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Control of the pericentrosomal H2O2 level by peroxiredoxin I is critical for mitotic progression.

Lim JM, Lee KS, Woo HA, Kang D, Rhee SG - J. Cell Biol. (2015)

Bottom Line: The intracellular concentration of H2O2 increases as the cell cycle progresses.Whereas the centrosome is shielded from H2O2 through its association with the H2O2-eliminating enzyme peroxiredoxin I (PrxI) during interphase, the centrosome-associated PrxI is selectively inactivated through phosphorylation by Cdk1 during early mitosis, thereby exposing the centrosome to H2O2 and facilitating inactivation of centrosome-bound phosphatases.Dephosphorylation of PrxI by okadaic acid-sensitive phosphatases during late mitosis again shields the centrosome from H2O2 and thereby allows the reactivation of Cdk1-opposing phosphatases at the organelle.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea.

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Effects of centrosome-targeted catalase and OA on Cdh1 phosphorylation and mitotic entry. (A and B) HeLa cells were infected with empty, Cat-PACT, or Cat-delPACT retroviral vectors and synchronized at prometaphase. Cell lysates were then subjected to immunoblot analysis with antibodies to the indicated proteins (A). The relative immunoblot intensities of Cdh1 and pCdh1 normalized by those of actin were determined as means ± SD from three independent experiments (B). *, P < 0.05; **, P < 0.005 (Student’s t test). (C and D) HeLa cells were cultured in the presence of the indicated concentrations of okadaic acid (OA) for 24 h (C) or transiently transfected for 48 h with control siRNA or with a mixtures of siRNAs for PP1, PP2Aα, and PP2Aβ (D), after which cell lysates were subjected to immunoblot analysis with antibodies to the indicated proteins. Data are representative of three experiments with similar results. Cont, control.
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fig4: Effects of centrosome-targeted catalase and OA on Cdh1 phosphorylation and mitotic entry. (A and B) HeLa cells were infected with empty, Cat-PACT, or Cat-delPACT retroviral vectors and synchronized at prometaphase. Cell lysates were then subjected to immunoblot analysis with antibodies to the indicated proteins (A). The relative immunoblot intensities of Cdh1 and pCdh1 normalized by those of actin were determined as means ± SD from three independent experiments (B). *, P < 0.05; **, P < 0.005 (Student’s t test). (C and D) HeLa cells were cultured in the presence of the indicated concentrations of okadaic acid (OA) for 24 h (C) or transiently transfected for 48 h with control siRNA or with a mixtures of siRNAs for PP1, PP2Aα, and PP2Aβ (D), after which cell lysates were subjected to immunoblot analysis with antibodies to the indicated proteins. Data are representative of three experiments with similar results. Cont, control.

Mentions: Using the antibodies to pCdh1, we investigated the effect of Cat-PACT expression on Ser40 phosphorylation in nocodazole-arrested cells. The amount of pCdh1 in HeLa cells expressing Cat-PACT was reduced by ∼30% compared with that in cells infected with the empty vector or expressing Cat-delPACT (Fig. 4, A and B), consistent with the notion that Cdh1 phosphorylation is highly influenced by pericentrosomal H2O2 level and that pCdh1 undergoes turnover at the centrosome (Raff et al., 2002).


Control of the pericentrosomal H2O2 level by peroxiredoxin I is critical for mitotic progression.

Lim JM, Lee KS, Woo HA, Kang D, Rhee SG - J. Cell Biol. (2015)

Effects of centrosome-targeted catalase and OA on Cdh1 phosphorylation and mitotic entry. (A and B) HeLa cells were infected with empty, Cat-PACT, or Cat-delPACT retroviral vectors and synchronized at prometaphase. Cell lysates were then subjected to immunoblot analysis with antibodies to the indicated proteins (A). The relative immunoblot intensities of Cdh1 and pCdh1 normalized by those of actin were determined as means ± SD from three independent experiments (B). *, P < 0.05; **, P < 0.005 (Student’s t test). (C and D) HeLa cells were cultured in the presence of the indicated concentrations of okadaic acid (OA) for 24 h (C) or transiently transfected for 48 h with control siRNA or with a mixtures of siRNAs for PP1, PP2Aα, and PP2Aβ (D), after which cell lysates were subjected to immunoblot analysis with antibodies to the indicated proteins. Data are representative of three experiments with similar results. Cont, control.
© Copyright Policy - openaccess
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4493999&req=5

fig4: Effects of centrosome-targeted catalase and OA on Cdh1 phosphorylation and mitotic entry. (A and B) HeLa cells were infected with empty, Cat-PACT, or Cat-delPACT retroviral vectors and synchronized at prometaphase. Cell lysates were then subjected to immunoblot analysis with antibodies to the indicated proteins (A). The relative immunoblot intensities of Cdh1 and pCdh1 normalized by those of actin were determined as means ± SD from three independent experiments (B). *, P < 0.05; **, P < 0.005 (Student’s t test). (C and D) HeLa cells were cultured in the presence of the indicated concentrations of okadaic acid (OA) for 24 h (C) or transiently transfected for 48 h with control siRNA or with a mixtures of siRNAs for PP1, PP2Aα, and PP2Aβ (D), after which cell lysates were subjected to immunoblot analysis with antibodies to the indicated proteins. Data are representative of three experiments with similar results. Cont, control.
Mentions: Using the antibodies to pCdh1, we investigated the effect of Cat-PACT expression on Ser40 phosphorylation in nocodazole-arrested cells. The amount of pCdh1 in HeLa cells expressing Cat-PACT was reduced by ∼30% compared with that in cells infected with the empty vector or expressing Cat-delPACT (Fig. 4, A and B), consistent with the notion that Cdh1 phosphorylation is highly influenced by pericentrosomal H2O2 level and that pCdh1 undergoes turnover at the centrosome (Raff et al., 2002).

Bottom Line: The intracellular concentration of H2O2 increases as the cell cycle progresses.Whereas the centrosome is shielded from H2O2 through its association with the H2O2-eliminating enzyme peroxiredoxin I (PrxI) during interphase, the centrosome-associated PrxI is selectively inactivated through phosphorylation by Cdk1 during early mitosis, thereby exposing the centrosome to H2O2 and facilitating inactivation of centrosome-bound phosphatases.Dephosphorylation of PrxI by okadaic acid-sensitive phosphatases during late mitosis again shields the centrosome from H2O2 and thereby allows the reactivation of Cdk1-opposing phosphatases at the organelle.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, South Korea.

Show MeSH
Related in: MedlinePlus