Alterations in a yeast protein resembling HIV Tat-binding protein relieve requirement for an acidic activation domain in GAL4.
The acidic transcriptional activation motif functions in all eukaryotes, which suggests that it makes contact with some universal component of the transcriptional apparatus. Transcriptional activation by the yeast regulatory protein GAL4 requires an acidic region at its carboxyl terminus. Here we implement a selection scheme to determine whether GAL4 can still function when this C-terminal domain has been deleted. It can, when accompanied by a mutation in the SUG1 gene which is an essential gene in yeast. Analysis of mutant SUG1 in combination with various alleles of GAL4 indicates that SUG1 acts through a transcriptional pathway that depends on GAL4, but requires a region of GAL4 other than the C-terminal acidic activation domain. The predicted amino-acid sequence of SUG1 closely resembles that of two human proteins, TBP1 and MSS1, which modulate expression mediated by the human immunodeficiency virus tat gene.
Swaffield
J C
JC
Department of Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8573.
Bromberg
J F
JF
Johnston
S A
SA
D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D001483:Base Sequence; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D015756:Genes, tat; D006678:HIV / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D046988:Proteasome Endopeptidase Complex; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D013489:Suppression, Genetic; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases; C069670:RPT6 protein, S cerevisiae