scholarly journals Alternatively Initiated Gene 50/RTA Transcripts Expressed during Murine and Human Gammaherpesvirus Reactivation from Latency

2008 ◽  
Vol 83 (1) ◽  
pp. 314-328 ◽  
Author(s):  
Kathleen S. Gray ◽  
Robert D. Allen ◽  
Michael L. Farrell ◽  
J. Craig Forrest ◽  
Samuel H. Speck
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Raw 264.7 ◽  
Virus Reactivation ◽  
Wild Type ◽  
Latently Infected ◽  
Distal Gene

ABSTRACT In the process of characterizing the requirements for expression of the essential immediate-early transcriptional activator (RTA) encoded by gene 50 of murine gammaherpesvirus 68 (MHV68), a recombinant virus was generated in which the known gene 50 promoter was deleted (G50pKO). Surprisingly, the G50pKO mutant retained the ability to replicate in permissive murine fibroblasts, albeit with slower kinetics than wild-type MHV68. 5′-rapid amplification of cDNA ends analyses of RNA prepared from G50pKO-infected fibroblasts revealed a novel upstream transcription initiation site, which was also utilized during wild-type MHV68 infection of permissive cells. Furthermore, the region upstream of the distal gene 50/RTA transcription initiation site exhibited promoter activity in both permissive NIH 3T12 fibroblasts as well as in the murine macrophage cell line RAW 264.7. In addition, in RAW 264.7 cells the activity of the distal gene 50/RTA promoter was strongly upregulated (>20-fold) by treatment of the cells with lipopolysaccharide. Reverse transcriptase PCR analyses of RNA prepared from Kaposi's sarcoma-associated herpesvirus- and Epstein-Barr virus-infected B-cell lines, following induction of virus reactivation, also revealed the presence of gene 50/RTA transcripts initiating upstream of the known transcription initiation site. The latter argues that alternative initiation of gene 50/RTA transcription is a strategy conserved among murine and human gammaherpesviruses. Infection of mice with the MHV68 G50pKO demonstrated the ability of this mutant virus to establish latency in the spleen and peritoneal exudate cells (PECs). However, the G50pKO mutant was unable to reactivate from latently infected splenocytes and also exhibited a significant reactivation defect from latently infected PECs, arguing in favor of a model where the proximal gene 50/RTA promoter plays a critical role in virus reactivation from latency, particularly from B cells. Finally, analyses of viral genome methylation in the regions upstream of the proximal and distal gene 50/RTA transcription initiation sites revealed that the distal promoter is partially methylated in vivo and heavily methylated in MHV68 latently infected B-cell lines, suggesting that DNA methylation may serve to silence the activity of this promoter during virus latency.

scholarly journals Nucleoprotein Structure of Immediate-Early Promoters Zp and Rp and of oriLyt of Latent Epstein-Barr Virus Genomes

2002 ◽  
Vol 76 (8) ◽  
pp. 4113-4118 ◽  
Author(s):  
Hans Helmut Niller ◽  
Daniel Salamon ◽  
Jörg Uhlig ◽  
Stefanie Ranf ◽  
Marcus Granz ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Epstein Barr Virus ◽  
Initiation Site ◽  
Transient Transfection ◽  
Immediate Early ◽  
Barr Virus ◽  
Latently Infected ◽  
Epstein Barr ◽  
Virus Genomes

ABSTRACT Genomic footprints across Rp, Zp, and oriLyt of Epstein-Barr virus (EBV) have been conducted in a panel of latently infected B-cell lines. Close protein-base contacts were found about 360 nucleotides upstream of the Zp initiation site. Gel shifts and transient transfection assays indicated that an Sp1-NF1 locus may serve as a repressive transcriptional element against Zp induction from latent EBV genomes.

Definition of the transcription initiation site of human plasminogen gene in liver and non hepatic cell lines

1990 ◽  
Vol 173 (3) ◽  
pp. 1013-1018 ◽  
Author(s):  
Nicoletta Malgaretti ◽  
Ludovica Bruno ◽  
Marco Pontoglio ◽  
Giulia Candiani ◽  
Germana Meroni ◽  
...  
Keyword(s):  
Cell Lines ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Hepatic Cell ◽  
Transcription Initiation Site ◽  
Human Plasminogen ◽  
Definition Of ◽  
Hepatic Cell Lines

scholarly journals Cellular factor YY1 downregulates the human papillomavirus 16 E6/E7 promoter, P97, in vivo and in vitro from a negative element overlapping the transcription-initiation site

2009 ◽  
Vol 90 (10) ◽  
pp. 2402-2412 ◽  
Author(s):  
Michael J. Lace ◽  
Yasushi Yamakawa ◽  
Masato Ushikai ◽  
James R. Anson ◽  
Thomas H. Haugen ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Transcription Initiation ◽  
Regulatory Region ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Wild Type ◽  
Hpv 16 ◽  
Human Papillomavirus 16

Cellular factors that bind to cis sequences in the human papillomavirus 16 (HPV-16) upstream regulatory region (URR) positively and negatively regulate the viral E6 and E7 oncogene promoter, P97. DNase I footprinting has revealed the binding of cellular proteins to two previously undetected cis elements overlapping and 3′ of the transcription-initiation site of the P97 promoter. Mutations within homologous motifs found in both of these cis elements abolished their negative function in vivo and the binding of the same cellular complex in vitro. This factor was identified as YY1 by complex mobility and binding specificity in comparison with vaccinia virus-expressed, purified recombinant YY1 protein and by antigenic reactivity with YY1 antisera. Cis mutations in the ‘initiator’ YY1 site activated the P97 promoter in vivo and in vitro. P97 was also activated threefold in vitro by depletion of endogenous YY1 with wild-type, but not mutant, YY1 oligonucleotides from the IgH kappa E3′ enhancer. Furthermore, increasing concentrations of exogenous, purified recombinant YY1 repressed wild-type P97 transcript levels by up to threefold, but did not influence the P97 promoter mutated in the ‘initiator’ YY1 site. Thus, the promoter-proximal YY1 site was not necessary for correct transcription initiation at the P97 promoter, but was found to be required for downregulation of P97 transcription in vivo and in vitro. In contrast to other viral and cellular promoters, where YY1 is thought to function as a positive transcription-‘initiator’ factor, HPV-16 P97 transcription is downregulated by YY1 from a critical motif overlapping the transcription start site.

Adenovirus 5 E2 transcription unit: an E1A-inducible promoter with an essential element that functions independently of position or orientation

1984 ◽  
Vol 4 (5) ◽  
pp. 875-882
Author(s):  
M J Imperiale ◽  
J R Nevins
Keyword(s):  
Transcription Initiation ◽  
Essential Element ◽  
Inducible Promoter ◽  
Initiation Site ◽  
Transcription Unit ◽  
Upstream Sequence ◽  
Wild Type ◽  
Promoter Sequences ◽  
Adenovirus 5 ◽  
Wild Type Promoter

Utilizing deletion mutants of a plasmid containing the adenovirus E2 gene, an E1A-inducible transcription unit, we determined the promoter sequences required for full expression in transient transfection assays. Wild-type expression was obtained from plasmids containing only 79 nucleotides of upstream sequence relative to the transcription initiation site. Removal of an additional nine nucleotides lowered expression 10-fold, and deletion to -59 resulted in near total loss of transcription. Wild-type levels of expression were restored to a -28 deletion mutant by insertion of the sequence from -21 to -262 from the wild-type promoter at the -28 position, in either orientation, even though when inserted in the opposite orientation the relevant sequences were ca. 270 nucleotides upstream from their normal position. Finally, this sequence could be placed at a distance of 4,000 nucleotides from the E2 cap site and still retain near total function. Thus, the E2 promoter element can function independent of orientation and position, properties characteristic of enhancer elements.

scholarly journals MicroRNA-181a Inhibits Activated B-Cell-Like Diffuse Large B-Cell Lymphoma Progression by Repressing CARD11

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Danxia Zhu ◽  
Cheng Fang ◽  
Wenting He ◽  
Chen Wu ◽  
Xiaodong Li ◽  
...  
Keyword(s):  
B Cell ◽  
Binding Site ◽  
Cell Lines ◽  
Expression Vector ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Wild Type ◽  
Protein Levels ◽  
Large B Cell Lymphoma ◽  
Large B Cell

We investigated the role of miR-181a in diffuse large B-cell lymphoma (DLBCL) and its potential target genes. miR-181a levels were lower in activated B-cell- (ABC-) like DLBCL cells than that in germinal center B-cell- (GCB-) like DLBCL cells. Overexpression of miR-181a in ABC-like DLBCL cell lines (OCI-LY10 and U2932) resulted in G0/G1 cell cycle arrest, increased apoptosis, and decreased invasiveness. miRNA target prediction programs (miRanda, TargetScan, and miRDB) identified caspase recruitment domain-containing protein 11 (CARD11) as a putative miR-181a target. CARD11 mRNA and protein levels were higher in the ABC-like DLBCL than that in GCB-like DLBCL. Moreover, CARD11 mRNA and protein levels were downregulated in the OCI-LY10 and U2932 cell lines overexpressing miR-181a. Dual luciferase reporter assays confirmed the miR-181a binding site in the CARD11 3′UTR region. OCI-LY10 and U2932 cells transfected with a CARD11 expression vector encoding miR-181a with a mutated binding site showed higher CARD11 protein levels, cell viability, G2/M phase cells, and invasiveness compared to those transfected with a wild-type CARD11 expression vector. Nude mice xenografted with OCI-LY10 cells with overexpressed wild-type miR-181a generated smaller tumors compared to those with overexpressed mutated binding site of CARD11 3′UTR and miR-181a. These results indicate that miR-181a inhibits ABC-like DLBCL by repressing CARD11.

Identification of the transcription initiation site of the asexually expressed rRNA genes of the malaria parasite Plasmodium berghei

1999 ◽  
Vol 99 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Rosalina M.L. van Spaendonk ◽  
Glenn A. McConkey ◽  
Jai Ramesar ◽  
Andrei Gabrielian ◽  
Thomas F. McCutchan ◽  
...  
Keyword(s):  
Plasmodium Berghei ◽  
Transcription Initiation ◽  
Malaria Parasite ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Rrna Genes ◽  
Parasite Plasmodium
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