Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have shown that the murine c-rel protein can act as a transcriptional transactivator in both yeast and mammalian cells. Fusion proteins generated by linking rel sequences to the DNA-binding domain of the yeast transcriptional activator GAL4 activate transcription from a reporter gene linked in cis to a GAL4 binding site. The full-length mouse c-rel protein (588 amino acids long) is a poor transactivator; however, the C-terminal portion of the protein between amino acid residues 403 to 568 is a potent transcriptional transactivator. Deletion of the N-terminal half of the c-rel protein augments its transactivation function. We propose that c-rel protein has an N-terminal regulatory domain and a C-terminal transactivation domain which together modulate its function as a transcriptional transactivator.
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PMID:The mouse c-rel protein has an N-terminal regulatory domain and a C-terminal transcriptional transactivation domain. 220 16

The product of the c-myc proto-oncogene is a nuclear phosphoprotein whose normal cellular function has not yet been defined. c-Myc has a number of biochemical properties, however, that suggest that it may function as a potential regulator of gene transcription. Specifically, it is a nuclear DNA-binding protein with a short half-life, a high proline content, segments that are rich in glutamine and acidic residues, and a carboxyl-terminal oligomerization domain containing the leucine zipper and helix-loop-helix motifs that serve as oligomerization domains in known regulators of transcription, such as C/EBP, Jun, Fos, GCN4, MyoD, E12, and E47. In an effort to establish that c-Myc might regulate transcription in vivo, we sought to determine whether regions of the c-Myc protein could activate transcription in an in vitro system. We report here that fusion proteins in which segments of human c-Myc are linked to the DNA-binding domain of the yeast transcriptional activator GAL4 can activate transcription from a reporter gene linked to GAL4-binding sites. Three independent activation regions are located between amino acids 1 and 143, a region that has been shown to be required for neoplastic transformation of primary rat embryo cells in cooperation with a mutated ras gene. These results demonstrate that domains of the c-Myc protein can function to regulate transcription in a model system and suggest that alterations of Myc transcriptional regulatory function may lead to neoplastic transformation.
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PMID:An amino-terminal c-myc domain required for neoplastic transformation activates transcription. 223 23

Complete 1H NMR resonance assignments are presented for the cysteine rich region of the DNA binding domain of the yeast transcriptional activator GAL4. The protein contains short helical regions between Asp-12 and Leu-19 and between Lys-30 and Trp-36. It is clearly distinct from the C2H2 class of zinc finger protein typified by the Xenopus laevis transcription factor (TF)IIIA. We also find that the first SP(X)(X) sequence, a recently proposed DNA binding motif (residues 41 to 44), appears to be tightly packed against the metal binding domain.
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PMID:Complete assignment of the 1H NMR spectrum and secondary structure of the DNA binding domain of GAL4. 226 11

We have purified extensively the transcriptional activator, GAL4, from a yeast strain overexpressing the gene product from the ADH1 promoter. Our purification followed GAL4 activity by its binding to a specific DNA target sequence, using filter binding assays. No specific binding activity was detected in extracts from a strain containing a disrupted copy of the GAL4 gene. The purification protocol included fractionation of a whole cell extract by ion-exchange and DNA-affinity chromatography on a column containing a 17-base pair oligomer encoding a near consensus GAL4 binding site. Two polypeptides co-eluted with the GAL4 DNA binding activity from the DNA-affinity column. One had an apparent molecular mass of 99 kDa (the predicted size of the GAL4 protein) and cross-reacted with antibodies raised against GAL4 epitopes from fusion proteins expressed in bacterial cells. The second polypeptide did not cross-react with the anti-GAL4 antibody and is presumed to be the GAL80 transcriptional repressor based on its size (48 kDa) and known physical association with the GAL4 protein. GAL4 binding activity elutes from a gel filtration column as a 155-kDa species suggesting that it exists in solution in a heterodimer complex of one GAL4 and one GAL80 molecule. The dissociation constant of the DNA-affinity-purified GAL4-GAL80 complex for a 900-base pair DNA fragment containing the UASGAL element from the GAL1-GAL10 divergent promoter was, Kd(effective) (0.15 M KCl) = 2.4 x 10(-9) M.
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PMID:Purification and characterization of the yeast transcriptional activator GAL4. 240 56

Many eukaryotic proteins involved in transcriptional regulation contain within their DNA-binding domains a polypeptide loop (the zinc finger) which interacts with DNA. In proteins possessing multiple zinc fingers, including TFIIIA, Sp1, SWI5 and oestrogen/glucocorticoid receptors, the region containing the zinc fingers confers DNA-binding specificity. By contrast, our results demonstrate that all but one of the 28 amino acids encompassing the single zinc-finger region of GAL4, the yeast transcriptional activator, can be replaced with the analogous zinc-finger region from another yeast-activator protein, PPR1, without changing the DNA-binding specificity of GAL4. A 14-amino-acid region adjacent to the zinc finger is necessary for determining specific recognition of DNA sequences.
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PMID:Altering DNA-binding specificity of GAL4 requires sequences adjacent to the zinc finger. 250 85

GAL4 is a yeast transcriptional activator protein that binds to specific 2-fold rotationally symmetric sites on DNA and stimulates transcription of the genes required for galactose catabolism. The DNA binding region of the protein is located within the first 74 amino acids and contains a "zinc finger" sequence motif. We show that a polypeptide comprising the first 147 amino acids of GAL4, designated GAL4 (1-147), binds DNA as a dimer in vitro. Although a protein containing only the first 74 amino acids, designated GAL4 (1-74), binds DNA specifically, its affinity is reduced relative to GAL4 (1-147). Addition of the strong dimerization domain of lambda repressor to GAL4 (1-74) generates a protein that binds as tightly as GAL4 (1-147). GAL4 (1-147) makes rotationally symmetric contacts with its recognition site when assayed by DNase I, exonuclease III and hydroxyl radical footprinting and by phosphate ethylation interference. Binding of GAL4 (1-147) in vitro requires either zinc or cadmium.
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PMID:An amino-terminal fragment of GAL4 binds DNA as a dimer. 251 24

Protein-protein interactions between two proteins have generally been studied using biochemical techniques such as crosslinking, co-immunoprecipitation and co-fractionation by chromatography. We have generated a novel genetic system to study these interactions by taking advantage of the properties of the GAL4 protein of the yeast Saccharomyces cerevisiae. This protein is a transcriptional activator required for the expression of genes encoding enzymes of galactose utilization. It consists of two separable and functionally essential domains: an N-terminal domain which binds to specific DNA sequences (UASG); and a C-terminal domain containing acidic regions, which is necessary to activate transcription. We have generated a system of two hybrid proteins containing parts of GAL4: the GAL4 DNA-binding domain fused to a protein 'X' and a GAL4 activating region fused to a protein 'Y'. If X and Y can form a protein-protein complex and reconstitute proximity of the GAL4 domains, transcription of a gene regulated by UASG occurs. We have tested this system using two yeast proteins that are known to interact--SNF1 and SNF4. High transcriptional activity is obtained only when both hybrids are present in a cell. This system may be applicable as a general method to identify proteins that interact with a known protein by the use of a simple galactose selection.
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PMID:A novel genetic system to detect protein-protein interactions. 254 63

The v-myb oncogene, like its cellular progenitor c-myb, encodes a short-lived nuclear protein involved in processes affecting growth and differentiation in a number of cell types. Fusion proteins, in which v-myb sequences are linked to the DNA binding domain of the yeast transcriptional activator GAL4, can activate transcription from a reporter gene linked in cis to a GAL4 binding site. The domain of v-myb responsible for transcriptional activation is located between residues 204 and 254, and is both necessary and sufficient for activation. Intact v-myb and c-myb proteins can also activate transcription, via a myb binding site linked in cis to a reporter gene. A v-myb protein bearing a deletion in the activator domain is no longer capable of stimulating transcription.
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PMID:Transcriptional activation by the v-myb oncogene and its cellular progenitor, c-myb. 266 42

We describe the activities of a wide array of deletion mutants of GAL4, a yeast transcriptional activator. We identify two short regions of GAL4, each of which activates transcription when fused to the DNA-binding region of the molecule. Very large portions of GAL4 are not required for gene activation.
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PMID:Deletion analysis of GAL4 defines two transcriptional activating segments. 302 47

We show that derivatives of the yeast transcriptional activator GAL4, synthesized in and purified from E. coli, stimulate transcription of a mammalian gene (the adenovirus E4 gene) in a HeLa cell nuclear extract. Stimulation depended upon GAL4 binding sites inserted in the template. When the GAL4 sites were placed immediately upstream of the E4 TATA box, GAL4 stimulated efficiently. When the GAL4 sites were further upstream from TATA, however, efficient stimulation by GAL4 required, in addition, a site for a mammalian transcriptional activator immediately upstream of TATA. Under these conditions, the GAL4 derivatives functioned synergistically with the proximally bound activator. Previous experiments have defined two "activating regions" in GAL4, and our current experiments define a third, whose function is observed in vitro but not in vivo.
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PMID:GAL4 derivatives function alone and synergistically with mammalian activators in vitro. 304 7


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