Role of septins in microbial infection

Hoan Van Ngo,Serge Mostowy

doi:10.1242/jcs.226266

Hoan Van Ngo, Serge Mostowy

Open Access

https://doi.org/10.1242/jcs.226266

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Abstract

Septins are widely recognized as a component of the cytoskeleton that is essential for cell division, and new work has shown that septins can recognise cell shape by assembling into filaments on membrane regions that display micrometer-scale curvature (e.g. at the cytokinetic furrow). Moreover, infection biology studies have illuminated important roles for septins in mediating the outcome of host-microbe interactions. In this Review, we discuss a selection of mechanistic insights recently gained from studying three infection paradigms: the rice blast fungus Magnaporthe oryzae, the poxvirus family member vaccinia virus and the Gram-negative bacterium Shigella flexneri These studies have respectively discovered that higher-order septin assemblies enable fungal invasion into plant cells, entrap viral particles at the plasma membrane and recognize dividing bacterial cells for delivery to lysosomes. Collectively, these insights illustrate how studying septin biology during microbial infection can provide fundamental advances in both cell and infection biology, and suggest new concepts underlying infection control.

Highlights

The study of how microbial pathogens cause disease has inspired a wide variety of research avenues in both cell and infection biology
In the case of M. oryzae, this fungal pathogen forms a large septin ring at the appressorium pore to promote the development of a penetration peg needed for its plant cell invasion
Work with vaccinia virus and S. flexneri have revealed a crucial role for host cell septins in entrapping pathogens to prevent their dissemination

Summary

Introduction

The study of how microbial pathogens cause disease has inspired a wide variety of research avenues in both cell and infection biology. Investigations using cellular and animal models have shown that septins can sense pathogenic microbes and promote host defence mechanisms to eliminate them (Mostowy and Shenoy, 2015; Torraca and Mostowy, 2016) In this Review, we highlight examples of infection by a pathogenic fungus, virus and bacterium to illustrate the breadth of discoveries made from studying septin biology during host–microbe interactions. SEPT7 group (AH) is necessary and sufficient for septin curvature sensing both in vitro and in vivo (Cannon et al, 2019), and that septin filaments can C reorganize in response to changes in membrane curvature (Beber et al, 2019) Considering their important roles in health and disease C (Hall and Russell, 2004; Mostowy and Cossart, 2012; Peterson C and Petty, 2010), how septins assemble and how they work in conjunction with actin, microtubules and phospholipids, are the C focus of intense investigation

G NC NC G G NC NC G

C Extracellular space

Conclusions and future perspectives