Saccharomyces cerevisiae Pex14p contains two independent Pex5p binding sites, which are both essential for PTS1 protein import.
Pex14p is a peroxisomal membrane-associated protein involved in docking of both Pex5p and Pex7p to the peroxisomal membrane. Previous studies have shown that, in humans, the N-terminal region of Pex14p interacts with WxxxF/Y motifs in Pex5p. Here, we report that Saccharomyces cerevisiae Pex14p contains two independent Pex5p binding sites, one in the N- and one in the C-terminus. Using deletion analysis we show that, in vivo, both of these interactions are needed for PTS1 import. Furthermore, we show that the characterized WxxxF/Y motifs of Pex5p are not essential for binding to the N-terminus of Pex14p but do play a role in the interaction with the Pex14 C-terminus. Thus, the data suggest that the mechanism of the Pex14p-Pex5p interaction in yeast is different from that previously reported for humans.
Williams
Chris
C
Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
van den Berg
Marlene
M
Distel
Ben
B
D020816:Amino Acid Motifs; D001665:Binding Sites / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D000074401:Peroxins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D021382:Protein Sorting Signals; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D020798:Two-Hybrid System Techniques
D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C499195:PEX14 protein, S cerevisiae; C499509:PEX5 protein, S cerevisiae; D000074401:Peroxins; D000074435:Peroxisome-Targeting Signal 1 Receptor; D021382:Protein Sorting Signals; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins