HETEROLOGOUS COMPLEMENTATION OF PEROXISOME FUNCTION IN YEAST - THE SACCHAROMYCES-CEREVISIAE PAS3 GENE RESTORES PEROXISOME BIOGENESIS IN A HANSENULA-POLYMORPHA PER9 DISRUPTION MUTANT

PER genes are essential for the biogenesis of peroxisomes in the yeast Hansenula polymorpha. Here we describe the functional complementation of a H. polymorpha per9 disruption strain (Delta per9) by a heterolog ous gene. The Saccharomyces cerevisiae Pas3p, a homologue of Per9p, re stored peroxisome biogenesis and peroxisomal protein import in the Del ta per9 mutant, allowing it to grow again on methanol as sole carbon a nd energy source. This result shows that heterologous complementation of peroxisome function in yeast is indeed feasible and furthermore sug gests that H. polymorpha Delta per9 may be the candidate of choice to attempt the isolation of Per9p homologues from higher eukaryotes by fu nctional complementation.