The functions of Pex11 family proteins in peroxisome biology

Abstract

Regulating peroxisome numbers within the cell, through synthesis and degradation events, is an essential part of cell homeostasis. New peroxisomes are made either de novo or by the division of pre-existing organelles. Elongation of the peroxisomal membrane, one of the initial steps in fission, is proposed to be followed by assembly of the membrane fission machinery at the site of tubulation, bilayer constriction and ultimately, membrane fission. A role for the peroxisomal membrane protein Pex11p in peroxisome fission has long been known. Recent reports have shed light on the mechanistic details behind Pex11p's membrane remodeling activity and the role of amphipathic helices in Pex11p. However, a number of additional tasks have been attributed to Pex11p, ranging from directing peroxisome inheritance to peroxisomal membrane protein reorganization. Furthermore, several Pex11-like proteins have been described, the functions of which differ from Pex11p. This chapter will discuss the current understanding of the role of the Pex11 protein family in peroxisome biogenesis.