Rat lung contains a developmentally regulated manganese superoxide dismutase mRNA-binding protein.
It has become increasingly clear that RNA-binding proteins play an important role in the regulation of gene expression. The presence in rat lung of a specific, redox-sensitive catalase RNA-binding protein was recently reported (Clerch, L. B., and D. Massaro, 1992. J. Biol. Chem. 267:2853). In order to determine if specific manganese superoxide dismutase (MnSOD) RNA-binding proteins exist, we tested whether protein in rat lung extract would bind to 32P-labeled MnSOD RNA. Using a gel mobility shift assay we show rat lung protein forms specific complexes with a 216 b fragment of the 3' untranslated region of MnSOD RNA and the binding requires the presence of free sulfhydryl groups. Competition studies indicate MnSOD RNA-binding protein is different from catalase RNA-binding protein. Furthermore, unlike catalase RNA-binding protein, rat lung MnSOD RNA-binding protein activity is developmentally regulated; there is less MnSOD RNA-protein binding activity in adult rat lung extract compared to prenatal or neonatal rat lung extracts. We conclude the lung contains developmentally regulated MnSOD mRNA-binding protein that is redox sensitive.
Department of Pediatrics, Georgetown University Medical Center, Washington, DC 20007.
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Fazzone
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D000818:Animals; D001665:Binding Sites; D008168:Lung / Q000196:embryology / Q000378:metabolism*; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000235:genetics*
D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D013482:Superoxide Dismutase