FEM1C helps our cells get rid of proteins that are no longer needed or are damaged. It does this through a larger “clean-up” system called the ubiquitin-proteasome pathway. FEM1C specifically recognizes proteins that have a short signal—usually involving arginine—right at the protein end (C-terminus). This signal is often called an “Arg/C-degron,” meaning it’s telling the cell that this protein should be removed.
Inside FEM1C, there is a key position called Asp126. “Asp” stands for aspartate, a negatively charged building block that helps recognize and draw in proteins with a positive arginine at their end. Changing Asp126 to something else—like histidine (Asp126His) or valine (Asp126Val)—alters that charge. Histidine has a partially positive charge, while valine is hydrophobic (it avoids water). Either way, the normal protein-binding process gets disrupted. As a result, FEM1C cannot properly attach to certain proteins, and those proteins may not be broken down as they should be.
When these unwanted proteins build up instead of being cleared, it may lead to problems that affect the nervous system. In particular, researchers have seen developmental delays, difficulties with speech, and trouble controlling movements in individuals who carry these FEM1C changes.
FEM1C