Immune complexity: gene expression dance (Introduction)

by David Turell , Thursday, May 27, 2021, 21:38 (1275 days ago) @ David Turell

Very fancy system allows researchers to watch:

https://phys.org/news/2021-05-key-early-gene-captured-real.html

"On scales too small for our eyes to see, the business of life happens through the making of proteins, which impart to our cells both structure and function. Cellular proteins get their marching orders from genetic instructions encoded in DNA, whose sequences are first copied and made into RNA in a multi-step process called transcription.

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"Now, scientists led by postdoctoral researcher Linda Forero-Quintero have, for the first time, observed early RNA transcription dynamics by recording where, when and how RNA polymerase enzymes kick off transcription by binding to a DNA sequence.

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"'This is the first time someone has looked at RNA polymerase phosphorylation dynamics in a single-copy gene," said Forero,

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"...they observed the start of the transcription cycle that happens when the RNA polymerase II (RNAP2) transcription enzyme becomes phosphorylated, or decorated with phosphate groups, on its amino acid tail.

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"The images obtained with this system translate into fluorescent intensity fluctuation. The researchers then used those signals to interpret the spatiotemporal organization of RNAP2 phosphorylation throughout the transcription cycle at a single-copy gene.

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"By fitting this statistical model to reproduce all the experimental results, the computational team then extended their analyses to glean new mechanistic and quantitative information about the different molecules and their states through the transcription process.

"For example, they estimated how many individual RNA polymerase molecules collect to form transient clusters in the region of the DNA's promoter, how long these clusters persist, and how, when and where the polymerases distribute themselves along the DNA. They found, for example, that each burst of transcription activity produces a cluster of between five and 40 RNA polymerases to form around the promoter region of the gene, of which 46% eventually succeed to transcribe RNA. They also found that each RNA takes approximately five minutes to be fully transcribed and processed prior to release."

Comment: We are sneaking into a means of viewing the most intricate aspects of genome function. Not by chance.