Identification and expression of the gene product encoding a CPD photolyase from Dunaliella salina.
Ultraviolet light induces photoproducts, cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts (6-4PPs), in cellular DNA, which cause cytotoxic and genotoxic effects on the cells. Cells have several DNA repair mechanisms to repair the damage and to maintain genetic information of the cells. Photoreactivation is one of the DNA repair mechanism to remove UV-induced DNA damage from cellular DNA catalyzed by photolyase under visible light. Two types of photolyase, CPD photolyase and (6-4) photolyase, are specific for CPDs and for (6-4)PPs. We have isolated a gene product encoding CPD photolyase, named PHR2, from Dunaliella salina which is a kind of unicellular alga. Sequence analysis showed that PHR2 encodes a protein that has 529 amino acids and is similar to other Class II CPD photolyase. The complementation assay of the photoreactivation deficiency of the Escherichia coli SY2 by PHR2 cDNA showed a significant increase in survival rate when cells were irradiated with UV-C. Real-time PCR analysis indicated that the transcription of PHR2 was induced by UV-C, white light, high salinity, and H(2)O(2).
Cheng
Long
L
Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University, Sichuan 610064, PR China.
Qiao
Dai Rong
DR
Lu
Xue Yan
XY
Xiong
Yan
Y
Bai
Lin Han
LH
Xu
Hui
H
Yang
Yang
Y
Cao
Yi
Y
D020418:Algal Proteins / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000235:genetics* / Q000502:physiology; D056890:Eukaryota / Q000201:enzymology; D008969:Molecular Sequence Data; D011740:Pyrimidine Dimers; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D015996:Survival Rate; D014466:Ultraviolet Rays / Q000009:adverse effects
D020418:Algal Proteins; D011740:Pyrimidine Dimers; C098727:pyrimidine(6-4)pyrimidone photolyase; D004255:Deoxyribodipyrimidine Photo-Lyase