Import of assembled PTS1 proteins into peroxisomes of the yeast Hansenula polymorpha: Yes and No!

Penicillium chrysogenum Pex5p mediates differential sorting of PTS1 proteins to microbodies of the methylotrophic yeast Hansenula polymorpha.

We have isolated the Penicillium chrysogenum pex5 gene encoding the receptor for microbody matrix proteins containing a type 1 peroxisomal targeting signal (PTS1). Pc-pex5 contains 2 introns and encodes a protein of approximately 75 kDa. P. chrysogenum pex5 disruptants appear to be highly unstable, show poor growth, and are unable to sporulate asexually. Furthermore, pex5 cells mislocalize a fl...

An isoform of pex5p, the human PTS1 receptor, is required for the import of PTS2 proteins into peroxisomes.

Mutations in the peroxisome targeting signal (PTS) 1 receptor gene, PEX5 , are responsible for complementation group (CG) 2 of the peroxisome biogenesis disorders (PBD). Of the two reported patients in this CG, cells from PBD018 (homozygous for the missense mutation N489K) are defective in the import of PTS1 proteins into peroxisomes, as expected. However, cells from PBD005 (homozygous for the ...

Damaged peroxisomes are subject to rapid autophagic degradation in the yeast Hansenula polymorpha.

Evidence is accumulating that damaged components of eukaryotic cells are removed by autophagic degradation (e.g., mitophagy). Here we show that peroxisomes that are damaged by the abrupt removal of the membrane protein Pex3 are massively and rapidly degraded even when the cells are placed at peroxisome-inducing conditions and hence need the organelles for growth. Pex3 degradation was induced by...

Import of proteins into peroxisomes and other microbodies.

The methylotrophic yeast Hansenula polymorpha contains an inducible import pathway for peroxisomal matrix proteins with an N-terminal targeting signal (PTS2 proteins).

Two main types of peroxisomal targeting signals have been identified that reside either at the extreme C terminus (PTS1) or the N terminus (PTS2) of the protein. In the methylotrophic yeast Hansenula polymorpha the majority of peroxisomal matrix proteins are of the PTS1 type. Thus far, for H. polymorpha only amine oxidase (AMO) has been shown to contain a PTS2 type signal. In the present study ...