Human cells build protein cages to trap invading Shigella

December 4, 2011

In research on the never-ending war between pathogen and host, scientists at the Pasteur Institute in Paris have discovered a novel defensive weapon, a cytoskeletal protein called septin, that humans cells deploy to cage the invading Shigella bacteria that cause potentially fatal human diarrhea, according to a presentation on Dec. 5, at the American Society for Cell Biology Annual Meeting in Denver.

Pascale Cossart, Ph.D., and Serge Mostowy, Ph.D., reported that the septin cages not only targeted the pathogens for degradation by autophagy, the cell's internal garbage disposal system, but also prevented the Shigella bacteria from spreading to other cells by impeding the pathogens' access to actin, a different component of the cell skeleton.

Shigella requires actin to rocket around the before punching into an adjacent cell, said the Pasteur researchers, who made their discovery in grown in culture in the laboratory.

First discovered in yeast as rings that pinch off dividing cells, septins are Guanosine-5'-triphosphate (GTP)-binding proteins that are integral to a cell's dynamic skeleton. Cossart, a Howard Hughes Medical Institute (HHMI) investigator, and Mostowy continue to investigate the properties of the individual septins, which total 14 in humans, to understand how they associate with other proteins as parts of complex nano-machines.

Before their studies revealed septin's new role in innate immunity, Cossart and Mostowy said that the cytoskeletal protein already was implicated in the pathogenesis of many human disorders including leukemia and as well as Parkinson's and Alzheimer's diseases.

Explore further: Study offers first explanation of how cells rapidly repair and maintain structure

Related Stories

How actin networks are actin'

January 2, 2008

Dynamic networks of growing actin filaments are critical for many cellular processes, including cell migration, intracellular transport, and the recovery of proteins from the cell surface. In this week’s issue of the open-access ...

Recommended for you

A world of parasites

May 25, 2018

Alex Betts, Craig MacLean and Kayla King from the Department of Zoology, shed light on their recent research published in Science, which addressed the impact that parasite communities have on evolutionary change and diversity.

Bumblebees confused by iridescent colors

May 25, 2018

Iridescence is a form of structural colour which uses regular repeating nanostructures to reflect light at slightly different angles, causing a colour-change effect.

A better B1 building block

May 25, 2018

Humans aren't the only earth-bound organisms that need to take their vitamins. Thiamine – commonly known as vitamin B1 – is vital to the survival of most every living thing on earth. But the average bacterium or plant ...

Plant symbioses—fragile partnerships

May 25, 2018

All plants require an adequate supply of inorganic nutrients, such as fixed nitrogen (usually in the form of ammonia or nitrate), for growth. A special group of flowering plants thus depends on close symbiotic relationships ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.