29 research outputs found
Affective reactions differ between Chinese and American healthy young adults: a cross-cultural study using the international affective picture system
Constitutive Activation of PrfA Tilts the Balance of Listeria monocytogenes Fitness Towards Life within the Host versus Environmental Survival
PrfA is a key regulator of Listeria monocytogenes pathogenesis and induces the expression of multiple virulence factors within the infected host. PrfA is post-translationally regulated such that the protein becomes activated upon bacterial entry into the cell cytosol. The signal that triggers PrfA activation remains unknown, however mutations have been identified (prfA* mutations) that lock the protein into a high activity state. In this report we examine the consequences of constitutive PrfA activation on L. monocytogenes fitness both in vitro and in vivo. Whereas prfA* mutants were hyper-virulent during animal infection, the mutants were compromised for fitness in broth culture and under conditions of stress. Broth culture prfA*-associated fitness defects were alleviated when glycerol was provided as the principal carbon source; under these conditions prfA* mutants exhibited a competitive advantage over wild type strains. Glycerol and other three carbon sugars have been reported to serve as primary carbon sources for L. monocytogenes during cytosolic growth, thus prfA* mutants are metabolically-primed for replication within eukaryotic cells. These results indicate the critical need for environment-appropriate regulation of PrfA activity to enable L. monocytogenes to optimize bacterial fitness inside and outside of host cells
Thermal and structural properties of commercial dental resins light-cured with blue emitting diodes (LEDs)
Effects of Monomer Composition and Original Filler Content on Filler Loading in the Resulting Centrifuged Composites
Insights into the sonochemical synthesis and properties of salt-free intrinsic plutonium colloids
Genomic organization of <it>Tropomodulins 2</it> and <it>4</it> and unusual intergenic and intraexonic splicing of <it>YL-1</it> and <it>Tropomodulin 4</it>
<p>Abstract</p> <p>Background</p> <p>The tropomodulins (TMODs) are a family of proteins that cap the pointed ends of actin filaments. Four TMODs have been identified in humans, with orthologs in mice. Mutations in actin or actin-binding proteins have been found to cause several human diseases, ranging from hypertrophic cardiomyopathy to immunodefiencies such as Wiskott-Aldrich syndrome. We had previously mapped <it>Tropomodulin 2 (TMOD2)</it> to the genomic region containing the gene for amyotrophic lateral sclerosis 5 (ALS5). We determined the genomic structure of Tmod2 in order to better analyze patient DNA for mutations; we also determined the genomic structure of <it>Tropomodulin 4 (TMOD4).</it></p> <p>Results</p> <p>In this study, we determined the genomic structure of <it>TMOD2</it> and <it>TMOD4</it> and found the organization of both genes to be similar. Sequence analysis of <it>TMOD2</it> revealed no mutations or polymorphisms in ALS5 patients or controls. Interestingly, we discovered that another gene, <it>YL-1,</it> intergenically splices into <it>TMOD4. YL-1</it> encodes six exons, the last of which is 291 bp from a 5' untranslated exon of <it>TMOD4.</it> We used 5' RACE and RT-PCR from <it>TMOD4</it> to identify several intergenic RACE products. <it>YL-1</it> was also found to undergo unconventional splicing using non-canonical splice sites within exons (intraexonic splicing) to produce several alternative transcripts.</p> <p>Conclusions</p> <p>The genomic structure of <it>TMOD2</it> and <it>TMOD4</it> have been delineated. This should facilitate future mutational analysis of these genes. In addition, intergenic splicing at <it>TMOD4/YL-1</it> was discovered, demonstrating yet another level of complexity of gene organization and regulation.</p