DNA chain unwinding and annealing reactions of lipocortin (annexin) I heterotetramer: regulation by Ca(2+) and Mg(2+)

Lipocortin I-S100 (calcyclin) heterotetramer exhibited ATPase activity in the presence of dsDNA but not ssDNA. To demonstrate its helicase activity, an 80-mer polynucleotide complementary to the replication origin of M13mp18 was synthesized, and the oligonucleotide, (dC)(20), was ligated to either i...

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Bibliographic Details
Published in:Biochemical and biophysical research communications 2002-02, Vol.291 (2), p.205-209
Main Authors: Hirata, Aiko, Hirata, Fusao
Format: Article
Language:English
Subjects:
Adenosine Triphosphatases - metabolism
Adenosine Triphosphate - pharmacology
Animals
Annexin A1 - metabolism
Calcium - pharmacology
DNA - metabolism
DNA Helicases - metabolism
Dose-Response Relationship, Drug
Magnesium - pharmacology
Nucleic Acid Hybridization
Phospholipids - pharmacology
S100 Proteins - metabolism
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Summary:Lipocortin I-S100 (calcyclin) heterotetramer exhibited ATPase activity in the presence of dsDNA but not ssDNA. To demonstrate its helicase activity, an 80-mer polynucleotide complementary to the replication origin of M13mp18 was synthesized, and the oligonucleotide, (dC)(20), was ligated to either its 5'- or 3'- end for binding to lipocortin. Lipocortin I heterotetramer displaced chains of the partially Y-shaped duplexes with a dC-tail at either the 5'- or 3'- end. The chain displacement required ATP and Mg(2+). Nonhydrolyzable ATP analogues were not effective. Lipocortin I heterotetramer also catalyzed annealing of the polynucleotides to M13mp18. Ca(2+) and phospholipids but not ATP and Mg(2+) were essential for this reaction. Since the chain displacing and annealing reactions were inhibited by monospecific anti-lipocortin I or anti-S100 antibodies, the present observations suggest that the lipocortin I heterotetramer regulates unwinding and annealing of DNA by Mg(2+) (plus ATP) and Ca(2+) (and phospholipids), respectively.
ISSN:0006-291X
DOI:10.1006/bbrc.2002.6422