A feedback transcriptional mechanism controls the level of the arginine/lysine transporter cat-1 during amino acid starvation

Alex B. Lopez, Chuanping Wang, Charlie C. Huang, Ibrahim Yaman, Yi Li, Kaushik Chakravarty, Peter F. Johnson, Cheng Ming Chiang, Martin D. Snider, Ronald C. Wek, Maria Hatzoglou

Research output: Contribution to journalArticle

63 Scopus citations

Abstract

The adaptive response to amino acid limitation in mammalian cells inhibits global protein synthesis and promotes the expression of proteins that protect cells from stress. The arginine/lysine transporter, cat-1, is induced during amino acid starvation by transcriptional and post-transcriptional mechanisms. It is shown in the present study that the transient induction of cat-1 transcription is regulated by the stress response pathway that involves phosphorylation of the translation initiation factor, eIF2 (eukaryotic initiation factor-2). This phosphorylation induces expression of the bZIP (basic leucine zipper protein) transcription factors C/EBP (CCAAT/enhancer-binding protein)-β and ATF (activating transcription factor) 4, which in turn induces ATF3. Transfection experiments in control and mutant cells, and chromatin immunoprecipitations showed that ATF4 activates, whereas ATF3 represses cat-1 transcription, via an AARE (amino acid response element), TGATGAAAC, in the first exon of the cat-1 gene, which functions both in the endogenous and in a heterologous promoter. ATF4 and C/EBPβ activated transcription when expressed in transfected cells and they bound as heterodimers to the AARE in vitro. The induction of transcription by ATF4 was inhibited by ATF3, which also bound to the AARE as a heterodimer with C/EBPβ. These results suggest that the transient increase in cat-1 transcription is due to transcriptional activation caused by ATF4 followed by transcriptional repression by ATF3 via a feedback mechanism.

Original languageEnglish (US)
Pages (from-to)163-173
Number of pages11
JournalBiochemical Journal
Volume402
Issue number1
DOIs
StatePublished - Feb 15 2007

Keywords

  • Activating transcription factor
  • Amino acid response element
  • Amino acid transporter
  • eIF2 phosphorylation
  • Stress response gene
  • Transcriptional regulation

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'A feedback transcriptional mechanism controls the level of the arginine/lysine transporter cat-1 during amino acid starvation'. Together they form a unique fingerprint.

  • Cite this

    Lopez, A. B., Wang, C., Huang, C. C., Yaman, I., Li, Y., Chakravarty, K., Johnson, P. F., Chiang, C. M., Snider, M. D., Wek, R. C., & Hatzoglou, M. (2007). A feedback transcriptional mechanism controls the level of the arginine/lysine transporter cat-1 during amino acid starvation. Biochemical Journal, 402(1), 163-173. https://doi.org/10.1042/BJ20060941