Peroxisome biogenesis and selective degradation converge at Pex14p.
We have analyzed the function of Hansenula polymorpha Pex14p in selective peroxisome degradation. Previously, we showed that Pex14p was involved in peroxisome biogenesis and functions in peroxisome matrix protein import. Evidence for the additional function of HpPex14p in selective peroxisome degradation (pexophagy) came from cells defective in HpPex14p synthesis. The suggestion that the absence of HpPex14p interfered with pexophagy was further analyzed by mutational analysis. These studies indicated that deletions at the C terminus of up to 124 amino acids of HpPex14p did not affect peroxisome degradation. Conversely, short deletions of the N terminus (31 and 64 amino acids, respectively) of the protein fully impaired pexophagy. Peroxisomes present in these cells remained intact for at least 6 h of incubation in the presence of excess glucose, conditions that led to the rapid turnover of the organelles in wild-type control cells. We conclude that the N terminus of HpPex14p contains essential information to control pexophagy in H. polymorpha and thus, that organelle development and turnover converge at Pex14p.
Bellu
A R
AR
Eukaryotic Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands.
Komori
M
M
van der Klei
I J
IJ
Kiel
J A
JA
Veenhuis
M
M
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics*; D005656:Fungal Proteins / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics*; D026901:Membrane Transport Proteins; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation; D000074401:Peroxins; D020675:Peroxisomes / Q000737:chemistry* / Q000378:metabolism*; D010766:Phosphorylation; D010843:Pichia / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
D000596:Amino Acids; D002352:Carrier Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C499195:PEX14 protein, S cerevisiae; D000074401:Peroxins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D005947:Glucose