A Position-Dependent Transcription-Activating Domain in TFIIIA

Mao, Xianzhi; Darby, Martyn K.

doi:10.1128/mcb.13.12.7496-7506.1993

Cited by 10 publications

(2 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The archetypal C2H2 zinc finger protein is the Xenopus transcription factor TFIIIA (10,11). TFIIIA has nine tandemly repeated zinc fingers and a C-terminal domain required for transcription (12,13). TFIIIA binds both the 5S RNA gene promoter (internal control region, ICR) and, in developing oocytes, is complexed with 5S RNA in a 7S RNP (14).…”

Section: Introductionmentioning

confidence: 99%

The role of zinc finger linkers in p43 and TFIIIA binding to 5S rRNA and DNA

Ryan

Darby

1998

Nucleic Acids Research

View full text Add to dashboard Cite

Transcription factor IIIA (TFIIIA) and p43 zinc finger protein form distinct complexes with 5S ribosomal RNA in Xenopus oocytes. Additionally, TFIIIA binds the internal promoter of the 5S RNA gene and supports assembly of a transcription initiation complex. Both proteins have nine tandemly repeated zinc fingers with almost identical linker lengths between corresponding fingers, yet p43 has no detectable affinity for the 5S RNA gene. TFIIIA zinc fingers 1-3 are connected by highly conserved linkers, first identified in the Drosophila protein Krüppel, that are found in many DNA binding zinc finger proteins. To understand the role of these linkers in RNA and DNA binding we exchanged three TFIIIA linker amino acids with the equivalent amino acids from p43. The major effect of linker substitution is a 50-fold reduction in DNA specificity, concomitant with an 8-fold reduction in affinity. N-Terminal zinc fingers from either TFIIIA or p43 bind to multiple specific sites on 5S RNA that are resistant to competition by tRNA or poly(rA). This mode of RNA binding is unaffected by linker substitution. These data suggest that zinc finger linkers significantly facilitate the specificity of DNA binding.

show abstract

Section: Introductionmentioning

confidence: 99%

The role of zinc finger linkers in p43 and TFIIIA binding to 5S rRNA and DNA

Ryan

Darby

1998

Nucleic Acids Research

View full text Add to dashboard Cite

show abstract

“…On the other hand, it possesses a transcriptional activation domain that is not needed for promoter recognition but is essential for transcriptional activation. Without this 14-amino acid domain at the C-terminus of Xenopus laevis TFIIIA, 5S rRNA gene transcription is undetectable in vitro (Mao and Darby, 1993). Furthermore, it has been reported that the three most C-terminal of the nine TFIIIA zinc fingers also exert a higher influence on transcription rate than on promoter recognition (Del Rio and Setzer, 1993).…”

Section: Pol III Transcription: High Efficiency Through Compact Gene Organizationmentioning

confidence: 99%

RNA Polymerase III Subunit Mutations in Genetic Diseases

Lata

Choquet

Sagliocco

et al. 2021

Front. Mol. Biosci.

View full text Add to dashboard Cite

RNA polymerase (Pol) III transcribes small untranslated RNAs such as 5S ribosomal RNA, transfer RNAs, and U6 small nuclear RNA. Because of the functions of these RNAs, Pol III transcription is best known for its essential contribution to RNA maturation and translation. Surprisingly, it was discovered in the last decade that various inherited mutations in genes encoding nine distinct subunits of Pol III cause tissue-specific diseases rather than a general failure of all vital functions. Mutations in the POLR3A, POLR3C, POLR3E and POLR3F subunits are associated with susceptibility to varicella zoster virus-induced encephalitis and pneumonitis. In addition, an ever-increasing number of distinct mutations in the POLR3A, POLR3B, POLR1C and POLR3K subunits cause a spectrum of neurodegenerative diseases, which includes most notably hypomyelinating leukodystrophy. Furthermore, other rare diseases are also associated with mutations in genes encoding subunits of Pol III (POLR3H, POLR3GL) and the BRF1 component of the TFIIIB transcription initiation factor. Although the causal relationship between these mutations and disease development is widely accepted, the exact molecular mechanisms underlying disease pathogenesis remain enigmatic. Here, we review the current knowledge on the functional impact of specific mutations, possible Pol III-related disease-causing mechanisms, and animal models that may help to better understand the links between Pol III mutations and disease.

show abstract

The only essential function of TFIIIA in yeast is the transcription of 5S rRNA genes.

Camier

Dechampesme²,

Sentenac³

1995

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We have developed a system to transcribe the yeast 5S rRNA gene in the absence of the transcription factor TFIIIA. A TFIIIA is one of the most extensively studied and, hence, characterized transcription factors, for several reasons. First, it has the striking property of binding both 5S DNA and 5S RNA.Furthermore, its study led to the discovery of the zinc-finger motifs, which are structural units found only in eukaryotes and which are responsible for DNA binding (2, 3). These properties, common to all TFIIIA proteins studied so far, were first identified inXenopus TFIIIA, whose study was facilitated by its presence in large amount in oocytes. Xenopus TFIIIA possesses nine zinc fingers with specialized functions. The three amino-terminal fingers are primarily responsible for DNA binding, whereas fingers 4-7 are involved in RNA binding. The three carboxyl-terminal fingers and a 14-amino acid sequence in the carboxyl region of TFIIIA are required for transcriptional activation (4-6). Multiple activities have been attributed to Xenopus TFIIIA, including a role in DNA relaxation, double-stranded DNA reassociation (7,8), and being a weak DNA-dependent ATPase (9). These activities could be directly relevant to the mechanism of gene activation. TFIIIA could also have a regulatory role. In Xenopus, in Vitro transcription complexes preassembled on 5S genes can prevent nucleosomal repression (10). In vivo, the relative equilibrium between the amount of TFIIIA and histone Hi is, at least for oocyte 5S genes, very likely a major determinant of the activation (11,12). Recently, it was also shown in a human homologous in vitro system that binding of TFIIIA could prevent nucleosomal repression (13). TFIIIA can also exert a negative-feedback regulation through its binding to 5S RNA. Indeed, it was shown that 5S rRNA inhibits its own synthesis by sequestering TFIIIA (14)(15)(16) (24). Plasmid pRS-RPR1-5S is derived from the multicopy plasmid pRS424-5'3'RPR described by Pagan-Ramos et al. (25), which contains the 5' and 3' sequences flanking the mature domain of the RPR1 gene, together with TRPI as the selectable marker. pRS424-5'3'RPR was linearized by digestion with EcoRI, which cuts at the end of the 84-bp RPR1 leader promoter sequence, blunt-ended by digestion with mung bean nuclease, dephosphorylated, and ligated with a DNA fragment containing the yeast 5S DNA sequence, which was amplified by PCR from the pBS-5S plasmid. The primer at the 5' end of 5S DNA used for the amplification was 18 nt long and began at nt +2 (the second G) of the 5S DNA. The sequence at the junction between RPR1 and 5S DNA is GATTGGCAG*GTTGCG; the G* represents G + 1 of the 5S DNA, and the underlined sequence corresponds to the upstream part of the 5' primer.Abbreviations: ICR, internal control region; Pol III, RNA polymerase III; 5-FOA, 5-fluoroorotic acid. tTo whom reprint requests should be addressed.

show abstract

A Position-Dependent Transcription-Activating Domain in TFIIIA

Cited by 10 publications

References 61 publications

The role of zinc finger linkers in p43 and TFIIIA binding to 5S rRNA and DNA

The role of zinc finger linkers in p43 and TFIIIA binding to 5S rRNA and DNA

RNA Polymerase III Subunit Mutations in Genetic Diseases

The only essential function of TFIIIA in yeast is the transcription of 5S rRNA genes.

Contact Info

Product

Resources

About