scholarly journals The role of SAGA in the transcription and export of mRNA

2019 ◽  
Vol 23 (2) ◽  
pp. 174-179
Author(s):  
E. N. Nabirochkina ◽  
M. M. Kurshakova ◽  
S. G. Georgieva ◽  
D. V. Kopytova
Keyword(s):  
Mrna Export ◽  
Rna Polymerase Iii ◽  
Polytene Chromosomes ◽  
Gene Localization ◽  
Regulation Of Transcription ◽  
Histone H2a ◽  
Messenger Ribonucleic Acid ◽  
Transcription Process ◽  
Transcription Sites ◽  
Active Transcription

SAGA/TFTC, which is a histone acetyltransferase complex, plays an important role in the regulation of transcription. We have identified that the metazoan TFTC/STAGA complexes had histone H2A and H2B deubiquitinase activity that is carried out by a DUBm (deubiquitination module). We studied the DUBm of SAGA in Drosophila melanogaster and identified Drosophila homologs of yeast DUBm components. Two subunits of DUBm (Sus1/ENY2 and Sgf11) were shown to have functions separate from DUBm function. Thus, Sus1/ENY2 was shown to be present in several different complexes. Sgf11 was found to be associated with the cap-binding complex (CBC) and recruited onto growing messenger ribonucleic acid (mRNA). Also, we have shown that Sgf11 interacted with the TREX-2/AMEX mRNA export complex and was essential for mRNA export from the nucleus. Immunostaining of the polytene chromosomes of Drosophila larvae revealed that Sgf11 is present at the sites of localization of snRNA genes. It was also found in immunostaining experiments that dPbp45, the subunit of the PBP complex, the key player in the snRNA transcription process, is associated not only with the snRNA gene localization sites, but with other sites of active transcription by PolII. We also revealed that Sgf11 was present at many active transcription sites in interbands and puffs on polytene chromosomes, Sgf11 was localized at all Brf1 (the component of the RNA polymerase III basal transcription complex) sites. We concluded that SAGA coactivated transcription of both the PolII and PolIII-dependent snRNA genes.

scholarly journals Two classes of active transcription sites and their roles in developmental regulation

2020 ◽  
Author(s):  
Sarah Robinson-Thiewes ◽  
John McCloskey ◽  
Judith Kimble
Keyword(s):  
Single Molecule ◽  
Developmental Regulation ◽  
Full Length ◽  
Genes Encoding ◽  
Transcription Sites ◽  
Core Components ◽  
Active Transcription ◽  
Multiple Levels ◽  
Nascent Transcripts ◽  
Transcriptional Output

AbstractGenes encoding powerful developmental regulators are exquisitely controlled, often at multiple levels. Here, we use single molecule FISH (smFISH) to investigate nuclear active transcription sites (ATS) and cytoplasmic mRNAs of three key regulatory genes along the C. elegans germline developmental axis. The genes encode ERK/MAP kinase and core components of the Notch-dependent transcription complex. Using differentially-labeled probes spanning either a long first intron or downstream exons, we identify two ATS classes that differ in transcriptional progression: iATS harbor partial nascent transcripts while cATS harbor full-length nascent transcripts. Remarkably, the frequencies of iATS and cATS are patterned along the germline axis in a gene-, stage- and sex-specific manner. Moreover, regions with more frequent iATS make fewer full-length nascent transcripts and mRNAs, whereas those with more frequent cATS produce more of them. We propose that the regulated balance of these two ATS classes has a major impact on transcriptional output during development.

scholarly journals Silk gland-specific tRNA(Ala) genes interact more weakly than constitutive tRNA(Ala) genes with silkworm TFIIIB and polymerase III fractions.

1994 ◽  
Vol 14 (3) ◽  
pp. 1806-1814 ◽  
Author(s):  
H S Sullivan ◽  
L S Young ◽  
C N White ◽  
K U Sprague
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Silk Gland ◽  
Flanking Sequence ◽  
Transcription Machinery ◽  
Polymerase Iii ◽  
Active Transcription ◽  
The Difference ◽  
Transcription Complexes

Constitutive and silk gland-specific tRNA(Ala) genes from silkworms have very different transcriptional properties in vitro. Typically, the constitutive type, which encodes tRNA(AlaC), directs transcription much more efficiently than does the silk gland-specific type, which encodes tRNA(AlaSG). We think that the inefficiency of the tRNA(AlaCG) gene underlies its capacity to be turned off in non-silk gland cells. An economical model is that the tRNA(AlaSG) promoter interacts poorly, relative to the tRNA(AlaC) promoter, with one or more components of the basal transcription machinery. As a consequence, the tRNA(AlaSG) gene directs the formation of fewer transcription complexes or of complexes with reduced cycling ability. Here we show that the difference in the number of active transcription complexes accounts for the difference in tRNA(AlaC) and tRNA(AlaSG) transcription rates. To determine whether a particular component of the silkworm transcription machinery is responsible for reduced complex formation on the tRNA(AlaSG) gene, we measured competition by templates for defined fractions of this machinery. We find that the tRNA(AlaSG) gene is greatly impaired, in comparison with the tRNA(AlaC) gene, in competition for either TFIIIB or RNA polymerase III. Competition for each of these fractions is also strongly influenced by the nature of the 5' flanking sequence, the promoter element responsible for the distinctive transcriptional properties of tRNA(AlaSG) and tRNA(AlaC) genes. These results suggest that differential interaction with TFIIIB or RNA polymerase III is a critical functional distinction between these genes.

scholarly journals Intron-dependent recruitment of pre-mRNA splicing factors to sites of transcription.

1996 ◽  
Vol 133 (4) ◽  
pp. 719-732 ◽  
Author(s):  
S Huang ◽  
D L Spector
Keyword(s):  
Spatial Association ◽  
Electron Microscopic Examination ◽  
Mrna Splicing ◽  
Splicing Factors ◽  
Electron Microscopic ◽  
Rna Transcripts ◽  
Highly Active ◽  
Transcription Sites ◽  
Active Transcription ◽  
Nascent Rna

We have examined the nuclear localization of transiently and stably expressed nascent RNA transcripts containing or lacking introns in order to determine if the spatial association of RNA transcripts and pre-mRNA splicing factors in nuclei is random or functionally significant. Our findings show that the association between nascent RNA and splicing factors in the nucleus is intron-dependent when the RNAs are either transiently or stably expressed. Furthermore, our data indicate that splicing factors are recruited to the transcription sites. The presence of both pre-and mRNA at these locations suggest that pre-mRNA splicing occurs at these sites of transcription. In addition, electron microscopic examination of the highly active transcription sites has revealed a granular appearance which closely resembles, but is functionally different from, interchromatin granule clusters. Our findings demonstrate that the nucleus is highly organized and dynamic with regard to the functions of the transcription and pre-mRNA splicing.

scholarly journals Nap1 Links Transcription Elongation, Chromatin Assembly, and Messenger RNP Complex Biogenesis

2008 ◽  
Vol 28 (7) ◽  
pp. 2113-2124 ◽  
Author(s):  
Brian C. Del Rosario ◽  
Lucy F. Pemberton
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromatin Remodeling ◽  
Transcription Elongation ◽  
Mrna Export ◽  
Transcript Level ◽  
Chromatin Assembly ◽  
Regulation Of Transcription ◽  
Histone Chaperones ◽  
Coding Region ◽  
Rnp Complex

ABSTRACT Chromatin remodeling is central to the regulation of transcription elongation. We demonstrate that the conserved Saccharomyces cerevisiae histone chaperone Nap1 associates with chromatin. We show that Nap1 regulates transcription of PHO5, and the increase in transcript level and the higher phosphatase activity plateau observed for Δnap1 cells suggest that the net function of Nap1 is to facilitate nucleosome reassembly during transcription elongation. To further our understanding of histone chaperones in transcription elongation, we identified factors that regulate the function of Nap1 in this process. One factor investigated is an essential mRNA export and TREX complex component, Yra1. Nap1 interacts directly with Yra1 and genetically with other TREX complex components and the mRNA export factor Mex67. Additionally, we show that the recruitment of Nap1 to the coding region of actively transcribed genes is Yra1 dependent and that its recruitment to promoters is TREX complex independent. These observations suggest that Nap1 functions provide a new connection between transcription elongation, chromatin assembly, and messenger RNP complex biogenesis.

scholarly journals Drosophila histone H2A.2 is associated with the interbands of polytene chromosomes.

1986 ◽  
Vol 83 (13) ◽  
pp. 4744-4748 ◽  
Author(s):  
P. R. Donahue ◽  
D. K. Palmer ◽  
J. M. Condie ◽  
L. M. Sabatini ◽  
M. Blumenfeld
Keyword(s):  
Polytene Chromosomes ◽  
Histone H2a

scholarly journals ICP27 Recruits Aly/REF but Not TAP/NXF1 to Herpes Simplex Virus Type 1 Transcription Sites although TAP/NXF1 Is Required for ICP27 Export

2005 ◽  
Vol 79 (7) ◽  
pp. 3949-3961 ◽  
Author(s):  
I-Hsiung Brandon Chen ◽  
Ling Li ◽  
Lindsey Silva ◽  
Rozanne M. Sandri-Goldin
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Mrna Export ◽  
Viral Transcription ◽  
Transcription Sites ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Herpes simplex virus type 1 (HSV-1) protein ICP27 interacts with the cellular export adaptor protein Aly/REF, which is part of the exon junction complex implicated in cellular mRNA export. We previously reported that Aly/REF was no longer associated with splicing factor SC35 sites during infection but instead colocalized with ICP27 in distinct structures. Here we show that these structures colocalize with ICP4 and are sites of HSV-1 transcription. ICP27 mutants with lesions in the region required for the interaction with Aly/REF failed to recruit Aly/REF to viral transcription sites; however, ICP27 export to the cytoplasm was unimpaired, indicating that the interaction of ICP27 with Aly/REF is not required for ICP27 shuttling. ICP27 has also been shown to interact with the cellular mRNA export receptor TAP/NXF1. We report that ICP27 interacts directly with TAP/NXF1 and does not require Aly/REF to bridge the interaction. The C terminus of ICP27 is required; however, the N-terminal leucine-rich region also contributes to the interaction of ICP27 with TAP/NXF1. In contrast to the results found for Aly/REF, mutants that failed to interact with TAP/NXF1 were not exported to the cytoplasm, and TAP/NXF1 was not recruited to sites of HSV-1 transcription. Therefore, the interaction of ICP27 with TAP/NXF1 occurs after ICP27 leaves viral transcription sites. We conclude that ICP27 and the viral RNAs to which it binds are exported via the TAP/NXF1 export receptor.

scholarly journals Dynamic multifactor hubs interact transiently with sites of active transcription in Drosophila embryos

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Mustafa Mir ◽  
Michael R Stadler ◽  
Stephan A Ortiz ◽  
Colleen E Hannon ◽  
Melissa M Harrison ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Single Molecule ◽  
High Speed ◽  
Light Sheet ◽  
Editorial Note ◽  
Regulation Of Transcription ◽  
Light Sheet Microscopy ◽  
4D Imaging ◽  
Active Transcription ◽  
Drosophila Embryos

The regulation of transcription requires the coordination of numerous activities on DNA, yet how transcription factors mediate these activities remains poorly understood. Here, we use lattice light-sheet microscopy to integrate single-molecule and high-speed 4D imaging in developing Drosophila embryos to study the nuclear organization and interactions of the key transcription factors Zelda and Bicoid. In contrast to previous studies suggesting stable, cooperative binding, we show that both factors interact with DNA with surprisingly high off-rates. We find that both factors form dynamic subnuclear hubs, and that Bicoid binding is enriched within Zelda hubs. Remarkably, these hubs are both short lived and interact only transiently with sites of active Bicoid-dependent transcription. Based on our observations, we hypothesize that, beyond simply forming bridges between DNA and the transcription machinery, transcription factors can organize other proteins into hubs that transiently drive multiple activities at their gene targets.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (<xref ref-type="decision-letter" rid="SA1">see decision letter</xref>).

Silk gland-specific tRNA(Ala) genes interact more weakly than constitutive tRNA(Ala) genes with silkworm TFIIIB and polymerase III fractions

1994 ◽  
Vol 14 (3) ◽  
pp. 1806-1814
Author(s):  
H S Sullivan ◽  
L S Young ◽  
C N White ◽  
K U Sprague
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Silk Gland ◽  
Flanking Sequence ◽  
Transcription Machinery ◽  
Polymerase Iii ◽  
Active Transcription ◽  
The Difference ◽  
Transcription Complexes

Constitutive and silk gland-specific tRNA(Ala) genes from silkworms have very different transcriptional properties in vitro. Typically, the constitutive type, which encodes tRNA(AlaC), directs transcription much more efficiently than does the silk gland-specific type, which encodes tRNA(AlaSG). We think that the inefficiency of the tRNA(AlaCG) gene underlies its capacity to be turned off in non-silk gland cells. An economical model is that the tRNA(AlaSG) promoter interacts poorly, relative to the tRNA(AlaC) promoter, with one or more components of the basal transcription machinery. As a consequence, the tRNA(AlaSG) gene directs the formation of fewer transcription complexes or of complexes with reduced cycling ability. Here we show that the difference in the number of active transcription complexes accounts for the difference in tRNA(AlaC) and tRNA(AlaSG) transcription rates. To determine whether a particular component of the silkworm transcription machinery is responsible for reduced complex formation on the tRNA(AlaSG) gene, we measured competition by templates for defined fractions of this machinery. We find that the tRNA(AlaSG) gene is greatly impaired, in comparison with the tRNA(AlaC) gene, in competition for either TFIIIB or RNA polymerase III. Competition for each of these fractions is also strongly influenced by the nature of the 5' flanking sequence, the promoter element responsible for the distinctive transcriptional properties of tRNA(AlaSG) and tRNA(AlaC) genes. These results suggest that differential interaction with TFIIIB or RNA polymerase III is a critical functional distinction between these genes.

scholarly journals Identification and Characterization of Elf1, a Conserved Transcription Elongation Factor in Saccharomyces cerevisiae

2005 ◽  
Vol 25 (22) ◽  
pp. 10122-10135 ◽  
Author(s):  
Donald Prather ◽  
Nevan J. Krogan ◽  
Andrew Emili ◽  
Jack F. Greenblatt ◽  
Fred Winston
Keyword(s):  
Synthetic Lethality ◽  
Transcription Elongation ◽  
Elongation Factor ◽  
Regulation Of Transcription ◽  
Elongation Factors ◽  
Genome Wide ◽  
Genes Encoding ◽  
Active Transcription ◽  
Identification And Characterization

ABSTRACT In order to identify previously unknown transcription elongation factors, a genetic screen was carried out to identify mutations that cause lethality when combined with mutations in the genes encoding the elongation factors TFIIS and Spt6. This screen identified a mutation in YKL160W, hereafter named ELF1 (elongation factor 1). Further analysis identified synthetic lethality between an elf1Δ mutation and mutations in genes encoding several known elongation factors, including Spt4, Spt5, Spt6, and members of the Paf1 complex. Genome-wide synthetic lethality studies confirmed that elf1Δ specifically interacts with mutations in genes affecting transcription elongation. Chromatin immunoprecipitation experiments show that Elf1 is cotranscriptionally recruited over actively transcribed regions and that this association is partially dependent on Spt4 and Spt6. Analysis of elf1Δ mutants suggests a role for this factor in maintaining proper chromatin structure in regions of active transcription. Finally, purification of Elf1 suggests an association with casein kinase II, previously implicated in roles in transcription. Together, these results suggest an important role for Elf1 in the regulation of transcription elongation.

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