The Transcription Factor-like Nuclear Regulator (TFNR) Contains a Novel 55-Amino-Acid Motif Repeated Nine Times and Maps Closely to SMN1

Kelter, Arndt-René; Herchenbach, Julia; Wirth, Brunhilde

doi:10.1006/geno.2000.6396

Cited by 18 publications

(21 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of the three different splice variants reported for human Bdp1 to date, only two forms, TFIIIB150 (60) and human hBЉ (56), have been characterized with respect to transcriptional activity in vitro. No study has examined the activity of the full-length human Bdp1 protein that was originally described as TFNR (27). Since we expected that additional domains in the longer TFNR protein might be functionally important for transcription from chromatin templates, we produced recombinant TFNR in insect cells.…”

Section: Resultsmentioning

confidence: 99%

“…TFIIIB, which is specific for genes with internal promoter elements (e.g., 5S RNA, tRNA, and VA1 RNA), is composed of a stable TATA-binding protein (TBP)-Brf1 complex that associates reversibly with the SANT domain protein Bdp1 (for a description of a universal nomenclature for TFIIIB components, see reference 70). Fulllength human Bdp1 is a large protein of 2,254 amino acids (aa) (27), the N-terminal portion of which has homology to yeast Bdp1. Unique structural features of the human protein include nine repeats of an acidic 55-aa motif with unknown function and a C-terminal domain (aa 1328 to 2254) displaying sequence motifs found in topoisomerase II and elongation factor 1␤.…”

mentioning

confidence: 99%

“…Unique structural features of the human protein include nine repeats of an acidic 55-aa motif with unknown function and a C-terminal domain (aa 1328 to 2254) displaying sequence motifs found in topoisomerase II and elongation factor 1␤. Although full-length human Bdp1 was first described as the "transcription factor-like nuclear regulator" (TFNR) (27), its transcriptional activity has not been characterized to date. However, two shorter splice variants of the gene were shown to reconstitute in vitro transcription of both U6/7SK (subclass 3) and VA1 (subclass 2) genes.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Different Functional Modes of p300 in Activation of RNA Polymerase III Transcription from Chromatin Templates

Mertens

Roeder

2008

Molecular and Cellular Biology

View full text Add to dashboard Cite

Transcriptional coactivators that regulate the activity of human RNA polymerase III (Pol III) in the context of chromatin have not been reported. Here, we describe a completely defined in vitro system for transcription of a human tRNA gene assembled into a chromatin template. Transcriptional activation and histone acetylation in this system depend on recruitment of p300 by general initiation factor TFIIIC, thus providing a new paradigm for recruitment of histone-modifying coactivators. Beyond its role as a chromatin-modifying factor, p300 displays an acetyltransferase-independent function at the level of preinitiation complex assembly. Thus, direct interaction of p300 with TFIIIC stabilizes binding of TFIIIC to core promoter elements and results in enhanced transcriptional activity on histone-free templates. Additional studies show that p300 is recruited to the promoters of actively transcribed tRNA and U6 snRNA genes in vivo. These studies identify TFIIIC as a recruitment factor for p300 and thus may have important implications for the emerging concept that tRNA genes or TFIIIC binding sites act as chromatin barriers to prohibit spreading of silenced heterochromatin domains.It is well established that assembly of regulatory DNA sequences into nucleosomes represses transcription by restricting access of the transcriptional machinery to DNA (reviewed in reference 28). Thus, overcoming nucleosomal repression through alteration of chromatin structure is essential for gene activation. Eukaryotic cells contain at least two general classes of chromatin-modifying factors, the ATP-dependent chromatin-remodeling complexes (43) and histone-modifying enzymes that effect histone acetylation, methylation, phosphorylation, and ubiquitination (63). Whereas the function and mechanism of action of both types of factors have been extensively studied on genes transcribed by RNA polymerase II (Pol II), much less is known about chromatin-modifying factors involved in the regulation of Pol III-dependent genes.Pol III synthesizes small structural RNAs such as 5S RNA, tRNA, adenovirus VA1 RNA, and U6 RNA. Accurate and specific transcription of DNA templates by Pol III requires the assistance of the general initiation transcription factors TFIIIB and TFIIIC and, in some cases, various gene-specific factors such as the 5S gene-specific factor TFIIIA (for review, see references 15 and 53). In the case of tRNA and VA1 genes (subclass 2 genes), gene-internal core promoter elements (A and B boxes) are recognized directly by TFIIIC, which in turn directs the sequential binding of TFIIIB and Pol III. Human TFIIIC has been chromatographically separated into two distinct activities, TFIIIC1 and TFIIIC2 (74). TFIIIC2 is a stable complex of six subunits (220, 110, 102, 90,63, and 35 kDa) that binds directly to the B box (10a, 30, 75). TFIIIC1 displays no strong DNA-binding activity on its own but stabilizes TFIIIC2 binding to A and B boxes (66, 74). Other factors derived from TFIIIC preparations, such as coactivator PC4, also stabilize TFIIIC bind...

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Different Functional Modes of p300 in Activation of RNA Polymerase III Transcription from Chromatin Templates

Mertens

Roeder

2008

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…Outside of these regions, the two proteins are not conserved, and the human protein differs from the yeast protein by a striking C-terminal extension containing a number of repeats with potential phosphorylation sites. A number of alternatively spliced BDP1 cDNAs have been isolated (Kelter et al 2000;Schramm et al 2000). Two of these encode strikingly different proteins, which are also shown in Figure 4.…”

Section: Identification Of Human Bdp1mentioning

confidence: 99%

Recruitment of RNA polymerase III to its target promoters

Schramm¹,

Hernandez²

2002

Genes Dev.

548

601

View full text Add to dashboard Cite

A key step in retrieving the information stored in the complex genomes of eukaryotes involves the identification of transcription units and, more specifically, the recognition of promoter sequences by RNA polymerase. In eukaryotes, the task of recognizing nuclear gene promoters and then transcribing the genes is divided among three highly related enzymes, RNA polymerases I, II, and III. Each of these RNA polymerases is dedicated to the transcription of specific sets of genes, and each depends on accessory factors, the so-called transcription factors, to recognize its cognate promoter sequences.RNA polymerase I is unique among the nuclear RNA polymerases in transcribing only one set of genes, the large, tandemly repeated, ribosomal RNA genes, and thus in having to recognize a single promoter structure. RNA polymerase II transcribes the protein-coding genes (mRNA genes) as well as some small nuclear RNA (snRNA) genes. The RNA polymerase II promoters can be divided into a core region, defined as the minimal region capable of directing transcription in vitro, and a regulatory region. The regulatory regions are highly varied in structure, reflecting the highly varied synthesis patterns of cellular proteins and the need for exquisite and complex regulation of these patterns. The core promoters themselves come in different types that, in mRNA-encoding genes, can contain a TATA box, an initiator, a downstream promoter element, or various combinations thereof. The assembly of a functional RNA polymerase II transcription complex on a promoter consisting of just a TATA box has been extensively studied. All the factors involved in the process have been identified, and much is known about how these factors interact with DNA and with each other to recruit, eventually, RNA polymerase II (for reviews, see Orphanides et al. 1996;Woychik and Hampsey 2002). How RNA polymerase II transcription complexes assemble on TATA-less promoters is, however, not as well understood.RNA polymerase III is dedicated to the transcription of an eclectic collection of genes whose main common features are that they encode structural or catalytic RNAs and that they are, as a rule, shorter than 400 base pairs (bp). This length limit is consistent with the elongation properties of RNA polymerase III, which recognizes a simple run of T residues as a termination signal. The genes transcribed by RNA polymerase III encode RNA molecules involved in fundamental metabolic processes, specifically components of the protein synthesis apparatus and components of the splicing and tRNA processing apparatus, as well as RNAs of unknown function. The RNA polymerase III promoters are more varied in structure than the uniform RNA polymerase I promoters, and yet not as diverse as the RNA polymerase II promoters. They have been divided into three main types, two of which are gene-internal and generally TATA-less, and one of which is gene-external and contains a TATA box. Remarkably, we have a good, and in some cases a very detailed, understanding of how RNA polymerase III ...

show abstract

“…37 The proteins constituting both TFIIIB-activities were identified and cloned. [38][39][40][41] TFIIIBα, being active in transcription of genes with promoter elements 5′ of the transcription start site (TSS) is composed of TBP, TFIIIB double prime (BDP1) and BRF2. TFIIIBβ, required for transcription of genes with gene-internal promoter elements, is composed of TBP, BDP1 and BRF1.…”

Section: Tfiiiamentioning

confidence: 99%

Contributions of in vitro transcription to the understanding of human RNA polymerase III transcription

et al. 2014

View full text Add to dashboard Cite

The discovery of constituents of eukaryotic transcription systems was enabled by the development of in vivo and in vitro methods for their study. Depending on the organism to be studied, the relative importance of each of these two general approaches has been different. Our knowledge about transcription of human genes would be considerably smaller without the results that were obtained by employing in vitro methods. Here, we will mainly focus on in vitro studies of gene expression that contributed to discoveries in the human RNA polymerase (RNAP) III transcription system.In contrast to unicellular yeast, it has until today been and will most likely remain for a many more years impossible to study human RNAP III transcription in cells that have been grown under conditions resembling at least approximately to an in vivo situation in a human being. For that reason, it has hitherto been difficult to address questions concerning the physiological regulation of human RNAP III transcription in its natural environment. However, the identification of the basal components of the RNAP III transcription system could be achieved without directly resorting to a human "in vivo model system." Yet, the identification of human RNAP III subunits and of accessory transcription factors repeatedly took advantage of in vivo systems that were established in other species. Many discoveries of components of the human RNAP III transcription system were fostered by work performed in unicellular (for example, S. cerevisiae and S. pombe) and multicellular eukaryotes (among others, X. laevis or D. melanogaster). Often, results obtained in these model systems helped researchers identify proteins of the human RNAP III transcription system. For instance, the amino acid sequences of transcription factors that were identified and cloned by employing in vivo and in vitro methods in these organisms served as guide for comparing and identifying orthologous transcription factors in human cells (e.g., TFIIIA, TFIIIB [BDP1], TFIIIC35 [GTF3C6]). However, several of the human RNAP III transcription factors were not cloned by homology, but due to extensive purification from human cells (TFIIIB [BRF2], PTF/SNAPc, TFIIIC [GTF3C1-5]). Purification of these factors by employing biochemical methods was only possible, because functional assays were developed that allowed detecting their specific activities. These assays included in vitro transcription, electrophoretic mobility shift assays (EMSA) and footprinting techniques (descriptions of these techniques are found in 1-3 ). Two techniques were essential for the biochemical purification and functional analysis of human transcription factors: (i) the elaboration of protocols that allowed deriving protein extracts from human cells and (ii) the development of cell-free in vitro transcription assays. [4][5][6] Template DNA for in vitro transcription was provided by genes cloned into plasmid DNA. In the case of RNAP III transcription, usually complete and generally short transcribed sequences were included into the...

show abstract

The Transcription Factor-like Nuclear Regulator (TFNR) Contains a Novel 55-Amino-Acid Motif Repeated Nine Times and Maps Closely to SMN1

Cited by 18 publications

References 32 publications

Different Functional Modes of p300 in Activation of RNA Polymerase III Transcription from Chromatin Templates

Different Functional Modes of p300 in Activation of RNA Polymerase III Transcription from Chromatin Templates

Recruitment of RNA polymerase III to its target promoters

Contributions of in vitro transcription to the understanding of human RNA polymerase III transcription

Contact Info

Product

Resources

About