scholarly journals Interaction between a complex of RNA polymerase III subunits and the 70-kDa component of transcription factor IIIB.

1993 ◽  
Vol 268 (28) ◽  
pp. 20721-20724
Author(s):  
M Werner ◽  
N Chaussivert ◽  
I.M. Willis ◽  
A Sentenac
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Polymerase Iii ◽  
Transcription Factor Iiib

scholarly journals Alignment of the B" Subunit of RNA Polymerase III Transcription Factor IIIB in Its Promoter Complex

1999 ◽  
Vol 274 (40) ◽  
pp. 28736-28744 ◽  
Author(s):  
Sheila M. A. Shah ◽  
Ashok Kumar ◽  
E. Peter Geiduschek ◽  
George A. Kassavetis
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
B Subunit ◽  
Polymerase Iii ◽  
Promoter Complex ◽  
Transcription Factor Iiib

scholarly journals Domains of the Brf component of RNA polymerase III transcription factor IIIB (TFIIIB): functions in assembly of TFIIIB-DNA complexes and recruitment of RNA polymerase to the promoter.

1997 ◽  
Vol 17 (9) ◽  
pp. 5299-5306 ◽  
Author(s):  
G A Kassavetis ◽  
C Bardeleben ◽  
A Kumar ◽  
E Ramirez ◽  
E P Geiduschek
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Binding Protein ◽  
Rna Polymerase Iii ◽  
Tata Binding Protein ◽  
Terminal Segment ◽  
Dna Complexes ◽  
Polymerase Iii ◽  
Transcription Factor Iiib ◽  
Derivatives Of

Saccharomyces cerevisiae transcription factor IIIB (TFIIIB) is composed of three subunits: the TATA-binding protein, the TFIIB-related protein Brf, and B". TFIIIB, which is brought to RNA polymerase III-transcribed genes indirectly through interaction with DNA-bound TFIIIC or directly through DNA recognition by the TATA-binding protein, in turn recruits RNA polymerase III to the promoter. N-terminally deleted derivatives of Brf have been examined for their ability to interact with DNA-bound TFIIIC and with the other components of TFIIIB and for participation in transcription. Brf(165-596), lacking 164 N-proximal TFIIB-homologous amino acids, is competent to participate in the assembly of TFIIIB-DNA complexes and in TFIIIC-independent transcription. Even deletion of the entire TFIIB-homologous half of the protein, as in Brf(317-596) and Brf(352-596), allows some interaction with DNA-bound TBP and with the B" component of TFIIIB to be retained. The function of Brf(165-596) in transcription has also been examined in the context of B" with small internal deletions. The ability of Brf with this sizable N-terminal segment deleted to function in TFIIIC-independent transcription requires segments of B" that are individually indispensable although required on an either/or basis, in the context of complete Brf. These findings suggest a functional complementarity and reciprocity between the Brf and B" components of TFIIIB.

scholarly journals Functional dissection of the B" component of RNA polymerase III transcription factor IIIB: a scaffolding protein with multiple roles in assembly and initiation of transcription.

1997 ◽  
Vol 17 (4) ◽  
pp. 1868-1880 ◽  
Author(s):  
A Kumar ◽  
G A Kassavetis ◽  
E P Geiduschek ◽  
M Hambalko ◽  
C J Brent
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Dna Complexes ◽  
Protein Footprinting ◽  
U6 Snrna ◽  
Polymerase Iii ◽  
Core Proteins ◽  
Transcription Factor Iiib ◽  
Dna Complex

Transcription factor IIIB (TFIIIB), the central transcription factor of Saccharomyces cerevisiae RNA polymerase III, is composed of TATA-binding protein, the TFIIB-related protein Brf, and B". B", the last component to enter the TFIIIB-DNA complex, confers extremely tight DNA binding on TFIIIB. Terminally and internally deleted B" derivatives were tested for competence to form TFIIIB-DNA complexes by TFIIIC-dependent and -independent pathways on the SUP4 tRNA(Tyr) and U6 snRNA (SNR6) genes, respectively, and for transcription. Selected TFIIIB-TFIIIC-DNA complexes assembled with truncated B" were analyzed by DNase I footprinting, and the surface topography of B" in the TFIIIB-DNA complex was also analyzed by hydroxyl radical protein footprinting. These analyses define functional domains of B" and also reveal roles in start site selection by RNA polymerase III and in clearing TFIIIC from the transcriptional start. Although absolutely required for transcription, B" can be extensively truncated. Core proteins retaining as few as 176 (of 594) amino acids remain competent to transcribe the SNR6 gene in vitro. TFIIIC-dependent assembly on DNA and transcription requires a larger core of B": two domains (I and II) that are required for SNR6 transcription on an either-or basis are simultaneously required for TFIIIC-dependent assembly of DNA complexes and transcription. Domains I and II of B" are buried upon assembly of the TFIIIB-DNA complex, as determined by protein footprinting. The picture of the TFIIIB-DNA complex that emerges is that B" serves as its scaffold and is folded over in the complex so that domains I and II are near one another.

scholarly journals Involvement of RNA Polymerase III in Immune Responses

2015 ◽  
Vol 35 (10) ◽  
pp. 1848-1859 ◽  
Author(s):  
Damian Graczyk ◽  
Robert J. White ◽  
Kevin M. Ryan
Keyword(s):  
Transcription Factor ◽  
Immune Responses ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Trna Genes ◽  
Malignant Cells ◽  
Polymerase Iii ◽  
Mouse Macrophages ◽  
Tightly Coupled ◽  
Pol Iii

Inflammation in the tumor microenvironment has many tumor-promoting effects. In particular, tumor-associated macrophages (TAMs) produce many cytokines which can support tumor growth by promoting survival of malignant cells, angiogenesis, and metastasis. Enhanced cytokine production by TAMs is tightly coupled with protein synthesis. In turn, translation of proteins depends on tRNAs, short abundant transcripts that are made by RNA polymerase III (Pol III). Here, we connect these facts by showing that stimulation of mouse macrophages with lipopolysaccharides (LPS) from the bacterial cell wall causes transcriptional upregulation of tRNA genes. The transcription factor NF-κB is a key transcription factor mediating inflammatory signals, and we report that LPS treatment causes an increased association of the NF-κB subunit p65 with tRNA genes. In addition, we show that p65 can directly associate with the Pol III transcription factor TFIIIB and that overexpression of p65 induces Pol III-dependent transcription. As a consequence of these effects, we show that inhibition of Pol III activity in macrophages restrains cytokine secretion and suppresses phagocytosis, two key functional characteristics of these cells. These findings therefore identify a radical new function for Pol III in the regulation of macrophage function which may be important for the immune responses associated with both normal and malignant cells.

scholarly journals Role of RNA Polymerase III Transcription Factors in the Selection of Integration Sites by the Dictyostelium Non-Long Terminal Repeat Retrotransposon TRE5-A

2006 ◽  
Vol 26 (22) ◽  
pp. 8242-8251 ◽  
Author(s):  
Oliver Siol ◽  
Moustapha Boutliliss ◽  
Thanh Chung ◽  
Gernot Glöckner ◽  
Theodor Dingermann ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Long Terminal Repeat ◽  
Integration Site ◽  
Rna Polymerase Iii ◽  
Terminal Repeat ◽  
Trna Genes ◽  
Ltr Retrotransposons ◽  
Polymerase Iii

ABSTRACT In the compact Dictyostelium discoideum genome, non-long terminal repeat (non-LTR) retrotransposons known as TREs avoid accidental integration-mediated gene disruption by targeting the vicinity of tRNA genes. In this study we provide the first evidence that proteins of a non-LTR retrotransposon interact with a target-specific transcription factor to direct its integration. We applied an in vivo selection system that allows for the isolation of natural TRE5-A integrations into a known genomic location upstream of tRNA genes. TRE5-A frequently modified the integration site in a way characteristic of other non-LTR retrotransposons by adding nontemplated extra nucleotides and generating small and extended target site deletions. Mutations within the B-box promoter of the targeted tRNA genes interfered with both the in vitro binding of RNA polymerase III transcription factor TFIIIC and the ability of TRE5-A to target these genes. An isolated B box was sufficient to enhance TRE5-A integration in the absence of a surrounding tRNA gene. The RNA polymerase III-transcribed ribosomal 5S gene recruits TFIIIC in a B-box-independent manner, yet it was readily targeted by TRE5-A in our assay. These results suggest a direct role of an RNA polymerase III transcription factor in the targeting process.

scholarly journals Transcription-independent TFIIIC-bound sites cluster near heterochromatin boundaries within lamina-associated domains in C. elegans

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Alexis V. Stutzman ◽  
April S. Liang ◽  
Vera Beilinson ◽  
Kohta Ikegami
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Mammalian Cells ◽  
Sex Chromosome ◽  
Rna Polymerase Iii ◽  
Chromatin Organization ◽  
Control Of Gene Expression ◽  
C Elegans ◽  
Polymerase Iii ◽  
The Individual

Abstract Background Chromatin organization is central to precise control of gene expression. In various eukaryotic species, domains of pervasive cis-chromatin interactions demarcate functional domains of the genomes. In nematode Caenorhabditis elegans, however, pervasive chromatin contact domains are limited to the dosage-compensated sex chromosome, leaving the principle of C. elegans chromatin organization unclear. Transcription factor III C (TFIIIC) is a basal transcription factor complex for RNA polymerase III, and is implicated in chromatin organization. TFIIIC binding without RNA polymerase III co-occupancy, referred to as extra-TFIIIC binding, has been implicated in insulating active and inactive chromatin domains in yeasts, flies, and mammalian cells. Whether extra-TFIIIC sites are present and contribute to chromatin organization in C. elegans remains unknown. Results We identified 504 TFIIIC-bound sites absent of RNA polymerase III and TATA-binding protein co-occupancy characteristic of extra-TFIIIC sites in C. elegans embryos. Extra-TFIIIC sites constituted half of all identified TFIIIC binding sites in the genome. Extra-TFIIIC sites formed dense clusters in cis. The clusters of extra-TFIIIC sites were highly over-represented within the distal arm domains of the autosomes that presented a high level of heterochromatin-associated histone H3K9 trimethylation (H3K9me3). Furthermore, extra-TFIIIC clusters were embedded in the lamina-associated domains. Despite the heterochromatin environment of extra-TFIIIC sites, the individual clusters of extra-TFIIIC sites were devoid of and resided near the individual H3K9me3-marked regions. Conclusion Clusters of extra-TFIIIC sites were pervasive in the arm domains of C. elegans autosomes, near the outer boundaries of H3K9me3-marked regions. Given the reported activity of extra-TFIIIC sites in heterochromatin insulation in yeasts, our observation raised the possibility that TFIIIC may also demarcate heterochromatin in C. elegans.

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