Peroxisomal matrix protein import: the transient pore model

Peroxisomes import folded, even oligomeric, proteins, which distinguishes the peroxisomal translocation machinery from the well-characterized translocons of other organelles. How proteins are transported across the peroxisomal membrane is unclear. Here, we propose a mechanistic model that conceptually divides the import process into three consecutive steps: the formation of a translocation pore by the import receptor, the ubiquitylation of the import receptors, and pore disassembly/ receptor recycling.