning development in the sporulating filamentous bacteria Streptomyces has been hampered by technical difficulties. Here we present a protocol to overcome these limitations by growing the new model species, Streptomyces venezuelae, in a commercially available microfluidic device which is connected to an inverted fluorescence widefield microscope. Unlike the classical model species, Streptomyces coelicolor, S. venezuelae sporulates in liquid, allowing the application of microfluidic growth chambers to cultivate and microscopically monitor the cellular development and differentiation of S. venezuelae over long time periods. In addition to monitoring morphological changes, the spatio-temporal distribution of fluorescently labeled target proteins can also be visualized by time-lapse microscopy. Moreover, the microfluidic platform offers the experimental flexibility to exchange the culture medium, which is used in the detailed protocol to stimulate sporulation of S. venezuelae in the microfluidic chamber. Images of the entire S. venezuelae life cycle are acquired at specific intervals and processed in the open-source software Fiji to produce movies of the recorded time-series.
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Affiliation(s)
- Susan Schlimpert
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park;
| | | | - Mark Buttner
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park
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48
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c-di-GMP signalling and the regulation of developmental transitions in streptomycetes. Nat Rev Microbiol 2015; 13:749-60. [PMID: 26499894 DOI: 10.1038/nrmicro3546] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The complex life cycle of streptomycetes involves two distinct filamentous cell forms: the growing (or vegetative) hyphae and the reproductive (or aerial) hyphae, which differentiate into long chains of spores. Until recently, little was known about the signalling pathways that regulate the developmental transitions leading to sporulation. In this Review, we discuss important new insights into these pathways that have led to the emergence of a coherent regulatory network, focusing on the erection of aerial hyphae and the synchronous cell division event that produces dozens of unigenomic spores. In particular, we highlight the role of cyclic di-GMP (c-di-GMP) in controlling the initiation of development, and the role of the master regulator BldD in mediating c-di-GMP signalling.
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49
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Ladwig N, Franz-Wachtel M, Hezel F, Soufi B, Macek B, Wohlleben W, Muth G. Control of Morphological Differentiation of Streptomyces coelicolor A3(2) by Phosphorylation of MreC and PBP2. PLoS One 2015; 10:e0125425. [PMID: 25927987 PMCID: PMC4416010 DOI: 10.1371/journal.pone.0125425] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/23/2015] [Indexed: 12/14/2022] Open
Abstract
During morphological differentiation of Streptomyces coelicolor A3(2), the sporogenic aerial hyphae are transformed into a chain of more than fifty spores in a highly coordinated manner. Synthesis of the thickened spore envelope is directed by the Streptomyces spore wall synthesizing complex SSSC which resembles the elongasome of rod-shaped bacteria. The SSSC includes the eukaryotic type serine/threonine protein kinase (eSTPK) PkaI, encoded within a cluster of five independently transcribed eSTPK genes (SCO4775-4779). To understand the role of PkaI in spore wall synthesis, we screened a S. coelicolor genomic library for PkaI interaction partners by bacterial two-hybrid analyses and identified several proteins with a documented role in sporulation. We inactivated pkaI and deleted the complete SCO4775-4779 cluster. Deletion of pkaI alone delayed sporulation and produced some aberrant spores. The five-fold mutant NLΔ4775-4779 had a more severe defect and produced 18% aberrant spores affected in the integrity of the spore envelope. Moreover, overbalancing phosphorylation activity by expressing a second copy of any of these kinases caused a similar defect. Following co-expression of pkaI with either mreC or pbp2 in E. coli, phosphorylation of MreC and PBP2 was demonstrated and multiple phosphosites were identified by LC-MS/MS. Our data suggest that elaborate protein phosphorylation controls activity of the SSSC to ensure proper sporulation by suppressing premature cross-wall synthesis.
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Affiliation(s)
- Nils Ladwig
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tuebingen, Interfakultaeres Institut für Zellbiologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 15,72076 Tübingen, Germany
| | - Felix Hezel
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Boumediene Soufi
- Proteome Center Tuebingen, Interfakultaeres Institut für Zellbiologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 15,72076 Tübingen, Germany
| | - Boris Macek
- Proteome Center Tuebingen, Interfakultaeres Institut für Zellbiologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 15,72076 Tübingen, Germany
| | - Wolfgang Wohlleben
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Günther Muth
- Interfakultaeres Institut für Mikrobiologie und Infektionsmedizin Tuebingen IMIT, Mikrobiologie/Biotechnologie, Eberhard Karls Universitaet Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
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50
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Jiang C, Caccamo PD, Brun YV. Mechanisms of bacterial morphogenesis: evolutionary cell biology approaches provide new insights. Bioessays 2015; 37:413-25. [PMID: 25664446 DOI: 10.1002/bies.201400098] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
How Darwin's "endless forms most beautiful" have evolved remains one of the most exciting questions in biology. The significant variety of bacterial shapes is most likely due to the specific advantages they confer with respect to the diverse environments they occupy. While our understanding of the mechanisms generating relatively simple shapes has improved tremendously in the last few years, the molecular mechanisms underlying the generation of complex shapes and the evolution of shape diversity are largely unknown. The emerging field of bacterial evolutionary cell biology provides a novel strategy to answer this question in a comparative phylogenetic framework. This relatively novel approach provides hypotheses and insights into cell biological mechanisms, such as morphogenesis, and their evolution that would have been difficult to obtain by studying only model organisms. We discuss the necessary steps, challenges, and impact of integrating "evolutionary thinking" into bacterial cell biology in the genomic era.
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Affiliation(s)
- Chao Jiang
- Department of Biology, Indiana University, Bloomington, IN, USA
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