H. polymorpha pex11 pex25 cells are peroxisome deficien

Peroxisome reintroduction in Hansenula polymorpha requires Pex25 and Rho1. Saraya R, Krikken AM, Veenhuis M, van der Klei IJ - J. Cell Biol. (2011) Bottom Line: Pex25 cells were not themselves peroxisome deficient but instead contained a slightly increased number of peroxisomes.Peroxisomes reappeared in pex11 pex25 cells upon synthesis of Pex25, but not of Pex11.These data therefore provide new and detailed insight into factors important for de novo peroxisome formation in yeast. View Article: PubMed Central - HTML - PubMed Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, Kluyver Centre for Genomics of Industrial Fermentation, University of Groningen, 9700 CC Groningen, Netherlands. ABSTRACT We identified two proteins, Pex25 and Rho1, which are involved in reintroduction of peroxisomes in peroxisome-deficient yeast cells. These are, together with Pex3, the first proteins identified as essential for this process. Of the three members of the Hansenula polymorpha Pex11 protein family-Pex11, Pex25, and Pex11C-only Pex25 was required for reintroduction of peroxisomes into a peroxisome-deficient mutant strain. In peroxisome-deficient pex3 cells, Pex25 localized to structures adjacent to the ER, whereas in wild-type cells it localized to peroxisomes. Pex25 cells were not themselves peroxisome deficient but instead contained a slightly increased number of peroxisomes. Interestingly, pex11 pex25 double deletion cells, in which both peroxisome fission (due to the deletion of PEX11) and reintroduction (due to deletion of PEX25) was blocked, did display a peroxisome-deficient phenotype. Peroxisomes reappeared in pex11 pex25 cells upon synthesis of Pex25, but not of Pex11. Reintroduction in the presence of Pex25 required the function of the GTPase Rho1. These data therefore provide new and detailed insight into factors important for de novo peroxisome formation in yeast. Show MeSH Major Fungal Proteins/metabolism* Peroxisomes/metabolism* Pichia/metabolism* rho GTP-Binding Proteins/metabolism* Minor Membrane Proteins/metabolism Mutation Related in: MedlinePlus	© Copyright Policy - openaccess Related In: Results - Collection License 1 - License 2 Show All Figures getmorefigures.php?uid=PMC3105547&req=5 fig3: H. polymorpha pex11 pex25 cells are peroxisome deficient. Electron microscopy analysis of pex11 pex25 cells (B) showing the absence of peroxisomal structures. (A) WT control. Cells were grown on glycerol/methanol and fixed with KMnO4. M, mitochondrion; N, nucleus; P, peroxisome; V, vacuole. Bar, 0.5 µm. (C) Cytosolic localization of Pex3-GFP when produced under control of the endogenous promoter in pex11 pex25 cells. The cell wall is indicated in blue. Bar, 1 µm. Mentions: To study the apparent peroxisome-deficient phenotype of pex11 pex25 cells in more detail, electron microscopy was performed. These studies failed to resolve any peroxisomal membrane remnants in pex11 pex25 cells (Fig. 3 B), akin to H. polymorpha pex3 or pex19 cells, at conditions that WT cells contained multiple peroxisomes (Fig. 3 A).

Peroxisome reintroduction in Hansenula polymorpha requires Pex25 and Rho1.

Saraya R, Krikken AM, Veenhuis M, van der Klei IJ - J. Cell Biol. (2011)

Bottom Line: Pex25 cells were not themselves peroxisome deficient but instead contained a slightly increased number of peroxisomes.Peroxisomes reappeared in pex11 pex25 cells upon synthesis of Pex25, but not of Pex11.These data therefore provide new and detailed insight into factors important for de novo peroxisome formation in yeast.

View Article: PubMed Central - HTML - PubMed

Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, Kluyver Centre for Genomics of Industrial Fermentation, University of Groningen, 9700 CC Groningen, Netherlands.

ABSTRACT

We identified two proteins, Pex25 and Rho1, which are involved in reintroduction of peroxisomes in peroxisome-deficient yeast cells. These are, together with Pex3, the first proteins identified as essential for this process. Of the three members of the Hansenula polymorpha Pex11 protein family-Pex11, Pex25, and Pex11C-only Pex25 was required for reintroduction of peroxisomes into a peroxisome-deficient mutant strain. In peroxisome-deficient pex3 cells, Pex25 localized to structures adjacent to the ER, whereas in wild-type cells it localized to peroxisomes. Pex25 cells were not themselves peroxisome deficient but instead contained a slightly increased number of peroxisomes. Interestingly, pex11 pex25 double deletion cells, in which both peroxisome fission (due to the deletion of PEX11) and reintroduction (due to deletion of PEX25) was blocked, did display a peroxisome-deficient phenotype. Peroxisomes reappeared in pex11 pex25 cells upon synthesis of Pex25, but not of Pex11. Reintroduction in the presence of Pex25 required the function of the GTPase Rho1. These data therefore provide new and detailed insight into factors important for de novo peroxisome formation in yeast.

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Related in: MedlinePlus

H. polymorpha pex11 pex25 cells are peroxisome deficient. Electron microscopy analysis of pex11 pex25 cells (B) showing the absence of peroxisomal structures. (A) WT control. Cells were grown on glycerol/methanol and fixed with KMnO4. M, mitochondrion; N, nucleus; P, peroxisome; V, vacuole. Bar, 0.5 µm. (C) Cytosolic localization of Pex3-GFP when produced under control of the endogenous promoter in pex11 pex25 cells. The cell wall is indicated in blue. Bar, 1 µm.

Related In: Results - Collection

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fig3: H. polymorpha pex11 pex25 cells are peroxisome deficient. Electron microscopy analysis of pex11 pex25 cells (B) showing the absence of peroxisomal structures. (A) WT control. Cells were grown on glycerol/methanol and fixed with KMnO4. M, mitochondrion; N, nucleus; P, peroxisome; V, vacuole. Bar, 0.5 µm. (C) Cytosolic localization of Pex3-GFP when produced under control of the endogenous promoter in pex11 pex25 cells. The cell wall is indicated in blue. Bar, 1 µm.

Mentions: To study the apparent peroxisome-deficient phenotype of pex11 pex25 cells in more detail, electron microscopy was performed. These studies failed to resolve any peroxisomal membrane remnants in pex11 pex25 cells (Fig. 3 B), akin to H. polymorpha pex3 or pex19 cells, at conditions that WT cells contained multiple peroxisomes (Fig. 3 A).