Pex25p

Pex25p is a peroxisomal membrane protein found in yeast, specifically in Saccharomyces cerevisiae. It is involved in the biogenesis and maintenance of peroxisomes, which are organelles responsible for various metabolic processes, including the breakdown of fatty acids and the detoxification of hydrogen peroxide. Pex25p plays a crucial role in the formation of peroxisomal membranes and the import of proteins into these organelles.

The Pex25p protein is characterized by its N-terminal peroxisomal targeting signal type 2 (PTS2), which directs it to the peroxisomal membrane. This targeting signal is recognized by the cytosolic receptor Pex7p, facilitating the translocation of Pex25p to the peroxisomal membrane. Once localized to the peroxisomal membrane, Pex25p interacts with other peroxins, such as Pex3p and Pex19p, to promote the insertion and assembly of peroxisomal membrane proteins.

Studies have shown that Pex25p is essential for the proliferation of peroxisomes. In yeast cells, the overexpression of Pex25p leads to an increase in the number of peroxisomes, suggesting its role in peroxisomal division or biogenesis. Conversely, the deletion of Pex25p results in the accumulation of peroxisomal membrane vesicles, indicating a defect in peroxisomal membrane formation and protein import.

In summary, Pex25p is a key player in peroxisomal biogenesis and maintenance. Its role in peroxisomal membrane formation, protein import, and organelle proliferation highlights its importance in the overall function and regulation of peroxisomes in yeast cells.