Biological complexity: how cells eat and poop (Introduction)

by David Turell , Sunday, January 02, 2022, 16:31 (1056 days ago) @ David Turell

Vesicle formation in cell walls is filmed:

https://phys.org/news/2021-12-high-resolution-lab-cells.html

"The study, published last month in the journal Developmental Cell, found that the intercellular machinery of a cell assembles into a highly curved basket-like structure that eventually grows into a closed cage. Scientists had previously believed that structure began as a flat lattice.

"Membrane curvature is important, Kural said: It controls the formation of the pockets that carry substances into and out of a cell.

"The pockets capture substances around the cell, forming around the extracellular substances, before turning into vesicles—small sacs one-one millionth the size of a red blood cell. Vesicles carry important things for a cell's health—proteins, for example—into the cell. But they can also be hijacked by pathogens that can infect cells.

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"'Simply put, in contrast to the previous studies, we made high-resolution movies of cells instead of taking snapshots," Kural said. "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 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 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."

Comment: Seeing it in action shows it at work, but the underlying biochemistry of dancing molecules still is not known. This process is seen in bacteria so the process is ancient.