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Updated: May 27, 2026
12:29
Investigation of Protein Recruitment to DNA Lesions Using 405 Nm Laser Micro-irradiation
Published on: March 20, 2018
DNA binding is essential for PprI function in response to radiation damage in Deinococcus radiodurans
Huiming Lu1, Huan Chen, Guangzhi Xu
1Institute of Nuclear-Agricultural Sciences, Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China.
DNA Repair
|November 5, 2011
Summary
The DNA-binding protein PprI is crucial for Deinococcus radiodurans survival after radiation. PprI regulates genes involved in DNA repair, demonstrating its essential role in cellular resistance to radiation damage.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Deinococcus radiodurans exhibits remarkable radioresistance due to an efficient DNA damage response.
- The regulatory protein PprI controls numerous genes post-radiation, but its mechanism remains unclear.
Purpose of the Study:
- To elucidate the regulatory mechanism of PprI in Deinococcus radiodurans' DNA damage response.
- To investigate the role of PprI's DNA-binding activity in cellular survival and radioresistance.
Main Methods:
- Global transcriptional profiling using microarrays and time-course sampling in wildtype and pprI mutant strains.
- In vitro DNA-binding assays with purified PprI and a helix-turn-helix (HTH) domain mutant.
- Chromatin immunoprecipitation (ChIP) assays to confirm PprI-DNA interactions in vivo.
- Phenotypic analysis of a DNA-binding deficient pprI mutant's resistance to radiation and mitomycin C.
Main Results:
- PprI up-regulates at least 210 genes post-radiation, including 21 DNA repair and replication genes.
- PprI specifically binds to the promoters of recA and pprA, confirmed by in vitro and ChIP assays.
- A PprI mutant lacking DNA-binding activity partially impairs resistance to gamma radiation, UV radiation, and mitomycin C.
Conclusions:
- PprI's DNA-binding activity is essential for programming the DNA repair process in D. radiodurans.
- PprI plays a critical role in cellular survival following radiation-induced DNA damage.
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