» Articles » PMID: 29660331

Biophysical Characterization of Actin Bundles Generated by the Chlamydia Trachomatis Tarp Effector

Overview
Publisher Elsevier
Specialty Biochemistry
Date 2018 Apr 17
PMID 29660331
Citations 8
Authors
Affiliations
Soon will be listed here.
Abstract

Chlamydia trachomatis entry into host cells is mediated by pathogen-directed remodeling of the actin cytoskeleton. The chlamydial type III secreted effector, translocated actin recruiting phosphoprotein (Tarp), has been implicated in the recruitment of actin to the site of internalization. Tarp harbors G-actin binding and proline rich domains required for Tarp-mediated actin nucleation as well as unique F-actin binding domains implicated in the formation of actin bundles. Little is known about the mechanical properties of actin bundles generated by Tarp or the mechanism by which Tarp mediates actin bundle formation. In order to characterize the actin bundles and elucidate the role of different Tarp domains in the bundling process, purified Tarp effectors and Tarp truncation mutants were analyzed using Total Internal Reflection Fluorescence (TIRF) microscopy. Our data indicate that Tarp mediated actin bundling is independent of actin nucleation and the F-actin binding domains are sufficient to bundle actin filaments. Additionally, Tarp-mediated actin bundles demonstrate distinct bending stiffness compared to those crosslinked by the well characterized actin bundling proteins fascin and alpha-actinin, suggesting Tarp may employ a novel actin bundling strategy. The capacity of the Tarp effector to generate novel actin bundles likely contributes to chlamydia's efficient mechanism of entry into human cells.

Citing Articles

An Overview of Selected Bacterial Infections in Cancer, Their Virulence Factors, and Some Aspects of Infection Management.

Ray A, Moore T, Pandit R, Burke A, Borsch D Biology (Basel). 2023; 12(7).

PMID: 37508393 PMC: 10376897. DOI: 10.3390/biology12070963.


The Early Effector Tarp Outcompetes Fascin in Forming F-Actin Bundles .

Aranjuez G, Kim J, Jewett T Front Cell Infect Microbiol. 2022; 12:811407.

PMID: 35300377 PMC: 8921475. DOI: 10.3389/fcimb.2022.811407.


Regulation of Actin Bundle Mechanics and Structure by Intracellular Environmental Factors.

Castaneda N, Park J, Kang E Front Phys. 2021; 9.

PMID: 34422787 PMC: 8376200. DOI: 10.3389/fphy.2021.675885.


Got mutants? How advances in chlamydial genetics have furthered the study of effector proteins.

Andersen S, Bulman L, Steiert B, Faris R, Weber M Pathog Dis. 2021; 79(2).

PMID: 33512479 PMC: 7862739. DOI: 10.1093/femspd/ftaa078.


Chlamydia trachomatis TmeA Directly Activates N-WASP To Promote Actin Polymerization and Functions Synergistically with TarP during Invasion.

Keb G, Ferrell J, Scanlon K, Jewett T, Fields K mBio. 2021; 12(1).

PMID: 33468693 PMC: 7845632. DOI: 10.1128/mBio.02861-20.


References
1.
Oztug Durer Z, McGillivary R, Kang H, Elam W, Vizcarra C, Hanein D . Metavinculin Tunes the Flexibility and the Architecture of Vinculin-Induced Bundles of Actin Filaments. J Mol Biol. 2015; 427(17):2782-98. PMC: 4540644. DOI: 10.1016/j.jmb.2015.07.005. View

2.
Srivastava J, Barber D . Actin co-sedimentation assay; for the analysis of protein binding to F-actin. J Vis Exp. 2008; (13). PMC: 2586866. DOI: 10.3791/690. View

3.
Jewett T, Fischer E, Mead D, Hackstadt T . Chlamydial TARP is a bacterial nucleator of actin. Proc Natl Acad Sci U S A. 2006; 103(42):15599-604. PMC: 1622868. DOI: 10.1073/pnas.0603044103. View

4.
Kliewe F, Scharf C, Rogge H, Darm K, Lindenmeyer M, Amann K . Studying the role of fascin-1 in mechanically stressed podocytes. Sci Rep. 2017; 7(1):9916. PMC: 5577297. DOI: 10.1038/s41598-017-10116-4. View

5.
Shin J, Mahadevan L, So P, Matsudaira P . Bending stiffness of a crystalline actin bundle. J Mol Biol. 2004; 337(2):255-61. DOI: 10.1016/j.jmb.2004.01.028. View