Archaeal Hsp14 drives substrate shuttling between small heat shock proteins and thermosome: insights into a novel substrate transfer pathway.
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Hsp14 dimer is the active form that captures unfolded substrates and shuttles them to the thermosome (Hsp60) for refolding.
"the dimer is the active form of Hsp14, and it forms an oligomeric storage form at a higher temperature...Hsp14 could transfer sHsp-captured substrate proteins to Hsp60, which then refolds them back to their active form"
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Hsp14 directly interacts with Hsp60 (thermosome) via an enthalpy-driven physical interaction.
"an enthalpy-driven direct physical interaction between Hsp14 and Hsp60"
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Hsp14 forms hetero-oligomers with Hsp20 at 50-70 degrees C via subunit exchange.
"We observed hetero-oligomer formation only at higher temperatures (50 °C-70 °C)"
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S. acidocaldarius lacks Hsp70, so Hsp14 fills the substrate transfer role normally played by Hsp70.
"Hsp70 is absent in thermophilic and hyperthermophilic archaea"
Heat shock response in Sulfolobus acidocaldarius and first implications for cross-stress adaptation.
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hsp14 plays crucial roles in the majority of stress conditions including heat, oxidative, and nutrient stress.
"The results demonstrated that the gene thβ encoding the β subunit of the thermosome, as well as hsp14 and hsp20, play crucial roles in the majority of stress conditions"
Defining heat shock response for the thermoacidophilic model crenarchaeon Sulfolobus acidocaldarius.
The genome of Sulfolobus acidocaldarius, a model organism of the Crenarchaeota.