Targeting sequences of the two major peroxisomal proteins in the methylotrophic yeast Hansenula polymorpha.
Dihydroxyacetone synthase (DAS) and methanol oxidase (MOX) are the major enzyme constituents of the peroxisomal matrix in the methylotrophic yeast Hansenula polymorpha when grown on methanol as a sole carbon source. In order to characterize their topogenic signals the localization of truncated polypeptides and hybrid proteins was analysed in transformed yeast cells by subcellular fractionation and electron microscopy. The C-terminal part of DAS, when fused to the bacterial beta-lactamase or mouse dihydrofolate reductase, directed these hybrid polypeptides to the peroxisome compartment. The targeting signal was further delimited to the extreme C-terminus, comprising the sequence N-K-L-COOH, similar to the recently identified and widely distributed peroxisomal targeting signal (PTS) S-K-L-COOH in firefly luciferase. By an identical approach, the extreme C-terminus of MOX, comprising the tripeptide A-R-F-COOH, was shown to be the PTS of this protein. Furthermore, on fusion of a C-terminal sequence from firefly luciferase including the PTS, beta-lactamase was also imported into the peroxisomes of H. polymorpha. We conclude that, besides the conserved PTS (or described variants), other amino acid sequences with this function have evolved in nature.
Hansen
H
H
Institut für Mikrobiologie, Heinrich-Heine-Universität Düsseldorf, FRG.
Didion
T
T
Thiemann
A
A
Veenhuis
M
M
Roggenkamp
R
R
D000429:Alcohol Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D019880:Aldehyde-Ketone Transferases; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002374:Catalase / Q000378:metabolism; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005822:Genetic Vectors; D007700:Kinetics; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008830:Microbodies / Q000201:enzymology*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010843:Pichia / Q000201:enzymology / Q000235:genetics* / Q000648:ultrastructure; D010957:Plasmids; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015183:Restriction Mapping; D017384:Sequence Deletion; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D014166:Transferases / Q000235:genetics* / Q000378:metabolism; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
D004271:DNA, Fungal; D009838:Oligodeoxyribonucleotides; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D000429:Alcohol Oxidoreductases; C029293:methanol oxidase; D002374:Catalase; D008156:Luciferases; D013762:Tetrahydrofolate Dehydrogenase; D014166:Transferases; D019880:Aldehyde-Ketone Transferases; C031222:formaldehyde transketolase; D001618:beta-Lactamases