PEX21

Pex21 is a peroxisomal membrane protein that is part of the peroxin family involved in peroxisome biogenesis and matrix protein import. In yeast models, Pex21 is encoded by the PEX21 gene and localizes to the peroxisomal membrane, where it participates in the assembly or maintenance of the peroxisomal import machinery.

In Saccharomyces cerevisiae and related fungi, Pex21 is associated with the network of peroxins that coordinate the import of matrix proteins bearing peroxisomal targeting signals. It is generally regarded as contributing to proper receptor docking or recycling, and its disruption can lead to impaired import of peroxisomal enzymes and, in some cases, loss or severe compromise of peroxisomes.

Pex21 homologs have been identified across several fungal species, suggesting a conserved role in peroxisome biogenesis. While the exact molecular interactions and mechanisms can vary among organisms, Pex21 is commonly discussed alongside other peroxins such as Pex14, Pex5, and Pex22 in the context of peroxisomal protein import.

Research on Pex21 has helped illuminate how peroxisomes assemble and maintain their protein import systems, contributing to a broader understanding of peroxisomal function in cellular metabolism and the study of related biological processes.