Effects of a Single Exposure to UVB Radiation on the Activities and Protein Levels of Copper-Zinc and Manganese Superoxide Dismutase in Cultured Human Keratinocytes

The lung activity of the antioxidant enzymes (AOEs) copper, zinc superoxide dismutase (Cu,Zn SOD), catalase (CAT), and glutathione peroxidase (GP), but not manganese superoxide dismutase (Mn SOD), increases in rats during late gestation; the concentrations of Cu,Zn SOD mRNA and CAT mRNA also rise. During early postnatal exposure to > 95% O2, the lung activity of Cu,Zn SOD, CAT, and GP increases. We now show 1) the lung concentration of Mn SOD mRNA and GP mRNA does not increase in late gestation; 2) Mn SOD activity and the concentration of its mRNA and of GP mRNA increase during exposure of neonatal rats to > 95% O2; and 3) as previously shown for CAT mRNA, the increase in lung concentration of the mRNAs for Cu,Zn SOD, Mn SOD, and GP during early postnatal hyperoxia occurs with a 70–80% prolongation of the half-life of these mRNAs. We conclude that 1) in late gestation the level at which lung AOE gene expression is regulated differs among the enzymes, 2) the level at which lung AOE gene expression is regulated shortly after birth in response to > 95% O2 is uniform among the enzymes, and 3) the lung's AOE response to neonatal hyperoxia is not merely a step-up of its prenatal regulation but involves different regulatory mechanisms based on increased stability of AOE mRNAs

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Molecular cloning and expression patterns of copper/zinc superoxide dismutase and manganese superoxide dismutase in Musca domestica

Gene ◽

10.1016/j.gene.2012.06.025 ◽

2012 ◽

Vol 505 (2) ◽

pp. 211-220 ◽

Cited By ~ 27

Author(s):

Ting Tang ◽

Da-Wei Huang ◽

Chuan-Qi Zhou ◽

Xiang Li ◽

Qi-Jing Xie ◽

...

Keyword(s):

Superoxide Dismutase ◽

Molecular Cloning ◽

Musca Domestica ◽

Manganese Superoxide Dismutase ◽

Expression Patterns ◽

Cloning And Expression ◽

Copper Zinc Superoxide Dismutase ◽

Zinc Superoxide Dismutase ◽

Manganese Superoxide ◽

Copper Zinc

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Manganese Superoxide Dismutase inSaccharomyces cerevisiaeAcquires Its Metal Co-factor through a Pathway Involving the Nramp Metal Transporter, Smf2p

Journal of Biological Chemistry ◽

10.1074/jbc.m108923200 ◽

2001 ◽

Vol 276 (50) ◽

pp. 47556-47562 ◽

Cited By ~ 83

Author(s):

Edward E-Ching Luk ◽

Valeria Cizewski Culotta

Keyword(s):

Superoxide Dismutase ◽

Manganese Superoxide Dismutase ◽

Protein Glycosylation ◽

Copper Trafficking ◽

Metal Transporter ◽

Trafficking Pathway ◽

Manganese Superoxide ◽

Steady State Levels ◽

Copper Zinc ◽

Intracellular Vesicles

Eukaryotes express both copper/zinc (SOD1)- and manganese (SOD2)-requiring superoxide dismutase enzymes that guard against oxidative damage. Although SOD1 acquires its copper through a specific copper trafficking pathway, nothing is known regarding the intracellular manganese trafficking pathway for SOD2. We demonstrate here that inSaccharomyces cerevisiaecells delivery of manganese to SOD2 in the mitochondria requires the Nramp metal transporter, Smf2p. SOD2 activity is greatly diminished insmf2Δ mutants, even though the mature SOD2 polypeptide accumulates to normal levels in mitochondria. Treatingsmf2Δ cells with manganese supplements corrected the SOD2 defect, as did elevating intracellular manganese through mutations inPMR1.Hence, manganese appears to be inaccessible to mitochondrial SOD2 insmf2mutants. Cells lackingSMF2also exhibited defects in manganese-dependent steps in protein glycosylation and showed an overall decrease in steady-state levels of accumulated manganese. By comparison, mutations in the cell surface Nramp transporter, Smf1p, had very little impact on manganese accumulation and trafficking. Smf2p resides in intracellular vesicles and shows no evidence of plasma membrane localization, even in anend4mutant blocked for endocytosis. We propose a model in which Smf2p-containing vesicles play a central role in manganese trafficking to the mitochondria and other cellular sites as well.

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