PEX13n

PEX13n is a proposed member of the peroxin family identified as a novel variant of PEX13 in select genome analyses. The designation "n" is used to indicate tentative status as a newly characterized paralog or splice isoform, rather than a fully established, universally conserved gene.

Molecular features and localization are predicted rather than definitively defined. PEX13n is expected to be associated with the peroxisomal membrane and to share core characteristics with other PEX13 proteins, including a tendency toward membrane binding and regions capable of mediating protein–protein interactions within the peroxisomal import machinery. Confirmed domain topology and interaction partners require further experimental validation.

Functionally, PEX13n is hypothesized to participate in peroxisomal matrix protein import as part of the translocation complex that mediates targeting and import of proteins bearing peroxisomal targeting signals. This inference is drawn from the known role of canonical PEX13 in the import pathway and indirect evidence from expression and localization studies in species that harbor the gene, but direct biochemical confirmation is limited.

Distribution, evolution, and orthology are variable. PEX13n appears to be present in some lineages but absent or unannotated in others, suggesting lineage-specific retention or recent duplication events. Its evolutionary relationship to other PEX13 family members is an active area of inquiry, with nomenclature reflecting its provisional status.

Clinical significance remains uncertain. There are no established disease associations attributed to PEX13n at this time, but given the central role of PEX13 in peroxisome biogenesis, future research could illuminate potential contributions to peroxisomal disorders if validated in additional systems.