Characterization of magnesium requirement of human 5' -tyrosyl DNA phosphodiesterase mediated reaction
- Authors
- Adhikari, S., Karmahapatra, S.K., Karve, T.M., Bandyopadhyay, S., Woodrick, J., Manthena, P.V., Glasgow, E., Byers, S., Saha, T., and Uren, A.
- ID
- ZDB-PUB-120314-17
- Date
- 2012
- Source
- BMC research notes 5(1): 134 (Journal)
- Registered Authors
- Glasgow, Eric
- Keywords
- none
- MeSH Terms
-
- Animals
- Calcium/metabolism
- Cell Extracts/chemistry
- DNA/metabolism
- Electrophoresis, Polyacrylamide Gel
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/enzymology*
- Enzyme Activation
- Escherichia coli/genetics
- Fish Proteins/isolation & purification
- Fish Proteins/metabolism*
- Humans
- MCF-7 Cells
- Magnesium/metabolism*
- Manganese/metabolism*
- Nuclear Proteins/genetics
- Nuclear Proteins/isolation & purification
- Nuclear Proteins/metabolism*
- Oligonucleotides/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/isolation & purification
- Recombinant Proteins/metabolism
- Tissue Extracts/chemistry
- Transcription Factors/genetics
- Transcription Factors/isolation & purification
- Transcription Factors/metabolism*
- Zebrafish/embryology
- Zebrafish/metabolism*
- Zinc/metabolism
- PubMed
- 22405347 Full text @ BMC Res. Notes
Background
Topo-poisons can produce an enzyme-DNA complex linked by a 3' - or 5' -phosphotyrosyl covalent bond. 3' -phosphotyrosyl bonds can be repaired by tyrosyl DNA phosphodiesterase-1 (TDP1), an enzyme known for years, but a complementary human enzyme 5' -tyrosyl DNA phosphodiesterase (hTDP2) that cleaves 5' -phosphotyrosyl bonds has been reported only recently. Although hTDP2 possesses both 3' - and 5' - tyrosyl DNA phosphodiesterase activity, the role of Mg2+ in its activity was not studied in sufficient details.
Results
In this study we showed that purified hTDP2 does not exhibit any 5' -phosphotyrosyl phosphodiesterase activity in the absence of Mg2+/Mn2+, and that neither Zn2+ or nor Ca2+ can activate hTDP2. Mg2+ also controls 3' -phosphotyrosyl activity of TDP2. In MCF-7 cell extracts and de-yolked zebrafish embryo extracts, Mg2+ controlled 5' -phosphotyrosyl activity. This study also showed that there is an optimal Mg2+ concentration above which it is inhibitory for hTDP2 activity.
Conclusion
These results altogether reveal the optimal Mg2+ requirement in hTDP2 mediated reaction.