The effect of calnexin deletion on the expression level of binding protein (BiP) under heat stress conditions in Saccharomyces cerevisiae

Abstract

Abstract:In order to investigate the effect of calnexin deletion on the induction of the main ER molecular chaperone BiP, we cultured the wild-type and calnexin-disrupted Saccharomyces cerevisiae strains under normal and stressed conditions. The growth rate of the calnexin-disrupted yeast was almost the same as that of the wild-type yeast under those conditions. However, the induced level of BiP mRNA in the ER was evidently higher in calnexin-disrupted S. cerevisiae than in the wild-type at 37ºC, but was almost the same in the two strains under normal conditions. The Western blot analysis results for BiP protein expression in the ER showed a parallel in the mRNA levels in the two strains. It is suggested that under heat stress conditions, the induction of BiP in the ER might recover part of the function of calnexin in calnexin-disrupted yeast, and result in the same growth rate as in wild-type yeast.

The expression profile of calnexin in Patinopecten yessoensis after acute high temperature stress

“…This suspection was further proved by the significant up-regulation of Py CNX mRNA observed at 1 h after acute high temperature stress. Similarly, the heat-induced expression of CNXs mRNA was also observed in yeasts ( Schizosaccharomyces pombe and Saccharomyces cerevisiae ) [ 10 , 36 ] and various plants ( Spinacia oleracea and Oryza sativa ) [37] , [38] , [39] , [40] . Moreover, the mRNA transcripts of Py CNX were down-regulated to the comparative level of Blank group at 3 h and 6 h, and then further significantly down-regulated from 12 to 48 h after acute high temperature stress, indicating that there might be a negative regulation mechanism of Py CNX response upon acute high temperature stress.…”