Induction of coordinated movement of Myxococcus xanthus cells

1982 ◽  
Vol 152 (1) ◽  
pp. 451-461
Author(s):  
L J Shimkets ◽  
D Kaiser
Keyword(s):  
Cell Envelope ◽  
Myxococcus Xanthus ◽  
Maximum Velocity ◽  
Gliding Motility ◽  
Fruiting Bodies ◽  
Whole Cells ◽  
Quiescent Cells ◽  
Cell Extracts ◽  
Lines Of Evidence

Rhythmically advancing waves of cells, called ripples, arise spontaneously during the aggregation of Myxococcus xanthus into fruiting bodies. Extracts prepared by washing rippling cells contain a substance that will induce quiescent cells to ripple. Three lines of evidence indicate that murein (peptidoglycan) is the ripple-inducing substance in the extracts. First, ripple-inducing activity is associated with the cell envelope of sonically disrupted M. xanthus cells. Second, whole cells, cell extracts, or purified murein from a variety of different bacteria are capable of inducing ripples. In contrast, extracts prepared from Methanobacterium spp. which contain pseudomurein instead of typical bacterial murein fail to induce ripples. Third, four components of M. xanthus murein, N-acetylglucosamine, N-acetylmuramic acid, diaminopimelate, and D-alanine, are able to induce ripples. Ripples produced by aggregating cells have a wavelength of 45 micrometers and a maximum velocity of 2 micrometers/min. Both of the multigene systems that control gliding motility appear to be required for rippling, and all known mutations at the spoC locus eliminate both rippling and sporulation.

scholarly journals The Orphan Response Regulator DigR Is Required for Synthesis of Extracellular Matrix Fibrils in Myxococcus xanthus

2006 ◽  
Vol 188 (12) ◽  
pp. 4384-4394 ◽  
Author(s):  
Martin Overgaard ◽  
Sigrun Wegener-Feldbrügge ◽  
Lotte Søgaard-Andersen
Keyword(s):  
Extracellular Matrix ◽  
Response Regulator ◽  
Cell Envelope ◽  
Transcriptional Profiling ◽  
Myxococcus Xanthus ◽  
Gliding Motility ◽  
Differentially Expressed ◽  
Type Iv Pilus ◽  
Receiver Domain ◽  
Type Iv

ABSTRACT In Myxococcus xanthus, two-component systems have crucial roles in regulating motility behavior and development. Here we describe an orphan response regulator, consisting of an N-terminal receiver domain and a C-terminal DNA binding domain, which is required for A and type IV pilus-dependent gliding motility. Genetic evidence suggests that phosphorylation of the conserved, phosphorylatable aspartate residue in the receiver domain is required for DigR activity. Consistent with the defect in type IV pilus-dependent motility, a digR mutant is slightly reduced in type IV pilus biosynthesis, and the composition of the extracellular matrix fibrils is abnormal, with an increased content of polysaccharides and decreased accumulation of the FibA metalloprotease. By using genome-wide transcriptional profiling, 118 genes were identified that are directly or indirectly regulated by DigR. These 118 genes include only 2, agmQ and cheY4, previously implicated in A and type IV pilus-dependent motility, respectively. In silico analyses showed that 36% of the differentially expressed genes are likely to encode exported proteins. Moreover, four genes encoding homologs of extracytoplasmic function (ECF) sigma factors, which typically control aspects of cell envelope homeostasis, are differentially expressed in a digR mutant. We suggest that the DigR response regulator has an important function in cell envelope homeostasis and that the motility defects in a digR mutant are instigated by the abnormal cell envelope and abnormal expression of agmQ and cheY4.

scholarly journals CglB adhesins secreted at bacterial focal adhesions mediate gliding motility

2020 ◽  
Author(s):  
Salim T. Islam ◽  
Laetitia My ◽  
Nicolas Y. Jolivet ◽  
Akeisha M. Belgrave ◽  
Betty Fleuchot ◽  
...  
Keyword(s):  
Cell Surface ◽  
Focal Adhesion ◽  
Cell Envelope ◽  
Myxococcus Xanthus ◽  
Focal Adhesions ◽  
Gliding Motility ◽  
Bacterial Motility ◽  
Force Microscopy ◽  
Coupling Protein ◽  
Novel Protein

AbstractThe predatory deltaproteobacterium Myxococcus xanthus uses a helically-trafficked motor at bacterial focal adhesion (bFA) sites to power gliding motility. Using TIRF and force microscopy, we herein identify the integrin αI-domain-like outer-membrane (OM) lipoprotein CglB as an essential substratum-coupling protein of the gliding motility complex. Similar to most known OM lipoproteins, CglB is anchored on the periplasmic side of the OM and thus a mechanism must exist to secrete it to the cell surface in order for it to interact with the underlying substratum. We reveal this process to be mediated by a predicted OM β-barrel structure of the gliding complex. This OM platform was found to regulate the conformational activation and secretion of CglB across the OM. These data suggest that the gliding complex promotes surface exposure of CglB at bFAs, thus explaining the manner by which forces exerted by inner-membrane motors are transduced across the cell envelope to the substratum; they also uncover a novel protein secretion mechanism, highlighting the ubiquitous connection between secretion and bacterial motility.

Flavobacterium akiainvivens sp. nov., from decaying wood of Wikstroemia oahuensis, Hawai‘i, and emended description of the genus Flavobacterium

2013 ◽  
Vol 63 (Pt_9) ◽  
pp. 3280-3286 ◽  
Author(s):  
Iris Kuo ◽  
Jimmy Saw ◽  
Durrell D. Kapan ◽  
Stephanie Christensen ◽  
Kenneth Y. Kaneshiro ◽  
...  
Keyword(s):  
Type Species ◽  
Original Description ◽  
Gliding Motility ◽  
Rrna Gene ◽  
Content Type ◽  
Phenotypic Differences ◽  
Whole Cells ◽  
Link Type ◽  
Decaying Wood ◽  
Type Strains

Strain IK-1T was isolated from decaying tissues of the shrub Wikstroemia oahuensis collected on O‘ahu, Hawai‘i. Cells were rods that stained Gram-negative. Gliding motility was not observed. The strain was oxidase-negative and catalase-positive. Zeaxanthin was the major carotenoid. Flexirubin-type pigments were not detected. The most abundant fatty acids in whole cells of IK-1T grown on R2A were iso-C15 : 0 and one or both of C16 : 1ω7c and C16 : 1ω6c. Based on comparisons of the nucleotide sequence of the 16S rRNA gene, the closest neighbouring type strains were Flavobacterium rivuli WB 3.3-2T and Flavobacterium subsaxonicum WB 4.1-42T, with which IK-1T shares 93.84 and 93.67 % identity, respectively. The G+C content of the genomic DNA was 44.2 mol%. On the basis of distance from its nearest phylogenetic neighbours and phenotypic differences, the species Flavobacterium akiainvivens sp. nov. is proposed to accommodate strain IK-1T ( = ATCC BAA-2412T = CIP 110358T) as the type strain. The description of the genus Flavobacterium is emended to reflect the DNA G+C contents of Flavobacterium akiainvivens IK-1T and other species of the genus Flavobacterium described since the original description of the genus.

THE EFFECT OF BACTERIAL CELL LYSIS AND OF PLANT EXTRACTS ON CELLULOSE PRODUCTION BY ACETOBACTER XYLINUM

1963 ◽  
Vol 41 (1) ◽  
pp. 1691-1702 ◽  
Author(s):  
T. E. Webb ◽  
J. Ross Colvin
Keyword(s):  
Bacterial Cell ◽  
Cell Envelope ◽  
Acetobacter Xylinum ◽  
Cellulose Synthesis ◽  
Additive Effects ◽  
Cellulose Production ◽  
Whole Cells ◽  
Negative Results ◽  
Heat Stable ◽  
Plant Sources

The production of cellulose by lysozyme lysates of Acetobacter xylinum is similar to that of a suspension of whole cells, in contrast to the negative results obtained with previous "cell-free" preparations. The results of differential centrifugation of these lysates suggests that most of the enzymes required for cellulose synthesis from glucose normally are held by the cell envelope and are not located in the cytoplasm. However, a heat-stable cofactor(s) is present in the supernatant derived from the cell contents which may stimulate cellulose synthesis by the cell envelopes.The addition of extracts from a number of plant sources increased cellulose synthesis by whole cells of A. xylinum. In particular, the supernatant prepared by centrifugation of an homogenate of tomatoes increased bacterial cellulose production at pH 6 by a factor of 3. Both dialyzable and non-dialyzable substances in the extract are responsible. Fractionation of the non-dialyzable portion of the extract by column chromatography suggests that the overall increase is due to additive effects of several compounds. Here also the compounds appear to act upon the bacterial cell envelope.

scholarly journals THE CELL ENVELOPES OF TWO EXTREMELY HALOPHILIC BACTERIA

1963 ◽  
Vol 18 (3) ◽  
pp. 681-689 ◽  
Author(s):  
A. D. Brown ◽  
C. D. Shorey
Keyword(s):  
Single Unit ◽  
Cell Envelope ◽  
Halophilic Bacteria ◽  
Layered Compound ◽  
Halobacterium Halobium ◽  
Chemical Analyses ◽  
Unit Membrane ◽  
Thin Sections ◽  
Whole Cells ◽  
Cell Envelopes

The cell envelope of Halobacterium halobium was seen in thin sections of permanganate-fixed cells to consist of one membrane. This membrane appeared mostly as a unit membrane but in a few preparations it resembled a 5-layered compound membrane. The cell envelope of Halobacterium salinarium at high resolution was always seen as a 5-layered structure different in appearance from the apparent compound membrane of H. halobium. The "envelopes" which were isolated in 12.5 per cent NaCl from each organism were indistinguishable from each other in the electron microscope and comprised, in each case, a single unit membrane with an over-all thickness of about 110 A. Some chemical analyses were made of isolated membranes after freeing them from salt by precipitating and washing with trichloroacetic acid. Such precipitated membranes consisted predominantly of protein, with little carbohydrate and no peptido-aminopolysaccharide (mucopeptide). Sectioned whole cells of H. halobium contained intracellular electron-opaque structures of unknown function.

scholarly journals Three-dimensional observations of an aperiodic oscillatory gliding motility behaviour in Myxococcus xanthus using confocal interference reflection microscopy

2019 ◽  
Author(s):  
Liam M. Rooney ◽  
Lisa S. Kölln ◽  
Ross Scrimgeour ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
...  
Keyword(s):  
Myxococcus Xanthus ◽  
Three Dimensional ◽  
Basal Membrane ◽  
Gliding Motility ◽  
The Novel ◽  
Force Transmission ◽  
Topological Information ◽  
Type Iv ◽  
Microscopy Techniques

The Delta-proteobacterium, Myxococcus xanthus, has been used as a model for bacterial motility and to provide insights of bacterial swarming behaviours. Fluorescence microscopy techniques have shown that various mechanisms are involved in gliding motility, but these have almost entirely been limited to 2D studies and there is currently no understanding of gliding motility in a 3D context. We present here the first use of confocal interference reflection microscopy (IRM) to study gliding bacteria, and we reveal aperiodic oscillatory behaviour with changes in the position of the basal membrane relative to the coverglass on the order of 90 nm in vitro. Firstly, we use a model plano-convex lens specimen to show how topological information can be obtained from the wavelength-dependent interference pattern in IRM. We then use IRM to observe gliding M. xanthus and show that cells undergo previously unobserved changes in their height as they glide. We compare the wild-type with mutants of reduced motility, which also exhibit the same changes in adhesion profile during gliding. We find that the general gliding behaviour is independent of the proton motive force-generating complex, AglRQS, and suggest that the novel behaviour we present here may be a result of recoil and force transmission along the length of the cell body following firing of the Type IV pili.

Genes required for both gliding motility and development in Myxococcus xanthus

1994 ◽  
Vol 14 (4) ◽  
pp. 785-795 ◽  
Author(s):  
Spencer D. MacNeil ◽  
Aram Mouzeyan ◽  
Patricia L Hartzell
Keyword(s):  
Myxococcus Xanthus ◽  
Gliding Motility

scholarly journals Three-Dimensional Observations of an Aperiodic Oscillatory Gliding Behavior in Myxococcus xanthus Using Confocal Interference Reflection Microscopy

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Liam M. Rooney ◽  
Lisa S. Kölln ◽  
Ross Scrimgeour ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
...  
Keyword(s):  
Myxococcus Xanthus ◽  
Three Dimensional ◽  
Oscillatory Behavior ◽  
Gliding Motility ◽  
Bacterial Cells ◽  
Force Transmission ◽  
Content Type ◽  
Gliding Bacteria ◽  
Microscopy Techniques

ABSTRACT The deltaproteobacterium Myxococcus xanthus is a model for bacterial motility and has provided unprecedented insights into bacterial swarming behaviors. Fluorescence microscopy techniques have been invaluable in defining the mechanisms that are involved in gliding motility, but these have almost entirely been limited to two-dimensional (2D) studies, and there is currently no understanding of gliding motility in a three-dimensional (3D) context. We present here the first use of confocal interference reflection microscopy (IRM) to study gliding bacteria, revealing aperiodic oscillatory behavior with changes in the position of the basal membrane relative to the substrate on the order of 90 nm in vitro. First, we use a model planoconvex lens specimen to show how topological information can be obtained from the wavelength-dependent interference pattern in IRM. We then use IRM to observe gliding M. xanthus bacteria and show that cells undergo previously unobserved changes in their adhesion profile as they glide. We compare the wild type with mutants that have reduced motility, which also exhibit the same changes in the adhesion profile during gliding. We find that the general gliding behavior is independent of the proton motive force-generating complex AglRQS and suggest that the novel behavior that we present here may be a result of recoil and force transmission along the length of the cell body following firing of the type IV pili. IMPORTANCE 3D imaging of live bacteria with optical microscopy techniques is a challenge due to the small size of bacterial cells, meaning that previous studies have been limited to observing motility behavior in 2D. We introduce the application of confocal multiwavelength interference reflection microscopy to bacteria, which enables visualization of 3D motility behaviors in a single 2D image. Using the model organism Myxococcus xanthus, we identified novel motility behaviors that are not explained by current motility models, where gliding bacteria exhibit aperiodic changes in their adhesion to an underlying solid surface. We concluded that the 3D behavior was not linked to canonical motility mechanisms and that IRM could be applied to study a range of microbiological specimens with minimal adaptation to a commercial microscope.

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