Unorthodox regulation of the <scp>MglA</scp> Ras‐like <scp>GTPase</scp> controlling polarity in <i>Myxococcus xanthus</i>

Dinet, Céline; Mignot, Tâm

doi:10.1002/1873-3468.14565

Cited by 9 publications

(11 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Distinct subcellular dynamics of DivIVA and RomR throughout the cell cycle of B. bacteriovorus suggest that these proteins play different roles. Both proteins have reported interaction partners in other species, which determine their function (12, 19, 33). Thus, to get insight into the protein landscape of DivIVA and RomR in B. bacteriovorus , we applied a proximity-dependent biotinylation (34) using miniTurbo (35), a proximity labelling derivative of BioID.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Distinct dynamics and proximity networks of hub proteins at the prey-invading cell pole in a predatory bacterium

Remy,

Santin,

Jonckheere

et al. 2023

Preprint

View full text Add to dashboard Cite

In bacteria, cell poles function as subcellular compartments where proteins localize during specific lifecycle stages, orchestrated by polar “hub” proteins. Whereas most described bacteria inherit an “old” pole from the mother cell and a “new” pole from cell division, polarizing cells at birth, non-binary division poses challenges for establishing cell polarity, particularly for daughter cells inheriting only new poles. We investigated polarity dynamics in the obligate predatory bacteriumBdellovibrio bacteriovorus, proliferating through filamentous growth followed by non-binary division within prey bacteria. Monitoring the subcellular localization of two proteins known as polar hubs in other species, RomR and DivIVA, revealed RomR as an early polarity marker inB. bacteriovorus. RomR already marks the future anterior poles of the progeny during the predator’s growth phase, in a define time window closely following the onset of divisome assembly and the end of chromosome segregation. In contrast to RomR’s stable unipolar localization in the progeny, DivIVA exhibits a dynamic pole-to-pole localization. This behaviour changes shortly before division of the elongated predator cell, where DivIVA accumulates at all septa and both poles.In vivoprotein interaction networks for DivIVA and RomR, mapped through endogenous miniTurbo-based proximity labeling, further underscore their distinct roles in cell polarization and the importance of the anterior “invasive” cell pole in prey-predator interactions. Our work emphasizes the strict spatiotemporal coordination of cellular processes underlyingB. bacteriovorusproliferation, offering insights into the subcellular organization of bacteria with filamentous growth and non-binary division.

show abstract

Section: Resultsmentioning

confidence: 99%

“…There, MglA recruits SgmX to stimulate pili extension and retraction (16, 17), pulling the cell forward. The posterior pole predominantly hosts MglB, which converts MglA (with the help of RomY (18)) to the inactive GDP-bound form (19). Intriguingly, RomR-SgmX and MglA-SgmX interactions were reported for the B. bacteriovorus homologs (20).…”

Section: Introductionmentioning

confidence: 99%

Distinct dynamics and proximity networks of hub proteins at the prey-invading cell pole in a predatory bacterium

Remy,

Santin,

Jonckheere

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Values for K m and k cat were calculated by fitting the data to the Michaelis-Menten equation as described below with nonlinear regression curve fitting using GraphPad Prism (version 9.4.1, GraphPad Software Inc.). We constructed the following model based on available literature 27,28,43,44 :…”

Section: Estimating Reactions Constantsmentioning

confidence: 99%

A novel molecular switch controls assembly of bacterial focal adhesions

Mignot

Attia

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

Cell motility is universally driven by focal adhesion complexes (FAs) assembled in the cell envelope to connect the underlying substrate to cytoskeletal motors, generating traction forces in a highly regulated manner. In bacteria, focal adhesion complexes (bFAs) assembly is mediated by the Agl-Glt motility machinery, however how this machinery is connected to the cytoskeleton via cytoplasmic platform proteins, MglA and AglZ, remains unknown. Here, combining in vitro and single cell approaches, we show that the cytoplasmic region of the transmembrane GltJ protein contains two cytosolic motifs that independently recruit MglA-GTP (Linker) and AglZ (GYF), thus driving bFA assembly. Remarkably, binding of MglA-GTP causes a switch in the conformation of an adjacent Zinc finger domain (ZnR) that becomes available to recruit MglB, a MglA GTPase-Activating Protein. This binding activates GTP hydrolysis, which dissociates MglA from GltJ and is important to regulate bFA stability in vivo. These findings thus unravel the molecular mechanism of bFA assembly and regulation. Remarkably, the large number of other bacterial receptor proteins containing adjacent GYF and ZnR domains suggests conservation of this novel type of molecular switches.

show abstract

“…The activity of the T4aPM in M. xanthus is regulated by the polarity module (41)(42)(43). The output of this module is generated by the small Ras-like GTPase MglA, which is a nucleotide-dependent molecular switch that is inactive in the GDP-bound and active in the GTP-bound state (44,45).…”

Section: Introductionmentioning

confidence: 99%

Combinatorial control of type IVa pili formation by the four polarized regulators MglA, SgmX, FrzS and SopA

Oklitschek,

Carreira,

Muratoğlu

et al. 2024

Preprint

View full text Add to dashboard Cite

Type IVa pili (T4aP) are widespread and enable bacteria to translocate across surfaces. T4aP engage in cycles of extension, surface adhesion and retraction, thereby pulling cells forward. Accordingly, the number and localization of T4aP are critical to efficient translocation. Here, we address how T4aP formation is regulated inMyxococcus xanthus, which translocates with a well-defined leading and lagging cell pole using T4aP at the leading pole. This localization is orchestrated by the small GTPase MglA and its downstream effector SgmX that both localize at the leading pole and recruit the PilB extension ATPase to the T4aP machinery at this pole. Here, we identify the previously uncharacterized protein SopA and show that it interacts directly with SgmX, localizes at the leading pole, stimulates polar localization of PilB, and is important for T4aP formation. We corroborate that MglA also recruits FrzS to the leading pole, and that FrzS stimulates SgmX recruitment. In addition, FrzS and SgmX separately recruit SopA. Precise quantification of T4aP formation and T4aP-dependent motility in various mutants support a model whereby the main pathway for stimulating T4aP formation is the MglA/SgmX pathway. FrzS stimulates this pathway by recruiting SgmX and SopA. SopA stimulates the MglA/SgmX pathway by stimulating the function of SgmX, likely by promoting the SgmX-dependent recruitment of PilB. The architecture of the MglA/SgmX/FrzS/SopA protein interaction network for orchestrating T4aP formation allows for combinatorial regulation of T4aP levels at the leading cell pole resulting in discrete levels of T4aP-dependent motility.

show abstract

Unorthodox regulation of the MglA Ras‐like GTPase controlling polarity in Myxococcus xanthus

Cited by 9 publications

References 104 publications

Distinct dynamics and proximity networks of hub proteins at the prey-invading cell pole in a predatory bacterium

Distinct dynamics and proximity networks of hub proteins at the prey-invading cell pole in a predatory bacterium

A novel molecular switch controls assembly of bacterial focal adhesions

Combinatorial control of type IVa pili formation by the four polarized regulators MglA, SgmX, FrzS and SopA

Contact Info

Product

Resources

About