Abstract
Nuclei from calf thymus tissue digested with micrococcal nuclease under nonchelating conditions yielded soluble nucleoprotein enriched in copper. Following limited digestion, the ratio of μg Cu:mg DNA was inversely related either to percent solubility of chromatin or to levels of enzyme maintaining an enzyme:A 260 ratio of 0.059. The enzyme appeared to cleave preferentially regions of chromatin where copper is localized, releasing no additional metal upon further digestion. Moreover, the highest copper: DNA ratio was always associated with the least-digested sample.
The distribution between copper and angiotensin II (AII) in chromatin fragments following slight nuclease digestion suggests a possible link between copper and nuclear AII binding. When nuclei are incubated with AII prior to digestion and dialysis, solubilized chromatin contained about three times more copper than buffer control. Metal profiles generated from gel (A-5 M) chromatography for these samples were distinctive: copper peaks appeared near or adjacent to linker DNA regions, and in the case of AII, coincided with fragments containing specific AII receptors; thus, there appears to be an enrichment of copper in these active nucleoprotein fragments.
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References
R. D. Kornberg,Annu. Rev. Biochem. 46, 931 (1977).
J. D. McGhee and G. Felsenfeld,Annu. Rev. Biochem. 94, 1115 (1980).
M. Cockell, D. Rhodes, and A. Klug,J. Mol. Biol. 170, 423 (1983).
S. Weishrod,Nature 297, 289 (1982).
R. P. Aaronson and E. Woo,J. Cell Biol. 90, 181 (1981).
D. E. Olins and A. Olins,J. Cell Biol. 53, 715 (1972).
D. A. Beary, D. L. Vizard, R. A. LaBiche, K. J. Hardy, and S. E. Bryan,Biochem. Biophys. Res. Commun. 104, 491 (1982).
S. E. Bryan, D. L. Vizard, D. A. Beary, R. A. LaBiche, and K. J. Hardy,Nucleic Acid Res. 9, 5811 (1981).
R. N. Re, D. L. Vizard, J. Brown, and S. E. Bryan,Biochem. Biophys. Res. Commun. 119, 220 (1984).
R. N. Re, D. L. Vizard, J. Brown, and S. E. Bryan,J. Hypertension (in press) (1985).
R. N. Re, R. A. LaBiche, and S. E. Bryan,Biochem. Biophys. Res. Commun. 110, 61 (1983).
J. N. Vanderbilt, K. S. Bloom, and J. N. Anderson,J. Biol. Chem 257, 13009 (1982).
C. D. Lewis and U. K. Laemmli,Cell 29, 171 (1982).
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Bryan, S.E., LeGros, L., Brown, J. et al. Copper-rich nucleoprotein generated by micrococcal nuclease. Biol Trace Elem Res 8, 219–229 (1985). https://doi.org/10.1007/BF02917461
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DOI: https://doi.org/10.1007/BF02917461
Index Entries
- Copper in thymus nuclei
- zinc, and Cu in nuclei
- copper, released by micrococcal nuclease
- copper, in active chromatin
- metal profiles (Cu and Zn), generated from gel chromatography
- copper, associated with linker DNA
- copper, associated with nuclear angiotensin II (AII) receptors
- nucleoprotein, copper-rich, micrococcal nuclease, Cu-rich nucleoprotein from
- nuclease, Cu-rich nucleoprotein from micrococcal nuclease