Hansenula polymorpha Swi1p and Snf2p are essential for methanol utilisation.
We have cloned the Hansenula polymorpha SWI1 and SNF2 genes by functional complementation of mutants that are defective in methanol utilisation. These genes encode proteins similar to Saccharomyces cerevisiae Swi1p and Snf2p, which are subunits of the SWI/SNF complex. This complex belongs to the family of nucleosome-remodeling complexes that play a role in transcriptional control of gene expression. Analysis of the phenotypes of constructed H. polymorpha SWI1 and SNF2 disruption strains indicated that these genes are not necessary for growth of cells on glucose, sucrose, or various organic nitrogen sources which involve the activity of peroxisomal oxidases. Both disruption strains showed a moderate growth defect on glycerol and ethanol, but were fully blocked in methanol utilisation. In methanol-induced cells of both disruption strains, two peroxisomal enzymes involved in methanol metabolism, alcohol oxidase and dihydroxyacetone synthase, were hardly detectable, whereas in wild-type cells these proteins were present at very high levels. We show that the reduction in alcohol oxidase protein levels in H. polymorpha SWI1 and SNF2 disruption strains is due to strongly reduced expression of the alcohol oxidase gene. The level of Pex5p, the receptor involved in import of alcohol oxidase and dihydroxyacetone synthase into peroxisomes, was also reduced in both disruption strains compared to that in wild-type cells.
Ozimek
Paulina
P
Eukaryotic Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands.
Lahtchev
Kantcho
K
Kiel
Jan A K W
JA
Veenhuis
Marten
M
van der Klei
Ida J
IJ
D000429:Alcohol Oxidoreductases / Q000235:genetics; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D000432:Methanol / Q000378:metabolism*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D020675:Peroxisomes / Q000378:metabolism / Q000648:ultrastructure; D010843:Pichia / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D011401:Promoter Regions, Genetic; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D000432:Methanol