Gcn4 negatively regulates expression of genes subjected to nitrogen catabolite repression
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- 作者：Sosa ; Eduardo ; Aranda ; Cristina ; Riego ; Lina ; Valenzuela ; Lourdes ; DeLuna ; Alexander ; Cantú ; José ; M. ; et. al.
- 关键词：Yeast ; Nitrogen catabolite repression ; Amino acid metabolism ; Transcriptional regulation ; Gln3 ; Gcn4
- 刊名：Biochemical and Biophysical Research Communications
- 出版年：2003
- 出版时间：October 31, 2003
- 年：2003
- 卷：310
- 期：4
- 页码：1175-1180
- 全文大小：137 K
文摘
It has been considered that three key elements participate in nitrogen catabolite repression (NCR) of Saccharomyces cerevisiae: the GLN3 and GAT1/NIL1-encoded transcriptional activators and their negative regulator Ure2. The fact that expression of various NCR-sensitive genes is not derepressed in the absence of Ure2 has led to the proposition that there must exist a protein with a similar function to that of Ure2. The results presented in this paper show that various NCR-sensitive genes are derepressed through GLN3-mediated transcriptional activation in a gcn4Δ mutant. This effect is additive to that exerted by the lack of Ure2 and to that evoked in rapamycin-treated cultures. Our results uncover the fact that NCR is not solely achieved through the action of Gln3, Gat1, and Ure2. Since Gcn4 regulates the expression of a broad spectrum of genes, the lack of this transcriptional activator could prevent the expression of a potential Gln3 antagonist. Alternatively, Gcn4 could directly hinder Gln3 functioning.