Mushrooms and humans have ‘hole-punch’ weapons

Researchers visualized the hole-punching protein as it latched onto and put a hole in the target cell. (Credit: liz west/Flickr)

An edible mushroom defends itself against pest roundworms and can eat them too. One trick it uses is a hole-punching protein—just like one used by human immune systems.

Published in PLOS Biology, a new study is the first to visualize the action of one of the pore-forming proteins (pleurotolysin) found in the edible oyster mushroom.

oyster mushroom
(Credit: USFWSmidwest/Flickr)

Humans, animals, plants, fungi, and bacteria all use pore-forming proteins as lethal, cell-killing weapons, says lead researcher Michelle Dunstone from Monash University. But she never believed they would be able to see these proteins in action.

“This is an amazing mechanism, and also amazing that we now have the technology to see these hole-punching proteins at work,” she adds.

“Now we’ve uncovered this process, we can look at how to block the hole-punching mechanism.”

Specialized instruments—including synchrotron light and cryo-electron microscopy—allowed the team to take molecular snapshots and observe the hole-punching protein as it latches onto and puts a hole in the target cell.

Along with biophysical and computational experiments, Dunstone and colleagues were able to show the way the pleurotolysin protein moves, unfolding and refolding to punch the hole in the target cell.

Dunstone says that by uncovering this fundamental process, they’ve also found its Achilles heel.

“The next step is to take what we’ve learnt from the oyster mushroom proteins and compare them with equivalent proteins across nature,” she says.

“We’re particularly interested in this family of proteins in humans, especially perforin, which we believe will behave in the same way.”

Researchers from Birkbeck College, London, collaborated on the project.

Source: Monash University