Decades-long dilemma solved with a new study of cell membranes

A recent study published in Developmental Cell has shown how cell membranes curve to consume material in their environment.

Cells can use their membrane to envelope material in their extracellular environment, then bring it into the cell, in a process known as endocytosis. After encircling a given substance, the membrane buds off into a vesicle, a tiny sac that carries substances around and in and out of the cell.

The cell membrane first needs to form a highly curved basket-like structure before closing around its target. Scientists previously believed the structure began as a flat lattice, but the mechanics of the membrane forming a pocket to move the substances it encounters has eluded scientists for almost forty years.

"It was a controversy in cellular studies, and we were able to use super-resolution fluorescence imaging to actually watch these pockets form within live cells, and so we could answer that question of how they are created," said Comert Kural, associate professor of physics at The Ohio State University and lead author of the study.

"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," continued Kural.

The newly understood mechanics contrast with previous hypotheses, which suggested that the protein scaffolds had to reorganize to accommodate membrane curvature in a much more energy-intensive process.

You can read more from the study here.