Oxidation of formaldehyde by alcohol oxidase of Candida boidinii

1975 ◽  
Vol 105 (1) ◽  
pp. 179-181 ◽  
Author(s):  
Hermann Sahm
Keyword(s):  
Alcohol Oxidase ◽  
Candida Boidinii

scholarly journals Peroxisomal assembly: membrane proliferation precedes the induction of the abundant matrix proteins in the methylotrophic yeast Candida boidinii

1990 ◽  
Vol 96 (4) ◽  
pp. 583-590
Author(s):  
M. Veenhuis ◽  
J.M. Goodman
Keyword(s):  
Early Stage ◽  
Morphological Changes ◽  
Polyclonal Antibodies ◽  
Alcohol Oxidase ◽  
Methylotrophic Yeast ◽  
Candida Boidinii ◽  
Peroxisomal Membrane ◽  
Cell Induction ◽  
The Matrix ◽  
Dihydroxyacetone Synthase

Peroxisomes are massively induced when methylotrophic yeasts are cultured in medium containing methanol. These organelles contain enzymes that catalyze the initial steps of methanol assimilation. In Candida boidinii, a methylotrophic yeast, the peroxisomal matrix (internal compartment) is composed almost exclusively of two proteins, alcohol oxidase and dihydroxyacetone synthase; catalase is present in much lower abundance. Monoclonal and polyclonal antibodies are available against peroxisomal matrix and membrane proteins. These were utilized to correlate the induction of specific proteins with the morphological changes occurring during peroxisomal proliferation. Cells cultured in glucose-containing medium contain two to five small microbodies, which are identifiable by catalase staining and immunoreactivity with a monoclonal antibody against PMP47, an integral peroxisomal membrane protein. Three stages of proliferation can be distinguished when cells are switched to methanol as the carbon source. (1) There is an early stage (within 1 h) in which several peroxisomes develop from a preexisting organelle. This is accompanied by an increase in catalase activity and an induction of PMP47, but no detectable induction of alcohol oxidase or dihydroxyacetone synthase is observed. (2) From 1 to 2.5 h there is further division of these microbodies until up to 30 small peroxisomes generally are present in each of one or two clusters per cell. Induction of alcohol oxidase, dihydroxyacetone synthase and PMP20, a protein that is distributed in the matrix and membrane, is detectable during this time. Serial sections reveal that some peroxisomes remain uninduced while others undergo proliferation. Such sections also show no obvious connections between peroxisomes within clusters.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The absence of Pmp47, a putative yeast peroxisomal transporter, causes a defect in transport and folding of a specific matrix enzyme.

1996 ◽  
Vol 134 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Y Sakai ◽  
A Saiganji ◽  
H Yurimoto ◽  
K Takabe ◽  
H Saiki ◽  
...  
Keyword(s):  
Single Gene ◽  
Alcohol Oxidase ◽  
Candida Boidinii ◽  
High Electron ◽  
Gene Encoding ◽  
Peroxisomal Membrane ◽  
Carboxyl Terminal ◽  
Dihydroxyacetone Synthase ◽  
Physiological And Biochemical ◽  
Solute Transporters

Candida boidinii Pmp47, an integral peroxisomal membrane protein, belongs to a family of mitochondrial solute transporters (e.g., ATP/ADP exchanger), and is the only known peroxisomal member of this family. However, its physiological and biochemical functions have been unrevealed because of the difficulties in the molecular genetics of C. boidinii. In this study, we first isolated the PMP47 gene, which was the single gene encoding for Pmp47 in a gene-engineerable strain S2 of C. boidinii. Sequence analysis revealed that it was very similar to PMP47A and PMP47B genes from a polyploidal C. Boidinii strain (ATCC32195). Next, the PMP47 gene was disrupted and the disruption strain (pmp47delta) was analyzed. Depletion of PMP47 from strain S2 resulted in a retarded growth on oleate and a complete loss of growth on methanol. Both growth substrates require peroxisomal metabolism. EM observations revealed the presence of peroxisomes in methanol- and oleate-induced cells of pmp47delta, but in reduced numbers, and the presence of material of high electron density in the cytoplasm in both cases. Methanol-induced cells of pmp47delta were investigated in detail. The activity of one of the methanol-induced peroxisome matrix enzymes, dihydroxyacetone synthase (DHAS), was not detected in pmp47delta. Further biochemical and immunocytochemical experiments revealed that the DHAS protein aggregated in the cytoplasm as an inclusion body, while two other peroxisome matrix enzymes, alcohol oxidase (AOD) and catalase, were active and found in peroxisomes. Two peroxisome-deficient mutants, strains M6 and M13 (described in previous studies), retained DHAS activity although it was mislocalized to the cytoplasm and the nucleus. We disrupted PMP47 in these peroxisome-deficient mutants. In both strains, M6-pmp47delta and M13-pmp47delta, DHAS was enzymatically active and was located in the cytoplasm and the nucleus. We suggest that an unknown small molecule, which PMP47 transports, is necessary for the folding or the translocation machinery of DHAS within peroxisomes. Pmp47 does not catalyze folding directly because active DHAS is observed in the M6-pmp47delta and M13-pmp47delta strains. Since both AOD and DHAS have the PTS1 motif sequences at their carboxyl terminal, our results first show that depletion of Pmp47 could dissect the peroxisomal import pathway (PTS1 pathway) of these proteins.

Alcohol oxidase and dihydroxyacetone synthase, the abundant peroxisomal proteins of methylotrophic yeasts, assemble in different cellular compartments

2001 ◽  
Vol 114 (15) ◽  
pp. 2863-2868
Author(s):  
Mary Q. Stewart ◽  
Renee D. Esposito ◽  
Jehangir Gowani ◽  
Joel M. Goodman
Keyword(s):  
Alcohol Oxidase ◽  
Protein Assembly ◽  
Matrix Proteins ◽  
Thiamine Pyrophosphate ◽  
Model Organisms ◽  
Candida Boidinii ◽  
Methylotrophic Yeasts ◽  
The Matrix ◽  
Cellular Compartments ◽  
Dihydroxyacetone Synthase

Alcohol oxidase (AO) and dihydroxyacetone synthase (DHAS) constitute the bulk of matrix proteins in methylotrophic yeasts, model organisms for the study of peroxisomal assembly. Both are homooligomers; AO is a flavin-containing octamer, whereas DHAS is a thiamine pyrophosphate-containing dimer. Experiments in recent years have demonstrated that assembly of peroxisomal oligomers can occur before import; indeed the absence of chaperones within the peroxisomal matrix calls into question the ability of this compartment to assemble proteins at all. We have taken a direct pulse-chase approach to monitor import and assembly of the two major proteins of peroxisomes in Candida boidinii. Oligomers of AO are not observed in the cytosol, consistent with the proteins inability to undergo piggyback import. Indeed, oligomerization of AO can be followed within the peroxisomal matrix, directly demonstrating the capacity of this compartment for protein assembly. By contrast, DHAS quickly dimerizes in the cytosol before import. Binding and import was slowed at 15°C; the effect on AO was more dramatic. In conclusion, our data indicate that peroxisomes assemble AO in the matrix, while DHAS undergoes dimerization prior to import.

Sign in / Sign up

Export Citation Format

Share Document