THE HANSENULA-POLYMORPHA PER1 GENE IS ESSENTIAL FOR PEROXISOME BIOGENESIS AND ENCODES A PEROXISOMAL MATRIX PROTEIN WITH BOTH CARBOXY-TERMINAL AND AMINO-TERMINAL TARGETING SIGNALS
Hr. Waterham et al., THE HANSENULA-POLYMORPHA PER1 GENE IS ESSENTIAL FOR PEROXISOME BIOGENESIS AND ENCODES A PEROXISOMAL MATRIX PROTEIN WITH BOTH CARBOXY-TERMINAL AND AMINO-TERMINAL TARGETING SIGNALS, The Journal of cell biology, 127(3), 1994, pp. 737-749
We describe the cloning of the Hansenula polymorpha PER1 gene and the
characterization of the gene and its product, PER1p. The gene was clon
ed by functional complementation of a per1 mutant of H. polymorpha, wh
ich was impaired in the import of peroxisomal matrix proteins (Pim(-)
phenotype). The DNA sequence of PER1 predicts that PER1p is a polypept
ide of 650 amino acids with no significant sequence similarity to othe
r known proteins. PER1 expression was low but significant in wild-type
H. polymorpha growing on glucose and increased during growth on any o
ne of a number of substrates which induce peroxisome proliferation. PE
R1p contains both a carboxy- (PTS1) and an amino-terminal (PTS2) perox
isomal targeting signal which both were demonstrated to be capable of
directing bacterial beta-lactamase to the organelle. In wild-type H. p
olymorpha PER1p is a protein of low abundance which was demonstrated t
o be localized in the peroxisomal matrix. Our results suggest that the
import of PER1p into peroxisomes is a prerequisite for the import of
additional matrix proteins and we suggest a regulatory function of PER
1p on peroxisomal protein import.