Whi2

Whi2 or Whiskey 2 is a 55 kDa globular,[1] cytoplasmatic scaffold protein in Saccharomyces cerevisiae, which plays an essential role in stress response pathways, apparently by passing input signals about nutrient availability on to stress responsive elements and autophagy/mitophagy mechanisms. It is encoded by a 1.46 kbp gene located on chromosome 15.[2]

Functional mechanism

Upon complexing with plasma membrane associated phosphatase Psr1, Whi2 induces general stress response by dephosphorylating general stress response transcription factor Msn2.[3] Whi2 is essential for Msn2 activity, moreover activation by Whi2 is dominant and independent of the PKA and TOR activation pathways.[4] Additionally, experiments are suggesting Whi2 for playing a role in Ras2 deactivation or degradation during nutrient depletion.[5]

References

  1. ↑ "Protein Overview: WHI2". YeastRC.org. Retrieved 17 April 2012.
  2. ↑ "WHI2 Summary". YeastGenome.org. Retrieved 4 January 2012.
  3. ↑ Kaida, D; Yashiroda, H; Toh-e, A; Kikuchi, Y (2002). "Yeast Whi2 and Psr1-phosphatase form a complex and regulate STRE-mediated gene expression". Genes to cells 7 (6): 543–52. doi:10.1046/j.1365-2443.2002.00538.x. PMID 12090248.
  4. ↑ Sadeh, Amit; Movshovich, Natalia; Volokh, Misha; Gheber, Larisa; Aharoni, Amir (2011). "Fine-tuning of the Msn2/4-mediated yeast stress responses as revealed by systematic deletion of Msn2/4 partners". Molecular Biology of the Cell 22 (17): 3127–38. doi:10.1091/mbc.E10-12-1007. PMC 3164460. PMID 21757539.
  5. ↑ Müller, Matthias; Reichert, Andreas S. (2011). "Mitophagy, mitochondrial dynamics and the general stress response in yeast". Biochemical Society Transactions 39 (5): 1514–9. doi:10.1042/BST0391514. PMID 21936844.
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