Import of newly synthesized PTS1 proteins into the peroxisome requires the PTS1 receptor (Pex5p), a predominantly cytoplasmic protein that cycles between the cytoplasm and peroxisome. We have identified Pex13p, a novel integral peroxisomal membrane from both yeast and humans that binds the PTS1 receptor via a cytoplasmically oriented SH3 domain. Although only a small amount of Pex5p is bound to peroxisomes at steady state (< 5%), loss of Pex13p further reduces the amount of peroxisome-associated Pex5p by approximately 40-fold. Furthermore, loss of Pex13p eliminates import of peroxisomal matrix proteins that contain either the type-1 or type-2 peroxisomal targeting signal but does not affect targeting and insertion of integral peroxisomal membrane proteins. We conclude that Pex13p functions as a docking factor for the predominantly cytoplasmic PTS1 receptor.
Pex13p is an SH3 protein of the peroxisome membrane and a docking factor for the predominantly cytoplasmic PTs1 receptor.
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S J Gould, J E Kalish, J C Morrell, J Bjorkman, A J Urquhart, D I Crane; Pex13p is an SH3 protein of the peroxisome membrane and a docking factor for the predominantly cytoplasmic PTs1 receptor.. J Cell Biol 1 October 1996; 135 (1): 85–95. doi: https://doi.org/10.1083/jcb.135.1.85
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