title: Circadian oscillation of nucleotide excision repair in mammalian brain.
abstract: The circadian clock regulates the daily rhythms in the physiology and behavior of many organisms, including mice and humans. These cyclical changes at molecular and macroscopic levels affect the organism's response to environmental stimuli such as light and food intake and the toxicity and efficacy of chemo- and radiotherapeutic agents. In this work, we investigated the circadian behavior of the nucleotide excision repair capacity in the mouse cerebrum to gain some insight into the optimal circadian time for favorable therapeutic response with minimal side effects in cancer treatment with chemotherapeutic drugs that produce bulky adducts in DNA. We find that nucleotide excision repair activity in the mouse cortex is highest in the afternoon/evening hours and is at its lowest in the night/early morning hours. The circadian oscillation of the repair capacity is caused at least in part by the circadian oscillation of the xeroderma pigmentosum A DNA damage recognition protein.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Tae-Hong
authors.initials: TH
authors.lastname: Kang
authors.forename: Joyce T
authors.initials: JT
authors.lastname: Reardon
authors.forename: Michael
authors.initials: M
authors.lastname: Kemp
authors.forename: Aziz
authors.initials: A
authors.lastname: Sancar
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D056926:CLOCK Proteins; D018797:Cell Cycle Proteins / Q000378:metabolism; D002940:Circadian Rhythm; D004260:DNA Repair; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D051760:Xeroderma Pigmentosum Group A Protein / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; D051760:Xeroderma Pigmentosum Group A Protein; C497315:Xpa protein, mouse; D056926:CLOCK Proteins; C538943:CLOCK protein, human; C538944:Clock protein, mouse