By Jon Atherton
Our cells continuously exchange material, constantly forming and deforming their tough membrane walls to consume what they need for tissue development and other important biological functions.
Scientists have previously thought that protein assembly occurred at the same speed as membrane deformation – a process called “endocytosis” – but the dynamic physical behavior of related molecules has remained unknown.
“Consider a popular restaurant that is always packed out,” says Mike Lacy, PhD ‘18, and first author of a new study in eLIFE. “It might be a fine dining destination where all the guests arrive together and all leave at closing time. Or, it might be a fast food place where customers are constantly coming and going through the line during opening hours.”
Led by Julien Berro, associate professor of Molecular Biophysics & Biochemistry, and of Cell Biology, at the Yale Nanobiology Institute, the scientists tagged individual molecules within living yeast cells and followed them under the microscope to understand their molecular behavior at the crowded site of endocytosis.
Surprisingly, they found individual molecules exchanging very quickly, staying an average of 1.5 seconds, a small fraction of the time the protein groups were generally present at the site.
The results inspire a rethink of how proteins interact with each other during endocytosis, the number of proteins involved, their energy demands, and how physical forces are produced in order to deform cell membranes.
Now of the University of Auckland, the research was a collaboration with former Yale West Campus faculty member David Baddeley.