Quantifying Turnover Dynamics of Selenoproteome by Isotopic Perturbation.

Selenium stays in body tissues until it is used to build selenoproteins, and these proteins break down slowly over time.

In human cells grown in the lab, nine selenoproteins have half-lives between 6 and 32 hours, with GPX4 degrading the fastest at about 6 hours, showing that their stability differs in a consistent pattern across the proteome without being driven by changes in gene expression.

Glutathione peroxidase 4 breaks down faster in cells than other selenium-containing proteins, suggesting it is controlled differently or serves a unique role in how cells manage selenium.

The SETRIP method uses a selenium isotope and chemical labeling to measure how quickly selenoproteins break down in cells, allowing precise tracking of selenium metabolism across the entire proteome.

Scientists can measure how quickly selenoproteins are made and broken down in cells using chemical labeling and advanced protein analysis, allowing precise tracking of selenium movement without radioactive materials.

Different selenoproteins break down at different speeds, between 6 and 32 hours, which shows that controlling how long these proteins last after they are made is a new way selenium regulates biological functions, alongside controlling gene activity and enzyme function.