title: Something old, something new, something borrowed; how the thermoacidophilic archaeon Sulfolobus solfataricus responds to oxidative stress.
abstract: To avoid molecular damage of biomolecules due to oxidation, all cells have evolved constitutive and responsive systems to mitigate and repair chemical modifications. Archaea have adapted to some of the most extreme environments known to support life, including highly oxidizing conditions. However, in comparison to bacteria and eukaryotes, relatively little is known about the biology and biochemistry of archaea in response to changing conditions and repair of oxidative damage. In this study transcriptome, proteome, and chemical reactivity analyses of hydrogen peroxide (H(2)O(2)) induced oxidative stress in Sulfolobus solfataricus (P2) were conducted. Microarray analysis of mRNA expression showed that 102 transcripts were regulated by at least 1.5 fold, 30 minutes after exposure to 30 microM H(2)O(2). Parallel proteomic analyses using two-dimensional differential gel electrophoresis (2D-DIGE), monitored more than 800 proteins 30 and 105 minutes after exposure and found that 18 had significant changes in abundance. A recently characterized ferritin-like antioxidant protein, DPSL, was the most highly regulated species of mRNA and protein, in addition to being post-translationally modified. As expected, a number of antioxidant related mRNAs and proteins were differentially regulated. Three of these, DPSL, superoxide dismutase, and peroxiredoxin were shown to interact and likely form a novel supramolecular complex for mitigating oxidative damage. A scheme for the ability of this complex to perform multi-step reactions is presented. Despite the central role played by DPSL, cells maintained a lower level of protection after disruption of the dpsl gene, indicating a level of redundancy in the oxidative stress pathways of S. solfataricus. This work provides the first "omics" scale assessment of the oxidative stress response for an archeal organism and together with a network analysis using data from previous studies on bacteria and eukaryotes reveals evolutionarily conserved pathways where complex and overlapping defense mechanisms protect against oxygen toxicity.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA.
authors.forename: Walid S
authors.initials: WS
authors.lastname: Maaty
authors.forename: Blake
authors.initials: B
authors.lastname: Wiedenheft
authors.forename: Pavel
authors.initials: P
authors.lastname: Tarlykov
authors.forename: Nathan
authors.initials: N
authors.lastname: Schaff
authors.forename: Joshua
authors.initials: J
authors.lastname: Heinemann
authors.forename: Jim
authors.initials: J
authors.lastname: Robison-Cox
authors.forename: Jacob
authors.initials: J
authors.lastname: Valenzuela
authors.forename: Amanda
authors.initials: A
authors.lastname: Dougherty
authors.forename: Paul
authors.initials: P
authors.lastname: Blum
authors.forename: C Martin
authors.initials: CM
authors.lastname: Lawrence
authors.forename: Trevor
authors.initials: T
authors.lastname: Douglas
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Young
authors.forename: Brian
authors.initials: B
authors.lastname: Bothner
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D048229:Sulfolobus solfataricus / Q000235:genetics / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; D006861:Hydrogen Peroxide; D010100:Oxygen