DNA repair protein shifts in aging neurons

Most cells handle DNA damage by dividing and replacing damaged copies. Neurons cannot do that. They are largely non-dividing and must maintain their genetic material over an entire lifetime. That puts enormous pressure on their internal repair systems.

Researchers focused on a protein called POLK, which plays a role in a process known as translesion synthesis. This allows cells to copy past damaged sections of DNA without getting stuck. The study found that in aging mice, POLK shifts its location within neurons. In younger animals, the protein is concentrated inside the cell nucleus, where DNA is stored. In older animals, it spreads outside the nucleus.

Why location matters

If POLK is not where it needs to be, it cannot do its job. Damage accumulates. That accumulation is associated with neurodegenerative conditions such as Parkinson’s and Alzheimer’s disease.

This is not yet proof that the POLK shift causes disease directly. The research was conducted in mice, and translation to humans requires further work. But it provides a concrete target. Understanding why POLK loses its nuclear position with age could open a path to intervening before damage builds up.

An overlooked corner of aging biology

DNA repair in neurons is less studied than in dividing cells. Neurons are difficult to work with outside the body, and they behave differently from typical cell lines used in lab research.

Still, the question at the center of this work is fundamental. How do long-lived cells keep their genetic material stable over time? The answer shapes how quickly the brain declines. POLK is now a new variable in that equation, and its age-related shift appears to begin precisely when neurons also start to show functional decline.

The findings add to a growing picture of how neurons age differently from other cells, and why targeting their specific biology may matter as much as any systemic intervention.

Read the original article