SCIENCE

C-terminal Amides: The Proteins Secret Weapon Against Cellular Damage

Sat Feb 01 2025
Cells are busy places. They need to keep their proteins in order which means fixing or removing the damaged ones and ensuring the healthy ones continue to do what they need to for the cell to live. This is done by a process known as protein homeostasis. When something goes wrong, proteins collect damage. This damage is caused by things like reactive molecules and cell stress. These damaged proteins are marked for removal by specific cellular systems. One kind of such markings are C-terminal amides. These amides are the reason why certain proteins are destroyed by the cell's quality control systems. So, what happens when a protein gets chemically damaged? A process called ubiquitylation takes place. CRISPR technology helped identify a key player in this game: FBXO31. It turns out, FBXO31 is a type of protein that recognizes C-terminal amide proteins and helps to degrade them. FBXO31 uses our body's special machinery called SCF-FBXO31 to do this. Its special binding pocket helps it find and grab onto C-terminal amides, which means it can recognize these damaged proteins while leaving the good ones alone. This process allows our cells to get rid of damaged proteins quickly. This is not just about efficiency. It shows how our body has special ways to keep us healthy by recognizing and removing damaged proteins. However things turn complex. There is a mutated version of FBXO31. This mutation can make cells toxic and causes the reprocessing of proteins that don't have C-terminal amides. This is linked with problems in human development. Going forward CTAPs (C-Terminal Amide Proteins) have potential to be an important target for future study. This is because they can represent a bigger picture of how our body handles cell damage. It is one of the many ways our body keeps us healthy and it is crucial for maintaining our body's health and stability.