Biosynthesis of peroxisomal enzymes in the methylotrophic yeast Hansenula polymorpha
AUTOR(ES)
Roa, Michèle
RESUMO
The dramatic expansion of the peroxisomal compartment known to occur in the methanol-utilizing yeast Hansenula polymorpha on transfer from glucose- to methanol-containing media was shown to be accompanied by the synthesis of at least six major polypeptides that dominate the polypeptide pattern of total cell extracts analyzed by NaDodSO4/polyacrylamide gel electrophoresis. Two of these polypeptides have been identified by immunochemical methods as the monomers of the peroxisomal enzymes alcohol oxidase and catalase. We have studied the biosynthesis of these two peroxisomal enzymes, both by in vitro translation and by in vivo labeling experiments. By the criterion of mobility in NaDodSO4/polyacrylamide gel electrophoresis, the in vitro- and in vivo-synthesized monomers were indistinguishable from each other, both in the case of alcohol oxidase and in that of catalase. Thus, neither of these peroxisomal enzymes appear to be synthesized as larger precursors. However, further analysis of in vitro-synthesized versus mature peroxisomal alcohol oxidase showed that the in vitro-synthesized form sedimented as a 5S monomer and not, like the mature peroxisomal enzyme, as a 20S octamer. Moreover, the in vitro-synthesized form was highly susceptible to trypsin digestion whereas the mature 20S octamer appeared to be resistant.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=390088Documentos Relacionados
- Architecture of peroxisomal alcohol oxidase crystals from the methylotrophic yeast Hansenula polymorpha as deduced by electron microscopy.
- The methylotrophic yeast Hansenula polymorpha contains an inducible import pathway for peroxisomal matrix proteins with an N-terminal targeting signal (PTS2 proteins).
- Peroxisomes in the methylotrophic yeast Hansenula polymorpha do not necessarily derive from pre-existing organelles.
- HARO7 Encodes Chorismate Mutase of the Methylotrophic Yeast Hansenula polymorpha and Is Derepressed upon Methanol Utilization
- Synthesis and subcellular location of peroxisomal membrane proteins in a peroxisome-deficient mutant of the yeast Hansenula polymorpha.