Characterization of peroxisome-deficient mutants of Hansenula polymorpha.
In the methylotrophic yeast Hansenula polymorpha, approximately 25% of all methanol-utilization-defective (Mut-) mutants are affected in genes required for peroxisome biogenesis (PER genes). Previously, we reported that one group of per mutants, termed Pim-, are characterized by the presence of a few small peroxisomes with the bulk of peroxisomal enzymes located in the cytosol. Here, we describe a second major group of per mutants that were observed to be devoid of any peroxisome-like structure (Per-). In each Per- mutant, the peroxisomal methanol-pathway enzymes alcohol oxidase, catalase and dihydroxyacetone synthase were present and active but located in the cytosol. Together, the Pim- and Per- mutant collections involved mutations in 14 different PER genes. Two of the genes, PER5 and PER7, were represented by both dominant-negative and recessive alleles. Diploids resulting from crosses of dominant per strains and wild-type H. polymorpha were Mut- and harbored peroxisomes with abnormal morphology. This is the first report of dominant-negative mutations affecting peroxisome biogenesis.
Department of Chemistry, Biochemistry, and Molecular Biology, Oregon Graduate Institute of Science and Technology, Portland 97291-1000, USA.
X
X
Tan
V I
VI
Titorenko
I J
IJ
van der Klei
G J
GJ
Sulter
P
P
Haima
H R
HR
Waterham
M
M
Eyers
W
W
Harder
M
M
Veenhuis
J M
JM
Cregg
D000429:Alcohol Oxidoreductases / Q000378:metabolism; D019880:Aldehyde-Ketone Transferases; D000483:Alleles; D002374:Catalase / Q000378:metabolism; D003433:Crosses, Genetic; D003600:Cytosol / Q000201:enzymology; D005656:Fungal Proteins / Q000378:metabolism; D005799:Genes, Dominant; D005800:Genes, Fungal; D005808:Genes, Recessive; D000432:Methanol / Q000378:metabolism; D008830:Microbodies; D010843:Pichia / Q000201:enzymology / Q000235:genetics* / Q000648:ultrastructure; D014166:Transferases / Q000378:metabolism
D005656:Fungal Proteins; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D002374:Catalase; D014166:Transferases; D019880:Aldehyde-Ketone Transferases; C031222:formaldehyde transketolase; D000432:Methanol