METHODS TO STUDY UNFOLDED PROTEIN RESPONSE PATHWAY IN YEAST

Abstract

Unfolded protein response pathway (UPR) is a homeostatic pathway conserved in the eukaryotes. It is characterized by transmembrane protein IRE1 (a sensor) and HAC1 a transducer. Most of the secretory and one third of transmembrane proteins are synthesized in the rough endoplasmic reticulum (ER). These proteins are translocated into ER for proper folding. However due to environmental cues, like glucose scarcity, intracellular Ca²⁺ imbalance, some of the proteins are not folded properly by resident chaperons. This led to the accumulation of unfolded or misfolded protein in the ER lumen causing ER stress. UPR pathway is involved in myriad of functions including homeostasis, growth and development and autophagy. In this review we have highlighted the different strategies which can be adopted to study this pathway. We have focused on the model organism Saccharomyces cerevisiae. The methods of gene disruption and analysis of HAC1 expression is discussed in light of RNA expression and unfolded protein response element.