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Cold Adaption in Budding Yeast. Babette Schade, Gregor Jansen, Malcolm Whiteway, Karl D. Entian, and David Y. Thomas (2004) Molecular Biology of the Cell , Vol. 15, 5492-5502. Sarah Carratt and Carmen Castaneda Department of Biology Loyola Marymount University BIOL 398/MATH 388
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Cold Adaption in Budding Yeast Babette Schade, Gregor Jansen, Malcolm Whiteway, Karl D. Entian, and David Y. Thomas (2004) Molecular Biology of the Cell, Vol. 15, 5492-5502 Sarah Carratt and Carmen Castaneda Department of Biology Loyola Marymount University BIOL 398/MATH 388 March 24, 2011
Stress Affects Transcriptional Response • QUESTION: • How do cold temperatures and other stress stimuli affect transcriptional response in S. cerevisiae? • This study looks at mechanisms responsible for growth and survival at low temperatures • FIGURES 1 & 2: • Identify the programmed responses to stress at 10°C • Contrast early and late cold response for functional categories • Compare cold shock as defined by Schade et al. (10°C) to Gasch (25°C)
Cells Respond to Stress • Unicellular organisms are affected by a variety of extreme changes in their environments • Developed programmed responses to stress into the genetic code, not random • The transcription of genes is changed • ~10% of the genome responds • Genes involved are defined as ESR • Little known about mechanisms responsible for growth and survival at low temperatures • Cold causes different changes in the physical and biochemical properties • Ability to adapt is determined by different regulatory mechanisms
Important Definitions for Figures • Division of time • Early cold response (ECR) = up to 2 hours • Late cold response (LCR) = 12-60 hours • Regulation and color codes • GREEN = down-regulated: repressed • RED = up-regulated: induced
Hierarchical cluster analysis shows • Along the horizontal we have genes clustered. • On the vertical axis the individual chips are clustered. • Longer time meant that more genes were active. • LCR genes are more active.
Distribution of Functional Categories and Regulation Response in ECR & LCR 3 1 1 3 2 2
Transcription: Increased LCR Down-Regulated Genes 1 1 • mRNA is synthesized from DNA • 833 genes for transcription • down-regulated: cell is attempting to conserve energy • up-regulated: innate attempt to maintain homeostasis
Protein Synthesis: Large Increase in LCR Down-Regulated Genes 2 2 • proteins synthesized from mRNA • 380 genes for protein synthesis • down-regulated: cell does NOT inefficient energy use • up-regulated: stays low, indicates no deficiencies
Stress Response: Increased LCR Up-Regulated Genes (Reversal) 3 3 • respond to environment (cold), emergencies, ect. • 294 genes for stress response • ECR: more down-regulated than up-regulated • LCR: more up-regulated genes than down-regulated • significance related to function
Gasch vs Schade: Defining Cold Shock in ECR • Gasch: 37 to 25 • Schade: 30 to 10 • key differences in regulation of lower region • indicates that there may be different genes • a/b: genes that changed at 25 (Gasch)
References • In this presentation, images and data were used from the following source: • Schade et. al. “Cold Adaption in Budding Yeast” (2004) Molecular Biology of the Cell, Vol. 15, 5492-5502
Acknowledgements • We would like to thank the following people for their help with this presentation: • Dr. Kam D. Dahlquist, Ph.D. • Dr. Ben G. Fitzpatrick, Ph.D.