Penicillium chrysogenum Pex14/17p--a novel component of the peroxisomal membrane that is important for penicillin production.
By genome analysis, we previously identified Pex14/17p as a putative novel peroxin of Penicillium chrysogenum. Here, we show that Pex14/17p is a component of the peroxisomal membrane that is essential for efficient peroxisomal targeting signal 1 and peroxisomal targeting signal 2 matrix protein import, implying that the protein is indeed a genuine peroxin. Additionally, a PEX14/17 deletion strain is affected in conidiospore formation. Pex14/17p has properties of both Pex14p and Pex17p, in that the N-terminus of this protein is similar to the highly conserved Pex5p-binding region present in the N-termini of Pex14p proteins, whereas its C-terminus shows weak similarity to yeast Pex17p proteins. We have identified a novel motif in both Pex17p and Pex14/17p that is absent in Pex14p. We show that an N-terminally truncated, but not a C-terminally truncated, Pex14/17p is able to complement both the matrix protein import and sporulation defects of a Delta pex14/17 strain, implying that it is the Pex17p-related portion of the protein that is crucial for its function as a peroxin. Possibly, this compensates for the fact that P. chrysogenum lacks an authenthic Pex17p. We also show that, in P. chrysogenum, Pex14/17p plays a role in making the penicillin biosynthesis process more efficient.
Opaliński
Lukasz
L
Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands.
Kiel
Jan A K W
JA
Homan
Tim G
TG
Veenhuis
Marten
M
van der Klei
Ida J
IJ
D005656:Fungal Proteins; D007425:Intracellular Membranes / Q000737:chemistry; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010406:Penicillins / Q000096:biosynthesis*; D010408:Penicillium chrysogenum / Q000737:chemistry*; D020675:Peroxisomes / Q000737:chemistry* / Q000648:ultrastructure
D005656:Fungal Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010406:Penicillins