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Regulatory RNA (regulatory + rna)
Selected AbstractsMolecular characterization and expression of maternally expressed gene 3 (Meg3/Gtl2) RNA in the mouse inner earJOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2006Shehnaaz S.M. Manji Abstract The pathways responsible for sound perception in the cochlea involve the coordinated and regulated expression of hundreds of genes. By using microarray analysis, we identified several transcripts enriched in the inner ear, including the maternally expressed gene 3 (Meg3/Gtl2), an imprinted noncoding RNA. Real-time PCR analysis demonstrated that Meg3/Gtl2 was highly expressed in the cochlea, brain, and eye. Molecular studies revealed the presence of several Meg3/Gtl2 RNA splice variants in the mouse cochlea, brain, and eye. In situ hybridizations showed intense Meg3/Gtl2 RNA staining in the nuclei of type I spiral ganglion cells and in cerebellum near the dorsal vestibular region of the cochlea. In embryonic mouse head sections, Meg3/Gtl2 RNA expression was observed in the otocyst, brain, eye, cartilage, connective tissue, and muscle. Meg3/Gtl2 RNA expression increased in the developing otocyst and localized to the spiral ganglion, stria vascularis, Reissner's membrane, and greater epithelial ridge (GER) in the cochlear duct. RT-PCR analysis performed on cell lines derived from the organ of Corti, representing neural, supporting, and hair cells, showed significantly elevated levels of Meg3/Gtl2 expression in differentiated neural cells. We propose that Meg3/Gtl2 RNA functions as a noncoding regulatory RNA in the inner ear and that it plays a role in pattern specification and differentiation of cells during otocyst development, as well as in the maintenance of a number of terminally differentiated cochlear cell types. © 2005 Wiley-Liss, Inc. [source] RivR and the small RNA RivX: the missing links between the CovR regulatory cascade and the Mga regulonMOLECULAR MICROBIOLOGY, Issue 6 2007Samantha A. Roberts Summary The CovR/S two-component system regulates the transcription of many genes that are crucial for the virulence of Streptococcus pyogenes (group A Streptococcus, GAS). Previously, we demonstrated that one gene repressed directly by CovR is rivR, which encodes a member of the RofA-like family of transcriptional regulators. In this study, we deleted rivR and its downstream gene rivX in a ,covR background. Microarray analysis revealed that the products of the rivRX locus exert positive control over the transcription of members of the Mga regulon. Using mutational analysis, we established that rivX encodes a small regulatory RNA. We found that RivR enhances transcriptional activation by Mga in vivo and in vitro. An M1 ,covR,rivRX strain is attenuated for virulence in a murine model of invasive soft tissue infection and this attenuation is complemented by rivRX expressed from a plasmid, demonstrating the importance of the rivRX locus in pathogenesis. This study provides the first link between the CovR and Mga regulatory networks. By integrating the signals received through these two global regulators, GAS is able to select from its repertoire different combinations of specific virulence factors to express in response to a broad spectrum of environmental conditions. [source] Biochemical and molecular responses to water stress in resurrection plantsPHYSIOLOGIA PLANTARUM, Issue 2 2004Giovanni Bernacchia A small group of angiosperms, known as resurrection plants, can tolerate extreme dehydration. They survive in arid environments because they are able to dehydrate, remain quiescent during long periods of drought, and then resurrect upon rehydration. Dehydration induces the expression of a large number of transcripts in resurrection plants. Gene products with a putative protective function such as LEA proteins have been identified; they are expressed at high levels in the cytoplasm or in chloroplasts upon dehydration and/or ABA treatment of vegetative tissue. An increase in sugar concentration is usually observed at the onset of desiccation in vegetative tissue of resurrection plants. These sugars may be effective in osmotic adjustment or they may stabilize membrane structures and proteins. Regulatory genes such as a protein translation initiation factor, homeodomain-leucine zipper genes and a gene probably working as a regulatory RNA have been isolated and characterized. The knowledge of the biochemical and molecular responses that occur during the onset of drought may help to improve water stress tolerance in plants of agronomic importance. [source] Current knowledge of microRNA characterization in agricultural animalsANIMAL GENETICS, Issue 3 2010H.-C. Liu Summary MicroRNA (miRNA) is a class of single-stranded small (19,24nt) regulatory RNA that silences gene expression post-transcriptionally. miRNAs regulate a wide range of biological processes through the recognition of complementary sequences between miRNAs and their target genes. Profiling studies in livestock have revealed that many miRNAs are species- and tissue-specific, indicating that miRNAs play important roles in essential biological processes in livestock, such as muscle and organ development, the immune response and metabolism. The allelic variation of miRNA target sites and possibly in miRNAs themselves are also likely to be contributing factors to many phenotypic differences in livestock. In this review, we summarize the current miRNA studies undertaken in livestock. [source] Transcriptional regulation of the methionine and cysteine transport and metabolism in streptococciFEMS MICROBIOLOGY LETTERS, Issue 2 2007Galina Yu Kovaleva Abstract In streptococci, unlike other Firmicutes, methionine biosynthesis is controlled by protein transcription factors, rather than regulatory RNAs. It was observed that most available streptococcal genomes contain orthologs of two transcriptional regulators of the LysR family: MtaR/MetR and CmbR/FhuR. Comparative genomics techniques were applied to identify two binding motifs occurring upstream of genes involved in metabolism and transport of methionine and cysteine and satisfying the LysR family requirements. The distribution of candidate binding sites allowed to set the correspondence between motifs and regulators (TATAGTTTnAAACTATA for MtaR/MetR and TGATA-N9 -TATCA-N2,4 -TGATA for CmbR). Two amino acid transporters were predicted to belong to the cysteine (CmbR) regulon. At least two cases of potential regulator change were observed for orthologous genes of the methionine and cysteine pathway. [source] Remodelling of the Escherichia coli outer membrane by two small regulatory RNAsMOLECULAR MICROBIOLOGY, Issue 1 2006Maude Guillier Summary Small non-coding RNAs that play important regulatory roles exist in numerous organisms. In Escherichia coli, about 60 small RNAs have been found and those that have been studied are involved in the response and adaptation to different stresses. RygA and RygB, two of these small RNAs, were identified on the basis of their conservation between different species and their ability to bind Hfq. They are adjacent on the chromosome and have sequence similarity at their 5, and 3, ends but distinct central regions, suggesting that they could regulate the expression of both common and distinct genes. A screen using a multicopy E. coli library led to identification of the response regulator OmpR and its associated sensor kinase EnvZ as positive regulators of rygA and rygB transcription. Therefore, RygA and RygB were renamed OmrA and OmrB respectively (for OmpR- regulated sRNAs A and B). When expressed at high levels, OmrA and OmrB RNAs negatively regulate the expression of several genes encoding multiple outer membrane proteins, including cirA, fecA, fepA and ompT. Taken together, these data suggest that OmrA and OmrB participate in the regulation of outer membrane composition in response to environmental conditions. [source] Identification of target genes and pathways associated with chicken microRNA miR-143ANIMAL GENETICS, Issue 4 2010N. Trakooljul Summary MicroRNA (miRNA) is a family of small regulatory RNAs that post-transcriptionally regulate many biological functions including growth and development. Recently, the expression of chicken miRNA miR-143 was identified by using a deep sequencing approach. In other vertebrate species, miR-143 functions as a regulator of adipocyte differentiation and as a tumour suppressor. However, little is known about the biological function(s) of miR-143 in chickens. To study the functions of chicken miR-143, DNA microarray analysis and a dual luciferase reporter assay were employed to identify genes directly targeted by miR-143 as well as other biologically relevant genes. Microarray analysis indicated that 124 genes were differentially expressed upon in vitro anti- miR-143 treatment in embryonic chick splenocytes (P -value cutoff <0.01). Many of these genes are associated with cell proliferation, apoptosis and tumourigenesis. Six of the up-regulated genes possess at least one potential miR-143 binding site in their 3,UTRs, of these the binding sites of PYCR2, PSTPIP1 and PDCD5 were validated by an in vitro luciferase reporter assay. In addition, several potential targets with important biological functions were identified by the miRanda algorithm and experimentally confirmed. These targets include KLF5, MAP3K7, TARDBP and UBE2E3, which have conserved miR-143 binding sites across multiple vertebrate species. Potential chicken specific miR-143 target sites were also validated for LPIN1, PCK2, PYCR2, METTL14, SLC2A2 and TNFSF10. Overall, the current study suggests that miR-143 is ubiquitously expressed among tissues and is likely to be involved in the regulation of cell proliferation and apoptosis. [source] | ||||||||||