Chlamydial virulence factor TarP mimics talin to disrupt the talin‐vinculin complex

Whitewood, Austin J.; Singh, Abhimanyu; Brown, David G.; Goult, Benjamin T.

doi:10.1002/1873-3468.13074

Cited by 12 publications

(14 citation statements)

References 49 publications

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“…it binds to multiple proteins that act downstream of adhesion, including RIAM and DLC1 30,31,57 . Using a fluorescence polarization assay described previously 58 , we measured the binding affinities of R8 ligands RIAM TBS1 and DLC1 peptides with R7R8wt and R7R8vvv ( Supplementary Fig. 10).…”

Section: Vinculin Can Bind To Talin Without Force Through a 'Threoninmentioning

confidence: 99%

Talin-vinculin precomplex drives adhesion maturation by accelerated force transmission and vinculin recruitment

Han

Azarova

Whitewood

et al. 2019

Preprint

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Talin, vinculin, and paxillin are mechanosensitive proteins that are recruited early to nascent integrin-based adhesions (NAs). Using machine learning, high-resolution traction force microscopy, single-particle-tracking and fluorescence fluctuation time-series analysis, we find that, only in the NAs that eventually mature to focal adhesions, all three molecules are recruited concurrently and in synchrony with force onset. Thereafter, vinculin assembles at ~5 fold higher rates than in non-maturing NAs. We identify a domain in talin, R8, which exposes a vinculinbinding-site (VBS) without requiring tension. Stabilizing this domain via mutation lowers tensionfree vinculin binding in conjunction with talin, impairs maturation of NAs, and reduces the rate of additional vinculin recruitment after force onset. Taken together, our data show that talin forms a complex with vinculin, before association with integrins, which is essential for NA maturation by talin's effective unfolding and exposure of additional VBSs that induce fast force growth and further vinculin binding. Cell-matrix adhesions are multi-molecular complexes that link the extracellular matrix (ECM), typically via integrin transmembrane receptors, to the actin cytoskeleton. Being both a forcetransmitter and a force-sensor, cell-matrix adhesions are critical to cell morphogenesis and mechanosensation (Discher et al., 2005;Parsons et al., 2010). Indeed, in response to ECM changes, adhesions undergo constant changes in morphology and motion that involve recruitment and recycling of a large number of adhesion molecules. For example, nascent adhesions (NAs) emerge within the actin-dense cell lamellipodia and then slide in the direction opposite to the protrusion as a result of polymerization-driven flow of the actin network (Parsons et al., 2010). Many of these NAs, which are less than 0.5 µm long, and thus in a light microscope only resolved as diffraction-limited spots, turn over early; but some of them mature into longer focal complexes (FCs, >0.5 µm in length) and focal adhesions (FAs, >2 µm in length) at the lamellipodia-lamella interface (Gardel et al., 2010;Parsons et al., 2010). During this progression, NAs go through multiple decision processes regarding fate and morphology. Compared to the well-studied FAs, for which the interconnection between structure, signaling, and force transmission is largely understood (Balaban et al.

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Section: Vinculin Can Bind To Talin Without Force Through a 'Threoninmentioning

confidence: 99%

Talin-vinculin precomplex drives adhesion maturation by accelerated force transmission and vinculin recruitment

Han

Azarova

Whitewood

et al. 2019

Preprint

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“…Some TarP orthologs have been shown to contain VBSs, which mediate the recruitment of vinculin through direct protein-protein interactions [13, 20, 22]. However, no VBS had been identified for CPn0572 thus far.…”

Section: Resultsmentioning

confidence: 99%

CPn0572, the C. pneumoniae ortholog of TarP, reorganizes the actin cytoskeleton via a newly identified F-actin binding domain and recruitment of vinculin

et al. 2019

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Chlamydia pneumoniae is one of the two major species of the Chlamydiaceae family that have a profound effect on human health. C. pneumoniae is linked to a number of severe acute and chronic diseases of the upper and lower respiratory tract including pneumonia, asthma, bronchitis and infection by the pathogen might play a role in lung cancer. Following adhesion, Chlamydiae secrete effector proteins into the host cytoplasm that modulate the actin cytoskeleton facilitating internalization and infection. Members of the conserved TarP protein family comprise such effector proteins that polymerize actin, and in the case of the C. trachomatis TarP protein, has been shown to play a critical role in pathogenesis. In a previous study, we demonstrated that, upon bacterial invasion, the C. pneumoniae TarP family member CPn0572 is secreted into the host cytoplasm and recruits and associates with actin via an actin-binding domain conserved in TarP proteins. We have now extended our analysis of CPn0572 and found that the CPn0572 actin binding and modulating capability is more complex. With the help of the fission yeast system, a second actin modulating domain was identified independent of the actin binding domain. Microscopic analysis of HEp-2 cells expressing different CPn0572 deletion variants mapped this domain to the C-terminal part of the protein as CPn0572536-755 binds F-actin in vitro and colocalizes with aberrantly thickened actin cables in vivo. Finally, microscopic and bioinformatic analysis revealed the existence of a vinculin binding sequence in CPn0572. Our findings contribute to the understanding of the function of the TarP family and underscore the existence of several actin binding domains and a vinculin binding site for host actin modulation.

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“…Vinculin is a major talin-binding partner that facilitates crosstalk between talin and actin through its talin-binding head domain (V-head) and its actin-binding tail domain (V-tail) [44,45]. Vinculin is also a central component of mechanosensitive adhesive complexes that forms between cells and the ECM [8]. The force-dependent interaction between talin and vinculin plays a crucial role in the initiation and growth of focal adhesions [6,7].…”

Section: Discussionmentioning

confidence: 99%

“…Talin is a ubiquitous cytosolic protein, predominantly detected at regions of cell-substratum or cell-cell adhesions [2][3][4]. Talin functions as an adapter for integrin in forming mechanosensitive intercellular or cellextracellular matrix (ECM) tensions, generating cell-cell junctions or focal adhesions between cell and ECM, respectively [6][7][8]. Via the dynamic correlation with its binding partner, vinculin, talin has been documented to participate in establishing bacterial infections via its role as the adapter to mediate the cytoskeleton-driven dynamics of the plasma membrane [5,[9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…However, colocalization under epifluorescent/confocal fluorescent microscope does not necessarily mean a physical interaction [7]. A practical step toward unraveling the complex molecular relationship, temporal and spatial, of protein-toprotein physical interaction is essential for accomplishing a comprehensive knowledge of the functional outcomes of a PPI [8]. The concept of spatial proximity between two protein targets is merging to be a practical approach for endogenous quantitative detection of spatial proximal complex of proteins at the single molecule level in fixed cells and tissue samples.…”

Section: Introductionmentioning

confidence: 99%

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Increased talin–vinculin spatial proximities in livers in response to spotted fever group rickettsial and Ebola virus infections

Liu

Xiao

Zhang

et al. 2020

Laboratory Investigation

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Talin and vinculin, both actin-cytoskeleton-related proteins, have been documented to participate in establishing bacterial infections, respectively, as the adapter protein to mediate cytoskeleton-driven dynamics of the plasma membrane. However, little is known regarding the potential role of the talin-vinculin complex during spotted fever group rickettsial and Ebola virus infections, two dreadful infectious diseases in humans. Many functional properties of proteins are determined by their participation in protein-protein complexes, in a temporal and/or spatial manner. To resolve the limitation of application in using mouse primary antibodies on archival, multiple formalin-fixed mouse tissue samples, which were collected from experiments requiring high biocontainment, we developed a practical strategic proximity ligation assay (PLA) capable of employing one primary antibody raised in mouse to probe talin-vinculin spatial proximal complex in mouse tissue. We observed an increase of talin-vinculin spatial proximities in the livers of spotted fever Rickettsia australis or Ebola virusinfected mice when compared with mock mice. Furthermore, using EPAC1-knockout mice, we found that deletion of EPAC1 could suppress the formation of spatial proximal complex of talin-vinculin in rickettsial infections. In addition, we observed increased colocalization between spatial proximity of talin-vinculin and filamentous actin-specific phalloidin staining in single survival mouse from an ordinarily lethal dose of rickettsial or Ebola virus infection. These findings may help to delineate a fresh insight into the mechanisms underlying liver specific pathogenesis during infection with spotted fever rickettsia or Ebola virus in the mouse model.

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Chlamydial virulence factor TarP mimics talin to disrupt the talin‐vinculin complex

Cited by 12 publications

References 49 publications

Talin-vinculin precomplex drives adhesion maturation by accelerated force transmission and vinculin recruitment

Talin-vinculin precomplex drives adhesion maturation by accelerated force transmission and vinculin recruitment

CPn0572, the C. pneumoniae ortholog of TarP, reorganizes the actin cytoskeleton via a newly identified F-actin binding domain and recruitment of vinculin

Increased talin–vinculin spatial proximities in livers in response to spotted fever group rickettsial and Ebola virus infections

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