scholarly journals An RNA motif advances transcription by preventing Rho-dependent termination

2015 ◽  
Vol 112 (50) ◽  
pp. E6835-E6843 ◽  
Author(s):  
Anastasia Sevostyanova ◽  
Eduardo A. Groisman
Keyword(s):  
Transcription Termination ◽  
Open Reading Frame ◽  
Leader Region ◽  
Nucleic Acid Binding ◽  
Coding Region ◽  
Reading Frame ◽  
Rna Conformation ◽  
Transcription Termination Factor ◽  
Nucleic Acid Binding Proteins ◽  
Rna Motif

The transcription termination factor Rho associates with most nascent bacterial RNAs as they emerge from RNA polymerase. However, pharmacological inhibition of Rho derepresses only a small fraction of these transcripts. What, then, determines the specificity of Rho-dependent transcription termination? We now report the identification of a Rho-antagonizing RNA element (RARE) that hinders Rho-dependent transcription termination. We establish that RARE traps Rho in an inactive complex but does not prevent Rho binding to its recruitment sites. Although translating ribosomes normally block Rho access to an mRNA, inefficient translation of an open reading frame in the leader region of the Salmonella mgtCBR operon actually enables transcription of its associated coding region by favoring an RNA conformation that sequesters RARE. The discovery of an RNA element that inactivates Rho signifies that the specificity of nucleic-acid binding proteins is defined not only by the sequences that recruit these proteins but also by sequences that antagonize their activity.

scholarly journals Mapping of Transcription Termination within the S Segment of SFTS Phlebovirus Facilitated Generation of NSs Deletant Viruses

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Benjamin Brennan ◽  
Veronica V. Rezelj ◽  
Richard M. Elliott
Keyword(s):  
Virus Infection ◽  
Reverse Genetics ◽  
Fluorescent Protein ◽  
Nonstructural Protein ◽  
Transcription Termination ◽  
Severe Disease ◽  
Open Reading Frame ◽  
Coding Region ◽  
Reading Frame ◽  
Green Fluorescent

ABSTRACT SFTS phlebovirus (SFTSV) is an emerging tick-borne bunyavirus that was first reported in China in 2009. Here we report the generation of a recombinant SFTSV (rHB29NSsKO) that cannot express the viral nonstructural protein (NSs) upon infection of cells in culture. We show that rHB29NSsKO replication kinetics are greater in interferon (IFN)-incompetent cells and that the virus is unable to suppress IFN induced in response to viral replication. The data confirm for the first time in the context of virus infection that NSs acts as a virally encoded IFN antagonist and that NSs is dispensable for virus replication. Using 3′ rapid amplification of cDNA ends (RACE), we mapped the 3′ end of the N and NSs mRNAs, showing that the mRNAs terminate within the coding region of the opposite open reading frame. We show that the 3′ end of the N mRNA terminates upstream of a 5′-GCCAGCC-3′ motif present in the viral genomic RNA. With this knowledge, and using virus-like particles, we could demonstrate that the last 36 nucleotides of the NSs open reading frame (ORF) were needed to ensure the efficient termination of the N mRNA and were required for recombinant virus rescue. We demonstrate that it is possible to recover viruses lacking NSs (expressing just a 12-amino-acid NSs peptide or encoding enhanced green fluorescent protein [eGFP]) or an NSs-eGFP fusion protein in the NSs locus. This opens the possibility for further studies of NSs and potentially the design of attenuated viruses for vaccination studies. IMPORTANCE SFTS phlebovirus (SFTSV) and related tick-borne viruses have emerged globally since 2009. SFTSV has been shown to cause severe disease in humans. For bunyaviruses, it has been well documented that the nonstructural protein (NSs) enables the virus to counteract the human innate antiviral defenses and that NSs is one of the major determinants of virulence in infection. Therefore, the use of reverse genetics systems to engineer viruses lacking NSs is an attractive strategy to rationally attenuate bunyaviruses. Here we report the generation of several recombinant SFTS viruses that cannot express the NSs protein or have the NSs open reading frame replaced with a reporter gene. These viruses cannot antagonize the mammalian interferon (IFN) response mounted to virus infection. The generation of NSs-lacking viruses was achieved by mapping the transcriptional termination of two S-segment-derived subgenomic mRNAs, which revealed that transcription termination occurs upstream of a 5′-GCCAGCC-3′ motif present in the virus genomic S RNA.

scholarly journals Arabidopsis Mitochondrial Transcription Termination Factor mTERF2 Promotes Splicing of Group IIB Introns

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 315
Author(s):  
Kwanuk Lee ◽  
Dario Leister ◽  
Tatjana Kleine
Keyword(s):  
Gene Expression ◽  
Plant Development ◽  
Transcription Termination ◽  
Green Plant ◽  
Messenger Rnas ◽  
Nucleic Acid Binding ◽  
Termination Factor ◽  
Mitochondrial Transcription ◽  
Transcription Termination Factor ◽  
Nucleic Acid Binding Proteins

Plastid gene expression (PGE) is essential for chloroplast biogenesis and function and, hence, for plant development. However, many aspects of PGE remain obscure due to the complexity of the process. A hallmark of nuclear-organellar coordination of gene expression is the emergence of nucleus-encoded protein families, including nucleic-acid binding proteins, during the evolution of the green plant lineage. One of these is the mitochondrial transcription termination factor (mTERF) family, the members of which regulate various steps in gene expression in chloroplasts and/or mitochondria. Here, we describe the molecular function of the chloroplast-localized mTERF2 in Arabidopsis thaliana. The complete loss of mTERF2 function results in embryo lethality, whereas directed, microRNA (amiR)-mediated knockdown of MTERF2 is associated with perturbed plant development and reduced chlorophyll content. Moreover, photosynthesis is impaired in amiR-mterf2 plants, as indicated by reduced levels of photosystem subunits, although the levels of the corresponding messenger RNAs are not affected. RNA immunoprecipitation followed by RNA sequencing (RIP-Seq) experiments, combined with whole-genome RNA-Seq, RNA gel-blot, and quantitative RT-PCR analyses, revealed that mTERF2 is required for the splicing of the group IIB introns of ycf3 (intron 1) and rps12.

Pax-6, a murine paired box gene, is expressed in the developing CNS

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1435-1449 ◽  
Author(s):  
C. Walther ◽  
P. Gruss
Keyword(s):  
Amino Acids ◽  
Neural Tube ◽  
Multigene Family ◽  
Ventricular Zone ◽  
Open Reading Frame ◽  
Cdna Clones ◽  
Coding Region ◽  
Paired Domain ◽  
Reading Frame ◽  
Pax Genes

A multigene family of paired-box-containing genes (Pax genes) has been identified in the mouse. In this report, we describe the expression pattern of Pax-6 during embryogenesis and the isolation of cDNA clones spanning the entire coding region. The Pax-6 protein consists of 422 amino acids as deduced from the longest open reading frame and contains, in addition to the paired domain, a paired-type homeodomain. Beginning with day 8 of gestation, Pax-6 is expressed in discrete regions of the forebrain and the hindbrain. In the neural tube, expression is mainly confined to mitotic active cells in the ventral ventricular zone along the entire anteroposterior axis starting at day 8.5 of development. Pax-6 is also expressed in the developing eye, the pituitary and the nasal epithelium.

Retroviral insertions in the murine His-1 locus activate the expression of a novel RNA that lacks an extensive open reading frame

1994 ◽  
Vol 14 (3) ◽  
pp. 1743-1751
Author(s):  
D S Askew ◽  
J Li ◽  
J N Ihle
Keyword(s):  
Cell Lines ◽  
Wild Mouse ◽  
Myeloid Cell ◽  
Single Copy ◽  
Open Reading Frame ◽  
Chromosome 2 ◽  
Coding Region ◽  
Reading Frame ◽  
Novel Gene ◽  
Myeloid Leukemias

The His-1 locus is a common site of viral insertion in murine myeloid leukemias induced by the wild mouse ecotropic retrovirus, CasBrM. In this report, we describe the cloning of a novel gene at the His-1 locus and show that His-1 expression is associated with the transformed phenotype. Northern (RNA) blot analysis identified His-1 transcripts in four transformed myeloid cell lines but in no normal tissues examined. Two of these cell lines were derived from retrovirus-induced myeloid leukemias that harbor integrated proviruses which drive His-1 gene expression by promoter insertion. The two other cell lines expressed a discrete 3-kb His-1 RNA that is derived from a novel gene consisting of three exons that span 6 kb on mouse chromosome 2. The His-1 gene is conserved as a single-copy sequence in multiple vertebrate species and is expressed as a spliced and polyadenylated RNA. A protein-coding region is not evident from analysis of the His-1 sequence because of the presence of multiple small open reading frames, none of which are greater than 219 bp. This lack of an extensive open reading frame is an unusual feature that is shared by other RNA molecules believed to function in the absence of translation.

scholarly journals The Open Reading Frame 3 Gene of Hepatitis E Virus Contains a cis-Reactive Element and Encodes a Protein Required for Infection of Macaques

2005 ◽  
Vol 79 (11) ◽  
pp. 6680-6689 ◽  
Author(s):  
Judith Graff ◽  
Hanh Nguyen ◽  
Claro Yu ◽  
William R. Elkins ◽  
Marisa St. Claire ◽  
...  
Keyword(s):  
Hepatitis E Virus ◽  
Phosphorylation Site ◽  
Hepatitis E ◽  
Open Reading Frame ◽  
Reactive Element ◽  
Genome Replication ◽  
Null Mutant ◽  
Coding Region ◽  
Reading Frame ◽  
Orf3 Protein

ABSTRACT An infectious cDNA clone of hepatitis E virus was mutated in order to prevent synthesis of either open reading frame 2 (ORF2) protein or ORF3 protein. HuH-7 cells transfected with an ORF2-null mutant produced ORF3, and those transfected with an ORF3-null mutant produced ORF2. Silent mutations introduced into a highly conserved nucleotide sequence in the ORF3 coding region eliminated the synthesis of both ORF2 and ORF3 proteins, suggesting that it comprised a cis-reactive element. A mutant that was not able to produce ORF3 protein did not produce a detectable infection in rhesus macaques. However, a mutant that encoded an ORF3 protein lacking a phosphorylation site reported to be critical for function was able to replicate its genome in cell culture and to induce viremia and seroconversion in rhesus monkeys, suggesting that phosphorylation of ORF3 protein was not necessary for genome replication or for production of infectious virions.

Nucleotide sequence and expression in vitro of cDNA derived from mRNA of int-1, a provirally activated mouse mammary oncogene

1985 ◽  
Vol 5 (12) ◽  
pp. 3337-3344
Author(s):  
Y K Fung ◽  
G M Shackleford ◽  
A M Brown ◽  
G S Sanders ◽  
H E Varmus
Keyword(s):  
Nucleotide Sequence ◽  
Mammary Tumor ◽  
Initiation Site ◽  
Open Reading Frame ◽  
In Vitro Translation ◽  
Cdna Clones ◽  
Coding Region ◽  
Reading Frame ◽  
Donor And Acceptor

The mouse int-1 gene is a putative mammary oncogene discovered as a target for transcriptionally activating proviral insertion mutations in mammary carcinomas induced by the mouse mammary tumor virus in C3H mice. We have isolated molecular clones of full- or nearly full-length cDNA transcribed from int-1 RNA (2.6 kilobases) in a virus-induced mammary tumor. Comparison of the nucleotide sequence of the cDNA clones with that of the int-1 gene (A. van Ooyen and R. Nusse, Cell 39:233-240, 1984) shows the following. The coding region of the int-1 gene is composed of four exons. The splice donor and acceptor sites conform to consensus; however, at least two closely spaced polyadenylation sites are used, and the transcriptional initiation site remains ambiguous. The major open reading frame is preceded by an open frame 10 codons in length. The mRNA encodes a 41-kilodalton protein with several striking features--a strongly hydrophobic amino terminus, a cysteine-rich carboxy terminus, and four potential glycosylation sites. There are no differences in nucleotide sequence between the known exons of the normal and a provirally activated allele. The length of the deduced open reading frame was further confirmed by in vitro translation of RNA transcribed from the cDNA clones with SP6 RNA polymerase.

scholarly journals Construction of a Self-Excisable Bacterial Artificial Chromosome Containing the Human Cytomegalovirus Genome and Mutagenesis of the Diploid TRL/IRL13 Gene

2002 ◽  
Vol 76 (5) ◽  
pp. 2316-2328 ◽  
Author(s):  
Dong Yu ◽  
Gregory A. Smith ◽  
Lynn W. Enquist ◽  
Thomas Shenk
Keyword(s):  
Bacterial Artificial Chromosome ◽  
Human Cytomegalovirus ◽  
Artificial Chromosome ◽  
Open Reading Frame ◽  
Wild Type Virus ◽  
Progeny Virus ◽  
Wild Type ◽  
Coding Region ◽  
Reading Frame ◽  
Strain Ad169

ABSTRACT The full-length genome of human cytomegalovirus strain AD169 was cloned as an infectious bacterial artificial chromosome (BAC) plasmid, pAD/Cre. The BAC vector, flanked by LoxP sites, was inserted immediately after the Us28 open reading frame without deletion of any viral sequences. The BAC vector contained the Cre recombinase-encoding gene disrupted by an intron under control of the simian virus 40 early promoter. When pAD/Cre was transfected into primary human foreskin fibroblast cells, Cre was expressed and mediated site-specific recombination between the two LoxP sites, excising the BAC DNA backbone. This gave rise to progeny virus that was wild type with the exception of an inserted 34-bp LoxP site. We performed site-directed mutagenesis on pAD/Cre to generate a series of viruses in which the TRL/IRL13 diploid genes were disrupted and subsequently repaired. The mutants reach the same titer as the wild-type virus, indicating that the TRL/IRL13 open reading frames are not required for virus growth in cell culture. The sequence of the TRL13 open reading frame in the low-passage Toledo strain of human cytomegalovirus is quite different from the corresponding region in the AD169 strain. One of multiple changes is a frameshift mutation. As a consequence, strain Toledo encodes a putative TRL13 protein whose C-terminal domain is larger (extending through the TRL14 coding region) and encodes in a reading frame different from that of strain AD169. We speculate that the strain AD169 coding region has drifted during passage in the laboratory. We propose that TRL13 has been truncated in strain AD169 and that the partially overlapping TRL14 open reading frame is not functional. This view is consistent with the presence of both TRL13 and -14 on all mRNAs that we have mapped from this region, an organization that would include the much longer strain Toledo TRL13 open reading frame on the mRNAs.

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