A 40-year-old problem in cell biology solved: How do cells eat?

Our eating habits shape anything in our bodies. Similarly, the way cells eat has a significant impact on the cells’ health. Yet, scientists don’t know how cells eat.

A new study by the Ohio State University demonstrates how cells eat substances around them. The study shows how cell membranes curve to create the “mouths” that allow the cells to consume things surrounding them.

Scientists found that the intercellular machinery assembles into a highly curved basket-like structure that eventually grows into a closed cage.

Comert Kural, associate professor of physics at The Ohio State University and lead author of the study, said, “Membrane curvature is important. It controls the formation of the pockets that carry substances into and out of a cell.”

These pockets pull in the substances around the cell, leading to formation around the extracellular substances before turning into vesicles – small sacs one-one millionth the size of a red blood cell. The vesicles contain things essential for a cell’s health. But they can also be hijacked by pathogens that can infect cells.

However, it remains elusive whether how these pockets formed from membranes that were previously believed to be flat.

Kural said, “It was a controversy in cellular studies. And we were able to use super-resolution fluorescence imaging to watch these pockets form within live cells, and so we could answer that question of how they are created.”

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

“That contrasts with previous hypotheses that the protein scaffolds of a cell had to go through an energy-intensive reorganization for the membrane to curve.”

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

“Understanding the origin and dynamics of membrane-bound vesicles is important – they can be utilized for delivering drugs for medicinal purposes but, at the same time, hijacked by pathogens such as viruses to enter and infect cells. Our results matter, not only for our understanding of the fundamentals of life but also for developing better therapeutic strategies.”

Journal Reference:

1. Nathan M. Willy et al. De novo endocytic clathrin coats develop curvature at the early stages of their formation. DOI: 10.1016/j.devcel.2021.10.019