Cell complexity: liquid phase separation (Introduction)

by David Turell , Friday, November 30, 2018, 00:19 (1968 days ago) @ David Turell

More on this new study:

https://phys.org/news/2018-11-tools-illuminate-mechanisms-overlooked-cellular.html

"Creating new tools that harness light to probe the mysteries of cellular behavior, Princeton researchers have made discoveries about the formation of cellular components called membraneless organelles and the key role these organelles play in cells.

"The tools developed by the researchers allow scientists to accurately probe intracellular phase separation—the process by which the chaotic liquid matter inside cells transforms into functioning cellular compartments called membraneless organelles.

"Long overlooked, these organelles have been shown to play critical roles in human health. The loss of their fluid-like consistency, for instance, is implicated in diseases including cancer, Alzheimer's, and amyotrophic lateral sclerosis (ALS). Previous work in Brangwynne's lab has shown the membraneless organelles play an important role in cell growth. And one of the two recent Cell papers demonstrates they also influence the genes controlling cellular behavior.

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"...the researchers examine how the formation of membraneless organelles affects the cell's nucleus. Using a second tool, named CasDrop, the researchers looked at chromatin, the mixture of DNA, RNA and protein inside the nucleus. They found that as membraneless organelles form within the nucleus, they deform the chromatin in unexpected ways. They showed that the droplets push out unwanted genes, but can simultaneous pull together specifically targeted genes. The droplets can thus function like little, mechanically-active machines to restructure the genome. (my bold)

"The CasDrop system builds on the revolutionary gene-editing technology called CRISPR, which utilizes a protein machine called Cas9, to address particular genes in the cell. Brangwynne and colleagues engineered Cas9 to function as a platform, which upon light activation causes other proteins to bind to the gene, and locally phase separate, forming little dew droplets on the field of chromatin."

Comment: Another layer of gene control involving a fascinating physical change in cells, liquid-liquid phase separation creating membraneless organelles! Amazing design requires a designing mind.