Particle physics experiments

High resolution lab experiments show how cells ‘eat’

A new study shows how cell membranes curve to create the “mouths” that allow cells to consume the things around them.

“Just as our eating habits fundamentally shape everything in our body, the way cells ‘eat’ is important to cell health,” said Comert kural, associate professor of physics at Ohio State University and lead author of the study. “And scientists didn’t understand, until now, the mechanics of how this happened.”

The study, published recently in the journal Development cell, found that the intercellular machinery of a cell assembles into a highly curved basket-like structure that eventually transforms into a closed cage. Scientists previously believed that the structure started out as a flat lattice.

The curvature of the membrane is important, Kural said: it controls the formation of pockets that carry substances in and out of a cell.

The pouches capture substances around the cell, forming around extracellular substances, before turning into vesicles – small bags a millionth the size of a red blood cell. Vesicles carry things important to a cell’s health – proteins, for example – into the cell. But they can also be diverted by pathogens that can infect cells.

But the question of how these pockets formed from membranes that were once thought to be flat had stuck researchers for nearly 40 years.

“It was a controversy in cell studies,” Kural said. “And we were able to use super-resolution fluorescence imaging to observe the formation of these pockets in living cells, so we were able to answer the question of how they are created.

“Simply put, unlike previous studies, we made high-resolution movies of cells instead of taking snapshots,” Kural said. “Our experiments revealed that protein scaffolds begin to deform the underlying membrane as soon as they are recruited to the sites of vesicle formation.”

This contrasts with previous assumptions that a cell’s protein scaffolds had to undergo energy-intensive reorganization in order for the membrane to curve, Kural said.

The way cells consume and expel vesicles plays a key role for living organisms. The process helps to remove bad cholesterol from the blood; it also transmits neural signals. The process is known to worsen in several diseases, including cancer and Alzheimer’s disease.

“It is important to understand the origin and dynamics of membrane-bound vesicles – they can be used to deliver drugs for medicinal purposes but, at the same time, diverted by pathogens such as viruses to enter and infect. cells, ”Kural said. “Our results are important, not only for our understanding of the fundamentals of life, but also for the development of better treatment strategies.”

Emanuele Cocucci, assistant professor at the Ohio State College of Pharmacy, co-authored this study, along with researchers from UC Berkeley, UC Riverside, Iowa State University, Purdue University and from the Chinese Academy of Sciences.

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