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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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Electron microscopy. Electron microscopy of pex11 pex25 RHO1ts cells that produce PAOX PEX25-mCherry. Cells were grown on glycerol/methanol/ammoniumsulphate for 5 h at permissive (35°C) and restrictive temperatures (44°C). Cross sections of the tubular-like structures are shown in B (overview of cell) and D (high magnification of B to show the tubular structure). (C) A longitudinal section through these tubular structures. Bar, 500 nm.
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fig10: Electron microscopy. Electron microscopy of pex11 pex25 RHO1ts cells that produce PAOX PEX25-mCherry. Cells were grown on glycerol/methanol/ammoniumsulphate for 5 h at permissive (35°C) and restrictive temperatures (44°C). Cross sections of the tubular-like structures are shown in B (overview of cell) and D (high magnification of B to show the tubular structure). (C) A longitudinal section through these tubular structures. Bar, 500 nm.

Mentions: We subsequently introduced the temperature-sensitive Rho1 mutation in the pex11 pex25 strain containing PEX25-mCherry under control of PAOX (strain pex11 pex25 PRHO1RHO1ts PAOXPEX25 mCherry). Cells were pregrown on glucose at the permissive temperature (35°C) to the late exponential growth phase and subsequently shifted to fresh glycerol/methanol-containing media and grown at the permissive or restrictive conditions. When grown at 35°C, peroxisomes were readily formed and marked by Pex25 mCherry (Fig. 9 H). The organelles were also readily detectable by electron microscopy (Fig. 10 A). However, at 44°C Pex25-mCherry initially (3–5 h of cultivation) was observed as a distinct spot (Fig. 9 I), most likely located at the ER/nuclear membrane, which disappeared again after further cultivation (not depicted). Synthesis of Pex25-mCherry in pex11 pex25 cells without the temperature-sensitive mutation in RHO1 resulted in peroxisome formation both at 35°C (Fig. 9 F) and 44°C (Fig. 9 G).


Peroxisome reintroduction in Hansenula polymorpha requires Pex25 and Rho1.

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

Electron microscopy. Electron microscopy of pex11 pex25 RHO1ts cells that produce PAOX PEX25-mCherry. Cells were grown on glycerol/methanol/ammoniumsulphate for 5 h at permissive (35°C) and restrictive temperatures (44°C). Cross sections of the tubular-like structures are shown in B (overview of cell) and D (high magnification of B to show the tubular structure). (C) A longitudinal section through these tubular structures. Bar, 500 nm.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3105547&req=5

fig10: Electron microscopy. Electron microscopy of pex11 pex25 RHO1ts cells that produce PAOX PEX25-mCherry. Cells were grown on glycerol/methanol/ammoniumsulphate for 5 h at permissive (35°C) and restrictive temperatures (44°C). Cross sections of the tubular-like structures are shown in B (overview of cell) and D (high magnification of B to show the tubular structure). (C) A longitudinal section through these tubular structures. Bar, 500 nm.
Mentions: We subsequently introduced the temperature-sensitive Rho1 mutation in the pex11 pex25 strain containing PEX25-mCherry under control of PAOX (strain pex11 pex25 PRHO1RHO1ts PAOXPEX25 mCherry). Cells were pregrown on glucose at the permissive temperature (35°C) to the late exponential growth phase and subsequently shifted to fresh glycerol/methanol-containing media and grown at the permissive or restrictive conditions. When grown at 35°C, peroxisomes were readily formed and marked by Pex25 mCherry (Fig. 9 H). The organelles were also readily detectable by electron microscopy (Fig. 10 A). However, at 44°C Pex25-mCherry initially (3–5 h of cultivation) was observed as a distinct spot (Fig. 9 I), most likely located at the ER/nuclear membrane, which disappeared again after further cultivation (not depicted). Synthesis of Pex25-mCherry in pex11 pex25 cells without the temperature-sensitive mutation in RHO1 resulted in peroxisome formation both at 35°C (Fig. 9 F) and 44°C (Fig. 9 G).

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
Related in: MedlinePlus