title: Mechanistic and biological considerations of oxidatively damaged DNA for helicase-dependent pathways of nucleic acid metabolism.
abstract: Cells are under constant assault from reactive oxygen species that occur endogenously or arise from environmental agents. An important consequence of such stress is the generation of oxidatively damaged DNA, which is represented by a wide range of non-helix distorting and helix-distorting bulkier lesions that potentially affect a number of pathways including replication and transcription; consequently DNA damage tolerance and repair pathways are elicited to help cells cope with the lesions. The cellular consequences and metabolism of oxidatively damaged DNA can be quite complex with a number of DNA metabolic proteins and pathways involved. Many of the responses to oxidative stress involve a specialized class of enzymes known as helicases, the topic of this review. Helicases are molecular motors that convert the energy of nucleoside triphosphate hydrolysis to unwinding of structured polynucleic acids. Helicases by their very nature play fundamentally important roles in DNA metabolism and are implicated in processes that suppress chromosomal instability, genetic disease, cancer, and aging. We will discuss the roles of helicases in response to nuclear and mitochondrial oxidative stress and how this important class of enzymes help cells cope with oxidatively generated DNA damage through their functions in the replication stress response, DNA repair, and transcriptional regulation.
authors.affiliation: Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224, USA.
authors.forename: Jack D
authors.initials: JD
authors.lastname: Crouch
authors.affiliation: Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224, USA. Electronic address: broshr@mail.nih.gov.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Brosh
mesh_terms: D000375:Aging; D000818:Animals; D063646:Carcinogenesis; D043171:Chromosomal Instability; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D006801:Humans; D009696:Nucleic Acids / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D009696:Nucleic Acids; D017382:Reactive Oxygen Species; D004247:DNA; D004265:DNA Helicases
keywords: DNA metabolism; DNA repair; Helicase; Human disease; Nucleic acid; Oxidatively damaged DNA; Reactive oxygen species; Replication