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Subgenomic mRNA regulation by a distal RNA element in a (+)-strand RNA virus.

Subgenomic (sg) mRNAs are synthesized by (+)-strand RNA viruses to allow for efficient translation of products encoded 3' in their genomes. This strategy also provides a means for regulating the expression of such products via modulation of sg mRNA accumulation. We have studied the mechanism by which sg mRNAs levels are controlled in tomato bushy stunt virus, a small (+)-strand RNA virus which synthesizes two sg mRNAs during infections. Neither the viral capsid nor movement proteins were found to play any significant role in modulating the accumulation levels of either sg mRNA. Deletion analysis did, however, identify a 12-nt-long RNA sequence located approximately 1,000 nt upstream from the site of initiation of sg mRNA2 synthesis that was required specifically for accumulation of sg mRNA2. Further analysis revealed a potential base-pairing interaction between this sequence and a sequence located just 5' to the site of initiation for sg mRNA2 synthesis. Mutant genomes in which this interaction was either disrupted or maintained were analyzed and the results indicated a positive correlation between the predicted stability of the base-pairing interaction and the efficiency of sg mRNA2 accumulation. The functional significance of the long-distance interaction was further supported by phylogenetic sequence analysis which revealed conservation of base-pairing interactions of similar stability and relative position in the genomes of different tombusviruses. It is proposed that the upstream sequence represents a cis-acting RNA element which facilitates sg mRNA accumulation by promoting efficient synthesis of sg mRNA2 via a long-distance RNA-RNA interaction.

Amino Acid Sequence↗

The structural characterization and antigenicity of the S protein of SARS-CoV.

The corona-like spikes or peplomers on the surface of the virion under electronic microscope are the most striking features of coronaviruses. The S (spike) protein is the largest structural protein, with 1,255 amino acids, in the viral genome. Its structure can be divided into three regions: a long N-terminal region in the exterior, a characteristic transmembrane (TM) region, and a short C-terminus in the interior of a virion. We detected fifteen substitutions of nucleotides by comparisons with the seventeen published SARS-CoV genome sequences, eight (53.3%) of which are non-synonymous mutations leading to amino acid alternations with predicted physiochemical changes. The possible antigenic determinants of the S protein are predicted, and the result is confirmed by ELISA (enzyme-linked immunosorbent assay) with synthesized peptides. Another profound finding is that three disulfide bonds are defined at the C-terminus with the N-terminus of the E (envelope) protein, based on the typical sequence and positions, thus establishing the structural connection with these two important structural proteins, if confirmed. Phylogenetic analysis reveals several conserved regions that might be potent drug targets.

Amino Acid Sequence↗

Family and parenting interventions in children and adolescents with conduct disorder and delinquency aged 10-17.

BACKGROUND: Conduct disorder and delinquency are significant problems for children and adolescents and their families, with the potential to consume much of the resources of the health, social care and juvenile justice systems. A number of family and parenting interventions have been recommended and are used for these conditions. The aim of this review was to determine if these interventions are effective in the management of conduct disorder and delinquency in children and adolescents, aged 10-17. OBJECTIVES: To determine if family and parenting interventions improve the child/adolescent's behaviour; parenting and parental mental health; family functioning and relations; and have an effect on the long term psychosocial outcomes for the child/adolescent. SEARCH STRATEGY: Randomised controlled trials were identified through searching the Cochrane Controlled Trial Register (CCTR), databases (MEDLINE, EMBASE, PsycINFO, CINAHL, Sociofile, ERIC, Healthstar), reference lists of articles and contact with authors. SELECTION CRITERIA: Randomised controlled trials with a major focus on parenting and/or family functioning were eligible for inclusion in the review. Trials needed to include at least one objective outcome measure (e.g. arrest rates) or have used a measure that had been published in peer review publications and validated for the relevant purpose. Studies were required to have a control group, which could be a no intervention group, a wait list group or a usual intervention group (e.g. probation). Trials in children and adolescents aged 10 to 17 years with conduct disorder and/or delinquency and their families were considered. Conduct disorder was defined by a standardised psychological assessment (for example, using a child behaviour checklist), or a psychiatric diagnosis. Delinquency was defined by a referral from a juvenile justice or another legal system for a child/adolescent who has committed a serious crime e.g assault and/or offended on at least two occasions. DATA COLLECTION AND ANALYSIS: Two reviewers independently reviewed all eligible studies for inclusion, assessed study quality (allocation concealment, blinding, follow up, clinically important outcomes) and extracted data. Heterogeneity was assessed using the Chi squared test of heterogeneity along with visual inspection of the data. A significance level less than 0.1 was interpreted as evidence of statistically significant heterogeneity. For data where heterogeneity was found the reviewers looked for an explanation. If studies with heterogeneous results were thought to be comparable the statistical synthesis of the results was done using a random effects model. This model takes into account within-study sampling error and between-studies variation in the assessment of uncertainty and will give wider confidence intervals to the effect size and hence a more conservative result. Sensitivity analysis was performed to explore the effects of the varying quality of the studies included on the results. MAIN RESULTS: Of the nine hundred and seventy titles initially identified through the search strategy, eight trials met the inclusion criteria. A total of 749 children and their families were randomised to receive a family and parenting intervention or to be in a control group. In seven of these studies the participants were juvenile delinquents and their families and in only one the participants were children/adolescents with conduct disorder who had not yet had contact with the juvenile justice system. At follow up, family and parenting interventions significantly reduced the time spent by juvenile delinquents in institutions (WMD 51.34 days, 95%CI 72.52 to 30.16). There was also a significant reduction in the risk of a juvenile delinquent being re arrested (RR 0.66, 95%CI 0.44 to 0.98) and in their rate of subsequent arrests at 1-3 years (SMD -0.56, 95% CI -1.100 to - 0.03). For both of these outcomes there was substantial heterogeneity in the results suggesting a need for caution in interpretation. At present there is insufficient evidence that family and parenting interventions reduce the risk of being incarcerated (RR=0.50, 95% CI 0.20 to 1.21). No significant difference was found for psychosocial outcomes such as family functioning, and child/adolescent behaviour. REVIEWER'S CONCLUSIONS: The evidence suggests that family and parenting interventions for juvenile delinquents and their families have beneficial effects on reducing time spent in institutions. This has an obvious benefit to the participant and their family and may result in a cost saving for society. These interventions may also reduce rates of subsequent arrest but at present these results need to be interpreted with caution due to the heterogeneity of the results.

Adolescent↗

S-fluoxetine in the prophylaxis of migraine: a phase II double-blind randomized placebo-controlled study.

S-fluoxetine is the long-acting enantiomer of the racemic antidepressant serotonin reuptake inhibitor. Sixty-five patients needing migraine prophylaxis were recruited into a phase II, double-blind, placebo-controlled trial. After a 1-month placebo run-in, 53 patients met entry criteria with regard to attack frequency and were randomized, 27 to S-fluoxetine and 26 to matching placebo. Three failed to start treatment and there were 17 early discontinuations, 9 from S-fluoxetine, 8 from placebo, at similar times and for similar reasons. The primary efficacy variable was attack frequency and analysis compared decline-from-baseline in the two groups. This was earlier and greater (1.7 attacks/28 days, or 52%) on active therapy than on placebo (1.1 attacks/28 days, or 27%), and statistically significant in month 2 (F = 4.93; p = 0.033) and month 4 (F = 4.55; p = 0.041). As secondary measures of efficacy, migraine-days per month and Patient's Global Impression of Disease Severity coherently reflected the changes in attack frequency. Mean attack severity and acute medication use (doses per attack) were unaltered by either treatment. There were no serious adverse events. Withdrawals for adverse events were four from each group but none was considered causally related. The finding of greater efficacy of S-fluoxetine than of placebo should be interpreted conservatively, since the analysis in the final month was made on only half of the entered patients. It supports progression to phase III evaluation, which was the purpose of the study.

Adult↗

A model of the molecular structure of toxin III from Anemonia sulcata.

A Chou and Fasman analysis of the Toxin III from Anemonia sulcata reveals that this short polypeptide (27 residues) probably is mostly made up of a nearly continuous beta-turn structure (7 beta-turns). This structure allows only one possible solution of disulfide bond formation (3-23, 4-17, 6-17). The resulting rigid structure has very few degrees of freedom. Molecular models indicate that one side of the molecule bearing tyr(7), trp(8), pro(25), glu(20) and lys(20) is very similar in its three-dimensional structure to that part of the molecule of variant III toxin from Centruroides sculpturatus as revealed by x-ray crystallography, bearing tyr(4), trp(47), gly(3), glu(2) and lys(1), all of which are invariant or allow only very conservative substitutions. This analysis, therefore, suggests a specific conformation for Toxin III.

Amino Acid Sequence↗

Isolation of a cDNA encoding a 70 kDa heat-shock cognate protein expressed in vegetative tissues of Arabidopsis thaliana.

A cDNA encoding a 70 kDa heat shock 'cognate' protein (hsc70) was isolated from Arabidopsis thaliana by using a rat hsc70 cDNA as probe. Sequence analysis demonstrated the conservation of functional domains and important amino acid residues among hsc70s in plants and animals. The expression of this gene was stress-inducible, and was found at a substantial level during normal growth in root, stem, leaf and flower tissues, but not in siliques. Multiple copies of this gene exist in the Arabidopsis genome.

Amino Acid Sequence↗

The Arabidopsis chloroplast ribosomal protein L21 is encoded by a nuclear gene of mitochondrial origin.

Many chloroplast genes of cyanobacterial origin have been transferred to the nucleus during evolution and their products are re-addressed to chloroplasts. The RPL21 gene encoding the plastid r-protein L21 has been lost in higher plant chloroplast genomes after the divergence from bryophytes. Based on phylogenetic analysis and intron conservation, we now provide evidence that in Arabidopsis a nuclear RPL21c gene of mitochondrial origin has replaced the chloroplast gene. The control of expression of this gene has been adapted to the needs of chloroplast development by the acquisition of plastid-specific regulatory promoter cis-elements.

Amino Acid Sequence↗

Genome analysis of a severe and a mild isolate of Papaya ringspot virus-type W found in Brazil.

Papaya ringspot virus-type W (PRSV-W) is one of the most economically threatening viruses of cucurbits in Brazil. Premunization is one of the most effective PRSV control measures currently applied in squash and zucchini crops. PRSV-W-1, a mild and premunizing strain of PRSV has been successfully used to protect cucurbits against both the severe PRSV-W-C strain and other Brazilian PRSVs. To aid in understanding the mechanism by which PRSV-W-1 premunization operates, the complete genome sequences of PRSV-W-1 and PRSV-W-C were determined. PRSV-W-1 had a genome size of 10,332 nucleotides, whereas indels within the coat protein encoding gene meant that the genome size of PRSV-W-C was six nucleotides shorter than that of the mild strain. The genomes of the two strains shared 94.63% nucleotide sequence identity, with the 5' UTR and P1 being the most variable regions, and the coat protein and 3' UTR being the most conserved. Rigorous recombination analysis revealed that neither PRSV-W-1 nor PRSV-W-C was obviously recombinant, there was significant evidence that many other fully sequenced PRSV genomes were recombinant.

Brazil↗

Phenotypic alterations of petal and sepal by ectopic expression of a rice MADS box gene in tobacco.

Floral organ development is controlled by a group of regulatory factors containing the MADS domain. In this study, we have isolated and characterized a cDNA clone from rice, OsMADS3, which encodes a MADS-domain containing protein. The OsMADS3 amino acid sequence shows over 60% identity to AG of Arabidopsis, PLE of Antirrhinum majus, and AG/PLE homologues of petunia, tobacco, tomato, Brassica napus, and maize. Homology in the MADS box region is most conserved. RNA blot analysis indicated that the rice MADS gene was preferentially expressed in reproductive organs, especially in stamen and carpel. In situ localization studies showed that the transcript was present primarily in stamen and carpel. The function of the rice OsMADS3 was elucidated by ectopic expression of the gene under the control of the CaMV 35S promoter in a heterologous tobacco plant system. Transgenic plants exhibited an altered morphology and coloration of the perianth organs. Sepals were pale green and elongated. Limbs of the corolla were split into sections which in some plants became antheroid structures attached to tubes that resembled filaments. The phenotypes mimic the results of ectopic expression of dicot AG gene or AG homologues. These results indicate that the OsMADS3 gene is possibly an AG homologue and that the AG genes appear to be structurally and functionally conserved between dicot and monocot.

Amino Acid Sequence↗

Crystal structure and mechanism of a carbon-carbon bond hydrolase.

BACKGROUND: Fumarylacetoacetate hydrolase (FAH) catalyzes the final step of tyrosine and phenylalanine catabolism, the hydrolytic cleavage of a carbon-carbon bond in fumarylacetoacetate, to yield fumarate and acetoacetate. FAH has no known sequence homologs and functions by an unknown mechanism. Carbon-carbon hydrolysis reactions are essential for the human metabolism of aromatic amino acids. FAH deficiency causes the fatal metabolic disease hereditary tyrosinemia type I. Carbon-carbon bond hydrolysis is also important in the microbial metabolism of aromatic compounds as part of the global carbon cycle. RESULTS: The FAH crystal structure has been determined by rapid, automated analysis of multiwavelength anomalous diffraction data. The FAH polypeptide folds into a 120-residue N-terminal domain and a 300-residue C-terminal domain. The C-terminal domain defines an unusual beta-strand topology and a novel 'mixed beta-sandwich roll' structure. The structure of FAH complexed with its physiological products was also determined. This structure reveals fumarate binding near the entrance to the active site and acetoacetate binding to an octahedrally coordinated calcium ion located in close proximity to a Glu-His dyad. CONCLUSIONS: FAH represents the first structure of a hydrolase that acts specifically on carbon-carbon bonds. FAH also defines a new class of metalloenzymes characterized by a unique alpha/beta fold. A mechanism involving a Glu-His-water catalytic triad is suggested based on structural observations, sequence conservation and mutational analysis. The histidine imidazole group is proposed to function as a general base. The Ca(2+) is proposed to function in binding substrate, activating the nucleophile and stabilizing a carbanion leaving group. An oxyanion hole formed from sidechains is proposed to stabilize a tetrahedral alkoxide transition state. The proton transferred to the carbanion leaving group is proposed to originate from a lysine sidechain. The results also reveal the molecular basis for mutations causing the hereditary tyrosinemia type 1.

Amino Acids↗

Genomic imprinting, methylation and molecular evolution of maize Enhancer of zeste (Mez) homologs.

Imprinted gene expression refers to differential transcription of alleles depending on their parental origin. To date, most examples of imprinted gene expression in plants occur in the triploid endosperm tissue. The Arabidopsis gene MEDEA displays an imprinted pattern of gene expression and has homology to the Drosophila Polycomb group (PcG) protein Enhancer-of-zeste (E(z)). We have tested the allele-specific expression patterns of the three maize E(z)-like genes Mez1, Mez2 and Mez3. The expression of Mez2 and Mez3 is not imprinted, with a bi-allelic pattern of transcription for both genes in both the endosperm and embryonic tissue. In contrast, Mez1 displays a bi-allelic expression pattern in the embryonic tissue, and a mono-allelic expression pattern in the developing endosperm tissue. We demonstrate that mono-allelic expression of the maternal Mez1 allele occurs throughout endosperm development. We have identified a 556 bp differentially methylated region (DMR) located approximately 700 bp 5' of the Mez1 transcription start site. This region is heavily methylated at CpG and CpNpG nucleotides on the non-expressed paternal allele but has low levels of methylation on the expressed maternal allele. Molecular evolutionary analysis indicates that conserved domains of all three Mez genes are under purifying selection. The common imprinted expression of Mez1 and MEDEA, in concert with their likely evolutionary origins, suggests that there may be a requirement for imprinting of at least one E(z)-like gene in angiosperms.

Alleles↗

Functional network analysis reveals extended gliomagenesis pathway maps and three novel MYC-interacting genes in human gliomas.

Gene expression profiling has proven useful in subclassification and outcome prognostication for human glial brain tumors. The analysis of biological significance of the hundreds or thousands of alterations in gene expression found in genomic profiling remains a major challenge. Moreover, it is increasingly evident that genes do not act as individual units but collaborate in overlapping networks, the deregulation of which is a hallmark of cancer. Thus, we have here applied refined network knowledge to the analysis of key functions and pathways associated with gliomagenesis in a set of 50 human gliomas of various histogenesis, using cDNA microarrays, inferential and descriptive statistics, and dynamic mapping of gene expression data into a functional annotation database. Highest-significance networks were assembled around the myc oncogene in gliomagenesis and around the integrin signaling pathway in the glioblastoma subtype, which is paradigmatic for its strong migratory and invasive behavior. Three novel MYC-interacting genes (UBE2C, EMP1, and FBXW7) with cancer-related functions were identified as network constituents differentially expressed in gliomas, as was CD151 as a new component of a network that mediates glioblastoma cell invasion. Complementary, unsupervised relevance network analysis showed a conserved self-organization of modules of interconnected genes with functions in cell cycle regulation in human gliomas. This approach has extended existing knowledge about the organizational pattern of gene expression in human gliomas and identified potential novel targets for future therapeutic development.

Adult↗

Molecular characterization of vitellogenin and its receptor with CRISPR-based sgRNA validation in the legume pod borer, Maruca vitrata (Geyer) (Lepidoptera: Crambidae).

Maruca vitrata, the legume pod borer, causes yield losses of up to 80% in grain legumes. Increasing insecticide resistance and environmental concerns necessitate sustainable pest management alternatives. In the present study, the complete vitellogenin (Vg) coding sequence (CDS), a key reproductive gene involved in oogenesis and embryonic development, was cloned and molecularly characterised from M. vitrata. The assembled Vg CDS (∼5.3 kb) shared 99.04% sequence identity with the reported M. vitrata Vg sequence (MG799570.1). Phylogenetic analysis demonstrated close evolutionary association with related Lepidopteran species, while protein domain analysis identified three conserved domains, namely LPD_N, DUF1943, and VWD. Among these, the single exon-encoded LPD_N domain was selected as the target region for CRISPR/Cas9-mediated editing. Homology models of Vg and vitellogenin receptor (VgR) (Global Model Quality Estimation (GMQE): 0.58 and 0.51) showed a favourable interaction by protein-protein docking (score: -295.66). Three single-guide RNAs (sgRNAs) were designed, synthesised through in-vitro transcription, and evaluated using in vitro cleavage assays. sgRNA1 targeting the LPD_N domain and sgRNA2 targeting the signal peptide region exhibited efficient site-specific cleavage activity, whereas sgRNA3 failed to induce cleavage because of an unfavourable secondary structure that likely impaired Cas9-sgRNA complex formation. Overall, this study provides the first CRISPR-oriented functional characterisation and sgRNA validation of the M. vitrata Vg gene, together with structural characterisation of VgR and Vg-VgR interaction analysis, providing preliminary molecular resources for future CRISPR/Cas9 studies and supporting future embryo microinjection and heritable genome editing for sustainable management of M. vitrata.

CRISPR/Cas9↗

An autonomous N-terminal transactivation domain in Fos protein plays a crucial role in transformation.

To date, three functional domains have been defined in c-Fos and v-Fos proteins and have been shown to play a role in transactivation: the leucine zipper mediating hetero-dimerization, the basic DNA contact site, and a C-terminally located transactivation domain (C-TA) harbouring the HOB1 and HOB2 motifs. While the bZip region, consisting of the leucine zipper and the DNA contact site, is indispensable for transformation, the C-TA domain is not required and is actually altered by internal deletions in the FBR-MuSV. We now show that the N-terminal regions of c-Fos and v-Fos contain a second transactivation domain (N-TA). A functionally crucial motif within the N-TA domain, termed NTM, was pinpointed to a approximately 25 amino acid stretch around positions 60-84 which is highly conserved in FosB. Analysis of LexA fusion proteins showed that the N-TA domains of both c-Fos and FosB function in an autonomous fashion in both fibroblasts and yeast. Most importantly, deletion of the NTM motif impairs the transforming properties of v-Fos. Apart from the bZip region, the N-TA domain is the only functional domain required for transformation by v-Fos, at least when its expression is driven by the strong FBR-MuSV-LTR promoter.

3T3 Cells↗

Molecular identification of adenoviruses in clinical samples by analyzing a partial hexon genomic region.

Here we present a system for adenovirus detection and genotyping based on PCR amplification and phylogenetic analysis of a conserved hexon gene fragment. The system was validated using 157 sequences (86 previously typed and 71 clinical samples) and correctly identified species and serotype in 100% and 84% of sequences, respectively. Known associations between specific serotypes and clinical syndromes are verified. Possible new associations are described to allow further independent testing.

Adenovirus Infections, Human↗

The mechanism of membrane targeting of human sphingosine kinase 1.

Sphingosine 1-phosphate is a bioactive sphingolipid that regulates cell growth and suppresses programmed cell death. The biosynthesis of sphingosine 1-phosphate is catalyzed by sphingosine kinase (SK) but the mechanism by which the subcellular localization and activity of SK is regulated in response to various stimuli is not fully understood. To elucidate the origin and structural determinant of the specific subcellular localization of SK, we performed biophysical and cell studies of human SK1 (hSK1) and selected mutants. In vitro measurements showed that hSK1 selectively bound phosphatidylserine over other anionic phospholipids and strongly preferred the plasma membrane-mimicking membrane to other cellular membrane mimetics. Mutational analysis indicates that conserved Thr54 and Asn89 in the putative membrane-binding surface are essential for lipid selectivity and membrane targeting both in vitro and in the cell. Also, phosphorylation of Ser225 enhances the membrane affinity and plasma membrane selectivity of hSK1, presumably by modulating the interaction of Thr54 and Asn89 with the membrane. Collectively, these studies suggest that the specific plasma membrane localization and activation of SK1 is mediated largely by specific lipid-protein interactions.

Amino Acid Sequence↗

Trends in educational placement and cost-benefit considerations in children with cochlear implants.

OBJECTIVES: To study the effect of cochlear implantation on the use of educational resources by profoundly hearing-impaired children and to determine trends in educational cost vs benefit. DESIGN: Retrospective study and cost-benefit analysis. SETTING: Outpatient pediatric cochlear implant program in an academic institution (The Listening Center at Johns Hopkins University School of Medicine, Baltimore, Md), in collaboration with public schools in Maryland and surrounding states. PATIENTS OR OTHER PARTICIPANTS: School-aged children with profound prelingual hearing impairment without other clearly defined disabilities. Thirty-five children with multiple-channel cochlear prostheses and a comparison group of 10 children without implants from 'total communication' programs in the Maryland public school system. INTERVENTIONS: Multiple-channel cochlear implantation and at least 1 year of a systematic auditory skill development program at the Listening Center, compared with standard educational management of children with conventional amplification. MAIN OUTCOME MEASURES: Classroom placement and number of hours of special educational support used. RESULTS: A correlation was observed between the length of cochlear implant experience and the rate of full-time placement in mainstream classrooms (r = 0.10; P= .04). There was also a negative correlation between the length of implant experience and the number of hours of special educational support used by fully mainstreamed children (Pearson product moment correlation = -0.10; P = .03). Children with greater than 2 years of implant experience were mainstreamed at twice the rate or more of age-matched children with profound hearing loss who did not have implants. They were also placed less frequently in self-contained classrooms and used fewer hours of special education support. A cost-benefit analysis based on conservative estimates of educational expenses from kindergarten to 12th grade shows a cost savings of cochlear implantation and appropriate auditory (re)habilitation that ranges from $30000 to $200000. CONCLUSIONS: Cochlear implantation accompanied by aural (re)habilitation increases access to acoustic information of spoken language, leading to higher rates of mainstream placement in schools and lower dependence on special education support services. The cost savings that results from a decrease in the use of support services indicates an educational cost benefit of cochlear implant (re)habilitation for many children.

Adolescent↗

Conserved signals in the 5' flanking region of eukaryotic nuclear tRNA genes.

The statistical analysis of 5' flanking regions of eukaryotic tRNA genes was done. The analysis of nucleotides in the sequence of fungi and invertebrates showed a high content of A and T in the flanking regions versus coding regions where G and C dominate. In contrast to these results in vertebrates sequences the preferences of any nucleotide in flanking regions was not observed. The analysis of tetrads showed five conserved signals: TTGT, (T/A)(T/A)ATA, A(C/T)(C/A)A in the tRNA genes of fungi, (A/T)TGA of invertebrates and (A/T)GAG of vertebrates. The analysis of 3' flanking regions did not show any conserved signals except well known poly-T tracks.

Animals↗