Senescent cells, those that persist in the body despite having halted cell division, undergo a process called cryptic transcription, whereby they produce RNA transcripts from short sequences nested within individual genes. It is unclear what, if any, functions these transcripts have, and the mechanism behind their expression has long eluded scientists. Now, Payel Sen, a molecular biologist at the National Institute on Aging within the National Institutes of Health (NIH), and her colleagues have begun to unravel how epigenetic changes regulate cryptic transcription, though questions remain. In a Nature Aging paper from March 30, the team revealed that modified histones—the proteins around which DNA is tightly wound in a chromosome—loosen their grip on DNA, potentially allowing the so-called cryptic sites inside genes to be spuriously transcribed.
Cryptic transcription by senescent cells was first observed in yeast and worms and later confirmed in mammalian cells. While its function, especially in mammalian ...
