Specific interactions with TBP and TFIIB in vitro suggest that 14-3-3 proteins may participate in the regulation of transcription when part of a DNA binding complex.
The 14-3-3 family of multifunctional proteins is highly conserved among animals, plants, and yeast. Several studies have shown that these proteins are associated with a G-box DNA binding complex and are present in the nucleus in several plant and animal species. In this study, 14-3-3 proteins are shown to bind the TATA box binding protein (TBP), transcription factor IIB (TFIIB), and the human TBP-associated factor hTAF(II)32 in vitro but not hTAF(II)55. The interactions with TBP and TFIIB were highly specific, requiring amino acid residues in the box 1 domain of the 14-3-3 protein. These interactions do not require formation of the 14-3-3 dimer and are not dependent on known 14-3-3 recognition motifs containing phosphoserine. The 14-3-3-TFIIB interaction appears to occur within the same domain of TFIIB that binds the human herpes simplex virus transcriptional activator VP16, because VP16 and 14-3-3 were able to compete for interaction with TFIIB in vitro. In a plant transient expression system, 14-3-3 was able to activate GAL4-dependent beta-glucuronidase reporter gene expression at low levels when translationally fused with the GAL4 DNA binding domain. The in vitro binding with general transcription factors TBP and TFIIB together with its nuclear location provide evidence supporting a role for 14-3-3 proteins as transcriptional activators or coactivators when part of a DNA binding complex.
Pan
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Program of Plant Molecular and Cellular Biology, Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611-0700, USA.
Sehnke
P C
PC
Ferl
R J
RJ
Gurley
W B
WB
D048948:14-3-3 Proteins; D000409:Alanine; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics; D001665:Binding Sites; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D017405:Herpes Simplex Virus Protein Vmw65 / Q000378:metabolism; D006801:Humans; D019684:Magnoliopsida / Q000235:genetics*; D016297:Mutagenesis, Site-Directed; D019697:Onions; D017354:Point Mutation; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators / Q000378:metabolism; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000378:metabolism; D015533:Transcriptional Activation; D014446:Tyrosine 3-Monooxygenase; D003313:Zea mays / Q000235:genetics
D048948:14-3-3 Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D017405:Herpes Simplex Virus Protein Vmw65; D011506:Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C091537:TAF7 protein, human; C106849:TAF9 protein, human; D035381:TATA-Binding Protein Associated Factors; D035181:TATA-Box Binding Protein; D015534:Trans-Activators; D035581:Transcription Factor TFIIB; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D014446:Tyrosine 3-Monooxygenase; D000409:Alanine