Lectures in University of Brawijaya, 2013 Biological Responses to Environmental Stress Tetsuro Ishii, PhD. Professor Emeritus, University of Tsukuba, Japan. Animals have developed defense system against environmental stress agents. Plant. Animal. poisons. Detoxification system
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Biological Responses to Environmental Stress
Tetsuro Ishii, PhD.
Professor Emeritus, University of Tsukuba, Japan
UV, As, Heavy metals
Stress causes upregulation of stress proteins stress agents
Detection by sensors
Activation of transcription factors
Biological Responses to Environmental Stress stress agents
1. Cellular response to heat
2. Cellular response to electrophiles and reactive oxygen species
3. Nrf2 target genes
Heat was necessary to create life stress agents
Yellowstone hot spring
Adaptation to heat is most important for life.
Heat shock induces various proteins in cells stress agents
Activation of heat shock factors
Induction of heat shock proteins (HSPs)
Has60, Hsp70, Hsp90, etc.
Heat shock protein (HSP) family stress agents
HSP60 (chaperonin, GroEL)
Some of these proteins are constitutively expressed and play their roles under normal temperature.
Some proteins return to native form following heat denaturation
denature or unfolding
Renature or refolding
But, many proteins became aggregated when denatured
Denatured/unfolded proteins tend to aggregate denaturation
Inhibition of protein aggregation by Dank-ClpB denaturation
Chaperonin inhibits protein aggregation denaturation
Urea + DTT
ATP-dependent folding of GFP-protein by chaperonin denaturation
Inhibition of protein aggregate by chaperonin
Double ring structure of chaperonin, GroEL denaturation
Discovery of chaperonin denaturation
“Molecular chaperon” was found in different systems
Functions of chaperonin during protein synthesis denaturation
Role of chaperons in protein synthesis denaturation