| ORIGINAL ARTICLE |
|
| Year : 2016 | Volume
: 7
| Issue : 1 | Page : 42-45 |
|
|
2,2,4-Triamino-5(2H)-oxazolone is a weak substrate for nucleotide excision repair
Katsuhito Kino1, Kaoru Sugasawa2, Hiroshi Miyazawa1, Fumio Hanaoka3
1 Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa, Japan
2 Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, Kobe, Japan
3 Department of Life Science, Faculty of Science, Gakushuin University, Tokyo, Japan
Correspondence Address:
Fumio Hanaoka
Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo - 171-8588
Japan
Katsuhito Kino
Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa - 769-2193
Japan
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/0976-9234.177068
|
|
|
Objective: 2,2,4-Triamino-5(2H)-oxazolone (Oz) is a guanine lesion produced by reactive oxygen radicals and photosensitized oxidation. This nucleobase is a potentially mutagenic lesion, and is removed by several base excision repair enzymes. Our purpose is to analyze whether Oz is the substrate of nucleotide excision repair (NER). Materials and Methods: A lymphoblastoid cell line from the patient with xeroderma pigmentosum (XP) complementation group C (XP3BE) was used. Cell-free NER reactions with covalently closed circular DNAs containing the Oz lesion were performed using the XP3BE whole cell extracts with or without the XPC-RAD23B complex. In addition, DNA fragments (180 bp in length) containing the Oz lesion were used for binding reactions with the XPC-RAD23B complex. Results: We analyzed the cell-free NER activity on Oz and the binding affinity of XPC-RAD23B, which initiates NER. Human cell-free NER activity on Oz was detected, though the reactivity to Oz was lower than that on ultra violet (UV)-induced pyrimidine (6-4) pyrimidone photoproduct (6-4PP). Also, binding of XPC-RAD23B with Oz was lower than that with 6-4PP. Conclusion: Because of the low binding affinity of Oz for XPC-RAD23B, NER efficiency on Oz is very low. Therefore, general NER is not the appropriate repair system for Oz. |
|
|
|
| [FULL TEXT] [PDF]* |
|
 |
|
