Thermotolerance and molecular chaperone function of an SGT1-like protein from the psychrophilic yeast, Glaciozyma antarctica

Nur Athirah Yusof, Noor Haza Fazlin Hashim, Travis Beddoe, Nor Muhammad Mahadi, Rosli Md Illias, Farah Diba Abu Bakar, Abdul Munir Abdul Murad

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8 Citations (Scopus)


The ability of eukaryotes to adapt to an extreme range of temperatures is critically important for survival. Although adaptation to extreme high temperatures is well understood, reflecting the action of molecular chaperones, it is unclear whether these molecules play a role in survival at extremely low temperatures. The recent genome sequencing of the yeast Glaciozyma antarctica, isolated from Antarctic sea ice near Casey Station, provides an opportunity to investigate the role of molecular chaperones in adaptation to cold temperatures. We isolated a G. antarctica homologue of small heat shock protein 20 (HSP20), GaSGT1, and observed that the GaSGT1 mRNA expression in G. antarctica was markedly increased following culture exposure at low temperatures. Additionally, we demonstrated that GaSGT1 overexpression in Escherichia coli protected these bacteria from exposure to both high and low temperatures, which are lethal for growth. The recombinant GaSGT1 retained up to 60 % of its native luciferase activity after exposure to luciferase-denaturing temperatures. These results suggest that GaSGT1 promotes cell thermotolerance and employs molecular chaperone-like activity toward temperature assaults.

Original languageEnglish
Pages (from-to)707-715
Number of pages9
JournalCell Stress and Chaperones
Issue number4
Publication statusPublished - 1 Jul 2016
Externally publishedYes


  • Cloning
  • Expression
  • HSP90
  • Luciferase
  • Molecular chaperone
  • SGT1

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