Effects of metals on the binding of protein factors to the mouse 2',5'-oligoadenylate synthetase ME-12 gene regulatory region.
We have previously demonstrated that using mouse 2',5'-oligoadenylate synthetase (2-5A synthetase) gene (ME-12) regulatory region AB as a probe, at least six complexes (C1-C6) can be detected by the mobility shift electrophoresis assay with extracts of murine BALB/c-3T3 cells. The formation of these complexes is greatly influenced by different buffer conditions and the presence of metals. C1 and C4 signals are stronger in Tris-HCl buffer than in phosphate buffer in the absence of added metals. Both Na+ and Mg2+ facilitate C1, C3, and C4 formation. Na+ also facilitates C3 and C4 formation with the interferon (IFN) response element B. Na+ has little effect on C2 formation with the regulatory region AB, whereas presence of Mg2+ at low concentrations gives a strong C2 signal. A new band, C7, was detected in the presence of 50 or 100 mM Na+. A relatively high Mg2+ concentration is required for C5 formation and Mg2+ interferes with C6 and C7 formation. Cu2+ and Zn2+ markedly inhibit formation of most complexes. However, a new band forms in 0.15 mM Cu2+ when 10 mM Mg2+ was also present. Co2+ enhances C2b and C3 formation and inhibits C4 formation. Mn2+ enhances C3, C1, and C2 formation to different degrees and inhibits C4 formation. At 0.15 and 0.25 mM, Mn2+ generates a new band. In competition experiments between Cu2+ and Mg2+, Cu2+ strongly inhibited Mg2+ effects on complex formation, except that 0.15 or 0.25 mM Cu2+ enhanced the C2a and C2b signals.
Yan
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Rockefeller University, New York, NY 10021.
Tamm
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D015088:2',5'-Oligoadenylate Synthetase / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003035:Cobalt / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000187:drug effects*; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D051379:Mice; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D011485:Protein Binding / Q000187:drug effects; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012964:Sodium / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
D004268:DNA-Binding Proteins; D008670:Metals; D003035:Cobalt; D008345:Manganese; D003300:Copper; D012964:Sodium; D015088:2',5'-Oligoadenylate Synthetase; D008274:Magnesium; D015032:Zinc