A5066494299- Bacterial Genetics and Biotechnology
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- RNA and protein synthesis mechanisms
- Escherichia coli research studies
- Algebraic Geometry and Number Theory
- Bacteriophages and microbial interactions
- Analytic Number Theory Research
- Meromorphic and Entire Functions
- Vibrio bacteria research studies
- Genomics and Phylogenetic Studies
- Coding theory and cryptography
- Photosynthetic Processes and Mechanisms
- Protein Structure and Dynamics
- Microbial Community Ecology and Physiology
- Gene Regulatory Network Analysis
- Photoreceptor and optogenetics research
- Lipid Membrane Structure and Behavior
- Advanced Differential Equations and Dynamical Systems
- Metal-Catalyzed Oxygenation Mechanisms
- History and Theory of Mathematics
- Cellular transport and secretion
- Probiotics and Fermented Foods
- Protist diversity and phylogeny
- Cell Image Analysis Techniques
Rikkyo University
2014-2025
National Institute of Genetics
2008-2017
Yamagata University
2014-2017
Nagoya University
2000-2012
Tokyo University of Science
2012
The University of Texas Health Science Center at Houston
2007-2008
The University of Texas at Austin
2007-2008
Brandeis University
2004
Osaka City University
1999
The determination and regulation of cell morphology are critical components cell-cycle control, fitness, development in both single-cell multicellular organisms. Understanding how environmental factors, chemical perturbations, genetic differences affect requires precise, unbiased, validated measurements cell-shape features.Here we introduce two software packages, Morphometrics BlurLab, that together enable automated, computationally efficient, unbiased identification cells morphological...
ABSTRACT Assembly of the cell division apparatus in bacteria starts with formation Z ring on cytoplasmic face membrane. This process involves accumulation FtsZ polymers at midcell and their interaction several FtsZ-binding proteins that collectively organize into a membrane-associated ring-like configuration. Three such proteins, FtsA, ZipA, ZapA, have previously been identified Escherichia coli . FtsA ZipA are essential help connect inner ZapA is protein not required for fission per se but...
Formation of the FtsZ ring (Z ring) in Escherichia coli is first step assembly divisome, a protein machine required for cell division. Although biochemical functions most divisome proteins are unknown, several, including ZipA, FtsA and FtsK, have overlapping roles ensuring that Z assembles at cytoplasmic membrane, it active. As shown previously, single amino acid change FtsA, R286W, also called FtsA*, bypasses requirement either ZipA or FtsK In this study, properties FtsA* were investigated...
Summary In Escherichia coli , chemoreceptor clustering at a cell pole seems critical for signal amplification and adaptation. However, little is known about the mechanism of localization itself. Here we examined whether aspartate (Tar) inserted directly into polar membrane by using its fusion to green fluorescent protein (GFP). After induction Tar–GFP, spots first appeared in lateral regions, later poles became predominantly fluorescent. Unexpectedly, Tar–GFP showed helical arrangement which...
Summary FtsN is the last known essential protein component to be recruited Escherichia coli divisome, and has several special properties. Here we report isolation of suppressor mutants ftsA that allow viability in absence ftsN . Cells producing FtsA suppressors exhibited a mild cell division deficiency FtsN, no obvious phenotype its presence. Remarkably, these altered proteins also could partially suppress deletion ftsK or zipA , were less toxic than wild‐type when excess, conferred...
RodZ interacts with MreB and both factors are required to maintain the rod shape of Escherichia coli. The assembly into filaments regulates subcellular arrangement a group enzymes that synthesizes peptidoglycan (PG) layer. However, it is still unknown how polymerization determines bacterial cells. Regulatory factor(s) likely be involved in controlling function dynamics MreB. We isolated suppressor mutations partially recover rodZ deletion mutants found some occurred mreB. All mreB were or...
Summary In bacteria, the actin‐like FtsA protein interacts with tubulin‐like FtsZ protein, helping to assemble cytokinetic Z ring, anchor it cytoplasmic membrane and recruit other essential divisome proteins. also itself, but is not clear whether this self‐interaction required for its full functionality. Here we describe new dominant negative missense mutations in Escherichia coli ftsA that specifically inhibit homodimerization simultaneously cause disruption of rings. The effects one...
Cell polarity determines the direction of cell growth in bacteria. MreB actin spatially regulates peptidoglycan synthesis to enable cells elongate bidirectionally. densely localizes cylindrical part rod and not polar regions Escherichia coli. When treated with A22, which inhibits polymerization, rod-shaped became round was diffusely distributed throughout cytoplasmic membrane. A22 removal resulted restoration shape. Initially, diffuse started re-assemble, MreB-free zones were subsequently...
The FtsZ protein is involved in bacterial cell division. In cell-walled bacteria, such as Bacillus subtilis, forms a ring-like structure, called the Z ring, at division site and acts scaffold for wall synthesis. inhibition of synthesis B. subtilis has been shown to interfere with function causing loss control. Spiroplasma, wall-less bacterium, lacks most genes division; however, ftsZ gene remains conserved. Spiroplasma eriocheiris (SeFtsZ) be determined. present study, we analyzed...
Many sensory systems involve multiple steps of signal amplification to produce a significant response. One such mechanism may be the clustering transmembrane receptors. In bacterial chemotaxis, where stoichiometric His-Asp phosphorelay from kinase CheA response regulator CheY plays central role, chemoreceptors (methyl-accepting chemotaxis proteins) cluster together with and adaptor CheW, at pole rod-shaped cell. This led proposal that occurs through an interaction between chemoreceptor...
In Escherichia coli, the Min system, consisting of three proteins, MinC, MinD, and MinE, negatively regulates FtsZ assembly at cell poles, helping to ensure that Z ring will assemble only midcell. Of MinC is sufficient inhibit Z-ring assembly. By binding which mostly localized membrane near sequestered away from midpoint, increasing probability there. Previously, it has been shown two halves have distinct functions. The N-terminal half for inhibition assembly, whereas C-terminal protein...
Gram-negative bacteria such as Escherichia coli are surrounded by an outer membrane, which encloses a peptidoglycan layer. Even if thinner than in many Gram-positive bacteria, the E. allows cells to withstand turgor pressure hypotonic medium. In hypertonic medium, treated with cell wall synthesis inhibitor penicillin G form wall-deficient cells. These so-called L-form grow well under anaerobic conditions (i.e., absence of oxidative stress), becoming deformed and dividing L-form. Upon removal...
Summary The bacterial actin homologue FtsA has a conserved C‐terminal membrane targeting sequence (MTS). Deletion or point mutations in the MTS, such as W408E, were shown previously to inactivate function and inhibit cell division. Because binds tubulin‐like FtsZ protein that forms Z ring, it is thought MTS of required, along with transmembrane ZipA, assemble ring anchor cytoplasmic membrane. Here, we show despite its reduced binding, FtsA‐W408E could localize recruit late division FtsI, but...
Abstract Peptidoglycan for elongation in Escherichia coli is synthesized by the Rod complex, which includes RodZ. Although various mutant strains of complex have been isolated, relationship between activity and overall physical chemical structures peptidoglycan not reported. We constructed a RodZ mutant, termed RMR, analyzed growth rate, morphology, other characteristics cells producing complexes containing RMR. The morphology RMR were abnormal, we isolated suppressor mutants from cells....
Summary Chemotactic adaptation to persisting stimulation involves reversible methylation of the chemoreceptors that form complexes with histidine kinase CheA at a cell pole. The methyltransferase CheR targets C‐terminal NWETF sequence chemoreceptor. In contrast, localization methylesterase CheB is largely unknown, although regulation its activity via phosphorylation central adaptation. this study, green fluorescent protein was fused full‐length or various parts: N‐terminal regulatory domain...
In the chemotaxis of Escherichia coli, polar clustering chemoreceptors, histidine kinase CheA, and adaptor protein CheW is thought to be involved in signal amplification adaptation. However, mechanism that leads localization receptor still largely unknown. this study, we examined effect covalent modification on aspartate chemoreceptor Tar fused green fluorescent (GFP). Amidation (and presumably methylation) Tar-GFP enhanced its own localization, although was small. The slight but significant...
Bacteria such as Escherichia coli must coordinate cell elongation and division. Elongation is regulated by an elongasome complex containing MreB actin the transmembrane protein RodZ, which regulates assembly of MreB, whereas division a divisome FtsZ tubulin. These complexes were previously thought to function separately. However, has been shown directly interact with switch from elongation, indicating that these collaborate regulate both processes. Here, we investigated role RodZ in...
RodZ is important for maintaining the rod shape of Escherichia coli. Loss causes conversion to a round and growth rate slower than that wild-type cells. Suppressor mutations simultaneously restore both rates were isolated. Most suppressor are found in mreB, mrdA, or mrdB. One was promoter region zipA, which encodes crucial component cell division machinery. In this study, we investigated mechanism suppression by mutation. ZipA slightly but significantly increased cells led delay division....
A cell wall is required to control shape and size maintain growth division. However, some bacterial species their morphology without a wall, calling into question the importance of size. It has been very difficult examine dispensability synthesis in rod-shaped bacteria such as Escherichia coli for maintenance because they lyse walls under normal culture conditions. Here, we show that wall-less E. L-form cells, which have heterogeneous morphology, can be converted mostly uniform oval solely...