Fig. 1.

Hypothetical model of peroxisome biogenesis. Peroxisomes can form de novo from the ER. This step requires the function of a group of peroxisomal proteins, mainly Pex3, Pex16 and Pex19. Peroxisomes can also proliferate by fission of existing organelles. In this process a yet unknown signal activates Pex11 proteins that lead to elongation of the organelle. The tubulated organelle attracts GTPases from the dynamin like family (DLPs) that assemble into highly ordered multimers on the elongated organelle, causing actual membrane fission. The assembly of the DLPs complex requires Fis1 and Mdv1. Next, the newly formed organelle imports matrix and membrane proteins