High-resolution lab experiments show how cells `eat'
Study solves a 40-year-old problem in cell biology
Date:
December 30, 2021
Source:
Ohio State University
Summary:
A new study shows how cell membranes curve to create the 'mouths'
that allow the cells to consume things that surround them.
FULL STORY ==========================================================================
A new study shows how cell membranes curve to create the "mouths" that
allow the cells to consume things that surround them.
========================================================================== "Just like our eating habits basically shape anything in our body, the
way cells 'eat' matters for the health of the cells," said Comert Kural, associate professor of physics at The Ohio State University and lead
author of the study.
"And scientists did not, until now, understand the mechanics of how that happened." 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.
But the question of how those pockets formed from membranes that were previously believed to be flat had stymied researchers for nearly
40 years.
"It was a controversy in cellular studies," Kural said. "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.
"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.
"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," Kural said. "Our results matter, not only for our understanding of the fundamentals of life, but also for developing better therapeutic strategies." Emanuele Cocucci, an assistant professor in
Ohio State's College of Pharmacy, co-authored this study, along with researchers from UC Berkeley, UC Riverside, Iowa State University,
Purdue University and the Chinese Academy of Sciences.
========================================================================== Story Source: Materials provided by Ohio_State_University. Original
written by Laura Arenschield. Note: Content may be edited for style
and length.
========================================================================== Journal Reference:
1. Nathan M. Willy, Joshua P. Ferguson, Ata Akatay, Scott Huber,
Umidahan
Djakbarova, Salih Silahli, Cemal Cakez, Farah Hasan, Henry C. Chang,
Alex Travesset, Siyu Li, Roya Zandi, Dong Li, Eric Betzig, Emanuele
Cocucci, Comert Kural. De novo endocytic clathrin coats develop
curvature at early stages of their formation. Developmental Cell,
2021; 56 (22): 3146 DOI: 10.1016/j.devcel.2021.10.019 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2021/12/211230130936.htm
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