Electrophile response element-mediated induction of the @entity1434 / XXXX exchange transporter gene expression.

@entity1 @entity4250 @entity2227 @entity10182 @entity43840 @entity19 @entity8156 @entity20568 @entity3409 @entity2197 @entity1434 @entity34739
In @entity1 cultured cells, the @entity1434 / @entity2227 exchange transport mediated by system x(c)- is important to maintain intracellular @entity2197 levels. System x(c)- consists of two protein components, @entity20568 and the heavy chain of @entity34739 antigen. The activity of system x(c)- is induced by various stimuli, including electrophilic agents like @entity43840 . In the present study, we have investigated the mechanism of the transcriptional regulation of @entity20568 mRNA by @entity43840 . The @entity20568 gene consisted of twelve exons and sequence analysis identified four electrophile response element (EpRE)-like sequences between -230 and -1 in the 5'-flanking region, designated EpRE-1 to EpRE-4. To identify sequences mediating the constitutive and induced expression of @entity20568 , a series of 5'-deletion mutants created from the 5'-flanking region were cloned into a luciferase reproter vector and transfected into BHK21 cells. The 5'-deletion analysis revealed that the sequence between -116 and -82 is essential for the basal expression and the sequence between -226 and -116 containing EpRE-1 is essential in response to @entity43840 . Mutational analysis demonstrated that EpRE-1 is critically involved in the response to @entity43840 . Other stress agents like @entity4250 , @entity3409 , and @entity8156 seemed to induce system x(c)- activity via the same sequence. Furthermore, the experiments using the @entity19 embryonic fibroblasts derived from the @entity10182 -deficient @entity19 revealed that the induction of @entity20568 gene by electrophilic agents is mediated by @entity10182 . EpRE occurs in a broad spectrum of genes for the proteins that are involved in the defense against xenobiotics and regulates their expression. The present results have demonstrated that @entity20568 is a novel member of this protein family.
