GAL11P: A yeast mutation that potentiates the effect of weak GAL4-derived activators

• Published in: Cell Vol. 63; no. 6; pp. 1299 - 1309
• Main Authors: Himmelfarb, Howard J., Pearlberg, Joseph, Last, Douglas H., Ptashne, Mark
• Format: Journal Article
• Language: English
• Published: Cambridge, MA Elsevier Inc 21.12.1990; Cell Press
• Subjects: Amino Acid Sequence; Animals; beta-Galactosidase - genetics; beta-Galactosidase - metabolism; Biological and medical sciences; Chromosome Deletion; Classical genetics, quantitative genetics, hybrids; DNA, Fungal - genetics; DNA-Binding Proteins - genetics; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; Gene Expression Regulation, Fungal; Genetics of eukaryotes. Biological and molecular evolution; Invertebrata; Mediator Complex; Models, Genetic; Molecular Sequence Data; Mutagenesis, Site-Directed; Mutation; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae Proteins; Sequence Homology, Nucleic Acid; TATA Box; Trans-Activators; Transcription Factors; Zinc Fingers; Yeast; Nucleotide sequence; Transcription; Zinc finger structure; DNA binding protein; Activation; Fungi; Plasmid; Mutagenesis; Ascomycetes; Mutation; Saccharomyces cerevisiae; Thallophyta
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/0092-8674(90)90425-E

A mutant yeast in which a weak GAL4-derived activator functions as a strong activator bears a single missense mutation in GAL11 (a.k.a. SPT13). The first 74 amino acids of GAL4, including the zinc-dependent DNA binding region, attached to an acidic activating sequence, are sufficient to respond both to GAL11 and to our mutant GAL11P (potentiator). PPR1, a yeast activator with a similar zinc finger sequence, also responds to GAL11 and to GAL11P, whereas regulators bearing unrelated DNA binding motifs do not. GAL11 itself works as a strong activator when tethered to DNA by fusion to the bacterial LexA protein, and deletion of GAL11 is known to cause a 5- to 10-fold reduction in GAL4 activity. We suggest that a complex of GAL4 and GAL11 constitutes a particularly strong activator; evidence that the putative GAL4-GAL11 complex ordinarily forms preferentially on DNA suggests a biological rationale for GAL11 action.