scholarly journals Archaeal Intrinsic Transcription Termination In Vivo

2009 ◽  
Vol 191 (22) ◽  
pp. 7102-7108 ◽  
Author(s):  
Thomas J. Santangelo ◽  
L'ubomíra Cubonová ◽  
Katherine M. Skinner ◽  
John N. Reeve

ABSTRACT Thermococcus kodakarensis (formerly Thermococcus kodakaraensis) strains have been constructed with synthetic and natural DNA sequences, predicted to function as archaeal transcription terminators, identically positioned between a constitutive promoter and a β-glycosidase-encoding reporter gene (TK1761). Expression of the reporter gene was almost fully inhibited by the upstream presence of 5′-TTTTTTTT (T8) and was reduced >70% by archaeal intergenic sequences that contained oligo(T) sequences. An archaeal intergenic sequence (t mcrA ) that conforms to the bacterial intrinsic terminator motif reduced TK1761 expression ∼90%, but this required only the oligo(T) trail sequence and not the inverted-repeat and loop region. Template DNAs were amplified from each T. kodakarensis strain, and transcription in vitro by T. kodakarensis RNA polymerase was terminated by sequences that reduced TK1761 expression in vivo. Termination occurred at additional sites on these linear templates, including at a 5′-AAAAAAAA (A8) sequence that did not reduce TK1761 expression in vivo. When these sequences were transcribed on supercoiled plasmid templates, termination occurred almost exclusively at oligo(T) sequences. The results provide the first in vivo experimental evidence for intrinsic termination of archaeal transcription and confirm that archaeal transcription termination is stimulated by oligo(T) sequences and is different from the RNA hairpin-dependent mechanism established for intrinsic bacterial termination.

2017 ◽  
Vol 114 (33) ◽  
pp. E6767-E6773 ◽  
Author(s):  
Julie E. Walker ◽  
Olivia Luyties ◽  
Thomas J. Santangelo

RNA polymerase activity is regulated by nascent RNA sequences, DNA template sequences, and conserved transcription factors. Transcription factors promoting initiation and elongation have been characterized in each domain, but transcription termination factors have been identified only in bacteria and eukarya. Here we describe euryarchaeal termination activity (Eta), the first archaeal termination factor capable of disrupting the transcription elongation complex (TEC), detail the rate of and requirements for Eta-mediated transcription termination, and describe a role for Eta in transcription termination in vivo. Eta-mediated transcription termination is energy-dependent, requires upstream DNA sequences, and disrupts TECs to release the nascent RNA to solution. Deletion of TK0566 (encoding Eta) is possible, but results in slow growth and renders cells sensitive to DNA damaging agents. Our results suggest that the mechanisms used by termination factors in archaea, eukarya, and bacteria to disrupt the TEC may be conserved, and that Eta stimulates release of stalled or arrested TECs.


2021 ◽  
Author(s):  
Jie Li ◽  
Lei Yue ◽  
Wenting Zhang ◽  
Zhihua Li ◽  
Bing Zhang ◽  
...  

Recently, aCPSF1 was reported to function as the long-sought global transcription termination factor of archaea, while the working mechanism remains elusive. This work, through analyzing transcript-3′end-sequencing data of Methanococcus maripaludis, found positive correlations of both the terminator uridine(U)-tract and aCPSF1 with hierarchical transcription termination efficiencies (TTEs) at the genome-wide level. In vitro assays determined that aCPSF1 specifically binds to the terminator U-tract with U-tract number-related binding abilities, and in vivo assays demonstrated the two are indispensable in dictating high TTEs, revealing that aCPSF1 and the terminator U-tract in synergy determine high TTEs. The N-terminal KH domains equip aCPSF1 of specific binding to terminator U-tract and the in vivo aCPSF1-terminator U-tract synergism; aCPSF1's nuclease activity was also required for TTEs. aCPSF1 also functioned as back-up termination for transcripts with weak intrinsic terminator signals. aCPSF1 orthologs from Lokiarchaeota and Thaumarchaeota exhibited similar U-tract synergy in dictating TTEs. Therefore, aCPSF1 and the intrinsic U-rich terminator could work in a noteworthy two-in-one termination mode in Archaea, which could be widely employed by archaeal phyla; using one factor recognizing U-rich terminator signal and cleaving transcript 3′-end, the archaeal aCPSF1-dependent transcription termination could display a simplified archetypal mode of the eukaryotic RNA polymerase II termination machinery.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jie Li ◽  
Lei Yue ◽  
Zhihua Li ◽  
Wenting Zhang ◽  
Bing Zhang ◽  
...  

Recently, aCPSF1 was reported to function as the long-sought global transcription termination factor of archaea; however, the working mechanism remains elusive. This work, through analyzing transcript-3′end-sequencing data of Methanococcus maripaludis, found genome-wide positive correlations of both the terminator uridine(U)-tract and aCPSF1 with hierarchical transcription termination efficacies (TTEs). In vitro assays determined that aCPSF1 specifically binds to the terminator U-tract with U-tract number-related binding affinity, and in vivo assays demonstrated the two elements are indispensable in dictating high TTEs, revealing that aCPSF1 and the terminator U-tract cooperatively determine high TTEs. The N-terminal KH domains equip aCPSF1 with specific-binding capacity to terminator U-tract and the aCPSF1-terminator U-tract cooperation; while the nuclease activity of aCPSF1 was also required for TTEs. aCPSF1 also guarantees the terminations of transcripts with weak intrinsic terminator signals. aCPSF1 orthologs from Lokiarchaeota and Thaumarchaeota exhibited similar U-tract cooperation in dictating TTEs. Therefore, aCPSF1 and the intrinsic U-rich terminator could work in a noteworthy two-in-one termination mode in archaea, which may be widely employed by archaeal phyla; using one trans-action factor to recognize U-rich terminator signal and cleave transcript 3′-end, the archaeal aCPSF1-dependent transcription termination may represent a simplified archetypal mode of the eukaryotic RNA polymerase II termination machinery.


2000 ◽  
Vol 74 (23) ◽  
pp. 11017-11026 ◽  
Author(s):  
Alexander Bukreyev ◽  
Brian R. Murphy ◽  
Peter L. Collins

ABSTRACT The intergenic sequences (IGS) between the first nine genes of human respiratory syncytial virus (RSV) vary in length from 1 to 56 nucleotides and lack apparent conserved sequence motifs. To investigate their influence on sequential transcription and viral growth, recombinant RSV strain A2, from which the SH gene had been deleted to facilitate manipulation, was further modified to contain an M-G IGS of 16, 30, 44, 58, 65, 72, 86, 100, 120, 140, or 160 nucleotides. All of the viruses were viable. For viruses with an M-G IGS of 100 nucleotides or more, plaque size decreased with increasing IGS length. In this same length range, increasing IGS length was associated with modest attenuation during single-step, but not multistep, growth in HEp-2 cells. Surprisingly, Northern blot analysis of the accumulation of six different mRNAs indicated that there was little or no change in transcription with increasing IGS length. Thus, the RSV polymerase apparently can readily cross IGS of various lengths, including unnaturally long ones, with little or no effect on the efficiency of termination and reinitiation. This finding supports the view that the IGS do not have much effect on sequential transcription and provides evidence from infectious virus that IGS length is not an important regulatory feature. To evaluate replication in vivo, BALB/c mice were infected intranasally with RSV containing an M-G IGS of 65, 140, or 160 nucleotides. Replication of the latter two viruses was decreased up to 5- and 25-fold in the upper and lower respiratory tracts, respectively, on day 3 following infection. However, the level of replication at both sites on days 4 and 5 was very similar to that of the virus with an IGS of 65 nucleotides. Thus, the modest attenuation in vivo associated with the longer IGS was additive to that conferred by deletion of the SH gene and might be useful to incrementally increase the level of attenuation of a live-attenuated vaccine virus.


1986 ◽  
Vol 6 (1) ◽  
pp. 294-301 ◽  
Author(s):  
D D Chang ◽  
J E Hixson ◽  
D A Clayton

Human mitochondrial DNA is transcribed from two distinct, strand-specific promoters located in the displacement loop region of the genome. The transcriptional control sequences identified by deletion mapping and site-directed mutagenesis studies span short regions surrounding the initiation sites and bear no obvious sequence homology to any nuclear or procaryotic promoters. In vitro transcription analyses also revealed several minor initiation sites that are characterized by a pyrimidine-rich region followed by a purine-rich region, a feature that is shared by the two major promoters. In this paper, we report a new class of minor promoters in human mitochondrial DNA. These minor promoters were localized to the same duplex DNA sequences that direct major transcriptional events, but they had transcriptional polarity opposite to that of the major promoters. Furthermore, nucleotide changes that affected the major form of transcription similarly affected transcription in the opposite direction. For one of these minor promoters, a corresponding in vivo RNA species initiating from the same site was identified. These observations indicate that the major transcriptional promoters in human mitochondria can function bidirectionally both in vivo and in vitro.


1986 ◽  
Vol 6 (1) ◽  
pp. 294-301
Author(s):  
D D Chang ◽  
J E Hixson ◽  
D A Clayton

Human mitochondrial DNA is transcribed from two distinct, strand-specific promoters located in the displacement loop region of the genome. The transcriptional control sequences identified by deletion mapping and site-directed mutagenesis studies span short regions surrounding the initiation sites and bear no obvious sequence homology to any nuclear or procaryotic promoters. In vitro transcription analyses also revealed several minor initiation sites that are characterized by a pyrimidine-rich region followed by a purine-rich region, a feature that is shared by the two major promoters. In this paper, we report a new class of minor promoters in human mitochondrial DNA. These minor promoters were localized to the same duplex DNA sequences that direct major transcriptional events, but they had transcriptional polarity opposite to that of the major promoters. Furthermore, nucleotide changes that affected the major form of transcription similarly affected transcription in the opposite direction. For one of these minor promoters, a corresponding in vivo RNA species initiating from the same site was identified. These observations indicate that the major transcriptional promoters in human mitochondria can function bidirectionally both in vivo and in vitro.


1993 ◽  
Vol 13 (11) ◽  
pp. 6866-6875 ◽  
Author(s):  
D C Hagen ◽  
L Bruhn ◽  
C A Westby ◽  
G F Sprague

Transcription activation of alpha-specific genes in Saccharomyces cerevisiae is regulated by two proteins, MCM1 and alpha 1, which bind to DNA sequences, called P'Q elements, found upstream of alpha-specific genes. Neither MCM1 nor alpha 1 alone binds efficiently to P'Q elements. Together, however, they bind cooperatively in a manner that requires both the P' sequence, which is a weak binding site for MCM1, and the Q sequence, which has been postulated to be the binding site for alpha 1. We analyzed a collection of point mutations in the P'Q element of the STE3 gene to determine the importance of individual base pairs for alpha-specific gene transcription. Within the 10-bp conserved Q sequence, mutations at only three positions strongly affected transcription activation in vivo. These same mutations did not affect the weak binding to P'Q displayed by MCM1 alone. In vitro DNA binding assays showed a direct correlation between the ability of the mutant sequences to form ternary P'Q-MCM1-alpha 1 complexes and the degree to which transcription was activated in vivo. Thus, the ability of alpha 1 and MCM1 to bind cooperatively to P'Q elements is critical for activation of alpha-specific genes. In all natural alpha-specific genes the Q sequence is adjacent to the degenerate side of P'. To test the significance of this geometry, we created several novel juxtapositions of P, P', and Q sequences. When the Q sequence was opposite the degenerate side, the composite QP' element was inactive as a promoter element in vivo and unable to form stable ternary QP'-MCM1-alpha 1 complexes in vitro. We also found that addition of a Q sequence to a strong MCM1 binding site allows the addition of alpha 1 to the complex. This finding, together with the observation that Q-element point mutations affected ternary complex formation but not the weak binding of MCM1 alone, supports the idea that the Q sequence serves as a binding site for alpha 1.


2001 ◽  
Vol 44 (S1) ◽  
pp. S339-S341
Author(s):  
K. E. Luker ◽  
G. D. Luker ◽  
C. M. Pica ◽  
J. L. Dahlheimer ◽  
T. J. Fahrner ◽  
...  

1986 ◽  
Vol 6 (9) ◽  
pp. 3262-3267
Author(s):  
D D Chang ◽  
D A Clayton

Transcription of the heavy strand of mouse mitochondrial DNA starts from two closely spaced, distinct sites located in the displacement loop region of the genome. We report here an analysis of regulatory sequences required for faithful transcription from these two sites. Data obtained from in vitro assays demonstrated that a 51-base-pair region, encompassing nucleotides -40 to +11 of the downstream start site, contains sufficient information for accurate transcription from both start sites. Deletion of the 3' flanking sequences, including one or both start sites to -17, resulted in the initiation of transcription by the mitochondrial RNA polymerase from alternative sites within vector DNA sequences. This feature places the mouse heavy-strand promoter uniquely among other known mitochondrial promoters, all of which absolutely require cognate start sites for transcription. Comparison of the heavy-strand promoter with those of other vertebrate mitochondrial DNAs revealed a remarkably high rate of sequence divergence among species.


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