Send to

Choose Destination
J Cell Biol. 2008 Dec 29;183(7):1275-86. doi: 10.1083/jcb.200806062.

The peroxisomal membrane protein import receptor Pex3p is directly transported to peroxisomes by a novel Pex19p- and Pex16p-dependent pathway.

Author information

Department of Biology, Faculty of Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan.


Two distinct pathways have recently been proposed for the import of peroxisomal membrane proteins (PMPs): a Pex19p- and Pex3p-dependent class I pathway and a Pex19p- and Pex3p-independent class II pathway. We show here that Pex19p plays an essential role as the chaperone for full-length Pex3p in the cytosol. Pex19p forms a soluble complex with newly synthesized Pex3p in the cytosol and directly translocates it to peroxisomes. Knockdown of Pex19p inhibits peroxisomal targeting of newly synthesized full-length Pex3p and results in failure of the peroxisomal localization of Pex3p. Moreover, we demonstrate that Pex16p functions as the Pex3p-docking site and serves as the peroxisomal membrane receptor that is specific to the Pex3p-Pex19p complexes. Based on these novel findings, we suggest a model for the import of PMPs that provides new insights into the molecular mechanisms underlying the biogenesis of peroxisomes and its regulation involving Pex3p, Pex19p, and Pex16p.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center