TY - JOUR
T1 - DNA binding is essential for PprI function in response to radiation damage in Deinococcus radiodurans
AU - Lu, Huiming
AU - Chen, Huan
AU - Xu, Guangzhi
AU - Shah, Amir Miraj Ul Hussain
AU - Hua, Yuejin
N1 - Funding Information:
This work was supported by grants from National Natural Science Foundation of China ( 30830006 , 31000045 ), a major scientific and technological project for significant new drugs creation (2009ZXJ09001-034), a grant from Special Fund for Agroscientific Research in the Public Interest ( 201103007 ), grants from China Postdoctoral Science Foundation ( 20090460101 , 201003728 ).
PY - 2012/2/1
Y1 - 2012/2/1
N2 - The extremely radioresistant bacterium. Deinococcus radiodurans possesses a rapid and efficient but poorly known DNA damage response mechanism that mobilizes one-third of its genome to survive lethal radiation damage. Deinococcal PprI serves as a general switch to regulate the expression of dozens of proteins from different pathways after radiation, including the DNA repair proteins RecA, PprA and SSB. However, the underlying mechanism is poorly understood. In this study, we analyzed the dynamic alteration in global transcriptional profiles in wildtype and. pprI mutant strains by combining microarrays and time-course sampling. We found that PprI up-regulated transcription of at least 210 genes after radiation, including 21 DNA repair and replication-related genes. We purified PprI and a helix-turn-helix (HTH) domain mutant and found that PprI specifically bound to the promoters of. recA and. pprA in vitro but did not bind nonspecific double-strand DNA. Chromatin immunoprecipitation (ChIP) assays confirmed that PprI specifically interacted with the promoter DNA of. recA and. pprA after radiation. Finally, we showed that a DNA-binding activity-deficient pprI mutant only partially restored resistance of the. pprI mutant strain to γ radiation, UV radiation, and mitomycin C. Taken together, these results indicate that DNA-binding activity is essential for PprI to program the DNA repair process and cellular survival of. D. radiodurans in response to radiation damage.
AB - The extremely radioresistant bacterium. Deinococcus radiodurans possesses a rapid and efficient but poorly known DNA damage response mechanism that mobilizes one-third of its genome to survive lethal radiation damage. Deinococcal PprI serves as a general switch to regulate the expression of dozens of proteins from different pathways after radiation, including the DNA repair proteins RecA, PprA and SSB. However, the underlying mechanism is poorly understood. In this study, we analyzed the dynamic alteration in global transcriptional profiles in wildtype and. pprI mutant strains by combining microarrays and time-course sampling. We found that PprI up-regulated transcription of at least 210 genes after radiation, including 21 DNA repair and replication-related genes. We purified PprI and a helix-turn-helix (HTH) domain mutant and found that PprI specifically bound to the promoters of. recA and. pprA in vitro but did not bind nonspecific double-strand DNA. Chromatin immunoprecipitation (ChIP) assays confirmed that PprI specifically interacted with the promoter DNA of. recA and. pprA after radiation. Finally, we showed that a DNA-binding activity-deficient pprI mutant only partially restored resistance of the. pprI mutant strain to γ radiation, UV radiation, and mitomycin C. Taken together, these results indicate that DNA-binding activity is essential for PprI to program the DNA repair process and cellular survival of. D. radiodurans in response to radiation damage.
KW - DNA damage
KW - Deinococcus radiodurans
KW - Ionizing radiation
KW - PprI
KW - Response regulator
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U2 - 10.1016/j.dnarep.2011.10.013
DO - 10.1016/j.dnarep.2011.10.013
M3 - Article
C2 - 22051194
AN - SCOPUS:84855821920
SN - 1568-7864
VL - 11
SP - 139
EP - 145
JO - DNA repair
JF - DNA repair
IS - 2
ER -