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A Genomic Survey of Heat Shock Transcription Factor Binding Sites in Saccharomyces cerevisiae. Sujuan Ye, Alexander M. Erkine, and Yunkai Liu Department of Computer Science University of South Dakota. Heat Shock Proteins.
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A Genomic Survey of Heat Shock Transcription Factor Binding Sites in Saccharomycescerevisiae Sujuan Ye, Alexander M. Erkine, and Yunkai Liu Department of Computer Science University of South Dakota
Heat Shock Proteins • Induced when a cell undergoes various types of environmental stresses like heat, cold and oxygen deprivation. • Present in all organisms - from bacteria to human. • Provide thermo-tolerance to cells exposed to heat stress. • Protect organisms against stress-induced damage. • Act as chaperones, which bind and stabilize proteins, aid protein folding. • Target proteins for degradation. (e.g. HSP60, HSP70, HSP100)
Two Regulatory Systems • Heat shock transcription factor (HSF), which binds to the heat shock elements (HSE) • Perfect(PFT):TTCnnGAAnnTTC • GAP(GAP): TTCn-{5bp}-nTTCnnGAA • STEP(STP): GAAn-{5bp}-nGAAn-{5bp}-nGAA • Msn2 and Msn4 transcription factors, which bind to the stress response element (STRE). • AGGGG-{1~100bp}-AGGGG
Distributions of HSE and STRE STRE HSE
GLE2 TATAAA GAACATTCTCGAA TATATA -2000 -1438 -600 -161 -1523 Transcription Interference • Some Hsf1-regulated genes lack HSE in the promoter region • Intergenic transcripts could regulate the transcription of adjacent gene by transcription interference. TTCAGGAAGCTTC TATAAA DAK2 TATATA -600 -1551 -107 -2000 -1531