In Vitro Transcriptional Activation by a Metabolic Intermediate: Activation by Leu3 Depends on α-Isopropylmalate
1992; American Association for the Advancement of Science; Volume: 258; Issue: 5085 Linguagem: Inglês
10.1126/science.1439822
ISSN1095-9203
AutoresJi-Ying Sze, Michael Woontner, Judith A. Jaehning, Gunter B. Kohlhaw,
Tópico(s)Plant biochemistry and biosynthesis
ResumoIn the absence of the leucine biosynthetic precursor α-isopropylmalate (α-IPM), the yeast LEU3 protein (Leu3p) binds DNA and acts as a transcriptional repressor in an in vitro extract. Addition of α-IPM resulted in a dramatic increase in Leu3p-dependent transcription. The presence of α-IPM was also required for Leu3p to compete effectively with another transcriptional activator, GAL4/VP16, for limiting transcription factors. Therefore, the addition of α-IPM appears to convert a transcriptional repressor into an activator. This represents an example in eukaryotes of direct transcriptional regulation by a small effector molecule.
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