The Effects Of Phosphorylation On The Structure And Function Of Motif A, An Intrinsically Disordered Region Within Sirt1

Aging Pathway
Analytical
Phosphorylation at a specific site within an intrinsically disordered region of the SIRT1 protein causes it to fold into an ordered structure, which significantly increases SIRT1 activity.
Author

Gemini

Published

April 28, 2026

Our bodies contain remarkable proteins that act as cellular defenders, protecting us from issues like aging and disease. One such protein, called sirtuin-1 (SIRT1), plays a crucial role in these defenses by modifying other proteins, essentially turning them on or off.

Scientists have been particularly interested in a segment of SIRT1, known as Motif A, which is usually quite flexible and lacks a fixed three-dimensional shape. Think of it like a loose string that can take on many forms. Despite its flexible nature, this “intrinsically disordered region” is known to be important for activating SIRT1.

A recent study sheds light on how this activation happens. It turns out that a process called phosphorylation—where a small chemical group, a phosphate, is added to the protein—is key. When a phosphate group is added to a specific spot on Motif A (at a location called Ser27), it causes this flexible string to snap into a more organized, folded structure.

This change in shape is a big deal because it significantly boosts SIRT1’s ability to perform its protective functions. Understanding how these subtle chemical modifications lead to dramatic structural changes and increased activity provides valuable insights into how our cells regulate vital processes. This knowledge could pave the way for new strategies to combat age-related conditions and various diseases.


Source: link to paper