SoylentNews is people
SoylentNews
Submission Preview
Dewdrops on a Spiderweb Reveal the Physics Behind Cell Structures
████ # This file was generated bot-o-matically! Edit at your own risk. ████
Dewdrops on a spiderweb reveal the physics behind cell structures [phys.org]:
January 29, 2021
Dewdrops on a spiderweb reveal the physics behind cell structures
As any cook knows, some liquids mix well with each other, but others do not. For example, when a tablespoon of vinegar is poured into water, a brief stir suffices to thoroughly combine the two liquids. However, a tablespoon of oil poured into water will coalesce into droplets that no amount of stirring can dissolve. The physics that governs the mixing of liquids is not limited to mixing bowls; it also affects the behavior of things inside cells. It's been known for several years that some proteins behave like liquids, and that some liquid-like proteins don't mix together. However, very little is known about how these liquid-like proteins behave on cellular surfaces.
"The separation between two liquids that won't mix, like oil and water, is known as 'liquid-liquid phase separation', and it's central to the function of many proteins," said Sagar Setru, a 2021 Ph.D. graduate who worked with both Sabine Petry, a professor of molecular biology, and Joshua Shaevitz, a professor of physics and the Lewis-Sigler Institute for Integrative Genomics.
Such proteins do not dissolve inside the cell. Instead, they condense with themselves or with a limited number of other proteins, allowing cells to compartmentalize certain biochemical activities without having to wrap them inside membrane-bound spaces.
"In molecular biology, the study of proteins that form condensed phases with liquid-like properties is a rapidly growing field," said Bernardo Gouveia, a graduate student chemical and biological engineering, working with Howard Stone, the Donald R. Dixon '69 and Elizabeth W. Dixon Professor of Mechanical and Aerospace Engineering, and chair of the department. Setru and Gouveia collaborated as co-first authors on an effort to better understand one such protein.
"We were curious about the behavior of the liquid-like protein TPX2. What makes this protein special is that it does not form liquid droplets in the cytoplasm as had been observed before, but instead seems to undergo phase separation on biological polymers called microtubules," said Setru. "TPX2 is necessary for making branched networks of microtubules, which is crucial for cell division. TPX2 is also overexpressed in some cancers, so understanding its behavior may have medical relevance."
Relevant PhysicsForums posts Rubber soled slippers generating static electricity [physicsforums.com]
13 hours ago
Permanent magnetic memory [physicsforums.com]
Jan 29, 2021
Have anybody considered travel with faster-than-infinite speeds? [physicsforums.com]
Jan 28, 2021
Is it possible to calculate an incandescent bulb's temperature from V? [physicsforums.com]
Jan 28, 2021
High Energy Maxwell-Boltzmann distribution? [physicsforums.com]
Jan 27, 2021
Why do we take k=1 in the derivation of F=k*ma? [physicsforums.com]
Jan 25, 2021
More from Other Physics Topics [physicsforums.com]
Journal Reference:
Sagar U. Setru, Bernardo Gouveia, Raymundo Alfaro-Aco, et al. A hydrodynamic instability drives protein droplet formation on microtubules to nucleate branches, Nature Physics (DOI: 10.1038/s41567-020-01141-8 [doi.org])
