Residues in the TATA-binding protein required to mediate a transcriptional response to retinoic acid in EC cells

Keaveney, Marie; Berkenstam, Anders; Feigenbutz, Monika; Vriend, Gerrit; Stunnenberg, Hendrik G.

doi:10.1038/365562a0

Cited by 54 publications

(45 citation statements)

References 31 publications

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“…Since the detailed mechanism of activation may vary for different promoters, we assayed activation from two reporter genes with different promoters to test the generality of defects observed with the various VP16C mutants. COS cells were transfected with an expression vector for Gal4(1-147) fused to wt or mutant VP16C and one of two reporter genes: either the adeno-virus type 2 (Ad2) E1B promoter region with five upstream Gal4 binding sites fused to CAT (pG5E1bCAT [29]) or the retinoic acid receptor ␤ (RAR␤) promoter region with four upstream Gal4 sites fused to luciferase (19). Reporter gene expression was measured and normalized to the expression observed following activation with Gal4-VP16Cwt ( Fig.…”

Section: Resultsmentioning

confidence: 99%

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

Kobayashi

Horn

Sullivan

et al. 1998

Molecular and Cellular Biology

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One class of transcriptional activation domains stimulates the concerted binding of TFIIA and TFIID to promoter DNA. To test whether this DA-complex assembly activity contributes significantly to the overall mechanism of activation in vivo, we analyzed mutants of the 38-amino-acid residue VP16C activation subdomain from herpes simplex virus. An excellent correlation was observed between the in vivo activation function of these mutants and their in vitro DA-complex assembly activity. Mutants severely defective for in vivo activation also showed reduced in vitro binding to native TFIIA. No significant correlation between in vivo activation function and in vitro binding to human TATA binding protein, human TFIIB, or Drosophila melanogaster TAF II 40 was observed for this set of VP16C mutants. These results argue that the ability of VP16C to increase the rate and extent of DA-complex assembly makes a significant contribution to the overall mechanism of transcriptional activation in vivo.Considerable experimental evidence indicates that transcriptional activators bound to enhancer and promoter proximal sequences stimulate transcription through interactions between their activation domains and components of the initiation complex assembled at the associated promoter (33,36,39,42,46). These interactions have been postulated to stimulate the assembly of initiation complexes at promoters or to affect the activities of general transcription factors in the assembled initiation complex so as to increase the rate of initiation by polymerase II (Pol II). But with few exceptions, relatively little is understood about the detailed mechanism by which specific activators stimulate transcription.Some activation domains have been found to increase both the rate and the final extent of an early step in initiation complex assembly, the concerted binding of TFIIA and TFIID to the TATA box and initiation site region of the promoter (8,9,24,28,49). This DA-complex assembly activity can be conveniently assayed in vitro by an electrophoretic mobility shift assay (EMSA) using agarose gels to separate the large DNAprotein complexes involved (28). Activators that stimulate DA-complex assembly also interact directly with TFIIA, as observed by coimmunoprecipitation and affinity column chromatography with recombinant proteins (24,32).An extensive mutational analysis of a well-studied activation domain with DA-complex assembly activity, the 38-residue Cterminal activation subdomain of herpes simplex virus type 1 VP16, called VP16C, has recently been completed (43a). A number of single-, double-, and triple-point mutants of this sequence with various levels of activation function in vivo in Saccharomyces cerevisiae were identified. Since wild-type (wt) VP16C exhibits DA-complex assembly activity (24), the isolation of these VP16C mutants allowed us to test whether this in vitro activity correlated with their in vivo activation function, as would be expected if DA-complex assembly contributes significantly to the overall mechanism of activation in...

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Section: Resultsmentioning

confidence: 99%

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

Kobayashi

Horn

Sullivan

et al. 1998

Molecular and Cellular Biology

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“…The choice of pFR-luc as the reporter vector followed examination of a series of additional GAL4-responsive vectors with variant promoters and TATA boxes, including pWHGG (41), M1, and M2 (42). These were the kind gift of Arnie J. Berk (UCLA).…”

Section: Methodsmentioning

confidence: 99%

BRCA1 Associates with Processive RNA Polymerase II

Krum¹,

Miranda²,

Lin³

et al. 2003

Journal of Biological Chemistry

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The human BRCA1 tumor suppressor interacts with transcriptional machinery, including RNA polymerase II (RNA pol II). We demonstrated that interaction with RNA pol II is a conserved feature of BRCA1 proteins from several species. We found that full-length BRCA1 proteins universally fail to activate transcription in classic GAL4-UAS one-hybrid assays and that the activity associated with the human BRCA1 C terminus was poorly conserved in closely related homologs of the gene. Fractionation studies demonstrated that BRCA1 proteins from all species tested interacted specifically with hyperphosphorylated pol II (IIO), in preference to hypophosphorylated RNA pol II (IIA) expected at promoters. BRCA1-RNA pol II complexes showed evidence of a multiply phosphorylated heptad repeat domain in the catalytic subunit (p220) of RNA pol II, and the complex was highly functional in transcriptional run-off assays. Interestingly, endogenous BRCA1 associated with a large fraction of the processive RNA pol II activity present in undamaged cells, and the interaction was disrupted by DNA-damaging agents. Preferential interaction with processive RNA pol II in undamaged cells places BRCA1 in position to link late events in transcription with repair processes in eukaryotic cells.Mutations in the BRCA1 tumor suppressor gene are associated with an increased risk of breast and ovarian cancer and an elevated incidence of certain other cancers (1-3). Genetic and biochemical data place BRCA1 as a downstream target of ATM/ ATR in cellular responses to genotoxic stress, and the BRCA1 protein has been implicated in chromatin remodeling and homologous recombination functions in mitotic and meiotic cells (4 -8). BRCA1 complexes contain E3 ubiquitin-ligase activity, but the precise target(s) remains an avenue of active study (9, 10). Although BRCA1 proteins show surprisingly low sequence identity, human BRCA1 can replace the mouse gene in genetically engineered animals (11, 12), a result that implies general conservation of important functional motifs. Comparative functional studies are thus likely to play an important role in identifying critical targets of BRCA1 in human cells.A distinct literature has evolved linking BRCA1 to roles in transcription. BRCA1 protein has been shown to associate with RNA polymerase II (RNA pol II) 1 and various transcriptional regulators (13). Early on, several groups demonstrated that the C-terminal domain (CTD; amino acids 1380 -1863) of human BRCA1 scored positively in transcriptional activator trap experiments using various forms of the so-called "one-hybrid" assay (14 -18). While not elucidating a specific function, ectopic expression of full-length human BRCA1 was then shown to increase expression of stress-responsive genes including p21 (19), GADD45 (20), and p27 (21) and decreased expression of other genes, including c-Myc-regulated genes (22) and certain estrogen-regulated genes (23). However, it remains an open question whether endogenous BRCA1 directly mediates recruitment of RNA pol II to promoters of these...

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“…To examine further the role of hTAF II 28 in transcriptional activation by Tax, experiments were performed with the entire HTLV-I promoter. To distinguish the effect of the endogenous TFIID from that induced by the transfection of expression vectors, TBP bearing the spm3 mutation was used (20,21). This mutant binds to both TATAAAA and TGTAAAA motifs whereas wild-type TBP recognizes only the former.…”

Section: Fig 2 Htafii28 Interacts In Vitro With Tax (A)mentioning

confidence: 99%

Human TAF _II 28 interacts with the human T cell leukemia virus type I Tax transactivator and promotes its transcriptional activity

Caron

Mengus

Dubrowskaya

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

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The Tax protein encoded by human T cell leukemia virus type I transactivates the viral promoter by forming a complex with several cellular factors bound to three repeats of a specific upstream regulatory sequence. We have shown that transactivation by Tax was correlated with its ability to interact with the C-terminal moiety of the TATA box-binding protein (TBP). In the present study, the ability of The viral protein Tax strongly activates transcription of the human T cell leukemia virus type I (HTLV-I) provirus and of a specific group of cellular genes (1). Various studies have established that Tax is recruited to the Tax-responsive element 1 of the HTLV-I promoter and to the serum-responsive element of the c-fos promoter (2-5) via interactions with cellular transcription factors. In agreement with this notion, a GAL4 DNA binding domain-Tax fusion protein stimulates transcription of a reporter gene under the control of GAL4 sites (6). Using this approach, we have shown that the transcriptional activity of the GAL4-Tax fusion protein involves a direct protein-protein interaction between Tax and TATA box-binding protein (TBP) (7).However, in vitro transcription experiments have established that activation by Tax requires the transcription factor complex TFIID comprised of TBP and TBP-associated factors (TAF II s) (8). To better understand the molecular mechanisms underlying activation by Tax, we investigated the interactions between Tax and hTAF II s. These experiments show a selective interaction of Tax with hTAF II 28. Increasing the intracellular concentration of hTAF II 28 augments the activity of GAL4-Tax, and the overexpression of both TBP and hTAF II 28 resulted in an additive increase in activation. The ability of hTAF II 28 to potentiate activation by Tax was dependent on its ability to interact with TBP. These observations support the notion that Tax activates transcription by interacting with TFIID through both TBP and hTAF II 28. MATERIALS AND METHODSTransfections. HeLa cells and COS-7 cells, grown in monolayers to 40% (HeLa cells) or 80% (COS-7 cells) confluence, were transfected by the calcium phosphate coprecipitation method (7). The total amount of simian virus 40 promotercontaining plasmids was adjusted to a constant level with pSG5, and the total amount of cytomegalovirus promotercontaining plasmids was adjusted to a constant level with pXJ41.

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Residues in the TATA-binding protein required to mediate a transcriptional response to retinoic acid in EC cells

Cited by 54 publications

References 31 publications

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

BRCA1 Associates with Processive RNA Polymerase II

Human TAF _II 28 interacts with the human T cell leukemia virus type I Tax transactivator and promotes its transcriptional activity

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Residues in the TATA-binding protein required to mediate a transcriptional response to retinoic acid in EC cells

Cited by 54 publications

References 31 publications

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

DA-Complex Assembly Activity Required for VP16C Transcriptional Activation

BRCA1 Associates with Processive RNA Polymerase II

Human TAF II 28 interacts with the human T cell leukemia virus type I Tax transactivator and promotes its transcriptional activity

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Human TAF _II 28 interacts with the human T cell leukemia virus type I Tax transactivator and promotes its transcriptional activity