Disease relevance of SPT15

• Third, not mutations suppressed toxicity due to overexpression of TBP in mot1-1 mutants [1].
• ADI activity at the adenovirus major late promoter requires a segment of DNA upstream from the TATA sequence, suggesting that ADI recognizes aspects of both TBP and DNA [2].
• Recombinant TBP purified from Escherichia coli is phosphorylated efficiently by CKII and, in the presence of a limiting amount of CKII, is able to substantially rescue transcription in CKII-deficient extract [3].
• We report here that the hepatitis B virus protein X (pX) specifically binds to TBP in vitro [4].
• Visualization of TBP oligomers binding and bending the HIV-1 and adeno promoters [5].

High impact information on SPT15

• CK2 associates with and normally activates the TATA binding protein (TBP) subunit of TFIIIB [6].
• Using a yeast heat shock gene flanked by mating-type silencers as a model system, we find that repressive, SIR-generated heterochromatin is permissive to the constitutive binding of an activator, HSF, and two components of the preinitiation complex (PIC), TBP and Pol II [7].
• The heterochromatic HMRa1 promoter is also occupied by TBP and Pol II, suggesting that SIR regulates gene expression not by restricting factor access to DNA but rather by blocking a step downstream of PIC recruitment [7].
• Transcriptional repression induced by DNA damage requires CK2 and coincides with downregulation of TBP-associated CK2 and dissociation of catalytic subunits from TBP-CK2 complexes [6].
• Solution structure of a TBP-TAF(II)230 complex: protein mimicry of the minor groove surface of the TATA box unwound by TBP [8].

Chemical compound and disease context of SPT15

• In this article are described equilibrium-binding studies of Saccharomyces cerevisiae TBP to 14 bp oligonucleotides bearing either the tightly bound and efficiently transcribed adenovirus major late promoter (TATAAAAG) or its inosine-substituted derivative (TITIIIIG) as a function of neutral osmolyte concentration [9].
• Yeast Sec18p and mammalian N-ethylmaleimide-sensitive fusion protein, which are involved in intracellular transport, yeast Pas1p, which is essential for peroxisome assembly, and mammalian TBP-1, which influences HIV gene expression, are 40% identical in the duplicated region [10].

Biological context of SPT15

• Mutations in the Saccharomyces cerevisiae gene SPT15, which encodes the TATA-binding protein TFIID, have been shown to cause pleiotropic phenotypes and to lead to changes in transcription in vivo [11].
• Genetic tests of the role of Abf1p in driving transcription of the yeast TATA box bindng protein-encoding gene, SPT15 [12].
• A homeologous gene pair consisting of S. cerevisiae SPT15 and its S. pombe homolog were present as a direct repeat on chromosome V, with the exogenous S. pombe sequences inserted either upstream or downstream of the endogenous S. cerevisiae gene [13].
• We present physical and genetic mapping data here showing that the MAG1 gene is located on chromosome V-R, proximal to and about 10 kilobase pairs away from the SPT15 gene coding for the yeast TATA-binding protein TFIID [14].
• The gene encoding Renilla luciferase is fused to a constitutive promoter (PGK1 or SPT15) and integrated into the yeast genome at the CAN1 locus as a control for normalizing the assay [15].

Anatomical context of SPT15

• A yeast activity can substitute for the HeLa cell TATA box factor [16].
• A complex of Kap114p and TBP was detected in the cytosol and could be reconstituted using recombinant proteins, suggesting that the interaction was direct [17].
• Using mutant TBPs with altered DNA binding specificity, similar to those described previously in yeast, we show that two Arabidopsis TBP isoforms are equally active with both pol II and pol III U-snRNA genes and with an mRNA gene transfected into plant protoplasts [18].
• TBP self-association may regulate many of its cellular functions, including transit of the nuclear membrane and participation in transcription initiation [19].
• Gene activity in a eukaryotic cell is regulated by accessory factors to RNA polymerase II, which include the general transcription factor complex TFIID, composed of TBP and TBP-associated factors (TAFs) [20].

Associations of SPT15 with chemical compounds

• The MAG1* 3-methyladenine DNA glycosylase gene is closely linked to the SPT15 TATA-binding TFIID gene on chromosome V-R in Saccharomyces cerevisiae [14].
• We show here that on glucose depletion, the S. cerevisiae Isw1 chromatin remodeling complex is required for the displacement of TBP from the PHO8 promoter [21].
• Here, using a formaldehyde-based in vivo cross-linking and chromatin immunoprecipitation assay, we have systematically analyzed the role of SAGA components in the recruitment of TATA-box binding protein (TBP) to SAGA-dependent promoters [22].
• We find that, although certain cysteine substitutions diminish interaction with Gal80, those substitutions have little effect on the activating function in vivo and interaction with TATA box-binding protein (TBP) in vitro [23].
• However, S220/225/232A was synthetically lethal when combined with an alanine substitution mutation at W285, which disrupts the TFIIA-TBP interface [24].

Physical interactions of SPT15

• NC2 and Not proteins are general negative regulators which interact with TATA box binding protein (TBP) [25].
• Taken together, our findings suggest that Rtf1 either directly or indirectly regulates the DNA binding properties of TBP and, consequently, the relative activities of different TATA elements in vivo [26].
• We found that overexpression of Abf1p in a yeast cell increased transcription of the TBP-encoding gene and that this stimulation depended upon the exact sequence of the Abf1p binding site (ABF1) present in the gene [12].
• MOT1 encodes an essential ATPase that functions as a general transcriptional regulator in vivo by modulating TATA-binding protein (TBP) DNA-binding activity [27].
• Although it is well known that the TAF N-terminal domain (TAND) at the amino-terminus of the TAF1 protein binds to TBP and thereby inhibits TBP function in vitro, the physiological role of this domain remains obscure [28].

Regulatory relationships of SPT15

• Substitution mutations in the small subunit of TFIIA (Toa2) at residue Y69 or W76 significantly impaired the ability of TFIIA to stimulate TBP-promoter binding in vitro [29].
• Importantly, the synthetic lethality for some of the TBP mutations is suppressed by a multicopy plasmid with SNR6 or by an spt3 mutation [30].
• Furthermore, TBP mutations that selectively inhibit Pol III transcription in vivo impair interactions between TBP and the BRF carboxy-terminal domain [31].
• Here we demonstrate that another region located on the C-terminal side of TAND2 (82-139 aa) can also bind to TBP and induce transcriptional activation when tethered to DNA as a GAL4 fusion protein [32].
• In some cases this spt16 toa2 lethality is suppressed by overexpression of TBP or the Nhp6 architectural transcription factor that is also a component of yFACT [33].

Other interactions of SPT15

• These results, taken together with previous studies, demonstrate a dependent pathway for the recruitment of TBP to GAL gene promoters consisting of the recruitment of SAGA by Gal4 and the subsequent recruitment of TBP by SAGA [34].
• Finally, we provide evidence that a specific interaction between Spt3 and TBP in vivo is important for Gal4 transcriptional activation at a step after SAGA recruitment [34].
• The function of Gcn5 as a histone acetyltransferase within the Ada and SAGA adaptor complexes indicates the importance of histone acetylation during steps in transcription activation mediated by interactions with transcription activators and general transcription factors (i.e., TBP) [35].
• Previous studies demonstrated that the SAGA (Spt-Ada-Gcn5-Acetyltransferase) complex facilitates the binding of TATA-binding protein (TBP) during transcriptional activation of the GAL1 gene of Saccharomyces cerevisiae [34].
• The results point to a promoter-specific Isw1p-dependent mechanism for targeted regulation of basal transcription by displacement of TBP from a promoter [21].

Analytical, diagnostic and therapeutic context of SPT15

• Chromatin immunoprecipitation experiments show that TBP binding to SNR6 is reduced in an nhp6ab mutant [30].
• The results of genetic crosses indicate that suppression of TBP mutants by mutations in RTF1 occurs in an allele-specific fashion [26].
• Here we use a DNA-crosslinking/immunoprecipitation assay to study in living cells the first step in the assembly of the preinitiation complex, the interaction between the TATA-box-binding protein (TBP) and its binding site, the TATA box [36].
• This orientation of yeast TBP in Pol III promoter-bound TFIIIB is the same as in Pol II promoter-bound TFIID and in TBP-DNA complexes that have been analyzed by X-ray crystallography [37].
• Towards an understanding of the basis for activator function, including the multiplicity of TBP interactions, we have now identified mutations in yeast TBP that selectively block activator (GAL4-VP16)-dependent but not basal transcription [38].

References