Class I peroxisomal membrane protein import

Most peroxisomal membrane proteins (PMPs) are inserted into the peroxisomal membrane by the receptor-chaperone PEX19 and the docking receptor PEX3 (Soukupova et al. 1999, Muntau et al. 2003, Fang et al. 2004, Fujiki et al. 2006, Matsuzono and Fujiki 2006, Matsuzono et al. 2006, Pinto et al. 2006, Sato et al. 2008, Sato et al. 2010, Schmidt et al. 2010, Hattula et al. 2014, reviewed in Fujiki et al. 2014, Mayerhofer 2016). PEX19 binds the PMP as it is translated in the cytosol. Recognition of the PMP by PEX 19 appears to depend on positively charged residues in the transmembrane domain of the PMP. The PEX19:PMP complex then interacts with PEX3 located in the peroxisomal membrane. Through a mechanism that is not yet clear, the PMP is inserted into the peroxisomal membrane and PEX19 dissociates from PEX3. A current model involves transfer of the PMP from PEX19 to a hydrophobic region of PEX3 followed by insertion of the PMP into the membrane (Chen et al. 2014, reviewed by Giannopoulou et al. 2016). The process does not appear to require hydrolysis of ATP or GTP.

Summary from Reactome (R-HSA-9603798), read 2026-09-23.