Changes in redox affect the activity of erythropoietin RNA binding protein

• Published in: FEBS letters 1995-02, Vol.359 (2), p.267-270
• Main Authors: Rondon, Isaac J., Scandurro, Aline B., Wilson, Russell B., Beckman, Barbara S.
• Format: Article
• Language: English
• Subjects: 2-ME; 2-mercaptoethanol; 3′-untranslated region; 3′-UTR; adenosine-uridine binding factor; AUBF; Cell Hypoxia; dithiothreitol; DTT; EPO, erythropoietin; ERBP; Erythropoietin; Erythropoietin - genetics; erythropoietin RNA binding protein; Ethylmaleimide - pharmacology; FBS; fetal bovine serum; GM-CSF; granulocyte-macrophage colony-stimulating factor; Humans; IRE-BP; iron-responsive element-binding protein; MEM; minimal essential medium; N-ethylmaleimide; NEM; Oxidants - pharmacology; Oxidation-Reduction; PBS; phosphate buffered saline; Protein Binding - drug effects; Redox; RNA binding protein; RNA, Messenger - metabolism; RNA-Binding Proteins - metabolism; Tumor Cells, Cultured
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(95)00066-I

We have previously identified a cytosolic protein, erythropoietin RNA binding protein (ERBP), which is up-regulated in certain tissues in response to hypoxia. To further characterize the interaction of ERBP and erythropoietin (EPO) mRNA, we have examined the role of reduction-oxidation in the EPO mRNA binding mechanism of ERBP isolated from human hepatoma cells (Hep3B). Reducing agents dithiothreitol (DTT) and 2-mercaptoethanol (2-ME) increased ERBP binding activity in a concentration-dependent manner, whereas the oxidizing agent, diamide, abolished ERBP binding activity. In addition, treatment of Hep3B cell lysates with the irreversible sulfhydryl alkylating agent N-ethylmaleimide resulted in inhibition of the EPO mRNA-ERBP complex. Taken together, these findings suggest that sulfhydryl groups may play a role in vivo in the regulation of EPO production through the modulation of ERBP binding activity.