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.

scholarly journals Tissue Transglutaminase Is an Integrin-Binding Adhesion Coreceptor for Fibronectin

2000 ◽  
Vol 148 (4) ◽  
pp. 825-838 ◽  
Author(s):  
Sergey S. Akimov ◽  
Dmitry Krylov ◽  
Laurie F. Fleischman ◽  
Alexey M. Belkin
Keyword(s):  
Cell Surface ◽  
Focal Adhesion ◽  
Factor Xiii ◽  
Tissue Transglutaminase ◽  
Focal Adhesions ◽  
Cross Linking ◽  
Binding Motifs ◽  
High Affinity ◽  
Β2 Integrins

The protein cross-linking enzyme tissue transglutaminase binds in vitro with high affinity to fibronectin via its 42-kD gelatin-binding domain. Here we report that cell surface transglutaminase mediates adhesion and spreading of cells on the 42-kD fibronectin fragment, which lacks integrin-binding motifs. Overexpression of tissue transglutaminase increases its amount on the cell surface, enhances adhesion and spreading on fibronectin and its 42-kD fragment, enlarges focal adhesions, and amplifies adhesion-dependent phosphorylation of focal adhesion kinase. These effects are specific for tissue transglutaminase and are not shared by its functional homologue, a catalytic subunit of factor XIII. Adhesive function of tissue transglutaminase does not require its cross-linking activity but depends on its stable noncovalent association with integrins. Transglutaminase interacts directly with multiple integrins of β1 and β3 subfamilies, but not with β2 integrins. Complexes of transglutaminase with integrins are formed inside the cell during biosynthesis and accumulate on the surface and in focal adhesions. Together our results demonstrate that tissue transglutaminase mediates the interaction of integrins with fibronectin, thereby acting as an integrin-associated coreceptor to promote cell adhesion and spreading.

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 Myxococcus xanthus dif Genes Are Required for Biogenesis of Cell Surface Fibrils Essential for Social Gliding Motility

2000 ◽  
Vol 182 (20) ◽  
pp. 5793-5798 ◽  
Author(s):  
Zhaomin Yang ◽  
Xiaoyuan Ma ◽  
Leming Tong ◽  
Heidi B. Kaplan ◽  
Lawrence J. Shimkets ◽  
...  
Keyword(s):  
Cell Surface ◽  
Myxococcus Xanthus ◽  
Bacterial Chemotaxis ◽  
Type Iv Pili ◽  
Gliding Motility ◽  
Genetic Studies ◽  
Developmental Defects ◽  
Bacterial Surface ◽  
Type Iv ◽  
Cell Surface Structures

ABSTRACT Myxococcus xanthus social (S) gliding motility has been previously reported by us to require the chemotaxis homologues encoded by the dif genes. In addition, two cell surface structures, type IV pili and extracellular matrix fibrils, are also critical to M. xanthus S motility. We have demonstrated here that M. xanthus dif genes are required for the biogenesis of fibrils but not for that of type IV pili. Furthermore, the developmental defects of dif mutants can be partially rescued by the addition of isolated fibril materials. Along with the chemotaxis genes of various swarming bacteria and the pilGHIJ genes of the twitching bacteriumPseudomonas aeruginosa, the M. xanthus dif genes belong to a unique class of bacterial chemotaxis genes or homologues implicated in the biogenesis of structures required for bacterial surface locomotion. Genetic studies indicate that the dif genes are linked to theM. xanthus dsp region, a locus known to be crucial forM. xanthus fibril biogenesis and S gliding.

scholarly journals Myxococcus xanthus Gliding Motors Are Elastically Coupled to the Substrate as Predicted by the Focal Adhesion Model of Gliding Motility

2014 ◽  
Vol 10 (5) ◽  
pp. e1003619 ◽  
Author(s):  
Rajesh Balagam ◽  
Douglas B. Litwin ◽  
Fabian Czerwinski ◽  
Mingzhai Sun ◽  
Heidi B. Kaplan ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Myxococcus Xanthus ◽  
Gliding Motility ◽  
Adhesion Model

Photonic force microscopy of local tension at cell surface focal adhesions

2006 ◽  
Author(s):  
François Bordeleau ◽  
Judicaël Bessard ◽  
Normand Marceau ◽  
Yunlong Sheng
Keyword(s):  
Cell Surface ◽  
Focal Adhesions ◽  
Force Microscopy

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 Flavobacterium johnsoniae PorV Is Required for Secretion of a Subset of Proteins Targeted to the Type IX Secretion System

2014 ◽  
Vol 197 (1) ◽  
pp. 147-158 ◽  
Author(s):  
Sampada S. Kharade ◽  
Mark J. McBride
Keyword(s):  
Cell Surface ◽  
Secretion System ◽  
Gliding Motility ◽  
Content Type ◽  
Flavobacterium Johnsoniae ◽  
Protein Secretion System ◽  
Surface Motility ◽  
Type Ix Secretion System ◽  
Carboxy Terminal ◽  
Novel Protein

Flavobacterium johnsoniaeexhibits gliding motility and digests many polysaccharides, including chitin. A novel protein secretion system, the type IX secretion system (T9SS), is required for gliding and chitin utilization. The T9SS secretes the cell surface motility adhesins SprB and RemA and the chitinase ChiA. Proteins involved in secretion by the T9SS include GldK, GldL, GldM, GldN, SprA, SprE, and SprT.Porphyromonas gingivalishas orthologs for each of these that are required for secretion of gingipain protease virulence factors by its T9SS.P. gingivalisporUandporVhave also been linked to T9SS-mediated secretion, andF. johnsoniaehas orthologs of these. Mutations inF. johnsoniaeporUandporVwere constructed to determine if they function in secretion. Cells of aporVdeletion mutant were deficient in chitin utilization and failed to secrete ChiA. They were also deficient in secretion of the motility adhesin RemA but retained the ability to secrete SprB. SprB is involved in gliding motility and is needed for formation of spreading colonies on agar, and theporVmutant exhibited gliding motility and formed spreading colonies. However, theporVmutant was partially deficient in attachment to glass, apparently because of the absence of RemA and other adhesins on the cell surface. TheporVmutant also appeared to be deficient in secretion of numerous other proteins that have carboxy-terminal domains associated with targeting to the T9SS. PorU was not required for secretion of ChiA, RemA, or SprB, indicating that it does not play an essential role in theF. johnsoniaeT9SS.

scholarly journals A Versatile Class of Cell Surface Directional Motors Gives Rise to Gliding Motility and Sporulation in Myxococcus xanthus

PLoS Biology ◽  
2013 ◽  
Vol 11 (12) ◽  
pp. e1001728 ◽  
Author(s):  
Morgane Wartel ◽  
Adrien Ducret ◽  
Shashi Thutupalli ◽  
Fabian Czerwinski ◽  
Anne-Valérie Le Gall ◽  
...  
Keyword(s):  
Cell Surface ◽  
Myxococcus Xanthus ◽  
Gliding Motility

scholarly journals Surface Viscoelasticity of Individual Gram-Negative Bacterial Cells Measured Using Atomic Force Microscopy

2008 ◽  
Vol 190 (12) ◽  
pp. 4225-4232 ◽  
Author(s):  
Virginia Vadillo-Rodriguez ◽  
Terry J. Beveridge ◽  
John R. Dutcher
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Cell Surface ◽  
Cell Envelope ◽  
Compressive Force ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cell Surface Structure

ABSTRACT The cell envelope of gram-negative bacteria is responsible for many important biological functions: it plays a structural role, it accommodates the selective transfer of material across the cell wall, it undergoes changes made necessary by growth and division, and it transfers information about the environment into the cell. Thus, an accurate quantification of cell mechanical properties is required not only to understand physiological processes but also to help elucidate the relationship between cell surface structure and function. We have used a novel, atomic force microscopy (AFM)-based approach to probe the mechanical properties of single bacterial cells by applying a constant compressive force to the cell under fluid conditions while measuring the time-dependent displacement (creep) of the AFM tip due to the viscoelastic properties of the cell. For these experiments, we chose a representative gram-negative bacterium, Pseudomonas aeruginosa PAO1, and we used regular V-shaped AFM cantilevers with pyramid-shaped and colloidal tips. We find that the cell response is well described by a three-element mechanical model which describes an effective cell spring constant, k 1, and an effective time constant, τ, for the creep deformation. Adding glutaraldehyde, an agent that increases the covalent bonding of the cell surface, produced a significant increase in k 1 together with a significant decrease in τ. This work represents a new attempt toward the understanding of the nanomechanical properties of single bacteria while they are under fluid conditions, which could be of practical value for elucidating, for instance, the biomechanical effects of drugs (such as antibiotics) on pathogens.

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