scholarly journals Perturbation of spermine synthase Gene Expression and Transcript Profiling Provide New Insights on the Role of the Tetraamine Spermine in Arabidopsis Defense against Pseudomonas viridiflava

2011 ◽  
Vol 156 (4) ◽  
pp. 2266-2277 ◽  
Author(s):  
María Elisa Gonzalez ◽  
Francisco Marco ◽  
Eugenio Gómez Minguet ◽  
Pedro Carrasco-Sorli ◽  
Miguel Angel Blázquez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcript Profiling ◽  
Spermine Synthase ◽  
Pseudomonas Viridiflava ◽  
Arabidopsis Defense

scholarly journals Listeria monocytogenes σB Modulates PrfA-Mediated Virulence Factor Expression

2009 ◽  
Vol 77 (5) ◽  
pp. 2113-2124 ◽  
Author(s):  
Juliane Ollinger ◽  
Barbara Bowen ◽  
Martin Wiedmann ◽  
Kathryn J. Boor ◽  
Teresa M. Bergholz
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Transcriptional Activation ◽  
Virulence Gene ◽  
Transcript Profiling ◽  
Virulence Gene Expression ◽  
Qrt Pcr ◽  
Genome Wide

ABSTRACT Listeria monocytogenes σB and positive regulatory factor A (PrfA) are pleiotropic transcriptional regulators that coregulate a subset of virulence genes. A positive regulatory role for σB in prfA transcription has been well established; therefore, observations of increased virulence gene expression and hemolytic activity in a ΔsigB strain initially appeared paradoxical. To test the hypothesis that L. monocytogenes σB contributes to a regulatory network critical for appropriate repression as well as induction of virulence gene expression, genome-wide transcript profiling and follow-up quantitative reverse transcriptase PCR (qRT-PCR), reporter fusion, and phenotypic experiments were conducted using L. monocytogenes prfA*, prfA* ΔsigB, ΔprfA, and ΔprfA ΔsigB strains. Genome-wide transcript profiling and qRT-PCR showed that in the presence of active PrfA (PrfA*), σB is responsible for reduced expression of the PrfA regulon. σB-dependent modulation of PrfA regulon expression reduced the cytotoxic effects of a PrfA* strain in HepG2 cells, highlighting the functional importance of regulatory interactions between PrfA and σB. The emerging model of the role of σB in regulating overall PrfA activity includes a switch from transcriptional activation at the P2 prfA promoter (e.g., in extracellular bacteria when PrfA activity is low) to posttranscriptional downregulation of PrfA regulon expression (e.g., in intracellular bacteria when PrfA activity is high).

Role of small nuclear RNAs in eukaryotic gene expression

2013 ◽  
Vol 54 ◽  
pp. 79-90 ◽  
Author(s):  
Saba Valadkhan ◽  
Lalith S. Gunawardane
Keyword(s):  
Gene Expression ◽  
Protein Interactions ◽  
Rna Stability ◽  
Splice Sites ◽  
Branch Site ◽  
Small Nuclear Rnas ◽  
Eukaryotic Gene Expression ◽  
Eukaryotic Gene ◽  
Rna Biogenesis

Eukaryotic cells contain small, highly abundant, nuclear-localized non-coding RNAs [snRNAs (small nuclear RNAs)] which play important roles in splicing of introns from primary genomic transcripts. Through a combination of RNA–RNA and RNA–protein interactions, two of the snRNPs, U1 and U2, recognize the splice sites and the branch site of introns. A complex remodelling of RNA–RNA and protein-based interactions follows, resulting in the assembly of catalytically competent spliceosomes, in which the snRNAs and their bound proteins play central roles. This process involves formation of extensive base-pairing interactions between U2 and U6, U6 and the 5′ splice site, and U5 and the exonic sequences immediately adjacent to the 5′ and 3′ splice sites. Thus RNA–RNA interactions involving U2, U5 and U6 help position the reacting groups of the first and second steps of splicing. In addition, U6 is also thought to participate in formation of the spliceosomal active site. Furthermore, emerging evidence suggests additional roles for snRNAs in regulation of various aspects of RNA biogenesis, from transcription to polyadenylation and RNA stability. These snRNP-mediated regulatory roles probably serve to ensure the co-ordination of the different processes involved in biogenesis of RNAs and point to the central importance of snRNAs in eukaryotic gene expression.

Cell-specific regulation of IRS-1 gene expression: role of E box and C/EBP binding site in HepG2 cells and CHO cells

Diabetes ◽  
1997 ◽  
Vol 46 (3) ◽  
pp. 354-362 ◽  
Author(s):  
K. Matsuda ◽  
E. Araki ◽  
R. Yoshimura ◽  
K. Tsuruzoe ◽  
N. Furukawa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Binding Site ◽  
Cho Cells ◽  
Hepg2 Cells ◽  
E Box ◽  
Specific Regulation
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