brahma: a regulator of Drosophila homeotic genes structurally related to the yeast transcriptional activator SNF2/SWI2.
TL;DR: The brahma (brm) gene encodes a 1638 residue protein that is similar to SNF2/SWI2, a protein involved in transcriptional activation in yeast, suggesting possible models for the role of brm in the transcriptionalactivation of homeotic genes.
About: This article is published in Cell.The article was published on 1992-02-07. It has received 951 citations till now. The article focuses on the topics: Homeotic gene & Homeotic selector gene.
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TL;DR: Based on their importance in biology and medicine, as well as the relatively simple mechanism of regulation, NR represent one of the most intensively studied and best-understood classes of transcription factors at the molecular level.
Abstract: Nuclear receptors (NR) comprise a family of transcription factors that regulate gene expression in a liganddependent manner. Members of the NR superfamily include receptors for steroid hormones, such as estrogens (ER) and glucocorticoids (GR), receptors for nonsteroidal ligands, such as thyroid hormones (TR) and retinoic acid (RAR), as well as receptors that bind diverse products of lipid metabolism, such as fatty acids and prostaglandins (for review, see Beato et al. 1995; Chambon 1995; Mangelsdorf and Evans 1995). The NR superfamily also includes a large number of so-called orphan receptors for which regulatory ligands have not been identified (Mangelsdorf and Evans 1995). Although many orphan receptors are likely to be regulated by small-molecular-weight ligands, other mechanisms of regulation, such as phosphorylation (Hammer et al. 1999; Tremblay et al. 1999) have also proven to be of importance. Remarkably, the sequence of the Caenorhabditis elegans genome has revealed the presence of >200 members of the NR family, suggesting a critical role of these proteins in environmental adaptation (Sluder et al. 1999). Although mammalian genomes are unlikely to contain such a large complement of these factors, >24 distinct classes of NR have been identified in humans, and these factors exert diverse roles in the regulation of growth, development, and homeostasis. Based on their importance in biology and medicine, as well as the relatively simple mechanism of regulation, NR represent one of the most intensively studied and best-understood classes of transcription factors at the molecular level. Members of the NR family regulate transcription by several mechanisms (Fig. 1). Nuclear receptors can activate or repress target genes by binding directly to DNA response elements as homoor heterodimers or by binding to other classes of DNA-bound transcription factors. A subset of NRs, including TR and RAR, can actively repress target genes in the presence or absence of ligand binding, and many NR have been demonstrated to inhibit transcription in a ligand-dependent manner by antagonizing the transcriptional activities of other classes of transcription factors. These activities have been linked to interactions with general classes of molecules that appear to serve coactivator or corepressor function. In this review, we will discuss recent progress concerning the molecular mechanisms by which NR cofactor interactions serve to activate or repress transcription.
2,200 citations
Cites background or methods from "brahma: a regulator of Drosophila h..."
...Homologs of SWI2/ SNF2 are present in flies (Brahma) and mammals (BRG1, hBrm), in each case functioning as components of large multiprotein complexes (Tamkun et al. 1992; Khavari et al. 1993; Muchardt and Yaniv 1993; Dingwall et al. 1995; Tsukiyama and Wu 1995)....
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...Remodeling complexes similar to the SWI/SNF complex have been characterized in Drosophila, including NURF (nucleosome remodeling factor) (Tamkun et al. 1992), ACF (ATP-utilizing chromatin assembly and remodeling factor) (Ito et al. 1997) and CHRAC (chromatin accessibility complex (VargaWeisz et al.…...
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2,045 citations
TL;DR: This work detail these known factor acetyltransferase (FAT) substrates and the demonstrated or potential roles of their acetylation in transcriptional processes.
Abstract: The state of chromatin (the packaging of DNA in eukaryotes) has long been recognized to have major effects on levels of gene expression, and numerous chromatin-altering strategies-including ATP-dependent remodeling and histone modification-are employed in the cell to bring about transcriptional regulation. Of these, histone acetylation is one of the best characterized, as recent years have seen the identification and further study of many histone acetyltransferase (HAT) proteins and their associated complexes. Interestingly, most of these proteins were previously shown to have coactivator or other transcription-related functions. Confirmed and putative HAT proteins have been identified from various organisms from yeast to humans, and they include Gcn5-related N-acetyltransferase (GNAT) superfamily members Gcn5, PCAF, Elp3, Hpa2, and Hat1: MYST proteins Sas2, Sas3, Esa1, MOF, Tip60, MOZ, MORF, and HBO1; global coactivators p300 and CREB-binding protein; nuclear receptor coactivators SRC-1, ACTR, and TIF2; TATA-binding protein-associated factor TAF(II)250 and its homologs; and subunits of RNA polymerase III general factor TFIIIC. The acetylation and transcriptional functions of these HATs and the native complexes containing them (such as yeast SAGA, NuA4, and possibly analogous human complexes) are discussed. In addition, some of these HATs are also known to modify certain nonhistone transcription-related proteins, including high-mobility-group chromatin proteins, activators such as p53, coactivators, and general factors. Thus, we also detail these known factor acetyltransferase (FAT) substrates and the demonstrated or potential roles of their acetylation in transcriptional processes.
1,789 citations
Cites background from "brahma: a regulator of Drosophila h..."
...The bromodomain (whose name is derived from Brahma, the Drosophila protein in which it was first described) (233) is a conserved sequence motif found in PCAF and the Gcn5 homologs as well as a variety of other transcription-related proteins (98)....
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TL;DR: These findings shed light on the biochemical function of the evolutionarily conserved Gcn5p-Ada complex, directly linking histone acetylation to gene activation, and indicate that histoneacetylation is a targeted phenomenon.
1,609 citations
Cites background from "brahma: a regulator of Drosophila h..."
...…number of proteins, many of which are involved in transcriptional an immediate and unexpected connection between histone acetylation and at least one class of transcriptionalactivation (Tamkun et al., 1992; Peterson and Hersko- witz, 1992; Yoshinaga et al., 1992; Laurent and Carlson, adaptors....
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TL;DR: New concepts include the existence of a Polycomb barrier to transcription elongation and the involvement of non-coding RNAs in the targeting of Polycomb complexes, which have an impact on the epigenetic programming of gene expression in many biological systems.
Abstract: Polycomb proteins form chromatin-modifying complexes that implement transcriptional silencing in higher eukaryotes. Hundreds of genes are silenced by Polycomb proteins, including dozens of genes that encode crucial developmental regulators in organisms ranging from plants to humans. Two main families of complexes, called Polycomb repressive complex 1 (PRC1) and PRC2, are targeted to repressed regions. Recent studies have advanced our understanding of these complexes, including their potential mechanisms of gene silencing, the roles of chromatin modifications, their means of delivery to target genes and the functional distinctions among variant complexes. Emerging concepts include the existence of a Polycomb barrier to transcription elongation and the involvement of non-coding RNAs in the targeting of Polycomb complexes. These findings have an impact on the epigenetic programming of gene expression in many biological systems.
1,325 citations
References
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Book•
15 Jan 2001
TL;DR: Molecular Cloning has served as the foundation of technical expertise in labs worldwide for 30 years as mentioned in this paper and has been so popular, or so influential, that no other manual has been more widely used and influential.
Abstract: Molecular Cloning has served as the foundation of technical expertise in labs worldwide for 30 years. No other manual has been so popular, or so influential. Molecular Cloning, Fourth Edition, by the celebrated founding author Joe Sambrook and new co-author, the distinguished HHMI investigator Michael Green, preserves the highly praised detail and clarity of previous editions and includes specific chapters and protocols commissioned for the book from expert practitioners at Yale, U Mass, Rockefeller University, Texas Tech, Cold Spring Harbor Laboratory, Washington University, and other leading institutions. The theoretical and historical underpinnings of techniques are prominent features of the presentation throughout, information that does much to help trouble-shoot experimental problems. For the fourth edition of this classic work, the content has been entirely recast to include nucleic-acid based methods selected as the most widely used and valuable in molecular and cellular biology laboratories. Core chapters from the third edition have been revised to feature current strategies and approaches to the preparation and cloning of nucleic acids, gene transfer, and expression analysis. They are augmented by 12 new chapters which show how DNA, RNA, and proteins should be prepared, evaluated, and manipulated, and how data generation and analysis can be handled. The new content includes methods for studying interactions between cellular components, such as microarrays, next-generation sequencing technologies, RNA interference, and epigenetic analysis using DNA methylation techniques and chromatin immunoprecipitation. To make sense of the wealth of data produced by these techniques, a bioinformatics chapter describes the use of analytical tools for comparing sequences of genes and proteins and identifying common expression patterns among sets of genes. Building on thirty years of trust, reliability, and authority, the fourth edition of Mol
215,169 citations
TL;DR: A new method for determining nucleotide sequences in DNA is described, which makes use of the 2',3'-dideoxy and arabinon nucleoside analogues of the normal deoxynucleoside triphosphates, which act as specific chain-terminating inhibitors of DNA polymerase.
Abstract: A new method for determining nucleotide sequences in DNA is described. It is similar to the “plus and minus” method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441-448] but makes use of the 2′,3′-dideoxy and arabinonucleoside analogues of the normal deoxynucleoside triphosphates, which act as specific chain-terminating inhibitors of DNA polymerase. The technique has been applied to the DNA of bacteriophage ϕX174 and is more rapid and more accurate than either the plus or the minus method.
62,728 citations
TL;DR: A technique for conveniently radiolabeling DNA restriction endonuclease fragments to high specific activity is described, and these "oligolabeled" DNA fragments serve as efficient probes in filter hybridization experiments.
23,324 citations
"brahma: a regulator of Drosophila h..." refers methods in this paper
...Filters were probed with DNA fragments labeled by the random-primer method (Feinberg and Vogelstein, 1983) and washed under conditions of high stringency (0....
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01 Jan 1984
TL;DR: In this article, a technique for conveniently radiolabeling DNA restriction endonuclease fragments to high specific activity is described, where DNA fragments are purified from agarose gels directly by ethanol precipitation and are then denatured and labeled with the large fragment of DNA polymerase I, using random oligonucleotides as primers.
Abstract: A technique for conveniently radiolabeling DNA restriction endonuclease fragments to high specific activity is described. DNA fragments are purified from agarose gels directly by ethanol precipitation and are then denatured and labeled with the large fragment of DNA polymerase I, using random oligonucleotides as primers. Over 70% of the precursor triphosphate is routinely incorporated into complementary DNA, and specific activities of over 10(9) dpm/microgram of DNA can be obtained using relatively small amounts of precursor. These "oligolabeled" DNA fragments serve as efficient probes in filter hybridization experiments.
21,435 citations
TL;DR: A thermostable DNA polymerase was used in an in vitro DNA amplification procedure, the polymerase chain reaction, which significantly improves the specificity, yield, sensitivity, and length of products that can be amplified.
Abstract: A thermostable DNA polymerase was used in an in vitro DNA amplification procedure, the polymerase chain reaction. The enzyme, isolated from Thermus aquaticus, greatly simplifies the procedure and, by enabling the amplification reaction to be performed at higher temperatures, significantly improves the specificity, yield, sensitivity, and length of products that can be amplified. Single-copy genomic sequences were amplified by a factor of more than 10 million with very high specificity, and DNA segments up to 2000 base pairs were readily amplified. In addition, the method was used to amplify and detect a target DNA molecule present only once in a sample of 10(5) cells.
17,663 citations
Additional excerpts
...chain reaction (Saiki et al., 1988)....
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