scholarly journals The bidirectional promoter of the divergently transcribed mouse Surf-1 and Surf-2 genes.

1991 ◽  
Vol 11 (3) ◽  
pp. 1281-1294 ◽  
Author(s):  
A C Lennard ◽  
M Fried

The ubiquitously expressed mouse Surf-1 and Surf-2 genes are divergently transcribed, and their heterogeneous start sites are separated by up to a maximum of only 73 bp. By using in vitro DNase I, dimethyl sulfate methylation, and gel retardation assays, we have identified five putative promoter control elements between and around the Surf-1 and Surf-2 start sites. The effects of each site on the regulation of Surf-1 and Surf-2 transcription have been studied in vivo, and four sites were found to be functional promoter elements. A novel binding site is required for efficient use of the intermediate but not the major start site of Surf-1. Three elements function in a bidirectional manner and are shared for efficient and accurate expression of both Surf-1 and Surf-2. One is an UEF (USF, MLTF) binding site which had a small effect on the use of the intermediate start sites of Surf-1 and also affected the major start sites of Surf-2. Another has sequence homology to the RPG alpha binding site associated with some ribosomal protein gene promoters and is required for efficient expression of the major but not intermediate start sites of Surf-1 and all start sites of Surf-2. The third, an RPG alpha-like site, is used for all start sites of both Surf-1 and Surf-2. Dissection of this cellular promoter region showed that different binding sites affect the use of different start sites and revealed a complex interaction between multiple elements that constitute a bona fide bidirectional promoter.

1991 ◽  
Vol 11 (3) ◽  
pp. 1281-1294
Author(s):  
A C Lennard ◽  
M Fried

The ubiquitously expressed mouse Surf-1 and Surf-2 genes are divergently transcribed, and their heterogeneous start sites are separated by up to a maximum of only 73 bp. By using in vitro DNase I, dimethyl sulfate methylation, and gel retardation assays, we have identified five putative promoter control elements between and around the Surf-1 and Surf-2 start sites. The effects of each site on the regulation of Surf-1 and Surf-2 transcription have been studied in vivo, and four sites were found to be functional promoter elements. A novel binding site is required for efficient use of the intermediate but not the major start site of Surf-1. Three elements function in a bidirectional manner and are shared for efficient and accurate expression of both Surf-1 and Surf-2. One is an UEF (USF, MLTF) binding site which had a small effect on the use of the intermediate start sites of Surf-1 and also affected the major start sites of Surf-2. Another has sequence homology to the RPG alpha binding site associated with some ribosomal protein gene promoters and is required for efficient expression of the major but not intermediate start sites of Surf-1 and all start sites of Surf-2. The third, an RPG alpha-like site, is used for all start sites of both Surf-1 and Surf-2. Dissection of this cellular promoter region showed that different binding sites affect the use of different start sites and revealed a complex interaction between multiple elements that constitute a bona fide bidirectional promoter.


1993 ◽  
Vol 13 (11) ◽  
pp. 6866-6875 ◽  
Author(s):  
D C Hagen ◽  
L Bruhn ◽  
C A Westby ◽  
G F Sprague

Transcription activation of alpha-specific genes in Saccharomyces cerevisiae is regulated by two proteins, MCM1 and alpha 1, which bind to DNA sequences, called P'Q elements, found upstream of alpha-specific genes. Neither MCM1 nor alpha 1 alone binds efficiently to P'Q elements. Together, however, they bind cooperatively in a manner that requires both the P' sequence, which is a weak binding site for MCM1, and the Q sequence, which has been postulated to be the binding site for alpha 1. We analyzed a collection of point mutations in the P'Q element of the STE3 gene to determine the importance of individual base pairs for alpha-specific gene transcription. Within the 10-bp conserved Q sequence, mutations at only three positions strongly affected transcription activation in vivo. These same mutations did not affect the weak binding to P'Q displayed by MCM1 alone. In vitro DNA binding assays showed a direct correlation between the ability of the mutant sequences to form ternary P'Q-MCM1-alpha 1 complexes and the degree to which transcription was activated in vivo. Thus, the ability of alpha 1 and MCM1 to bind cooperatively to P'Q elements is critical for activation of alpha-specific genes. In all natural alpha-specific genes the Q sequence is adjacent to the degenerate side of P'. To test the significance of this geometry, we created several novel juxtapositions of P, P', and Q sequences. When the Q sequence was opposite the degenerate side, the composite QP' element was inactive as a promoter element in vivo and unable to form stable ternary QP'-MCM1-alpha 1 complexes in vitro. We also found that addition of a Q sequence to a strong MCM1 binding site allows the addition of alpha 1 to the complex. This finding, together with the observation that Q-element point mutations affected ternary complex formation but not the weak binding of MCM1 alone, supports the idea that the Q sequence serves as a binding site for alpha 1.


1990 ◽  
Vol 10 (8) ◽  
pp. 4256-4265 ◽  
Author(s):  
C J Brandl ◽  
K Struhl

In the gal-his3 hybrid promoter his3-GG1, the yeast upstream activator protein GCN4 stimulates transcription when bound at the position normally occupied by the TATA element. This TATA-independent activation by GCN4 requires two additional elements in the gal enhancer region that are distinct from those involved in normal galactose induction. Both additional elements appear to be functionally distinct from a classical TATA element because they cannot be replaced by the TFIID-binding sequence TATAAA. One of these elements, termed Q, is essential for GCN4-activated transcription and contains the sequence GTCAC CCG, which overlaps (but is distinct from) a GAL4 binding site. Surprisingly, relatively small increases in the distance between Q and the GCN4 binding site significantly reduce the level of transcription. The Q element specifically interacts with a yeast protein (Q-binding protein [QBP]) that may be equivalent to Y, a protein that binds at a sequence that forms a constraint to nucleosome positioning. Analysis of various deletion mutants indicates that the sequence requirements for binding by QBP in vitro are indistinguishable from those necessary for Q activity in vivo, strongly suggesting that QBP is required for the function of this TATA-independent promoter. These results support the view that transcriptional activation can occur by an alternative mechanism in which the TATA-binding factor TFIID either is not required or is not directly bound to DNA. In addition, they suggest a potential role of nucleosome positioning for the activity of a promoter.


2008 ◽  
Vol 412 (2) ◽  
pp. 287-298 ◽  
Author(s):  
Maria Ekerot ◽  
Marios P. Stavridis ◽  
Laurent Delavaine ◽  
Michael P. Mitchell ◽  
Christopher Staples ◽  
...  

DUSP6 (dual-specificity phosphatase 6), also known as MKP-3 [MAPK (mitogen-activated protein kinase) phosphatase-3] specifically inactivates ERK1/2 (extracellular-signal-regulated kinase 1/2) in vitro and in vivo. DUSP6/MKP-3 is inducible by FGF (fibroblast growth factor) signalling and acts as a negative regulator of ERK activity in key and discrete signalling centres that direct outgrowth and patterning in early vertebrate embryos. However, the molecular mechanism by which FGFs induce DUSP6/MKP-3 expression and hence help to set ERK1/2 signalling levels is unknown. In the present study, we demonstrate, using pharmacological inhibitors and analysis of the murine DUSP6/MKP-3 gene promoter, that the ERK pathway is critical for FGF-induced DUSP6/MKP-3 transcription. Furthermore, we show that this response is mediated by a conserved binding site for the Ets (E twenty-six) family of transcriptional regulators and that the Ets2 protein, a known target of ERK signalling, binds to the endogenous DUSP6/MKP-3 promoter. Finally, the murine DUSP6/MKP-3 promoter coupled to EGFP (enhanced green fluorescent protein) recapitulates the specific pattern of endogenous DUSP6/MKP-3 mRNA expression in the chicken neural plate, where its activity depends on FGFR (FGF receptor) and MAPK signalling and an intact Ets-binding site. These findings identify a conserved Ets-factor-dependent mechanism by which ERK signalling activates DUSP6/MKP-3 transcription to deliver ERK1/2-specific negative-feedback control of FGF signalling.


1991 ◽  
Vol 11 (2) ◽  
pp. 1048-1061
Author(s):  
I J Lee ◽  
L Tung ◽  
D A Bumcrot ◽  
E S Weinberg

A protein, denoted UHF-1, was found to bind upstream of the transcriptional start site of both the early and late H4 (EH4 and LH4) histone genes of the sea urchin Strongylocentrotus purpuratus. A nuclear extract from hatching blastulae contained proteins that bind to EH4 and LH4 promoter fragments in a band shift assay and produced sharp DNase I footprints upstream of the EH4 gene (from -133 to -106) and the LH4 gene (from -94 to -66). DNase I footprinting performed in the presence of EH4 and LH4 promoter competitor DNAs indicated that UHF-1 binds more strongly to the EH4 site. A sequence match of 11 of 13 nucleotides was found within the two footprinted regions: [sequence: see text]. Methylation interference and footprinting experiments showed that UHF-1 bound to the two sites somewhat differently. DNA-protein UV cross-linking studies indicated that UHF-1 has an electrophoretic mobility on sodium dodecyl sulfate-acrylamide gels of approximately 85 kDa and suggested that additional proteins, specific to each promoter, bind to each site. In vitro and in vivo assays were used to demonstrate that the UHF-1-binding site is essential for maximal transcription of the H4 genes. Deletion of the EH4 footprinted region resulted in a 3-fold decrease in transcription in a nuclear extract and a 2.6-fold decrease in expression in morulae from templates that had been injected into eggs. In the latter case, deletion of the binding site did not grossly disrupt the temporal program of expression from the injected EH4 genes. LH4 templates containing a 10-bp deletion in the consensus region or base substitutions in the footprinted region were transcribed at 14 to 58% of the level of the wild-type LH4 template. UHF-1 is therefore essential for maximal expression of the early and late H4 genes.


1988 ◽  
Vol 8 (10) ◽  
pp. 4557-4560
Author(s):  
O Bakker ◽  
J N Philipsen ◽  
B C Hennis ◽  
G Ab

The estrogen-dependent binding of a protein to the upstream region of the chicken vitellogenin gene was detected by using in vivo dimethyl sulfate, genomic DNase I, and in vitro exonuclease III footprinting. The site is located between base pairs -848 and -824, and its sequence resembles that of the nuclear factor I binding site. The results suggest that a nuclear factor binding to this site is involved in the regulation of the vitellogenin gene.


2005 ◽  
Vol 79 (18) ◽  
pp. 11824-11836 ◽  
Author(s):  
Mingzhou Chen ◽  
Jean-Claude Cortay ◽  
Ian R. Logan ◽  
Vasileia Sapountzi ◽  
Craig N. Robson ◽  
...  

ABSTRACT Using a C-terminal domain (PCT) of the measles virus (MV) phosphoprotein (P protein) as bait in a yeast two-hybrid screen, a cDNA identical to the recently described human p53-induced-RING-H2 (hPIRH2) cDNA was isolated. A glutathione S-transferase-hPIRH2 fusion protein expressed in bacteria was able to pull down P protein when mixed with an extract from P-expressing HeLa cells in vitro, and myc-tagged hPIRH2 could be reciprocally coimmunoprecipitated with MV P protein from human cells. Additionally, immunoprecipitation experiments demonstrated that hPIRH2-myc, MV P, and nucleocapsid (N) proteins form a ternary complex. The hPIRH2 binding site was mapped to the C-terminal X domain region of the P protein by using a yeast two-hybrid assay. The PCT binding site was mapped on hPIRH2 by using a novel yeast two-hybrid tagged PCR approach and by coimmunoprecipitation of hPIRH2 cysteine mutants and mouse/human PIRH2 chimeras. The hPIRH2 C terminus could mediate the interaction with MV P which was favored by the RING-H2 motif. When coexpressed with an enhanced green fluorescent protein-tagged hPIRH2 protein, MV P alone or in a complex with MV N was able to redistribute hPIRH2 to outside the nucleus, within intracellular aggregates. Finally, MV P efficiently stabilized hPIRH2-myc expression and prevented its ubiquitination in vivo but had no effect on the stability or ubiquitination of an alternative ubiquitin E3 ligase, Mdm2. Thus, MV P protein is the first protein from a pathogen that is able to specifically interact with and stabilize the ubiquitin E3 ligase hPIRH2 by preventing its ubiquitination.


1996 ◽  
Vol 109 (3) ◽  
pp. 569-578 ◽  
Author(s):  
H. Herrmann ◽  
M.D. Munick ◽  
M. Brettel ◽  
B. Fouquet ◽  
J. Markl

We have isolated from a rainbow trout (Oncorhynchus mykiss) spleen cDNA library a clone coding for vimentin. The deduced amino acid sequence reveals a high degree of identity with vimentin from carp (81%), frog (71%), chick and human (73% each). Large stretches in the central alpha-helical rod are identical within all four classes of vertebrates, but in 17 residues spread over the entire rod, the two fish differ distinctly from the tetrapod species. In addition, in the more diverged non-helical head domain, a nonapeptide motif previously shown to be important for regular filament formation is conserved. Recombinant trout vimentin assembles into bona fide filaments in vitro, with a temperature optimum between 18 and 24 degrees C. Above 27 degrees C, however, filament assembly is abruptly abolished and short filaments with thickened ends as well as structures without typical intermediate filament appearance are formed. This distinguishes its assembly properties significantly from amphibian, avian and mammalian vimentin. Also in vivo, after cDNA transfection into vimentin-free mammalian epithelial cells, trout vimentin does not form typical intermediate filament arrays at 37 degrees C. At 28 degrees C, and even more pronounced at 22 degrees C, the vimentin-positive material in the transfected cells is reorganized in the perinuclear region with a partial fibrillar appearance, but typical intermediate filament arrays are not formed. Together with immunoblotting and immunolocalization data from trout tissues, where vimentin is predominantly found in glial and white blood cells, we conclude that vimentin is indeed important in its filamentous form in fish and other vertebrates, possibly fulfilling cellular functions not directly evident in gene targeting experiments carried out in mice.


2020 ◽  
Vol 48 (21) ◽  
pp. 11942-11957
Author(s):  
Giulia Miglietta ◽  
Marco Russo ◽  
Giovanni Capranico

Abstract Genomic DNA and cellular RNAs can form a variety of non-B secondary structures, including G-quadruplex (G4) and R-loops. G4s are constituted by stacked guanine tetrads held together by Hoogsteen hydrogen bonds and can form at key regulatory sites of eukaryote genomes and transcripts, including gene promoters, untranslated exon regions and telomeres. R-loops are 3-stranded structures wherein the two strands of a DNA duplex are melted and one of them is annealed to an RNA. Specific G4 binders are intensively investigated to discover new effective anticancer drugs based on a common rationale, i.e.: the selective inhibition of oncogene expression or specific impairment of telomere maintenance. However, despite the high number of known G4 binders, such a selective molecular activity has not been fully established and several published data point to a different mode of action. We will review published data that address the close structural interplay between G4s and R-loops in vitro and in vivo, and how these interactions can have functional consequences in relation to G4 binder activity. We propose that R-loops can play a previously-underestimated role in G4 binder action, in relation to DNA damage induction, telomere maintenance, genome and epigenome instability and alterations of gene expression programs.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Adam JM Wollman ◽  
Sviatlana Shashkova ◽  
Erik G Hedlund ◽  
Rosmarie Friemann ◽  
Stefan Hohmann ◽  
...  

Transcription is regulated through binding factors to gene promoters to activate or repress expression, however, the mechanisms by which factors find targets remain unclear. Using single-molecule fluorescence microscopy, we determined in vivo stoichiometry and spatiotemporal dynamics of a GFP tagged repressor, Mig1, from a paradigm signaling pathway of Saccharomyces cerevisiae. We find the repressor operates in clusters, which upon extracellular signal detection, translocate from the cytoplasm, bind to nuclear targets and turnover. Simulations of Mig1 configuration within a 3D yeast genome model combined with a promoter-specific, fluorescent translation reporter confirmed clusters are the functional unit of gene regulation. In vitro and structural analysis on reconstituted Mig1 suggests that clusters are stabilized by depletion forces between intrinsically disordered sequences. We observed similar clusters of a co-regulatory activator from a different pathway, supporting a generalized cluster model for transcription factors that reduces promoter search times through intersegment transfer while stabilizing gene expression.


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