Expression of ubiquitin specific peptidase and ATG7 genes in U87 glioma cells upon glutamine deprivation

Abstract

We have studied the effect of glutamine deprivation on the expression of genes encoding for ubiquitin specific peptidases (USP) and ubiquitin activating enzyme E1-like protein/autophagy related 7 (GSA7/ATG7) in U87 glioma cells in relation to inhibition of inositol requiring enzyme-1 (IRE1). It was shown that exposure of control glioma cells (transfected by empty vector) upon glutamine deprivation led to suppression of USP1 and ATG7 mRNA expression and up-regulated USP25 mRNA. At the same time, glutamine deprivation did not significantly change USP4, USP10, USP14, and USP22 gene expressions in these cells. Inhibition of ІRE1 signaling enzyme function in U87 glioma cells increased effect of glutamine deprivation on the expression of USP1 gene and introduced sensitivity of USP4 and USP14 genes to this condition. Therefore, glutamine deprivation affected the expression level of most studied genes in gene specific manner in relation to the functional activity of IRE1 enzyme, a central mediator of endoplasmic reticulum stress, which controls cell proliferation and tumor growth.

Keywords

• ATG7
• glutamine deprivation
• IRE1 inhibition
• mRNA expression
• U87 glioma cells
• USPs