Biosynthesis and regulation of the peroxisomal methanol oxidase from the methylotrophic yeast Hansenula polymorpha

1984 ◽  
Vol 194 (3) ◽  
pp. 489-493 ◽  
Author(s):  
Rainer Roggenkamp ◽  
Zbigniew Janowicz ◽  
Brigitte Stanikowski ◽  
Cornelis P. Hollenberg
1989 ◽  
Vol 9 (3) ◽  
pp. 988-994
Author(s):  
R Roggenkamp ◽  
T Didion ◽  
K V Kowallik

The crystalloid core in peroxisomes of the methylotrophic yeast Hansenula polymorpha is composed of the octameric flavoprotein methanol oxidase (MOX). We transformed yeast cells with a high-copy-number vector harboring the cloned MOX gene in order to study the effects on regulation, protein import, and peroxisome biosynthesis. In transformed wild-type cells, no increase in expression of MOX was detectable. Mutants defective in MOX activity were isolated by a specific selection procedure. Two structural MOX mutants are described that allow overproduction of a fully active enzyme upon transformation at quantities of about two-thirds of the total cellular protein. The overproduced protein was imported into peroxisomes, altering their morphology (in thin sections) and stability in cell lysates; the organelles showed a tendency to form rectangular bodies, and their lumina were completely filled with the crystalloid structure. The overall size of the peroxisomes was increased severalfold in comparison with the size of nontransformed yeast cells. The results suggest high capacities of peroxisomal growth conferred by overproduction and import of a single protein.


1989 ◽  
Vol 9 (3) ◽  
pp. 988-994 ◽  
Author(s):  
R Roggenkamp ◽  
T Didion ◽  
K V Kowallik

The crystalloid core in peroxisomes of the methylotrophic yeast Hansenula polymorpha is composed of the octameric flavoprotein methanol oxidase (MOX). We transformed yeast cells with a high-copy-number vector harboring the cloned MOX gene in order to study the effects on regulation, protein import, and peroxisome biosynthesis. In transformed wild-type cells, no increase in expression of MOX was detectable. Mutants defective in MOX activity were isolated by a specific selection procedure. Two structural MOX mutants are described that allow overproduction of a fully active enzyme upon transformation at quantities of about two-thirds of the total cellular protein. The overproduced protein was imported into peroxisomes, altering their morphology (in thin sections) and stability in cell lysates; the organelles showed a tendency to form rectangular bodies, and their lumina were completely filled with the crystalloid structure. The overall size of the peroxisomes was increased severalfold in comparison with the size of nontransformed yeast cells. The results suggest high capacities of peroxisomal growth conferred by overproduction and import of a single protein.


FEBS Letters ◽  
1993 ◽  
Vol 334 (1) ◽  
pp. 128-132 ◽  
Author(s):  
I.J. van der Klei ◽  
K.N. Faber ◽  
I. Keizer-Gunnink ◽  
C. Gietl ◽  
W. Harder ◽  
...  

2003 ◽  
Vol 14 (2) ◽  
pp. 786-797 ◽  
Author(s):  
Paulina Ozimek ◽  
Ralf van Dijk ◽  
Kantcho Latchev ◽  
Carlos Gancedo ◽  
Dong Yuan Wang ◽  
...  

Hansenula polymorpha ass3 mutants are characterized by the accumulation of inactive alcohol oxidase (AO) monomers in the cytosol, whereas other peroxisomal matrix proteins are normally activated and sorted to peroxisomes. These mutants also have a glutamate or aspartate requirement on minimal media. Cloning of the corresponding gene resulted in the isolation of the H. polymorpha PYC gene that encodes pyruvate carboxylase (HpPyc1p). HpPyc1p is a cytosolic, anapleurotic enzyme that replenishes the tricarboxylic acid cycle with oxaloacetate. The absence of this enzyme can be compensated by addition of aspartate or glutamate to the growth media. We show that HpPyc1p protein but not the enzyme activity is essential for import and assembly of AO. Similar results were obtained in the related yeast Pichia pastoris. In vitro studies revealed that HpPyc1p has affinity for FAD and is capable to physically interact with AO protein. These data suggest that in methylotrophic yeast pyruvate carboxylase plays a dual role in that, besides its well-characterized metabolic function as anapleurotic enzyme, the protein fulfils a specific role in the AO sorting and assembly process, possibly by mediating FAD-binding to AO monomers.


2017 ◽  
pp. 257-282 ◽  
Author(s):  
Kostyantyn Dmytruk ◽  
Olena Kurylenko ◽  
Justyna Ruchala ◽  
Olena Ishchuk ◽  
Andriy Sibirny

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