PEX25

PEX25 is a protein encoded by the *PEX25* gene in humans, located on chromosome 6 at position 6p21.3. It plays a critical role in the biogenesis and maintenance of peroxisomes, specialized organelles involved in lipid metabolism, detoxification, and reactive oxygen species (ROS) management. Peroxisomes are essential for breaking down very-long-chain fatty acids, branched-chain fatty acids, and certain amino acids, as well as synthesizing essential molecules like plasmalogens, which are vital for cell membrane integrity.

The PEX25 protein belongs to the peroxisomal membrane protein (PEX) family, specifically the PEX19-dependent import pathway. It functions as a receptor for peroxisomal membrane proteins (PMPs) during their post-translational import into peroxisomes. PEX25 interacts with other PEX proteins, such as PEX14 and PEX16, to facilitate the proper assembly and trafficking of PMPs. Mutations in *PEX25* have been linked to peroxisome biogenesis disorders (PBDs), a group of rare genetic conditions characterized by defective peroxisome function.

Clinical manifestations of PEX25-related PBDs can vary widely but often include developmental delays, neurological abnormalities, and metabolic dysfunctions. For instance, patients may exhibit features such as hypotonia, seizures, or abnormalities in lipid metabolism, such as elevated very-long-chain fatty acids in plasma. The severity of symptoms depends on the specific mutation and its impact on peroxisome structure and function.

Research into PEX25 has primarily focused on its role in peroxisome assembly and the molecular mechanisms underlying PBDs. Understanding PEX25’s function may also provide insights into broader cellular processes, including lipid homeostasis and oxidative stress responses. Further study is needed to develop targeted therapies for PBDs and related metabolic disorders.