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Phosphorylation of Pex11p does not regulate peroxisomal fission in the yeast Hansenula polymorpha.

Thomas AS, Krikken AM, van der Klei IJ, Williams CP - Sci Rep (2015)

Bottom Line: Our data demonstrate that mutations to the phosphorylation site do not disturb the function of Pex11p in peroxisomal fission, nor do they alter the localization of Pex11p.Also, no effect on peroxisome inheritance was observed.Taken together, these data lead us to conclude that peroxisomal fission in H. polymorpha is not modulated by phosphorylation of Pex11p.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, the Netherlands.

ABSTRACT
Pex11p plays a crucial role in peroxisomal fission. Studies in Saccharomyces cerevisiae and Pichia pastoris indicated that Pex11p is activated by phosphorylation, which results in enhanced peroxisome proliferation. In S. cerevisiae but not in P. pastoris, Pex11p phosphorylation was shown to regulate the protein's trafficking to peroxisomes. However, phosphorylation of PpPex11p was proposed to influence its interaction with Fis1p, another component of the organellar fission machinery. Here, we have examined the role of Pex11p phosphorylation in the yeast Hansenula polymorpha. Employing mass spectrometry, we demonstrate that HpPex11p is also phosphorylated on a Serine residue present at a similar position to that of ScPex11p and PpPex11p. Furthermore, through the use of mutants designed to mimic both phosphorylated and unphosphorylated forms of HpPex11p, we have investigated the role of this post-translational modification. Our data demonstrate that mutations to the phosphorylation site do not disturb the function of Pex11p in peroxisomal fission, nor do they alter the localization of Pex11p. Also, no effect on peroxisome inheritance was observed. Taken together, these data lead us to conclude that peroxisomal fission in H. polymorpha is not modulated by phosphorylation of Pex11p.

No MeSH data available.


Related in: MedlinePlus

Phosphorylation of HpPex11p does not affect peroxisome abundance.Fluorescence microscopy images of pex11Δ cells grown on glucose (A) or methanol (B-D), using confocal laser scanning microscopy (CLSM). GFP-SKL was used to mark peroxisomes in glucose-grown cells, whereas PMP47-GFP was used to mark peroxisomes in methanol-grown cells. Besides fluorescent markers, cells produced WT or phosphorylation single mutant (A-C) or double mutant (D) forms of Pex11p, as indicated above panels. All scale bars represent 1 μm.
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f2: Phosphorylation of HpPex11p does not affect peroxisome abundance.Fluorescence microscopy images of pex11Δ cells grown on glucose (A) or methanol (B-D), using confocal laser scanning microscopy (CLSM). GFP-SKL was used to mark peroxisomes in glucose-grown cells, whereas PMP47-GFP was used to mark peroxisomes in methanol-grown cells. Besides fluorescent markers, cells produced WT or phosphorylation single mutant (A-C) or double mutant (D) forms of Pex11p, as indicated above panels. All scale bars represent 1 μm.

Mentions: Next, fluorescence microscopy analysis (Fig. 2A–C; Fig. 3A–C) revealed that peroxisome numbers were comparable between strains expressing WT or mutant versions of HpPex11p, independent of whether cells were grown on glucose (Fig. 2A) or methanol (Fig. 2B,C). Western blotting revealed that Pex11p levels were comparable among strains (Fig. 3E). These findings suggest that phosphorylation of Serine 174 has no significant effect on peroxisome proliferation in glucose or methanol grown H. polymorpha.


Phosphorylation of Pex11p does not regulate peroxisomal fission in the yeast Hansenula polymorpha.

Thomas AS, Krikken AM, van der Klei IJ, Williams CP - Sci Rep (2015)

Phosphorylation of HpPex11p does not affect peroxisome abundance.Fluorescence microscopy images of pex11Δ cells grown on glucose (A) or methanol (B-D), using confocal laser scanning microscopy (CLSM). GFP-SKL was used to mark peroxisomes in glucose-grown cells, whereas PMP47-GFP was used to mark peroxisomes in methanol-grown cells. Besides fluorescent markers, cells produced WT or phosphorylation single mutant (A-C) or double mutant (D) forms of Pex11p, as indicated above panels. All scale bars represent 1 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477233&req=5

f2: Phosphorylation of HpPex11p does not affect peroxisome abundance.Fluorescence microscopy images of pex11Δ cells grown on glucose (A) or methanol (B-D), using confocal laser scanning microscopy (CLSM). GFP-SKL was used to mark peroxisomes in glucose-grown cells, whereas PMP47-GFP was used to mark peroxisomes in methanol-grown cells. Besides fluorescent markers, cells produced WT or phosphorylation single mutant (A-C) or double mutant (D) forms of Pex11p, as indicated above panels. All scale bars represent 1 μm.
Mentions: Next, fluorescence microscopy analysis (Fig. 2A–C; Fig. 3A–C) revealed that peroxisome numbers were comparable between strains expressing WT or mutant versions of HpPex11p, independent of whether cells were grown on glucose (Fig. 2A) or methanol (Fig. 2B,C). Western blotting revealed that Pex11p levels were comparable among strains (Fig. 3E). These findings suggest that phosphorylation of Serine 174 has no significant effect on peroxisome proliferation in glucose or methanol grown H. polymorpha.

Bottom Line: Our data demonstrate that mutations to the phosphorylation site do not disturb the function of Pex11p in peroxisomal fission, nor do they alter the localization of Pex11p.Also, no effect on peroxisome inheritance was observed.Taken together, these data lead us to conclude that peroxisomal fission in H. polymorpha is not modulated by phosphorylation of Pex11p.

View Article: PubMed Central - PubMed

Affiliation: Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, the Netherlands.

ABSTRACT
Pex11p plays a crucial role in peroxisomal fission. Studies in Saccharomyces cerevisiae and Pichia pastoris indicated that Pex11p is activated by phosphorylation, which results in enhanced peroxisome proliferation. In S. cerevisiae but not in P. pastoris, Pex11p phosphorylation was shown to regulate the protein's trafficking to peroxisomes. However, phosphorylation of PpPex11p was proposed to influence its interaction with Fis1p, another component of the organellar fission machinery. Here, we have examined the role of Pex11p phosphorylation in the yeast Hansenula polymorpha. Employing mass spectrometry, we demonstrate that HpPex11p is also phosphorylated on a Serine residue present at a similar position to that of ScPex11p and PpPex11p. Furthermore, through the use of mutants designed to mimic both phosphorylated and unphosphorylated forms of HpPex11p, we have investigated the role of this post-translational modification. Our data demonstrate that mutations to the phosphorylation site do not disturb the function of Pex11p in peroxisomal fission, nor do they alter the localization of Pex11p. Also, no effect on peroxisome inheritance was observed. Taken together, these data lead us to conclude that peroxisomal fission in H. polymorpha is not modulated by phosphorylation of Pex11p.

No MeSH data available.


Related in: MedlinePlus