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Maria Schumacher, Kuo-Hsiang Huang, Wenjie Zeng, Anuradha Janakiraman
Cell division in most bacteria is mediated by the tubulin-like FtsZ protein, which polymerizes in a GTP-dependent manner to form the cytokinetic Z ring. A diverse repertoire of FtsZ binding proteins affect FtsZ localization and polymerization to ensure correct Z ring formation. Many of these proteins bind the C-terminal domain (CTD) of FtsZ, which serves as a hub for FtsZ regulation. FtsZ ring-associated proteins, ZapA-D (Zaps), are important FtsZ regulatory proteins that stabilize FtsZ assembly and enhance Z ring formation by increasing lateral assembly of FtsZ protofilaments, which then form the Z ring...
January 18, 2017: Journal of Biological Chemistry
Maureen Laroche, Jean-Michel Berenger, Oleg Mediannikov, Didier Raoult, Philippe Parola
BACKGROUND: Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated. METHODOLOGY/PRINCIPAL FINDINGS: In this study, seven triatomines species involved in the transmission of T...
January 17, 2017: PLoS Neglected Tropical Diseases
N Baranova, M Loose
Bacterial cytokinesis is commonly initiated by the Z-ring, a dynamic cytoskeletal structure that assembles at the site of division. Its primary component is FtsZ, a tubulin-like GTPase, that like its eukaryotic relative forms protein filaments in the presence of GTP. Since the discovery of the Z-ring 25years ago, various models for the role of FtsZ have been suggested. However, important information about the architecture and dynamics of FtsZ filaments during cytokinesis is still missing. One reason for this lack of knowledge has been the small size of bacteria, which has made it difficult to resolve the orientation and dynamics of individual FtsZ filaments in the Z-ring...
2017: Methods in Cell Biology
Elena Rivas-Marín, Inés Canosa, Damien P Devos
Bacteria from the Planctomycetes, Verrucomicrobia, and Chlamydiae (PVC) superphylum are exceptions to the otherwise dominant mode of division by binary fission, which is based on the interaction between the FtsZ protein and the peptidoglycan (PG) biosynthesis machinery. Some PVC bacteria are deprived of the FtsZ protein and were also thought to lack PG. How these bacteria divide is still one of the major mysteries of microbiology. The presence of PG has recently been revealed in Planctomycetes and Chlamydiae, and proteins related to PG synthesis have been shown to be implicated in the division process in Chlamydiae, providing important insights into PVC mechanisms of division...
2016: Frontiers in Microbiology
Carla Coltharp, Jie Xiao
We propose that the essential function of the most highly conserved protein in bacterial cytokinesis, FtsZ, is not to generate a mechanical force to drive cell division. Rather, we suggest that FtsZ acts as a signal-processing hub to coordinate cell wall synthesis at the division septum with a diverse array of cellular processes, ensuring that the cell divides smoothly at the correct time and place, and with the correct septum morphology. Here, we explore how the polymerization properties of FtsZ, which have been widely attributed to force generation, can also be advantageous in this signal processing role...
January 2017: BioEssays: News and Reviews in Molecular, Cellular and Developmental Biology
Paul W Groundwater, Rajeshwar Narlawar, Vivian Wan Yu Liao, Anusri Bhattacharya, Shalini Srivastava, Kishore Kunal, Munikumar Reddy Doddareddy, Pratik M Oza, Ramesh Reddy Mamidi, Emma Claire Louise Marrs, John David Perry, David E Hibbs, Dulal Panda
Inhibition of FtsZ assembly has been found to stall bacterial cell division. Here, we report the identification of a potent carbocyclic curcumin analogue, (2Z,6E)-2-{(E)-1-hydroxy-3-(4-hydroxyphenyl)allylidene}-6-(4-hydroxy-benzylidene)cyclohexanone (2d), that inhibits Bacillus subtilis 168 cell proliferation by targeting the assembly of FtsZ. 2d also showed potent inhibitory activity (MICs 2-4 mg/L) against several clinically important species of Gram positive bacteria, including methicillin-resistant Staphylococcus aureus...
December 21, 2016: Biochemistry
Spencer A Clark, Vijay Singh, Daniel Vega Mendoza, William Margolin, Eric T Kool
We describe a novel molecular strategy for engendering a strong light-up signal in fluorescence tagging of the genetically encoded HaloTag protein domain. We designed a set of haloalkane-derivatized dyes having twisted internal charge transfer (TICT) structures potentially narrow enough to partially fit into the enzyme's haloalkane-binding channel. Testing a range of short chain lengths revealed a number of active dyes, with seven carbons yielding optimum light-up signal. The dimethylaminostilbazolium chloroheptyl dye (1d) yields a 27-fold fluorescence emission enhancement (λex = 535 nm; Em(max) = 616 nm) upon reaction with the protein...
December 21, 2016: Bioconjugate Chemistry
Patrick Hardt, Ina Engels, Marvin Rausch, Mike Gajdiss, Hannah Ulm, Peter Sass, Knut Ohlsen, Hans-Georg Sahl, Gabriele Bierbaum, Tanja Schneider, Fabian Grein
The assembly of the bacterial cell wall requires synchronization of a multitude of biosynthetic machineries and regulatory networks. The eukaryotic-like serine/threonine kinase PknB has been implicated in coordinating cross-wall formation, autolysis and cell division in Staphylococcus aureus. However, the signal molecule sensed by this kinase remained elusive so far. Here, we provide compelling biochemical evidence that PknB interacts with the ultimate cell wall precursor lipid II, triggering kinase activity...
December 12, 2016: International Journal of Medical Microbiology: IJMM
Hai Zheng, Po-Yi Ho, Meiling Jiang, Bin Tang, Weirong Liu, Dengjin Li, Xuefeng Yu, Nancy E Kleckner, Ariel Amir, Chenli Liu
Bacteria tightly regulate and coordinate the various events in their cell cycles to duplicate themselves accurately and to control their cell sizes. Growth of Escherichia coli, in particular, follows a relation known as Schaechter's growth law. This law says that the average cell volume scales exponentially with growth rate, with a scaling exponent equal to the time from initiation of a round of DNA replication to the cell division at which the corresponding sister chromosomes segregate. Here, we sought to test the robustness of the growth law to systematic perturbations in cell dimensions achieved by varying the expression levels of mreB and ftsZ We found that decreasing the mreB level resulted in increased cell width, with little change in cell length, whereas decreasing the ftsZ level resulted in increased cell length...
December 27, 2016: Proceedings of the National Academy of Sciences of the United States of America
Samuel H Ho, David A Tirrell
Reliable methods to determine the subcellular localization of bacterial proteins are needed for the study of prokaryotic cell biology. We describe here a simple and general technique for imaging of bacterial proteins in situ by fluorescence microscopy. The method uses the eukaryotic enzyme N-myristoyltransferase to modify the N-terminus of the protein of interest with an azido fatty acid. Subsequent strain-promoted azide-alkyne cycloaddition allows conjugation of dyes and imaging of tagged proteins by confocal fluorescence microscopy...
November 23, 2016: Journal of the American Chemical Society
Dong-Seok Lee, Younhee Kim, Heung-Shick Lee
In this study, we analyzed the whcD gene from Corynebacterium glutamicum, which encodes a homolog of whiB, a Streptomyces coelicolor gene required for the sporulation of aerial hyphae. Deletion of the gene (ΔwhcD) severely affected cell growth in C. glutamicum. The ΔwhcD strain exhibited a large, filamentous, branched, and bud-shaped morphology with multiple septa. The transcription levels of the cell division genes involved in Z-ring assembly and septal peptidoglycan synthesis, including ftsZ, sepF, ftsQ, and ftsI, were markedly decreased in the ΔwhcD strain...
November 24, 2016: Microbiology
Francesco Cicala, James D Moore, Jorge Cáceres-Martínez, Miguel A Del Río-Portilla, Mónica Hernández-Rodríguez, Rebeca Vásquez-Yeomans, Axayácatl Rocha-Olivares
"Candidatus Xenohaliotis californiensis" (or Ca. Xc) is the etiological agent of the withering syndrome (WS), a chronic wasting disease affecting most if not all North American species of abalone, and has been described as a Rickettsiales-like prokaryote. Genetic data about this species is limited to the 16S rRNA gene. The inability to grow it axenically has hindered its genetic and genomic characterization and, in consequence, a thorough analysis of its systematics. Here, we amplified and sequenced five genes (16S rRNA, 23S rRNA, ftsZ, virD4, and virB11) of Ca...
October 11, 2016: International Journal of Systematic and Evolutionary Microbiology
Joshua S MacCready, Jory Schossau, Katherine W Osteryoung, Daniel C Ducat
The oscillatory Min system of Escherichia coli defines the cell division plane by regulating the site of FtsZ-ring formation and represents one of the best-understood examples of emergent protein self-organization in nature. The oscillatory patterns of the Min-system proteins MinC, MinD and MinE (MinCDE) are strongly dependent on the geometry of membranes they bind. Complex internal membranes within cyanobacteria could disrupt this self-organization by sterically occluding or sequestering MinCDE from the plasma membrane...
November 5, 2016: Molecular Microbiology
Patrick Studer, Titu Staubli, Noémi Wieser, Patrick Wolf, Markus Schuppler, Martin J Loessner
L-forms are cell wall-deficient bacteria that divide through unusual mechanisms, involving dynamic perturbations of the cellular shape and generation of vesicles, independently of the cell-division protein FtsZ. Here we describe FtsZ-independent mechanisms, involving internal and external vesicles, by which Listeria monocytogenes L-forms proliferate. Using micromanipulation of single cells and vesicles, we show that small vesicles are formed by invagination within larger intracellular vesicles, receive cytoplasmic content, and represent viable progeny...
November 23, 2016: Nature Communications
Andrea Mura, Daniela Fadda, Amilcar J Perez, Madeline L Danforth, Daniela Musu, Ana Isabel Rico, Marcin Krupka, Dalia Denapaite, Ho-Ching T Tsui, Malcolm E Winkler, Pavel Branny, Miguel Vicente, William Margolin, Orietta Massidda
: Streptococcus pneumoniae is an ovoid-shaped Gram-positive bacterium that grows by carrying out peripheral and septal peptidoglycan (PG) synthesis, analogous to model bacilli such as Escherichia coli and Bacillus subtilis In the model bacilli, FtsZ and FtsA proteins assemble into a ring at midcell and are dedicated to septal PG synthesis, but not peripheral PG synthesis; hence inactivation of FtsZ or FtsA results in long filamentous cells unable to divide. Here we demonstrate that FtsA and FtsZ colocalize at midcell in S...
November 21, 2016: Journal of Bacteriology
Dipanwita Bhattacharya, Ashutosh Kumar, Dulal Panda
WhmD is considered to have a role in the septation and division of Mycobacterium smegmatis cells. Since FtsZ is the central protein of the septum, we determined the effect of WhmD on the assembly of Mycobacterium smegmatis FtsZ (MsFtsZ) in vitro. WhmD increased both the rate and extent of the assembly of MsFtsZ in vitro. WhmD also increased the amount of polymerized MsFtsZ as evident from a sedimentation assay. Further, the assembly promoting activity of WhmD occurred in the presence of GTP. MsFtsZ polymerized to form thin filaments in the absence of WhmD while MsFtsZ formed thick filaments in the presence of WhmD suggesting that WhmD enhanced the bundling of MsFtsZ filaments...
February 2017: International Journal of Biological Macromolecules
Hwajung Choi, Kyungjin Min, Bunzo Mikami, Hye-Jin Yoon, Hyung Ho Lee
FtsZ, a tubulin homologue, is an essential protein of the Z-ring assembly in bacterial cell division. It consists of two domains, the N-terminal and C-terminal core domains, and has a conserved C-terminal tail region. Lateral interactions between FtsZ protofilaments and several Z-ring associated proteins (Zaps) are necessary for modulating Z-ring formation. ZapD, one of the positive regulators of Z-ring assembly, directly binds to the C-terminal tail of FtsZ and promotes stable Z-ring formation during cytokinesis...
November 30, 2016: Molecules and Cells
Divya Balasubramanian, Preethi T Ragunathan, Jingyi Fei, Carin K Vanderpool
Hundreds of small RNAs (sRNAs) have been identified in diverse bacterial species, and while the functions of most remain unknown, some regulate key processes, particularly stress responses. The sRNA DicF was identified over 25 years ago as an inhibitor of cell division but since then has remained uncharacterized. DicF consists of 53 nucleotides and is encoded by a gene carried on a prophage (Qin) in the genomes of many Escherichia coli strains. We demonstrated that DicF inhibits cell division via direct base pairing with ftsZ mRNA to repress translation and prevent new synthesis of the bacterial tubulin homolog FtsZ...
January 2016: MSystems
Jingjing Sun, Xiaojian Gao, Jiang Qun, Xuedi Du, Keran Bi, Xiaojun Zhang, Li Lin
This study aimed to evaluate the survival and gene expression of Vibrio harveyi under starvation conditions. The microcosms V. harveyi were incubated in sterilized seawater for 4 weeks at room temperature. Overall, the cell numeration declined rapidly about 10(3) CFU/ml during starvation, with a tiny rebound at day 21. Scanning electron microscopy revealed that rod-shaped cells became sphere with a rippled cell surface. By polymerase chain reaction (PCR) assay, nine genes, named luxR, toxR, vhhB, flaA, topA, fur, rpoS, mreB and ftsZ, were detected in the non-starved cells...
November 2016: FEMS Microbiology Letters
Desmond A Moore, Zakiya N Whatley, Chandra P Joshi, Masaki Osawa, Harold P Erickson
: FtsZ, a bacterial tubulin homologue, is a cytoskeletal protein that assembles into protofilaments that are one subunit thick. These protofilaments assemble further to form a "Z ring" at the center of prokaryotic cells. The Z ring generates a constriction force on the inner membrane and also serves as a scaffold to recruit cell wall remodeling proteins for complete cell division in vivo One model of the Z ring proposes that protofilaments associate via lateral bonds to form ribbons; however, lateral bonds are still only hypothetical...
January 1, 2017: Journal of Bacteriology
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