101
|
Bakó L, Nuotio S, Dudits D, Schell J, Koncz C. RNAPII: a specific target for the cell cycle kinase complex. Results Probl Cell Differ 1994; 20:25-64. [PMID: 8036318 DOI: 10.1007/978-3-540-48037-2_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- L Bakó
- Institute of Plant Physiology, Hungarian Academy of Sciences, Szeged
| | | | | | | | | |
Collapse
|
102
|
Choy B, Green MR. Eukaryotic activators function during multiple steps of preinitiation complex assembly. Nature 1993; 366:531-6. [PMID: 8255291 DOI: 10.1038/366531a0] [Citation(s) in RCA: 250] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Eukaryotic activator proteins (activators) stimulate transcription by increasing assembly of the preinitiation complex. We have developed methods to quantify the stable assembly of general transcription factors into transcriptional complexes in response to activators. We show that activators function during at least two stages of preinitiation complex assembly: first, to recruit the general transcription factor TFIIB, and then at a second step, after TFIIB entry. It is at this second step that the TATA-box binding protein associated factors act. This step also seems to be critical for activators to stimulate transcription synergistically.
Collapse
Affiliation(s)
- B Choy
- Program in Molecular Medicine, University of Massachusetts Medical Center, Worcester 01605
| | | |
Collapse
|
103
|
Abstract
Transcription associated with a terminal deoxynucleotide transferase gene initiator element is shown to respond to the transcription factor GAL4-VP16 both in vivo and in vitro. High-level transcription requires both an intact initiator element and bound activator. Transcription from this initiator-directed promoter is synergistic in vivo in that five GAL4 DNA binding sites yield 36 times the expression of a single site. Promoters dominated by initiator and TATA elements respond similarly to several GAL4-based activators, including GAL4-Sp1, GAL4-CTF, GAL4(1-147), GAL4-p53, GAL4-C/EBP, and GAL4-ER(EF), as well as GAL4-VP16 and Sp1. These and other similarities suggest that primary activation of TATA- and initiator-dominated promoters occurs at common steps. Since the initial assembly steps do not appear to be common for the two promoter types, the results place interesting constraints on models for how activation occurs.
Collapse
Affiliation(s)
- C Chang
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90024-1569
| | | |
Collapse
|
104
|
Abstract
An RNA polymerase II activator often contains several regions that contribute to its potency, an organization ostensibly analogous to the modular architecture of promoters and enhancers. The regulatory significance of this parallel organization has not been systematically explored. We considered this problem by examining the activation domain of the Epstein-Barr virus transactivator ZEBRA. We performed our experiments in vitro so that the activator concentrations, stabilities, and affinities for DNA could be monitored. ZEBRA and various amino-terminal deletion derivatives, expressed in and purified from Escherichia coli, were assayed in a HeLa cell nuclear extract for the ability to activate model reporter templates bearing one, three, five, and seven upstream ZEBRA binding sites. Our data show that ZEBRA contains four modules that contribute to its potency in vitro. The modules operate interchangeably with promoter sites to determine the transcriptional response such that the loss of modules can be compensated for by increasing promoter sites. Potassium permanganate footprinting was used to show that transcriptional stimulation is a consequence of the activator's ability to promote preinitiation complex assembly. Kinetic measurements of transcription complex assembly in a reconstituted system indicate that ZEBRA promotes formation of a subcomplex requiring the TFIIA and TFIID fractions, where TFIIA acts as an antirepressor. We propose a model in which the concentration of DNA-bound activation modules in the vicinity of the gene initiates synergistic transcription complex assembly.
Collapse
|
105
|
Function of the growth-regulated transcription initiation factor TIF-IA in initiation complex formation at the murine ribosomal gene promoter. Mol Cell Biol 1993. [PMID: 8413268 DOI: 10.1128/mcb.13.11.6723] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Alterations in the rate of cell proliferation are accompanied by changes in the transcription of rRNA genes. In mammals, this growth-dependent regulation of transcription of genes coding for rRNA (rDNA) is due to reduction of the amount or activity of an essential transcription factor, called TIF-IA. Extracts prepared from quiescent cells lack this factor activity and, therefore, are transcriptionally inactive. We have purified TIF-IA from exponentially growing cells and have shown that it is a polypeptide with a molecular mass of 75 kDa which exists as a monomer in solution. Using a reconstituted transcription system consisting of purified transcription factors, we demonstrate that TIF-IA is a bona fide transcription initiation factor which interacts with RNA polymerase I. Preinitiation complexes can be assembled in the absence of TIF-IA, but formation of the first phosphodiester bonds of nascent rRNA is precluded. After initiation, TIF-IA is liberated from the initiation complex and facilitates transcription from templates bearing preinitiation complexes which lack TIF-IA. Despite the pronounced species specificity of class I gene transcription, this growth-dependent factor has been identified not only in mouse but also in human cells. Murine TIF-IA complements extracts from both growth-inhibited mouse and human cells. The analogous human activity appears to be similar or identical to that of TIF-IA. Therefore, despite the fact that the RNA polymerase transcription system has evolved sufficiently rapidly that an rDNA promoter from one species will not function in another species, the basic mechanisms that adapt ribosome synthesis to cell proliferation have been conserved.
Collapse
|
106
|
Abstract
An RNA polymerase II activator often contains several regions that contribute to its potency, an organization ostensibly analogous to the modular architecture of promoters and enhancers. The regulatory significance of this parallel organization has not been systematically explored. We considered this problem by examining the activation domain of the Epstein-Barr virus transactivator ZEBRA. We performed our experiments in vitro so that the activator concentrations, stabilities, and affinities for DNA could be monitored. ZEBRA and various amino-terminal deletion derivatives, expressed in and purified from Escherichia coli, were assayed in a HeLa cell nuclear extract for the ability to activate model reporter templates bearing one, three, five, and seven upstream ZEBRA binding sites. Our data show that ZEBRA contains four modules that contribute to its potency in vitro. The modules operate interchangeably with promoter sites to determine the transcriptional response such that the loss of modules can be compensated for by increasing promoter sites. Potassium permanganate footprinting was used to show that transcriptional stimulation is a consequence of the activator's ability to promote preinitiation complex assembly. Kinetic measurements of transcription complex assembly in a reconstituted system indicate that ZEBRA promotes formation of a subcomplex requiring the TFIIA and TFIID fractions, where TFIIA acts as an antirepressor. We propose a model in which the concentration of DNA-bound activation modules in the vicinity of the gene initiates synergistic transcription complex assembly.
Collapse
Affiliation(s)
- T Chi
- Department of Biological Chemistry, UCLA School of Medicine 90024-1737
| | | |
Collapse
|
107
|
Schnapp A, Schnapp G, Erny B, Grummt I. Function of the growth-regulated transcription initiation factor TIF-IA in initiation complex formation at the murine ribosomal gene promoter. Mol Cell Biol 1993; 13:6723-32. [PMID: 8413268 PMCID: PMC364735 DOI: 10.1128/mcb.13.11.6723-6732.1993] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Alterations in the rate of cell proliferation are accompanied by changes in the transcription of rRNA genes. In mammals, this growth-dependent regulation of transcription of genes coding for rRNA (rDNA) is due to reduction of the amount or activity of an essential transcription factor, called TIF-IA. Extracts prepared from quiescent cells lack this factor activity and, therefore, are transcriptionally inactive. We have purified TIF-IA from exponentially growing cells and have shown that it is a polypeptide with a molecular mass of 75 kDa which exists as a monomer in solution. Using a reconstituted transcription system consisting of purified transcription factors, we demonstrate that TIF-IA is a bona fide transcription initiation factor which interacts with RNA polymerase I. Preinitiation complexes can be assembled in the absence of TIF-IA, but formation of the first phosphodiester bonds of nascent rRNA is precluded. After initiation, TIF-IA is liberated from the initiation complex and facilitates transcription from templates bearing preinitiation complexes which lack TIF-IA. Despite the pronounced species specificity of class I gene transcription, this growth-dependent factor has been identified not only in mouse but also in human cells. Murine TIF-IA complements extracts from both growth-inhibited mouse and human cells. The analogous human activity appears to be similar or identical to that of TIF-IA. Therefore, despite the fact that the RNA polymerase transcription system has evolved sufficiently rapidly that an rDNA promoter from one species will not function in another species, the basic mechanisms that adapt ribosome synthesis to cell proliferation have been conserved.
Collapse
MESH Headings
- Animals
- Carcinoma, Ehrlich Tumor
- Cell Division
- Cell Nucleus/metabolism
- Chromatography, Gel
- Cytoplasm/metabolism
- DNA, Ribosomal/metabolism
- Electrophoresis, Polyacrylamide Gel
- Gene Expression Regulation, Neoplastic
- Genes, MHC Class I
- HeLa Cells
- Humans
- Kinetics
- Mice
- Promoter Regions, Genetic
- RNA, Ribosomal/genetics
- Templates, Genetic
- Transcription Factors/isolation & purification
- Transcription Factors/metabolism
- Transcription, Genetic
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- A Schnapp
- Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg
| | | | | | | |
Collapse
|
108
|
Abstract
The ubiquitous transcription factor TFIIB is required for initiation by RNA polymerase II and serves as a target of some regulatory factors. The carboxy-terminal portion of TFIIB contains a large imperfect direct repeat reminiscent of the structural organization of the TATA-binding component (TBP) of TFIID, as well as sequence homology to conserved regions of bacterial sigma factors. The present study shows that the carboxy-terminal portion of TFIIB, like that of TBP, is folded into a compact protease-resistant core. The TFIIB core, unlike the TBP core, is inactive in transcription but retains structural features that enable it to form a complex with promoter-bound TFIID. The protease-susceptible amino terminus appears to contain components responsible for direct interaction with RNA polymerase II (in association with TFIIF) either on the promoter (in association with TFIID) or independently. In addition, core TFIIB (but not intact TFIIB) extends the footprint of TBP on promoter DNA, suggesting that TFIIB has a cryptic DNA-binding potential. These results are consistent with a model in which TFIIB, in a manner functionally analogous to that of bacterial sigma factors, undergoes an RNA polymerase II-dependent conformational change with resultant DNA interactions during the pathway leading to a functional preinitiation complex.
Collapse
|
109
|
Malik S, Lee DK, Roeder RG. Potential RNA polymerase II-induced interactions of transcription factor TFIIB. Mol Cell Biol 1993; 13:6253-9. [PMID: 8413225 PMCID: PMC364684 DOI: 10.1128/mcb.13.10.6253-6259.1993] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The ubiquitous transcription factor TFIIB is required for initiation by RNA polymerase II and serves as a target of some regulatory factors. The carboxy-terminal portion of TFIIB contains a large imperfect direct repeat reminiscent of the structural organization of the TATA-binding component (TBP) of TFIID, as well as sequence homology to conserved regions of bacterial sigma factors. The present study shows that the carboxy-terminal portion of TFIIB, like that of TBP, is folded into a compact protease-resistant core. The TFIIB core, unlike the TBP core, is inactive in transcription but retains structural features that enable it to form a complex with promoter-bound TFIID. The protease-susceptible amino terminus appears to contain components responsible for direct interaction with RNA polymerase II (in association with TFIIF) either on the promoter (in association with TFIID) or independently. In addition, core TFIIB (but not intact TFIIB) extends the footprint of TBP on promoter DNA, suggesting that TFIIB has a cryptic DNA-binding potential. These results are consistent with a model in which TFIIB, in a manner functionally analogous to that of bacterial sigma factors, undergoes an RNA polymerase II-dependent conformational change with resultant DNA interactions during the pathway leading to a functional preinitiation complex.
Collapse
Affiliation(s)
- S Malik
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021
| | | | | |
Collapse
|
110
|
|
111
|
Hisatake K, Roeder RG, Horikoshi M. Functional dissection of TFIIB domains required for TFIIB-TFIID-promoter complex formation and basal transcription activity. Nature 1993; 363:744-7. [PMID: 8515820 DOI: 10.1038/363744a0] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The protein TFIIB is a general transcription initiation factor that interacts with a promoter complex (D.DNA) containing the TATA-binding subunit (TFIID tau, or TBP) of TFIID to facilitate subsequent interaction with RNA polymerase II (ref. 2) through the associated TFIIF (ref. 3). The potential bridging function of TFIIB raises the possibility of two structural domains and emphasizes the importance of TFIIB structure-function studies for a further understanding of preinitiation complex assembly and function. Here we show that human TFIIB (refs 5,6) is comprised of functionally distinct N- and C-terminal domains. The C-terminal domain, containing the direct repeats and associated basic regions, is necessary and sufficient for interaction with the D.DNA complex. By contrast, the N-terminal domain that is dispensable for formation of the TFIID tau-TFIIB-promoter (D.B.DNA) complex is required for subsequent events leading to basal transcription initiation. On the basis of these results, we discuss structural and functional similarities between TFIIB and TFIID tau, which have similar structural organization and motifs.
Collapse
Affiliation(s)
- K Hisatake
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021
| | | | | |
Collapse
|
112
|
Barberis A, Müller CW, Harrison SC, Ptashne M. Delineation of two functional regions of transcription factor TFIIB. Proc Natl Acad Sci U S A 1993; 90:5628-32. [PMID: 8516311 PMCID: PMC46774 DOI: 10.1073/pnas.90.12.5628] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Human transcription factor TFIIB, a protein of 316 amino acids, was subjected to limited proteolysis in order to define stable structural domains. We find that the C-terminal region of TFIIB, residues 106-316, is relatively stable, while the N-terminal region is very sensitive to proteases. Like full-length TFIIB, the stable domain, which we refer to as TFIIBc, interacts with the TATA-binding protein (TBP) on DNA. However, TFIIBc is unable to substitute for TFIIB in an in vitro transcription assay. We show by gel mobility-shift experiments that TFIIBc arrests formation of the transcription complex after binding to TBP, and we conclude that the N-terminal region of TFIIB, which is missing from TFIIBc, is responsible for the recruitment of RNA polymerase II to the promoter. We also show that TFIIBc inhibits transcription by competing with full-length TFIIB for the interaction with TBP, either in the presence or in the absence of the TBP-associated factors. The acidic transcriptional activator GAL4-VP16 does not favor the assembly of the functional transcription complex over the nonfunctional complex containing TFIIBc. Thus, if the function of GAL4-VP16 is enhancement of the interaction between TFIIB and the TFIID-DNA complex, then this function can also be exerted on the protease-resistant domain TFIIBc.
Collapse
Affiliation(s)
- A Barberis
- Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138
| | | | | | | |
Collapse
|
113
|
Abstract
Transcription factor TFIIB is an essential component of the RNA polymerase II initiation complex. TFIIB carries out at least two functions: it interacts directly with the TATA-binding protein (TBP) and helps to recruit RNA polymerase II into the initiation complex. The sequence of TFIIB reveals a potential zinc-binding domain and an imperfect duplication of approximately 70 amino acids. Mutagenesis of cysteine codons within the putative zinc finger results in mutant proteins that bind normally to TBP but are unable to recruit RNA polymerase II-TFIIF into the initiation complex. Changing the two most highly conserved amino acids in the TFIIB repeats reduces the ability of TFIIB to interact with TBP. Therefore, the two functions of TFIIB can be assigned to two separable functional domains of the protein.
Collapse
Affiliation(s)
- S Buratowski
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142
| | | |
Collapse
|
114
|
Ha I, Roberts S, Maldonado E, Sun X, Kim LU, Green M, Reinberg D. Multiple functional domains of human transcription factor IIB: distinct interactions with two general transcription factors and RNA polymerase II. Genes Dev 1993; 7:1021-32. [PMID: 8504927 DOI: 10.1101/gad.7.6.1021] [Citation(s) in RCA: 197] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Transcription factor IIB (TFIIB) plays a pivotal role in the formation of transcription-competent initiation complexes. TFIIB was found to interact with the TATA-binding protein, the small subunit of TFIIF, and RNA polymerase II. These interactions require distinct domains in TFIIB. Using the gel mobility-shift assay, it was found that the amino terminus of TFIIB was necessary for the formation of complexes containing RNA polymerase II and TFIIF, whereas the carboxy-terminal domain, which is composed of two imperfect direct repeats and includes a putative amphipathic alpha-helix, was sufficient for the formation of complexes containing the TATA-binding protein and TFIIB (DB complex). Protein-protein interaction analyses demonstrate that the amphipathic alpha-helix in TFIIB is important for the interaction with the TATA-binding protein. Specific residues mapping to the carboxyl terminus of the second direct repeat were found to be crucial for the interaction of TFIIB and RNA polymerase II. The interaction with the small subunit of TFIIF was mapped to the amino terminus of TFIIB, which includes a zinc finger.
Collapse
Affiliation(s)
- I Ha
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635
| | | | | | | | | | | | | |
Collapse
|
115
|
Yasutomo Y, Shimada N, Kimura N, Nagata N. Estradiol up-regulates the stimulatory GTP-binding protein expression in the MCF-7 human mammary carcinoma cell line. FEBS Lett 1993; 322:25-9. [PMID: 8387027 DOI: 10.1016/0014-5793(93)81103-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of estradiol treatment of the human mammary carcinoma cell MCF-7 on the adenylyl cyclase system was examined. Treatment with 10 nM estradiol for 72 h increased the basal level of cAMP, and isoproterenol-, PGE2- or calcitonin-stimulated cAMP production. Estradiol also increased the response to cholera toxin but did not alter the response to forskolin. No significant change in growth rate was observed during the 72 h of estradiol treatment. In MCF-7 cell membranes the responsiveness to isoproterenol, PGE2, or cholera toxin was also enhanced by estradiol treatment. The cholera toxin-catalyzed ADP-ribosylation of Gs alpha in MCF-7 cell membranes was significantly increased by 72 h of treatment with estradiol. Consistent with this observation, the level of Gs alpha immunoreactivity was increased in the estradiol-treated cell membranes. On the other hand, pertussis toxin did not change the responsiveness to isoproterenol, PGE2 or calcitonin in either control or estradiol-treated cells. In addition, ADP-ribosylation with pertussis toxin also did not reveal any change in Gi. These results clearly indicate that Gs expression is under the control of estradiol, and that this effect may contribute to the increased sensitivity of hormone-stimulated adenylyl cyclase activities in MCF-7 cells.
Collapse
Affiliation(s)
- Y Yasutomo
- Third Department of Internal Medicine, National Defence Medical College, Saitama, Japan
| | | | | | | |
Collapse
|
116
|
Contribution of sequences downstream of the TATA element to a protein-DNA complex containing the TATA-binding protein. Mol Cell Biol 1993. [PMID: 8455632 DOI: 10.1128/mcb.13.4.2593] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A TATA complex that forms on the hsp70 promoter has been found to depend on sequence-specific interactions that occur at the transcription start and regions further downstream. The complex was detected with a gel shift assay and further characterized with interference assays. Antibodies reveal that the TATA-binding protein is in the complex. Interference assays localize specific contacts in the TATA element, the start site, and in a region approximately 25 bp downstream of the start site that contribute to either the assembly or the maintenance of the complex. Contact at the TATA element is made in the minor groove, as has been reported for the recombinant TATA-binding protein. Mutation in the TATA element or the start site of hsp70 causes complex formation to be more strongly dependent on contacts in the +25 region than in the normal core promoter. Examination of the hsp26 and histone H4 genes indicates that similar contacts contribute to the TATA complexes that form on these promoters. The results suggest that specific contacts downstream of the TATA element could play a key role in establishing the transcriptional potential of a gene by contributing to the interaction of the TATA-binding protein.
Collapse
|
117
|
Colgan J, Wampler S, Manley JL. Interaction between a transcriptional activator and transcription factor IIB in vivo. Nature 1993; 362:549-53. [PMID: 8464496 DOI: 10.1038/362549a0] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Transcription of messenger RNA-encoding genes in vitro requires many protein factors. Transcription factor IID, possibly with the cooperation of TFIIA, binds to the TATA element of the promoter, forming a complex that can bind TFIIB (refs 6, 7) followed by RNA polymerase II (refs 6, 8) and other factors. One or more of these steps is thought to be facilitated by gene-specific transcriptional activation proteins; this seems to require TFIID-associated auxiliary factors and may involve direct contact between the activator and TFIID and/or TFIIB. If such contact is necessary in vivo, activation might conceivably be blocked by a TFIIB derivative containing the sequences necessary for this interaction, but lacking those necessary for binding to the rest of the transcriptional apparatus, an effect similar to that referred to as squelching or transcriptional interference. Here we show that the activity of the glutamine-rich fushi tarazu activation domain is indeed blocked by truncated TFIIB derivatives in Drosophila Schneider L2 cells, suggesting that it is mediated by interactions with TFIIB.
Collapse
Affiliation(s)
- J Colgan
- Department of Biological Sciences, Columbia University, New York, New York 10027
| | | | | |
Collapse
|
118
|
Schaeffer L, Roy R, Humbert S, Moncollin V, Vermeulen W, Hoeijmakers JH, Chambon P, Egly JM. DNA repair helicase: a component of BTF2 (TFIIH) basic transcription factor. Science 1993; 260:58-63. [PMID: 8465201 DOI: 10.1126/science.8465201] [Citation(s) in RCA: 590] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The human BTF2 basic transcription factor (also called TFIIH), which is similar to the delta factor in rat and factor b in yeast, is required for class II gene transcription. A strand displacement assay was used to show that highly purified preparation of BTF2 had an adenosine triphosphate-dependent DNA helicase activity, in addition to the previously characterized carboxyl-terminal domain kinase activity. Amino acid sequence analysis of the tryptic digest generated from the 89-kilodalton subunit of BTF2 indicated that this polypeptide corresponded to the ERCC-3 gene product, a presumed helicase implicated in the human DNA excision repair disorders xeroderma pigmentosum and Cockayne's syndrome. These findings suggest that transcription and nucleotide excision repair may share common factors and hence may be considered to be functionally related.
Collapse
Affiliation(s)
- L Schaeffer
- UPR 6520 (CNRS), Unité 184 (INSERM), Faculté de Médecine, Strasbourg, France
| | | | | | | | | | | | | | | |
Collapse
|
119
|
Purnell BA, Gilmour DS. Contribution of sequences downstream of the TATA element to a protein-DNA complex containing the TATA-binding protein. Mol Cell Biol 1993; 13:2593-603. [PMID: 8455632 PMCID: PMC359594 DOI: 10.1128/mcb.13.4.2593-2603.1993] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A TATA complex that forms on the hsp70 promoter has been found to depend on sequence-specific interactions that occur at the transcription start and regions further downstream. The complex was detected with a gel shift assay and further characterized with interference assays. Antibodies reveal that the TATA-binding protein is in the complex. Interference assays localize specific contacts in the TATA element, the start site, and in a region approximately 25 bp downstream of the start site that contribute to either the assembly or the maintenance of the complex. Contact at the TATA element is made in the minor groove, as has been reported for the recombinant TATA-binding protein. Mutation in the TATA element or the start site of hsp70 causes complex formation to be more strongly dependent on contacts in the +25 region than in the normal core promoter. Examination of the hsp26 and histone H4 genes indicates that similar contacts contribute to the TATA complexes that form on these promoters. The results suggest that specific contacts downstream of the TATA element could play a key role in establishing the transcriptional potential of a gene by contributing to the interaction of the TATA-binding protein.
Collapse
Affiliation(s)
- B A Purnell
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
| | | |
Collapse
|
120
|
Yonaha M, Aso T, Kobayashi Y, Vasavada H, Yasukochi Y, Weissman SM, Kitajima S. Domain structure of a human general transcription initiation factor, TFIIF. Nucleic Acids Res 1993; 21:273-9. [PMID: 8441635 PMCID: PMC309103 DOI: 10.1093/nar/21.2.273] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The structural and functional domains of a general transcription initiation factor, TFIIF (RAP30/74, FC), have been investigated using various deletion mutants of each subunit, both in vivo and in vitro. An in vivo assay showed that the N-terminal sequence containing residues of 1-110 of RAP30 that is located close to a sigma homology region interacts with a minimum sequence of residues 62-171 of RAP74 to form a heteromeric interaction. Reconstitution of in vitro transcription activity by deletion mutants of RAP74 clearly indicated that both N-terminal residues 73-205 and C-terminal residues 356-517 are essential for full activity, the former interacting with RAP30, thus complexing with RNA polymerase II. From these data, the functional significance of domain structure of TFIIF is discussed in terms of its sigma homology sequences and complex formation with RNA polymerase II in the initiation and elongation of transcription.
Collapse
Affiliation(s)
- M Yonaha
- Department of Molecular Genetics, Tokyo Medical and Dental University, Japan
| | | | | | | | | | | | | |
Collapse
|
121
|
Zawel L, Reinberg D. Initiation of transcription by RNA polymerase II: a multi-step process. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1993; 44:67-108. [PMID: 8434126 DOI: 10.1016/s0079-6603(08)60217-2] [Citation(s) in RCA: 287] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- L Zawel
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854
| | | |
Collapse
|
122
|
The Basic Transcriptional Machinery. Gene Expr 1993. [DOI: 10.1007/978-1-4684-6811-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
123
|
Dvir A, Peterson SR, Knuth MW, Lu H, Dynan WS. Ku autoantigen is the regulatory component of a template-associated protein kinase that phosphorylates RNA polymerase II. Proc Natl Acad Sci U S A 1992; 89:11920-4. [PMID: 1465419 PMCID: PMC50669 DOI: 10.1073/pnas.89.24.11920] [Citation(s) in RCA: 287] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The carboxyl-terminal domain of RNA polymerase II contains a tandemly repeated heptapeptide sequence. Previous work has shown that this sequence is phosphorylated at multiple sites by a template-associated protein kinase, in a reaction that is closely associated with the initiation of RNA synthesis. We have purified this kinase to apparent homogeneity from human (HeLa) cells. The purified kinase phosphorylates native RNA polymerase II only in the presence of DNA and the general transcription factors TFIID (TBP), TFIIB, and TFIIF. Two kinase components are required for full activity: a catalytic component and a DNA-binding regulatory component. The regulatory component has been identified as Ku autoantigen, based on the molecular weights of its component polypeptides, its DNA-binding properties, and its reactivity with anti-Ku monoclonal antibodies. The Ku autoantigen recruits the catalytic component of the kinase to the template. Ku autoantigen has been previously proposed to interact with DNA by a characteristic bind-and-slide mechanism. This mode of interaction may provide a mechanism for targeting the kinase to the transcription complex and other DNA-bound substrates.
Collapse
Affiliation(s)
- A Dvir
- Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309
| | | | | | | | | |
Collapse
|
124
|
Gong DW, Hashimoto S, Wada K, Roeder RG, Nakatani Y, Horikoshi M. Imperfect conservation of a sigma factor-like subregion in Xenopus general transcription factor RAP30. Nucleic Acids Res 1992; 20:6414. [PMID: 1475205 PMCID: PMC334539 DOI: 10.1093/nar/20.23.6414] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- D W Gong
- Laboratory of Molecular Biology, NINDS, NIH, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|
125
|
Garrett K, Serizawa H, Hanley J, Bradsher J, Tsuboi A, Arai N, Yokota T, Arai K, Conaway R, Conaway J. The carboxyl terminus of RAP30 is similar in sequence to region 4 of bacterial sigma factors and is required for function. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)35928-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
126
|
Abstract
A suppressor gene was identified, which in high copy number rescues a temperature-sensitive mutation in yeast TATA-binding protein (TBP). Suppression was allele specific because the suppressor did not rescue the temperature-sensitive phenotype of another TBP mutant. This suppressor gene encodes a 596-amino-acid protein of which the amino-terminal half is homologous to the Pol II-specific factor TFIIB. Disruption of this gene, termed BRF1, showed it to be essential for growth of yeast. Deletion of sequences at either the amino or carboxyl terminus of BRF1 gave both temperature- and cold-sensitive phenotypes. These temperature- and cold-sensitive strains were used to prepare extracts deficient in BRF1 activity and were tested for transcriptional activity by RNA polymerases I, II, and III in vitro. BRF1-deficient extracts are defective in Pol III transcription and can be reconstituted for Pol III transcription by the addition of recombinant BRF1. Western analysis shows that BRF1 is present in TFIIIB but not the TFIIIC fraction, suggesting that it is a component of TFIIIB. We propose that BRF1 plays a role in Pol III initiation analogous to the role played by TFIIB for Pol II in its interaction with TBP and polymerase. The identification of a Pol III-specific TFIIB-like factor extends the previously noted similarity of transcriptional initiation by the three nuclear polymerases.
Collapse
Affiliation(s)
- T Colbert
- Fred Hutchinson Cancer Research Center, Seattle, Washington 98104-2092
| | | |
Collapse
|
127
|
Wang W, Gralla JD, Carey M. The acidic activator GAL4-AH can stimulate polymerase II transcription by promoting assembly of a closed complex requiring TFIID and TFIIA. Genes Dev 1992; 6:1716-27. [PMID: 1516830 DOI: 10.1101/gad.6.9.1716] [Citation(s) in RCA: 142] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The assembly of activated RNA polymerase II (pol II) transcription complexes has been investigated by assaying whether pre-assembly of intermediate complexes reduces the extended time required for start-site melting. The results show that a closed complex requiring factors IIA, IID, and the acidic activator GAL4-AH forms in a rate-limiting step. This directs the templates into a productive assembly pathway. Factor TFIIB is then added rapidly, affording further protection against diversion into nonproductive pathways. These events are followed by a series of rapid steps in which the remaining general factors are assembled onto the template, which is then melted using the energy of ATP hydrolysis.
Collapse
Affiliation(s)
- W Wang
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90024-1569
| | | | | |
Collapse
|
128
|
Lu H, Zawel L, Fisher L, Egly JM, Reinberg D. Human general transcription factor IIH phosphorylates the C-terminal domain of RNA polymerase II. Nature 1992; 358:641-5. [PMID: 1495560 DOI: 10.1038/358641a0] [Citation(s) in RCA: 332] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phosphorylation of the carboxy-terminal domain of the largest subunit of RNA polymerase II is believed to control the transition from transcription initiation to elongation. The general transcription factor IIH (TFIIH) contains a kinase activity capable of phosphorylating this domain. Factors that promote the association of RNA polymerase II with the preinitiation complex stimulate this activity. The transcription factor IIE, which is required for the stable association of TFIIH with the preinitiation complex, affects the processivity of TFIIH kinase.
Collapse
Affiliation(s)
- H Lu
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854-5635
| | | | | | | | | |
Collapse
|
129
|
Ham J, Steger G, Yaniv M. How do eukaryotic activator proteins stimulate the rate of transcription by RNA polymerase II? FEBS Lett 1992; 307:81-6. [PMID: 1322325 DOI: 10.1016/0014-5793(92)80906-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A large number of activator proteins have now been identified in higher and lower eukaryotes, which bind to the regulatory regions of protein-encoding genes and increase the rate at which they are transcribed by RNA polymerase II. The mechanism by which activators function is being intensively studied and some of the targets of transcriptional activation domains have now been identified. These studies have also revealed novel classes of regulatory factors, which were not anticipated by extrapolating from the principles obtained with prokaryotic promoters.
Collapse
Affiliation(s)
- J Ham
- Département des Biotechnologies, Institut Pasteur, Paris, France
| | | | | |
Collapse
|
130
|
The interaction of RNA polymerase II with the adenovirus-2 major late promoter is precluded by phosphorylation of the C-terminal domain of subunit IIa. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50045-x] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
131
|
Hagler J, Shuman S. Ternary complex formation by vaccinia virus RNA polymerase at an early viral promoter: analysis by native gel electrophoresis. J Virol 1992; 66:2982-9. [PMID: 1373199 PMCID: PMC241057 DOI: 10.1128/jvi.66.5.2982-2989.1992] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have resolved, by native gel electrophoresis, two intermediates in the transcription of a vaccinia virus early gene by the virus-encoded RNA polymerase. Polymerase holoenzyme containing the vaccinia virus early transcription factor (VETF) forms a complex of VETF bound to the promoter as the first step in a pathway leading to establishment of a committed ternary elongation complex. Formation of the VETF-DNA complex is stimulated by magnesium but is uninfluenced by nucleoside triphosphates. A stable binary complex of RNA polymerase bound to DNA is not detected. Assembly of a gel-stable polymerase-DNA complex depends on conditions permissive for RNA synthesis. Nucleotide omission experiments suggest that at least a tetrameric RNA must be made before a ternary complex is stabilized. RNA analysis indicates that complexes containing nascent transcripts 20 nucleotides long are stable and active. Ternary complex formation requires hydrolyzable ATP. This is consistent with an essential role for the ATPase activity of VETF at a step subsequent to DNA binding, as proposed by Broyles (S. S. Broyles, J. Biol. Chem. 266:15545-15548, 1991). The ternary complex, once formed, is resistant to dissociation by competitor DNA, as well as by salt, Sarkosyl, and heparin. The effects of these inhibitory agents on transcription complex formation suggest that they target different steps in the assembly pathway.
Collapse
Affiliation(s)
- J Hagler
- Program in Molecular Biology, Sloan-Kettering Institute, New York, New York 10021
| | | |
Collapse
|
132
|
Kobayashi Y, Kitajima S, Yasukochi Y. Isolation and nucleotide sequence of a rat cDNA homologous to human RAP30. Nucleic Acids Res 1992; 20:1994. [PMID: 1579505 PMCID: PMC312320 DOI: 10.1093/nar/20.8.1994] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Y Kobayashi
- Department of Molecular Genetics, Tokyo Medical and Dental University, Japan
| | | | | |
Collapse
|
133
|
Stone N, Reinberg D. Protein kinases from Aspergillus nidulans that phosphorylate the carboxyl-terminal domain of the largest subunit of RNA polymerase II. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42702-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
134
|
The general transcription factor RAP30 binds to RNA polymerase II and prevents it from binding nonspecifically to DNA. Mol Cell Biol 1992. [PMID: 1729606 DOI: 10.1128/mcb.12.1.30] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RAP30/74 is a human general transcription factor that binds to RNA polymerase II and is required for initiation of transcription in vitro regardless of whether the promoter has a recognizable TATA box (Z. F. Burton, M. Killeen, M. Sopta, L. G. Ortolan, and J. F. Greenblatt, Mol. Cell. Biol. 8:1602-1613, 1988). Part of the amino acid sequence of RAP30, the small subunit of RAP30/74, has limited homology with part of Escherichia coli sigma 70 (M. Sopta, Z. F. Burton, and J. Greenblatt, Nature (London) 341:410-414, 1989). To determine which sigmalike activities of RAP30/74 could be attributed to RAP30, we purified human RAP30 and a RAP30-glutathione-S-transferase fusion protein that had been produced in E. coli. Bacterially produced RAP30 bound to RNA polymerase II in the absence of RAP74. Both partially purified natural RAP30/74 and recombinant RAP30 prevented RNA polymerase II from binding nonspecifically to DNA. In addition, nonspecific transcription by RNA polymerase II was greatly inhibited by RAP30-glutathione-S-transferase. DNA-bound RNA polymerase II could be removed from DNA by partially purified RAP30/74 but not by bacterially expressed RAP30. Thus, the ability of RAP30/74 to recruit RNA polymerase II to a promoter-bound preinitiation complex may be an indirect consequence of its ability to suppress nonspecific binding of RNA polymerase II to DNA.
Collapse
|
135
|
Flores O, Lu H, Reinberg D. Factors involved in specific transcription by mammalian RNA polymerase II. Identification and characterization of factor IIH. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)45947-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
136
|
Finkelstein A, Kostrub CF, Li J, Chavez DP, Wang BQ, Fang SM, Greenblatt J, Burton ZF. A cDNA encoding RAP74, a general initiation factor for transcription by RNA polymerase II. Nature 1992; 355:464-7. [PMID: 1734284 DOI: 10.1038/355464a0] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
RAP30/74 (also known as TFIIF, beta gamma and FC is one of several general factors required for initiation by RNA polymerase II. The small RAP30 subunit of RAP30/74 binds directly to polymerase and appears structurally and functionally homologous to bacterial sigma factors in their RNA polymerase-binding region. RAP30/74 or recombinant RAP30 suppresses nonspecific binding of RNA polymerase II to DNA and is required for RNA polymerase II to assemble stably into a preinitiation complex containing promoter DNA and the general factors TFIID, TFIIA and TFIIB; both RAP30 and RAP74 are physical components of the preinitiation complex. A complementary DNA encoding human RAP30 has been isolated, and here we report the isolation of a cDNA encoding human RAP74. RAP30 and RAP74 produced in Escherichia coli can be used in place of natural human RAP30/74 to direct accurate transcription initiation by RNA polymerase II in vitro.
Collapse
Affiliation(s)
- A Finkelstein
- Department of Biochemistry, Michigan State University, E. Lansing 48824
| | | | | | | | | | | | | | | |
Collapse
|
137
|
Killeen MT, Greenblatt JF. The general transcription factor RAP30 binds to RNA polymerase II and prevents it from binding nonspecifically to DNA. Mol Cell Biol 1992; 12:30-7. [PMID: 1729606 PMCID: PMC364066 DOI: 10.1128/mcb.12.1.30-37.1992] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RAP30/74 is a human general transcription factor that binds to RNA polymerase II and is required for initiation of transcription in vitro regardless of whether the promoter has a recognizable TATA box (Z. F. Burton, M. Killeen, M. Sopta, L. G. Ortolan, and J. F. Greenblatt, Mol. Cell. Biol. 8:1602-1613, 1988). Part of the amino acid sequence of RAP30, the small subunit of RAP30/74, has limited homology with part of Escherichia coli sigma 70 (M. Sopta, Z. F. Burton, and J. Greenblatt, Nature (London) 341:410-414, 1989). To determine which sigmalike activities of RAP30/74 could be attributed to RAP30, we purified human RAP30 and a RAP30-glutathione-S-transferase fusion protein that had been produced in E. coli. Bacterially produced RAP30 bound to RNA polymerase II in the absence of RAP74. Both partially purified natural RAP30/74 and recombinant RAP30 prevented RNA polymerase II from binding nonspecifically to DNA. In addition, nonspecific transcription by RNA polymerase II was greatly inhibited by RAP30-glutathione-S-transferase. DNA-bound RNA polymerase II could be removed from DNA by partially purified RAP30/74 but not by bacterially expressed RAP30. Thus, the ability of RAP30/74 to recruit RNA polymerase II to a promoter-bound preinitiation complex may be an indirect consequence of its ability to suppress nonspecific binding of RNA polymerase II to DNA.
Collapse
Affiliation(s)
- M T Killeen
- Department of Molecular and Medical Genetics, University of Toronto, Ontario, Canada
| | | |
Collapse
|
138
|
Bohan CA, Kashanchi F, Ensoli B, Buonaguro L, Boris-Lawrie KA, Brady JN. Analysis of Tat transactivation of human immunodeficiency virus transcription in vitro. Gene Expr 1992; 2:391-407. [PMID: 1282057 PMCID: PMC6057369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/1992] [Accepted: 06/15/1992] [Indexed: 12/26/2022]
Abstract
The HIV Tat protein is a potent transactivator of HIV transcription, increasing both RNA initiation and elongation. We now demonstrate that purified, full-length 86 amino acid Tat protein specifically transactivates the HIV LTR in vitro to a high level (25- to 60-fold). Tat transactivation was specifically blocked by anti-Tat serum, but not preimmune serum. Tat did not transactivate transcription from the control adenovirus major late promoter (AdMLP). HIV transcription was blocked at various functional steps during initiation and elongation complex formation. Similar to the control AdMLP, HIV basal initiation complex assembly was sensitive to the addition of 0.015% sarkosyl prior to the addition of nucleoside triphosphates. Resistance to 0.05% sarkosyl required the addition of G, C, and U, which constitute the first 13 bases of the HIV RNA transcript. The addition of Tat to the in vitro transcription relieved the 0.015% sarkosyl block. These Tat-induced complexes were sensitive to 0.05% sarkosyl, suggesting that transcriptional initiation had not occurred. Consistent with this hypothesis, the addition of G, C, and U to the Tat-induced transcription complexes allowed the rapid conversion to transcription initiation complexes. Tat also facilitated the formation of 0.015% sarkosyl-resistant complexes in a reconstituted transcription system containing partially purified transcription factors and polymerase II. Following the formation of stable initiation complexes, Tat increased the rate and efficiency of transcription elongation on the HIV but not the AdML template. Kinetic analysis of Tat transactivation suggests that approximately 30% of the Tat initiation complexes are converted to elongation complexes. We conclude that Tat, in addition to its demonstrated role in RNA elongation, facilitates transcription initiation in vitro.
Collapse
Affiliation(s)
- C A Bohan
- Laboratory of Molecular Virology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | | | | | | | | | | |
Collapse
|
139
|
Weinmann R. The basic RNA polymerase II transcriptional machinery. Gene Expr 1992; 2:81-91. [PMID: 1633439 PMCID: PMC6057384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
All genes encoding proteins in eukaryotes are transcribed by RNA polymerase II. The first step in analyzing transcriptional regulation requires understanding the general mechanisms of RNA polymerase II-specific gene transcription. The basal promoter, a template containing a TATA box devoid of upstream regulatory sequences, has been used to identify and characterize the factors which, together with RNA polymerase II, govern transcription in mammalian systems: TFIIA, TFIIB, TFIID, TFIIE, TFIIF, TFIIG, TFIIH, and TFIIJ. Interactions between regulatory transcription factors and basal elements of the transcriptional machinery affect the transcriptional rate in a positive or negative fashion. As these multiple proteins are purified, and their coding sequences are isolated, we come closer to reproducing these processes in vitro with pure components, and thus to elucidating the complex interactions among them.
Collapse
Affiliation(s)
- R Weinmann
- Wistar Institute of Anatomy and Biology, Philadelphia, PA 19104
| |
Collapse
|
140
|
Lu H, Flores O, Weinmann R, Reinberg D. The nonphosphorylated form of RNA polymerase II preferentially associates with the preinitiation complex. Proc Natl Acad Sci U S A 1991; 88:10004-8. [PMID: 1946417 PMCID: PMC52855 DOI: 10.1073/pnas.88.22.10004] [Citation(s) in RCA: 257] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The two forms of RNA polymerase II that exist in vivo, phosphorylated (IIO) and nonphosphorylated (IIA), were purified to apparent homogeneity from HeLa cells. The nonphosphorylated form preferentially binds to the preinitiation complex. RNA polymerase II in the complex was converted by a cellular protein kinase to the phosphorylated form.
Collapse
Affiliation(s)
- H Lu
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854
| | | | | | | |
Collapse
|
141
|
Dunn J, Dunn A, Heppner D, Kim P. A discrete thyroxine-rich iodopeptide of 20,000 daltons from rabbit thyroglobulin. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)70070-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|