• Media type: E-Article
  • Title: Submillimolar Levels of Calcium Regulates DNA Structure at the Dinucleotide Repeat (TG/AC)n
  • Contributor: Dobi, A.; Agoston, D. V.
  • imprint: National Academy of Sciences of the United States of America, 1998
  • Published in: Proceedings of the National Academy of Sciences of the United States of America
  • Language: English
  • ISSN: 0027-8424
  • Origination:
  • Footnote:
  • Description: <p>Submillimolar levels of calcium, similar to the physiological total (bound + free) intranuclear concentration (0.01-1 mM), induced a conformational change within d(TG/AC)<sub>n</sub>, one of the frequent dinucleotide repeats of the mammalian genome. This change is calcium-specific, because no other tested cation induced it and it was detected as a concentration-dependent transition from B- to a non-B-DNA conformation expanding from 3<sup>′</sup>end toward the 5<sup>′</sup>of the repeat. Genomic footprinting of various rat brain regions revealed the existence of similar non-B-DNA conformation within a d(TG/AC)<sub>28</sub>repeat of the endogenous enkephalin gene only in enkephalin-expressing caudate nucleus and not in the nonexpressing thalamus. Binding assays demonstrated that DNA could bind calcium and can compete with calmodulin for calcium.</p>
  • Access State: Open Access