scholarly journals TFIIIC1 acts through a downstream region to stabilize TFIIIC2 binding to RNA polymerase III promoters.

1996 ◽  
Vol 16 (12) ◽  
pp. 6841-6850 ◽  
Author(s):  
Z Wang ◽  
R G Roeder

An in vitro system reconstituted with highly purified RNA polymerase III, TFIIIC2, and TFIIIB has been used to identify two chromatographically distinct human RNA polymerase III transcription factors, TFIIIC1 and TFIIIC1', which are functionally equivalent to the previously defined TFIIIC1 (S. T. Yoshinaga, P. A. Boulanger, and A. J. Berk, Proc. Natl. Acad. Sci. USA 84:3585-3589, 1987). Interactions between TFIIIC2, TFIIIC1 (or TFIIIC1'), and the VA1 and tRNA1(Met) templates have been investigated by DNase I footprint analysis. Homogeneous TFIIIC2 alone shows only a weak footprint over the B-box region of the VA1 and tRNA1(Met) templates, whereas TFIIIC1 (or TFIIIC1') alone shows both a strong interaction over the downstream termination region and a very weak interaction near the A-box region. Importantly, when both factors are present simultaneously, TFIIIC1 (or TFIIIC1') dramatically enhances the level of TFIIIC2 binding and extends the footprint to a region that includes the A box. The downstream termination region is essential for this cooperative interaction between TFIIIC2 and TFIIIC1 (or TFIIIC1') on the VA1 and tRNA1(Met) templates and plays a role in the overall accuracy and efficiency of RNA polymerase III transcription.

1999 ◽  
Vol 77 (5) ◽  
pp. 431-438 ◽  
Author(s):  
Jürgen Müller ◽  
Bernd-Joachim Benecke

Transcription of the human 7SL RNA gene by RNA polymerase III depends on the concerted action of transcription factors binding to the gene-internal and gene-external parts of its promoter. Here, we investigated which transcription factors interact with the human 7SL RNA gene promoter and which are required for transcription of the human 7SL RNA gene. A-box/B-box elements were previously identified in 5S RNA, tRNA, and virus associated RNA genes and are recognized by transcription factor IIIC (TFIIIC). The gene-internal promoter region of the human 7SL RNA gene shows only limited similarity to those elements. Nevertheless, competition experiments and the use of highly enriched factor preparations demonstrate that TFIIIC is required for human 7SL transcription. The gene-external part of the promoter includes an authentic cAMP-responsive element previously identified in various RNA polymerase II promoters. Here we demonstrate that members of the activating transcription factor/cyclic AMP-responsive element binding protein (ATF/CREB) transcription factor family bind specifically to this element in vitro. However, the human 7SL RNA gene is not regulated by cAMP in vivo. Furthermore, in vitro transcription of the gene does not depend on ATF/CREB transcription factors. It rather appears that a transcription factor with DNA-binding characteristics like ATF/CREB proteins but otherwise different properties is required for human 7SL RNA transcription.Key words: 7SL RNA, ATF, CRE, TFIIIC, RNA polymerase III.


1985 ◽  
Vol 5 (1) ◽  
pp. 40-45 ◽  
Author(s):  
A B Lassar ◽  
D H Hamer ◽  
R G Roeder

We have constructed recombinant simian virus 40 molecules containing Xenopus 5S RNA and tRNA genes. Recombinant minichromosomes containing these genes were isolated to study the interaction of RNA polymerase III transcription factors with these model chromatin templates. Minichromosomes containing a tRNAMet gene can be isolated in a stable complex with transcription factors (IIIB and IIIC) and are active in vitro templates for purified RNA polymerase III. In contrast, minichromosomes containing a 5S RNA gene are refractory to transcription by purified RNA polymerase III in either the absence or the presence of other factors.


1987 ◽  
Vol 7 (11) ◽  
pp. 3880-3887 ◽  
Author(s):  
L G Fradkin ◽  
S K Yoshinaga ◽  
A J Berk ◽  
A Dasgupta

The inhibition of transcription by RNA polymerase III in poliovirus-infected cells was studied. Experiments utilizing two different cell lines showed that the initiation step of transcription by RNA polymerase III was impaired by infection of these cells with the virus. The observed inhibition of transcription was not due to shut-off of host cell protein synthesis by poliovirus. Among four distinct components required for accurate transcription in vitro from cloned DNA templates, activities of RNA polymerase III and transcription factor TFIIIA were not significantly affected by virus infection. The activity of transcription factor TFIIIC, the limiting component required for transcription of RNA polymerase III genes, was severely inhibited in infected cells, whereas that of transcription factor TFIIIB was inhibited to a lesser extent. The sequence-specific DNA-binding of TFIIIC to the adenovirus VA1 gene internal promoter, however, was not altered by infection of cells with the virus. We conclude that (i) at least two transcription factors, TFIIIB and TFIIIC, are inhibited by infection of cells with poliovirus, (ii) inactivation of TFIIIC does not involve destruction of its DNA-binding domain, and (iii) sequence-specific DNA binding by TFIIIC may be necessary but is not sufficient for the formation of productive transcription complexes.


1995 ◽  
Vol 15 (3) ◽  
pp. 1642-1650 ◽  
Author(s):  
J A Martignetti ◽  
J Brosius

Rodent BC1 RNA represents the first example of a neural cell-specific RNA polymerase III (Pol III) transcription product. By developing a rat brain in vitro system capable of supporting Pol III-directed transcription, we showed that the rat BC1 RNA intragenic promoter elements, comprising an A box element and a variant B box element, as well as its upstream region, containing octamer-binding consensus sequences and functional TATA and proximal sequence element sites, are necessary for transcription. The BC1 B box, lacking the invariant A residue found in the consensus B boxes of tRNAs, represents a functionally related and possibly distinct promoter element. The transcriptional activity of the BC1 B box element is greatly increased, in both a BC1 RNA and a chimeric tRNA(Leu) gene construct, when the BC1 5' flanking region is present and is appropriately spaced. Moreover, a tRNA consensus B-box sequence can efficiently replace the BC1 B box only if the BC1 upstream region is removed. These interactions, identified only in a homologous in vitro system, between upstream Pol II and intragenic Pol III promoters suggest a mechanism by which the tissue-specific BC1 RNA gene and possibly other Pol III-transcribed genes can be regulated.


2000 ◽  
Vol 20 (24) ◽  
pp. 9182-9191 ◽  
Author(s):  
Heather A. Hirsch ◽  
Liping Gu ◽  
R. William Henry

ABSTRACT The retinoblastoma protein (RB) represses RNA polymerase III transcription effectively both in vivo and in vitro. Here we demonstrate that the general transcription factors snRNA-activating protein complex (SNAPc) and TATA binding protein (TBP) are important for RB repression of human U6 snRNA gene transcription by RNA polymerase III. RB is associated with SNAPc as detected by both coimmunoprecipitation of endogenous RB with SNAPc and cofractionation of RB and SNAPc during chromatographic purification. RB also interacts with two SNAPc subunits, SNAP43 and SNAP50. TBP or a combination of TBP and SNAPcrestores efficient U6 transcription from RB-treated extracts, indicating that TBP is also involved in RB regulation. In contrast, the TBP-containing complex TFIIIB restores adenovirus VAI but not human U6 transcription in RB-treated extracts, suggesting that TFIIIB is important for RB regulation of tRNA-like genes. These results suggest that different classes of RNA polymerase III-transcribed genes have distinct general transcription factor requirements for repression by RB.


1987 ◽  
Vol 7 (11) ◽  
pp. 3880-3887
Author(s):  
L G Fradkin ◽  
S K Yoshinaga ◽  
A J Berk ◽  
A Dasgupta

The inhibition of transcription by RNA polymerase III in poliovirus-infected cells was studied. Experiments utilizing two different cell lines showed that the initiation step of transcription by RNA polymerase III was impaired by infection of these cells with the virus. The observed inhibition of transcription was not due to shut-off of host cell protein synthesis by poliovirus. Among four distinct components required for accurate transcription in vitro from cloned DNA templates, activities of RNA polymerase III and transcription factor TFIIIA were not significantly affected by virus infection. The activity of transcription factor TFIIIC, the limiting component required for transcription of RNA polymerase III genes, was severely inhibited in infected cells, whereas that of transcription factor TFIIIB was inhibited to a lesser extent. The sequence-specific DNA-binding of TFIIIC to the adenovirus VA1 gene internal promoter, however, was not altered by infection of cells with the virus. We conclude that (i) at least two transcription factors, TFIIIB and TFIIIC, are inhibited by infection of cells with poliovirus, (ii) inactivation of TFIIIC does not involve destruction of its DNA-binding domain, and (iii) sequence-specific DNA binding by TFIIIC may be necessary but is not sufficient for the formation of productive transcription complexes.


1985 ◽  
Vol 5 (1) ◽  
pp. 40-45
Author(s):  
A B Lassar ◽  
D H Hamer ◽  
R G Roeder

We have constructed recombinant simian virus 40 molecules containing Xenopus 5S RNA and tRNA genes. Recombinant minichromosomes containing these genes were isolated to study the interaction of RNA polymerase III transcription factors with these model chromatin templates. Minichromosomes containing a tRNAMet gene can be isolated in a stable complex with transcription factors (IIIB and IIIC) and are active in vitro templates for purified RNA polymerase III. In contrast, minichromosomes containing a 5S RNA gene are refractory to transcription by purified RNA polymerase III in either the absence or the presence of other factors.


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