title: Global transcriptome analysis of the heat shock response of Shewanella oneidensis.
abstract: Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of S. oneidensis to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress by using whole-genome DNA microarrays for S. oneidensis. Approximately 15% (n = 711) of the total predicted S. oneidensis genes (n = 4,648) represented on the microarray were significantly up- or downregulated (P < 0.05) over a 25-min period after shift to the heat shock temperature. As expected, the majority of the genes that showed homology to known chaperones and heat shock proteins in other organisms were highly induced. In addition, a number of predicted genes, including those encoding enzymes in glycolysis and the pentose cycle, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed downregulated coexpression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, a putative regulatory site with high conservation to the Escherichia coli sigma32-binding consensus sequence was identified upstream of a number of heat-inducible genes.
authors.affiliation: Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
authors.forename: Haichun
authors.initials: H
authors.lastname: Gao
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Xueduan
authors.initials: X
authors.lastname: Liu
authors.forename: Tingfen
authors.initials: T
authors.lastname: Yan
authors.forename: Liyou
authors.initials: L
authors.lastname: Wu
authors.forename: Eric
authors.initials: E
authors.lastname: Alm
authors.forename: Adam
authors.initials: A
authors.lastname: Arkin
authors.forename: Dorothea K
authors.initials: DK
authors.lastname: Thompson
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018869:Heat-Shock Response; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D020543:Proteome; D020592:Shewanella / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D020543:Proteome