Dataset Information

Regulatory mimicry in Listeria monocytogenes actin-based motility.

ABSTRACT: The actin-based motility of the intracellular pathogen Listeria monocytogenes relies on ActA, a bacterial factor with a structural domain allowing it to mimic the actin nucleation-promoting activity of host cell proteins of the WASP/WAVE family. Here, we used an RNAi-based genetic approach in combination with computer-assisted image analysis to investigate the role of host factors in L. monocytogenes cell-to-cell spread. We showed that the host cell serine/threonine kinase CK2 is required for efficient actin tail formation by L. monocytogenes. Furthermore, CK2-mediated phosphorylation of ActA regulated its affinity for the actin-nucleating ARP2/3 complex, as is the case for CK2-mediated phosphorylation of WASP and WAVE. Thus, ActA not only displays structural mimicry of WASP/WAVE family members, but also regulatory mimicry, having precisely co-opted the host machinery regulating these proteins. Comparisons based on ActA amino acid sequence suggest that unrelated pathogens that display actin-based motility may have evolved a similar strategy of regulatory mimicry.

SUBMITTER: Chong R

PROVIDER: S-EPMC2752869 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Regulatory mimicry in Listeria monocytogenes actin-based motility.

Chong Ryan R Swiss Rachel R Briones Gabriel G Stone Kathryn L KL Gulcicek Erol E EE Agaisse Hervé H

Cell host & microbe 20090901 3

The actin-based motility of the intracellular pathogen Listeria monocytogenes relies on ActA, a bacterial factor with a structural domain allowing it to mimic the actin nucleation-promoting activity of host cell proteins of the WASP/WAVE family. Here, we used an RNAi-based genetic approach in combination with computer-assisted image analysis to investigate the role of host factors in L. monocytogenes cell-to-cell spread. We showed that the host cell serine/threonine kinase CK2 is required for ef ...[more]

PMID: 19748468

Similar Datasets

Project description:Listeria monocytogenes is a pathogenic bacterium that moves within infected cells and spreads directly between cells by harnessing the cell's dendritic actin machinery. This motility is dependent on expression of a single bacterial surface protein, ActA, a constitutively active Arp2,3 activator, and has been widely studied as a biochemical and biophysical model system for actin-based motility. Dendritic actin network dynamics are important for cell processes including eukaryotic cell motility, cytokinesis, and endocytosis. Here we experimentally altered the degree of ActA polarity on a population of bacteria and made use of an ActA-RFP fusion to determine the relationship between ActA distribution and speed of bacterial motion. We found a positive linear relationship for both ActA intensity and polarity with speed. We explored the underlying mechanisms of this dependence with two distinctly different quantitative models: a detailed agent-based model in which each actin filament and branched network is explicitly simulated, and a three-state continuum model that describes a simplified relationship between bacterial speed and barbed-end actin populations. In silico bacterial motility required a cooperative restraining mechanism to reconstitute our observed speed-polarity relationship, suggesting that kinetic friction between actin filaments and the bacterial surface, a restraining force previously neglected in motility models, is important in determining the effect of ActA polarity on bacterial motility. The continuum model was less restrictive, requiring only a filament number-dependent restraining mechanism to reproduce our experimental observations. However, seemingly rational assumptions in the continuum model, e.g. an average propulsive force per filament, were invalidated by further analysis with the agent-based model. We found that the average contribution to motility from side-interacting filaments was actually a function of the ActA distribution. This ActA-dependence would be difficult to intuit but emerges naturally from the nanoscale interactions in the agent-based representation.

Dataset Information

Regulatory mimicry in Listeria monocytogenes actin-based motility.

Publications

Regulatory mimicry in Listeria monocytogenes actin-based motility.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets