Peroxisome Biogenesis: Involvement of ARF and Coatomer

Abstract

Peroxisomal membrane protein (Pmp)26p (RnPex11p), a major constituent of induced rat liver peroxisomal membrane, was found to contain a COOH-terminal, cytoplasmically exposed consensus dilysine motif with the potential to bind coatomer. Biochemical as well as immunocytochemical evidence is presented showing that peroxisomes incubated with preparations of bovine brain or rat liver cytosol recruit ADP-ribosylation factor (ARF) and coatomer in a strictly guanosine 5′-O-(3-thiotriphosphate)–dependent manner. Consistent with this observation, ldlF cells expressing a temperature-sensitive mutant version of the ε-subunit of coatomer exhibit elongated tubular peroxisomes possibly due to impaired vesiculation at the nonpermissive temperature. Since overexpression of Pex11p in Chinese hamster ovary wild-type cells causes proliferation of peroxisomes, these data suggest that Pex11p plays an important role in peroxisome biogenesis by supporting ARF- and coatomer-dependent vesiculation of the organelles.

Peroxisomal Ascorbate Peroxidase Resides within a Subdomain of Rough Endoplasmic Reticulum in Wild-Type Arabidopsis Cells

“…That BFA interferes with the formation of coated vesicles at ER and Golgi membranes (Nebenfü hr et al, 2002) suggests the involvement of vesicle transport in peroxisomal sorting and/or biogenesis. In support of this hypothesis, the AAA-ATPases Pex1p and Pex6p from Pichia pastoris were localized in cell fractionation experiments to vesicles that were distinct from peroxisomes (Faber et al, 1998), and Just and coworkers demonstrated that rat liver Pex11p may promote vesiculation of peroxisomes by recruiting ADP-ribosylation factor and coatomer (Passreiter et al, 1998;Anton et al, 2000). Although similar experimental data are not yet available for plant proteins, a set of 15 Arabidopsis Pex orthologs, including Pex1p, Pex3p, Pex6p, and Pex11p, have been identified through recent comparisons of human, mouse, and yeast Pex sequences with Arabidopsis sequences (Baker et al, 2000;Mullen et al, 2001a;Charlton and Ló pez-Huertas, 2002).…”

Formation of Peroxisomes from Peroxisomal Ghosts in a Peroxisome-deficient Mammalian Cell Mutant upon Complementation by Protein Microinjection

“…Moreover, the ADP-ribosylation factor and coatomers known to be important in membrane vesicle formation also seem to be involved in peroxisome biogenesis (30). The functions of these factors were discussed in terms of both vesicle formation from the endoplasmic reticulum and the fission of preexisting peroxisomes (30). Thus, it is again a current question as to whether peroxisomes are formed from preexisting peroxisomes or endoplasmic reticulum.…”

“…In a yeast species, the proteins involved in the secretory pathways and peroxisome assembly seem to be functionally overlapping (29). Moreover, the ADP-ribosylation factor and coatomers known to be important in membrane vesicle formation also seem to be involved in peroxisome biogenesis (30). The functions of these factors were discussed in terms of both vesicle formation from the endoplasmic reticulum and the fission of preexisting peroxisomes (30).…”

The Dynamin-like GTPase DLP1 Is Essential for Peroxisome Division and Is Recruited to Peroxisomes in Part by PEX11

“…Of the many PEX 1 genes and products (peroxins) required for peroxisome biogenesis, only PEX11 has been shown to have a conserved role in peroxisome division (7)(8)(9)(10)(11)(12)(13). The overexpression of PEX11 promotes peroxisome elongation and subsequent division, whereas loss of PEX11 results in reduced peroxisome abundance (7,8,12,14).…”