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
2019 ◽  
Author(s):  
Liam M. Rooney ◽  
Lisa S. Kölln ◽  
Ross Scrimgeour ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
...  

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.


mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Liam M. Rooney ◽  
Lisa S. Kölln ◽  
Ross Scrimgeour ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
...  

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.


1989 ◽  
Vol 171 (2) ◽  
pp. 819-830 ◽  
Author(s):  
K Stephens ◽  
P Hartzell ◽  
D Kaiser

2010 ◽  
Vol 74 (2) ◽  
pp. 229-249 ◽  
Author(s):  
Emilia M. F. Mauriello ◽  
Tâm Mignot ◽  
Zhaomin Yang ◽  
David R. Zusman

SUMMARY In bacteria, motility is important for a wide variety of biological functions such as virulence, fruiting body formation, and biofilm formation. While most bacteria move by using specialized appendages, usually external or periplasmic flagella, some bacteria use other mechanisms for their movements that are less well characterized. These mechanisms do not always exhibit obvious motility structures. Myxococcus xanthus is a motile bacterium that does not produce flagella but glides slowly over solid surfaces. How M. xanthus moves has remained a puzzle that has challenged microbiologists for over 50 years. Fortunately, recent advances in the analysis of motility mutants, bioinformatics, and protein localization have revealed likely mechanisms for the two M. xanthus motility systems. These results are summarized in this review.


Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Yinuo Li ◽  
Renate Lux ◽  
Andrew E. Pelling ◽  
James K. Gimzewski ◽  
Wenyuan Shi

Myxococcus xanthus possesses a social gliding motility that requires type IV pili (TFP). According to the current model, M. xanthus pili attach to an external substrate and retract, pulling the cell body forward along their long axis. By analogy with the situation in other bacteria employing TFP-dependent motility, M. xanthus pili have been assumed to be composed of pilin (PilA) subunits, but this has not previously been confirmed. The first 28 amino acids of the M. xanthus PilA protein share extensive homology with the N-terminal oligomerization domain of pilins in other bacterial species. To facilitate purification, the authors engineered a truncated form of M. xanthus PilA lacking the first 28 amino acids and purified this protein in soluble form. Polyclonal antibody generated against this protein was reactive with native pilin and pili. Using this antibody, it was confirmed that TFP of M. xanthus are indeed composed of PilA, and that TFP are located unipolarly and required for social gliding motility via retraction. Using tethering as well as motility assays, details of pili function in M. xanthus social motility were further examined.


2007 ◽  
Vol 189 (21) ◽  
pp. 7937-7941 ◽  
Author(s):  
Cui-ying Zhang ◽  
Ke Cai ◽  
Hong Liu ◽  
Yong Zhang ◽  
Hong-wei Pan ◽  
...  

ABSTRACT The mts locus in salt-tolerant Myxococcus fulvus HW-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation. The homologous genes in Myxococcus xanthus are also important for social motility and fruiting-body development. The mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species.


2005 ◽  
Vol 187 (5) ◽  
pp. 1716-1723 ◽  
Author(s):  
Yinuo Li ◽  
Víctor H. Bustamante ◽  
Renate Lux ◽  
David Zusman ◽  
Wenyuan Shi

ABSTRACT Myxococcus xanthus moves on solid surfaces by using two gliding motility systems, A motility for individual-cell movement and S motility for coordinated group movements. The frz genes encode chemotaxis homologues that control the cellular reversal frequency of both motility systems. One of the components of the core Frz signal transduction pathway, FrzE, is homologous to both CheA and CheY from the enteric bacteria and is therefore a novel CheA-CheY fusion protein. In this study, we investigated the role of this fusion protein, in particular, the CheY domain (FrzECheY). FrzECheY retains all of the highly conserved residues of the CheY superfamily of response regulators, including Asp709, analogous to phosphoaccepting Asp57 of Escherichia coli CheY. While in-frame deletion of the entire frzE gene caused both motility systems to show a hyporeversal phenotype, in-frame deletion of the FrzECheY domain resulted in divergent phenotypes for the two motility systems: hyperreversals of the A-motility system and hyporeversals of the S-motility system. To further investigate the role of FrzECheY in A and S motility, point mutations were constructed such that the putative phosphoaccepting residue, Asp709, was changed from D to A (and was therefore never subject to phosphorylation) or E (possibly mimicking constitutive phosphorylation). The D709A mutant showed hyperreversals for both motilities, while the D709E mutant showed hyperreversals for A motility and hyporeversal for S motility. These results show that the FrzECheY domain plays a critical signaling role in coordinating A and S motility. On the basis of the phenotypic analyses of the frzE mutants generated in this study, a model is proposed for the divergent signal transduction through FrzE in controlling and coordinating A and S motility in M. xanthus.


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