A Study of Bus Stop Accessibility: Public Health Students Working in Partnership with the Center for Independent Living

Over 54 million U.S. citizens report living with at least one disability. The Americans with Disabilities Act stipulates legislation that prohibits the discrimination of persons on the basis of disability. Rather than riding the bus in areas that offer a fixed-route bus system, individuals with disabilities often rely on expensive and limited paratransit services, or on family and friends. It has been proposed that with improvements in bus accessibility, riders with disabilities could use the fixed-route system more often and increase their options for independence and community participation. During their 2008 spring semester, participants in the University of Florida College of Public Health and Health Professions’ course, Assessment and Surveillance, partnered with the Center for Independent Living (CIL) of North Central Florida to conduct an accessibility study of the Gainesville, Florida fixed-route bus system. Students focused on factors that make bus stops user-friendly for persons with disabilities. This paper presents the rationale, methods, and findings from this accessibility study and efforts undertaken to forge a mutually beneficial partnership among UF-PHHP students and the CIL

The DNA/RNA-Dependent RNA Polymerase QDE-1 Generates Aberrant RNA and dsRNA for RNAi in a Process Requiring Replication Protein A and a DNA Helicase

The Neurospora RNA-dependent RNA polymerase QDE-1 is an RNA polymerase that can use both RNA and DNA as templates, suggesting a new mechanism for small RNA production

Brain Derived Neurotrophic Factor (BDNF) Expression Is Regulated by MicroRNAs miR-26a and miR-26b Allele-Specific Binding

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays an essential role in neuronal development and plasticity. MicroRNA (miRNAs) are small non-coding RNAs of about 22-nucleotides in length regulating gene expression at post-transcriptional level. In this study we explore the role of miRNAs as post-transcriptional inhibitors of BDNF and the effect of 3′UTR sequence variations on miRNAs binding capacity. Using an in silico approach we identified a group of miRNAs putatively regulating BDNF expression and binding to BDNF 3′UTR polymorphic sequences. Luciferase assays demonstrated that these miRNAs (miR-26a1/2 and miR-26b) downregulates BDNF expression and that the presence of the variant alleles of two single nucleotide polymorphisms (rs11030100 and rs11030099) mapping in BDNF 3′UTR specifically abrogates miRNAs targeting. Furthermore we found a high linkage disequilibrium rate between rs11030100, rs11030099 and the non-synonymous coding variant rs6265 (Val66Met), which modulates BDNF mRNA localization and protein intracellular trafficking. Such observation led to hypothesize that miR-26s mediated regulation could extend to rs6265 leading to an allelic imbalance with potentially functional effects, such as peptide's localization and activity-dependent secretion. Since rs6265 has been previously implicated in various neuropsychiatric disorders, we evaluated the distribution of rs11030100, rs11030099 and rs6265 both in a control and schizophrenic group, but no significant difference in allele frequencies emerged. In conclusion, in the present study we identified two novel miRNAs regulating BDNF expression and the first BDNF 3′UTR functional variants altering miRNAs-BDNF binding

From transcription to translation: new insights in the structure and function of Argonaute protein

Argonaute proteins play a central role in gene silencing pathways mediated by small RNA molecules. The ancestral function of small RNA-dependent silencing is related to genome protection against parasitic nucleic acids, such as transposons and viruses. However, new classes of small RNAs are continuously being uncovered in all higher eukaryotes in which they play important functions in processes ranging from embryonic development to differentiation to cell proliferation and metabolism. Small RNAs have variegated biogenesis pathways and accomplish distinct functions. Nevertheless, it appears that all small RNAs work merely as guides in recognizing the target RNAs invariably relying on the interaction with Argonaute proteins and associated factors for their biological function. Here, we discuss recent findings on the structure and regulation of mammalian Argonaute proteins and overview the various roles that these versatile proteins play in regulating gene expression

From transcription to translation: new insights in the structure and function of Argonaute protein

Argonaute proteins play a central role in gene silencing pathways mediated by small RNA molecules. The ancestral function of small RNA-dependent silencing is related to genome protection against parasitic nucleic acids, such as transposons and viruses. However, new classes of small RNAs are continuously being uncovered in all higher eukaryotes in which they play important functions in processes ranging from embryonic development to differentiation to cell proliferation and metabolism. Small RNAs have variegated biogenesis pathways and accomplish distinct functions. Nevertheless, it appears that all small RNAs work merely as guides in recognizing the target RNAs invariably relying on the interaction with Argonaute proteins and associated factors for their biological function. Here, we discuss recent findings on the structure and regulation of mammalian Argonaute proteins and overview the various roles that these versatile proteins play in regulating gene expression

Inhibition of eukaryotic translation initiation factor 5a (Eif5a) hypusination suppress p53 translation and alters the association of eif5a to the ribosomes

The eukaryotic translation initiation factor 5A (eIF5A) is an essential protein for the viability of the cells whose proposed function is to prevent the stalling of the ribosomes during translation elongation. eIF5A activity requires a unique and functionally essential post-translational modification, the change of a lysine to hypusine. eIF5A is recognized as a promoter of cell proliferation, but it has also been suggested to induce apoptosis. To date, the precise molecular mechanism through which eIF5A affects these processes remains elusive. In the present study, we explored whether eIF5A is involved in controlling the stress-induced expression of the key cellular regulator p53. Our results show that treatment of HCT-116 colon cancer cells with the deoxyhypusine (DHS) inhibitor N1-guanyl-1,7-diamineheptane (GC7) caused both inhibition of eIF5A hypusination and a significant reduction of p53 expression in UV-treated cells, and that eIF5A controls p53 expression at the level of protein synthesis. Furthermore, we show that treatment with GC7 followed by UV-induced stress counteracts the pro-apoptotic process triggered by p53 up-regulation. More in general, the importance of eIF5A in the cellular stress response is illustrated by the finding that exposure to UV light promotes the binding of eIF5A to the ribosomes, whereas UV treatment complemented by the presence of GC7 inhibits such binding, allowing a decrease of de novo synthesis of p53 protein

qiRNA is a new type of small interfering RNA induced by DNA damage

RNA interference pathways use small RNAs to mediate gene silencing in eukaryotes. In addition to small interfering RNAs (siRNA) and microRNAs, several types of endogenously produced small RNAs play important roles in gene regulation, germ cell maintenance and transposon silencing 1–4. Production of some of these RNAs requires the synthesis of aberrant RNAs (aRNAs) or pre-siRNAs, which are specifically recognized by RNA-dependent RNA polymerases (RdRPs) to make double stranded RNA (dsRNA). The mechanism for aRNA synthesis and recognition is largely unknown. Here we show that DNA damage induces the expression of the Argonaute protein QDE-2 and a novel class of small RNAs in the filamentous fungus Neurospora. This class of small RNAs, named qiRNAs for their association with QDE-2, are about 20–21 nt long (several nt shorter than Neurospora siRNAs) with a strong preference for uridine at the 5′ end and originate mostly from the ribosomal DNA locus. Production of qiRNAs requires the RdRP QDE-1, the Werner/Bloom RecQ DNA helicase homolog QDE-3 and dicers. qiRNA biogenesis also requires DNA damage-induced aRNAs as precursor, a process that is dependent on QDE-1 and QDE-3. Surprisingly, our results suggest that QDE-1 is the DNA-dependent RNA polymerase that produces aRNAs. In addition, the Neurospora RNAi mutants exhibit increased sensitivity to DNA damage, suggesting a role for qiRNAs in DNA damage response by inhibiting protein translation

Silencing of Ago-2 Interacting Protein SERBP1 Relieves KCC2 Repression by miR-92 in Neurons

RNA-binding proteins (RBPs) play important roles in modulating miRNA-mediated mRNA target repression. Argonaute2 (Ago2) is an essential component of the RNA-induced silencing complex (RISC) that plays a central role in silencing mechanisms via small non-coding RNA molecules known as siRNAs and miRNAs. Small RNAs loaded into Argonaute proteins catalyze endoribonucleolytic cleavage of target RNAs or recruit factors responsible for translational silencing and mRNA target destabilization. In previous studies we have shown that KCC2, a neuronal Cl (−) extruding K (+) Cl (−) co-transporter 2, is regulated by miR-92 in neuronal cells. Searching for Ago2 partners by immunoprecipitation and LC-MS/MS analysis, we isolated among other proteins the Serpine mRNA binding protein 1 (SERBP1) from SH-SY5Y neuroblastoma cells. Exploring the role of SERBP1 in miRNA-mediated gene silencing in SH-SY5Y cells and primary hippocampal neurons, we demonstrated that SERBP1 silencing regulates KCC2 expression through the 3′ untranslated region (UTR). In addition, we found that SERBP1 as well as Ago2/miR-92 complex bind to KCC2 3′UTR. Finally, we demonstrated the attenuation of miR-92-mediated repression of KCC2 3′UTR by SERBP1 silenc-ing. These findings advance our knowledge regarding the miR-92-mediated modulation of KCC2 translation in neuronal cells and highlight SERBP1 as a key component of this gene regulation