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1.
Chinese Journal of Biotechnology ; (12): 775-783, 2019.
Article in Chinese | WPRIM | ID: wpr-771332

ABSTRACT

Messenger RNA (mRNA) can be modified by more than 100 chemical modifications. Among these modifications, N6-methyladenosine (m⁶A) is one of the most prevalent modifications. During the processes of cells differentiation, embryo development or stress, m⁶A can be modified on key mRNAs and regulate the progress of cells through modulating mRNA metabolism and translation. Other mRNA modifications, including N1-methyladenosine (m¹A), 5-methylcytosine (m⁵C) and pseudouridine, together with m⁶A form the epitranscriptome of mRNA that accurately modulate the mRNA translation. Here we review the types and characteristic of mRNA epigenetic modifications, especially the recent progresses of the function of m⁶A, we also expect the main research direction of m⁶A epigenetic modification in the future.


Subject(s)
Adenosine , Genetics , Metabolism , Cell Differentiation , Genetics , Embryonic Development , Genetics , Epigenesis, Genetic , Gene Expression Regulation , RNA Processing, Post-Transcriptional , RNA, Messenger , Metabolism
2.
Frontiers of Medicine ; (4): 481-489, 2018.
Article in English | WPRIM | ID: wpr-771290

ABSTRACT

N-methyladenosine (mA) is the most common post-transcriptional RNA modification throughout the transcriptome, affecting fundamental aspects of RNA metabolism. mA modification could be installed by mA "writers" composed of core catalytic components (METTL3/METTL14/WTAP) and newly defined regulators and removed by mA "erasers" (FTO and ALKBH5). The function of mA is executed by mA "readers" that bind to mA directly (YTH domain-containing proteins, eIF3 and IGF2BPs) or indirectly (HNRNPA2B1). In the past few years, advances in mA modulators ("writers," "erasers," and "readers") have remarkably renewed our understanding of the function and regulation of mA in different cells under normal or disease conditions. However, the mechanism and the regulatory network of mA are still largely unknown. Moreover, investigations of the mA physiological roles in human diseases are limited. In this review, we summarize the recent advances in mA research and highlight the functional relevance and importance of mA modification in in vitro cell lines, in physiological contexts, and in cancers.


Subject(s)
Adenosine , Metabolism , Cell Differentiation , Physiology , Humans , Neoplasms , Metabolism , RNA , Metabolism , RNA Processing, Post-Transcriptional
3.
Biol. Res ; 50: 22, 2017. graf
Article in English | LILACS | ID: biblio-950873

ABSTRACT

BACKGROUND: Hypertrophic scarring (HS) is a severe disease, and results from unusual wound healing. Col1A1 could promote the hypertrophic scar formation, and the expression of Col1A1 in HS tissue was markedly higher than that in the normal. In present study, we aimed to identify miRNAs as post-transcriptional regulators of Col1A1 in HS. METHODS: MicroRNA-98 was selected as the key miRNA comprised in HS. The mRNA levels of miR-98 in HS tissues and the matched normal skin tissues were determined by qRT-PCR. MTT and flow cytometry were used to determine the influence of miR-98 on cell proliferation and apoptosis of HSFBs, respectively. Col1A1 was found to be the target gene of miR-98 using luciferase reporter assay. Luciferase assay was performed to determine the relative luciferase activity in mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor with Col1A13'-UTR wt or Col1A13'-UTR mt reporter plasmids. The protein expression of Col1A1 in HSFBs after transfection with mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor were determined by western blotting. RESULTS: The mRNA level of miR-98 in HS tissues was much lower than that in the control. Transfection of HSFBs with a miR-98 mimic reduced the cell viability of HSFBs and increased the apoptosis portion of HSFBs, while inhibition of miR-98 increased cell viability and decreased apoptosis portion of HSFBs. miR-98 inhibitor increased the relative luciferase activity significantly when cotransfected with the Col1A1-UTR reporter plasmid, while the mutant reporter plasmid abolished the miR-98 inhibitor-mediated increase in luciferase activity. Western blotting revealed that overex-pression of miR-98 decreased the expression of Col1A1. CONCLUSIONS: Overexpression of miR-98 repressed the proliferation of HSFBs by targeting Col1A1.


Subject(s)
Humans , RNA Processing, Post-Transcriptional/genetics , Apoptosis/genetics , Collagen Type I/metabolism , MicroRNAs/genetics , Fibroblasts/metabolism , Case-Control Studies , Down-Regulation , Cicatrix, Hypertrophic/genetics , Cicatrix, Hypertrophic/metabolism , Collagen Type I/genetics , MicroRNAs/metabolism , Cell Proliferation
4.
Protein & Cell ; (12): 100-113, 2016.
Article in English | WPRIM | ID: wpr-757185

ABSTRACT

The let-7 miRNA was one of the first miRNAs discovered in the nematode, Caenorhabditis elegans, and its biological functions show a high level of evolutionary conservation from the nematode to the human. Unlike in C. elegans, higher animals have multiple isoforms of let-7 miRNAs; these isoforms share a consensus sequence called the 'seed sequence' and these isoforms are categorized into let-7 miRNA family. The expression of let-7 family is required for developmental timing and tumor suppressor function, but must be suppressed for the self-renewal of stem cells. Therefore, let-7 miRNA biogenesis must be carefully controlled. To generate a let-7 miRNA, a primary transcript is produced by RNA polymerase II and then subsequently processed by Drosha/DGCR8, TUTase, and Dicer. Because dysregulation of let-7 processing is deleterious, biogenesis of let-7 is tightly regulated by cellular factors, such as the RNA binding proteins, LIN28A/B and DIS3L2. In this review, we discuss the biological functions and biogenesis of let-7 miRNAs, focusing on the molecular mechanisms of regulation of let-7 biogenesis in vertebrates, such as the mouse and the human.


Subject(s)
Animals , Base Sequence , Gene Expression Regulation , Humans , MicroRNAs , Chemistry , Genetics , Metabolism , RNA Processing, Post-Transcriptional , RNA Stability , Transcription, Genetic
5.
Article in Chinese | WPRIM | ID: wpr-291613

ABSTRACT

<p><b>OBJECTIVE</b>To put the insight into the trichloroethylene (TCE)-induced effect on the differential expression of subcellular proteins in human normal liver cell line (L-02).</p><p><b>METHODS</b>The membrane proteins and nuclear proteins of TCE-treated (8.0 mmol/L) group and controls were extracted by subcellular proteome extraction kit, respectively. The TCE-induced differentially expressions were analyzed by a two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization tandem time-of-flight spectrometry (MALDI-TOF-MS). Bioinformatics analysis was used to reveal the biological processes and predict transmembrane domains of differential expressed proteins. The expression of ATP synthase subunit beta (ATP5B), heterogeneous nuclear ribonucleoprotein H2 (hnRNP H2) and far up steam element-binding protein 1 (FUBP1) were measured under TCE treatment by Western blot.</p><p><b>RESULTS</b>After TCE treatment for 24 h in L-02 cells, 14 membrane proteins and 18 nuclear proteins were identified as differential expression. After treated with TCE in concentrations of 0, 2.0, 4.0 and 8.0 mmol/L for 24 h, the relative levels of ATP5B expression were 1.00±0.03, 1.21±0.14, 1.25±0.12 and 1.48±0.17 (F = 8.51, P = 0.007), the relative levels of hnRNP H2 expression were 1.00±0.09, 1.22±0.15, 1.43±0.21, 1.53±0.17 (F = 6.57, P = 0.015), respectively; the relative levels of FUBP1 expression were 1.00±0.11, 0.91±0.07, 0.73±0.04 and 0.67±0.03 (F = 15.81, P = 0.001), respectively, which were consistent with the results in proteomics. The bioinformatics analysis showed that the most dominant biological process were involved in RNA processing (10 proteins, P = 2.46×10(-6)), especially in RNA splicing (9 proteins, P = 1.77×10(-7)).</p><p><b>CONCLUSION</b>The exposure of TCE could alter the expression of membrane proteins and nuclear proteins in L-02 cells. These abnormal expressed proteins involved in RNA splicing would provide novel clues for further understanding of TCE-induced hepatotoxicity.</p>


Subject(s)
Blotting, Western , Cell Line , DNA Helicases , DNA-Binding Proteins , Hepatocytes , Heterogeneous-Nuclear Ribonucleoprotein Group F-H , Humans , Mitochondrial Proton-Translocating ATPases , Proteome , Proteomics , RNA Processing, Post-Transcriptional , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Trichloroethylene
6.
Article in English | WPRIM | ID: wpr-183085

ABSTRACT

A growing body of evidence suggests that epigenetic modifications are promising potential mechanisms in cancer research. Among the molecules that mediate epigenetic mechanisms, histone deacetylases (HDACs) are critical regulators of gene expression that promote formation of heterochromatin by deacetylating histone and non-histone proteins. Aberrant regulation of HDACs contributes to malignant transformation and progression in a wide variety of human cancers, including hepatocellular carcinoma (HCC), gastric cancer, lung cancer, and other cancers. Thus, the roles of HDACs have been extensively studied because of their potential as therapeutic targets. However, the underlying mechanism leading to deregulation of individual HDACs remains largely unknown. Some reports have suggested that functional microRNAs (miRNAs) modulate epigenetic effector molecules including HDACs. Here, we describe the oncogenic or tumor suppressive functions of HDAC families and their regulatory miRNAs governing HDAC expression in hepatocarcinogenesis.


Subject(s)
Carcinogenesis/genetics , Carcinoma, Hepatocellular/genetics , Epigenesis, Genetic/genetics , Gene Expression Regulation, Neoplastic/genetics , Histone Deacetylases/genetics , Histones/metabolism , Humans , Liver Neoplasms/genetics , MicroRNAs/genetics , RNA Processing, Post-Transcriptional/genetics , Tumor Suppressor Proteins/genetics
7.
Indian J Exp Biol ; 2014 Jun; 52(6): 579-588
Article in English | IMSEAR | ID: sea-153736

ABSTRACT

The interaction of a newly synthesized antitumor complex cis-dichloro-1,2-propylenediamine-N,N,N',N'-tetraacetato ruthenium (III) (RAP) with DNA was investigated in vitro through a number of techniques including comet assay, immunoprecipitation, and immunolocalization of certain nucleolar proteins (the upstream binding factor (UBF) and fibrillarin) involved in DNA transcription, rRNA processing, and ribosomal assembly. The results showed that RAP binds to the DNA of two cell lines (H4 and Hs-683) causing a delay in cell proliferation rate leading to a number of cellular modifications. These modifications include DNA-damage assessed by the single cell gel electrophoresis method (comet assay) and variation in the expression of nucleolar proteins; UBF was more abundant in RAP treated cells, this was explained by the high affinity of this protein to DNA modified by RAP. On the other hand, fibrillarin was found in less quantities in RAP treated cells which was explained by a de-regulation of the ribosomal machinery caused by RAP.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Line, Tumor , DNA Damage , Drug Evaluation, Preclinical , Humans , Nuclear Proteins/metabolism , Organometallic Compounds/pharmacology , Protein Transport/drug effects , RNA Processing, Post-Transcriptional/drug effects , Tissue Distribution/drug effects , Transcription, Genetic/drug effects
8.
Biomédica (Bogotá) ; 34(supl.1): 41-49, abr. 2014. ilus, tab
Article in English | LILACS | ID: lil-712420

ABSTRACT

Introduction: Aminoglycosides like streptomycin are well-known for binding at specific regions of ribosome RNA and then acting as translation inhibitors. Nowadays, several pathogens have been detected to acquire an undefined strategy involving mutation at non structural ribosome genes like those acting as RNA methylases. rsmG is one of those genes which encodes an AdoMet-dependent methyltransferase responsible for the synthesis of m 7 G527 in the 530 loop of bacterial 16S rRNA. This loop is universally conserved, plays a key role in ribosomal accuracy, and is a target for streptomycin binding. Loss of the m 7 G527 modification confers low-level streptomycin resistance and may affect ribosomal functioning. Objectives: After taking into account genetic information indicating that some clinical isolates of human pathogens show streptomycin resistance associated with mutations at rsmG , we decided to explore new hot spots for mutation capable of impairing the RsmG in vivo function and of promoting low-level streptomycin resistance. Materials and methods: To gain insights into the molecular and genetic mechanism of acquiring this aminoglycoside resistance phenotype and the emergence of high-level streptomycin resistance in rsmG mutants, we mutated Escherichia coli rsmG and also performed a genotyping study on rpsL from several isolates showing the ability to grow at higher streptomycin concentrations than parental strains. Results: We found that the mutations at rpsL were preferentially present in these mutants, and we observed a clear synergy between rsmG and rpsL genes to induce streptomycin resistance. Conclusion: We contribute to understand a common mechanism that is probably transferable to other ribosome RNA methylase genes responsible for modifications at central sites for ribosome function.


Introducción. Los aminoglucósidos son moléculas antibióticas capaces de inhibir la síntesis de proteínas bacterianas tras su unión al ribosoma procariota. La resistencia a aminoglucósidos está clásicamente asociada a mutaciones en genes estructurales del ribosoma bacteriano; sin embargo, varios estudios recientes han demostrado, de forma recurrente, la presencia de un nuevo mecanismo dependiente de mutación que no involucra genes estructurales. El gen rsmG es uno de ellos y se caracteriza por codificar una metiltransferasa que sintetiza el nucleósido m 7 G527 localizado en el loop 530 del ribosoma bacteriano, este último caracterizado como sitio preferencial al cual se une la estreptomicina. Objetivo. Partiendo de las recientes asociaciones clínicas entre las mutaciones en el gen rsmG y la resistencia a estreptomicina, este estudio se propuso la caracterización de nuevos puntos calientes de mutación en este gen que puedan causar resistencia a estreptomicina usando Escherichia coli como modelo de estudio. Materiales y métodos. Se indagó sobre el mecanismo genético y molecular por el cual se adquiere la resistencia a estreptomicina y su transición a la resistencia a altas dosis mediante mutagénesis dirigida del gen rsmG y genotipificación del gen rpsL . Resultados. Se encontró que la mutación N39A en rsmG inactiva la proteína y se reportó un nuevo conjunto de mutaciones en rpsL que confieren resistencia a altas dosis de estreptomicina. Conclusiones. Aunque los mecanismos genéticos subyacentes permanecen sin esclarecer, se concluyó que dichos patrones secuenciales de mutación podrían tener lugar en otros genes modificadores del ARN bacteriano debido a la conservación evolutiva y al papel crítico que juegan tales modificaciones en la síntesis de proteínas.


Subject(s)
Aminoglycosides/pharmacology , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Escherichia coli Proteins/genetics , Mutation, Missense , Methyltransferases/genetics , Point Mutation , RNA Processing, Post-Transcriptional/genetics , RNA, Bacterial/metabolism , /metabolism , Streptomycin/pharmacology , Amino Acid Sequence , Binding Sites/genetics , Catalytic Domain/genetics , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/metabolism , Escherichia coli/drug effects , Escherichia coli/enzymology , Methylation , Models, Molecular , Molecular Sequence Data , Methyltransferases/chemistry , Methyltransferases/metabolism , Phylogeny , Protein Conformation , RNA, Bacterial/genetics , /genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolism , S-Adenosylmethionine/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Deletion , Sequence Homology, Amino Acid
9.
ABCS health sci ; 38(3): 153-161, set.-dez. 2013.
Article in Portuguese | LILACS | ID: lil-698570

ABSTRACT

A principal e mais conhecida função plaquetária ainda está relacionada à parada de sangramento após um dano vascular. No entanto, plaquetas estão envolvidas em diversos processos, tais como iniciar e amplificar a inflamação, interagir com células da resposta imune, além de participar na progressão tumoral, angiogênese e metástase. Neste sentido, está claro que plaquetas apresentam funções no processo inflamatório e podem influenciar respostas imune, além de desordens plaquetárias autoimune erelacionadas a presença de auto-anticorpos após transfusões, comopor exemplo, na lesão pulmonar aguda associada à transfusão. Após muita especulação, recentes observações têm estabelecido novos paradigmas relacionando plaquetas à biologia molecular. Plaquetas humanas contêm fatores de spliceossomo, incluindo pequenos RNAs nucleares, proteínas de splicing e pre-mRNA endógenos. Outro ponto importante é o controle do número de plaquetas circulantes, resultado do equilíbrio entre a produção e destruição dessas células. Assim, é proposto um processo de morte programada da célula anucleada que determina seu tempo de vida. Esse processo é alvo de especulações desde a década de 60 e ainda permanece em discussão. A noção geral de que plaquetas funcionais são importantes para o sucesso de processos hematogênicos corroboram com inovações experimentais e também ligam a processos de interação plaquetas-células tumorais e seu microambiente que regula a progressão maligna. Plaquetas contribuem na sobrevivência e disseminação de células tumorais. Desta forma, discutimos aqui os mecanismos pelos quais as plaquetas atuam na imunidade, na inflamação e no câncer, uma vez que estas pequenas células são mais versáteis do que se pensava.


The principal and the most known function of platelets still remains stopping hemorrhage following vascular injury. However, platelets are involved in diverse processes such as triggering inflammation, participating in the immune response, besides tumor progression, angiogenesis, and metastasis. In this sense, it is becoming increasingly clear that platelets display inflammatory functions and can influence both innate and adaptive immune responses, such as autoimmune and alloimmune platelet disorders, and transfusion-related acute lung injury (TRALI). Despite much speculation recent observations have established new paradigms relevant to influence of platelets on molecular biology. Primary human platelets contain essential spliceosome factors including small nuclear RNAs, splicing proteins, and endogenous pre-mRNAs. Other point is, like all lineages of blood cells, the steady state number of mature platelets is the result of a balance between their production and destruction. Thus, it isproposed a programmed anuclear cell death delimits platelet lifespan is subject of speculation since the 1960s and has remainedelusive. The general notion that functional platelets are importantfor successful hematogenous tumor metastasis dates more than 4 decades and has been corroborated in numerous experimentalsettings. The dynamic crosstalk between tumors and their microenvironment is increasingly recognized as a key regulator ofmalignant progression. These contributions of platelets to tumorcell survival and spread suggest platelets as a new avenue forresearch. Here, we discuss the mechanisms by which plateletscontribute to immunity, inflammation, and cancer, since thesesmall cells are more versatile than we once thought.


Subject(s)
Humans , Male , Female , Hemostasis , Inflammation , Neoplasms , Blood Platelets , RNA Processing, Post-Transcriptional , Blood Transfusion , Molecular Biology
10.
Mem. Inst. Oswaldo Cruz ; 107(8): 1076-1079, Dec. 2012. ilus, tab
Article in English | LILACS | ID: lil-660661

ABSTRACT

To characterise the trypanosomatid-exclusive RNA-binding protein TcRBP19, we analysed the phenotypic changes caused by its overexpression. Although no evident changes were observed when TcRBP19 was ectopically expressed in epimastigotes, the metacyclogenesis process was affected. Notably, TcRBP19 overexpression also led to a decrease in the number of infected mammalian cells. These findings suggest that TcRBP19 may be involved in the life cycle progression of the Trypanosoma cruzi parasite.


Subject(s)
Animals , Protozoan Proteins/physiology , RNA-Binding Proteins/genetics , Trypanosoma cruzi/genetics , Gene Expression Regulation , Life Cycle Stages , RNA Processing, Post-Transcriptional/genetics , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/physiology , Trypanosoma cruzi/growth & development , Trypanosoma cruzi/metabolism
11.
Article in English | WPRIM | ID: wpr-352913

ABSTRACT

TAR DNA binding protein-43(TDP-43) and fused in sarcoma/translocated in liposarcoma protein (FUS/TLS) have been found to be associated with two neurodegenerative diseases - amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Mutations in TDP-43 and FUS/TLS lead to abnormal protein expressions, which result in altered RNA processing. The pathological changes of TDP-43 and FUS/TLS-associated ALS and FTD are similar. Although the interactions between ALS and FTD remain unknown, it is speculated that TDP-43 and FUS/TLS-associated neurodegenerative diseases may share similar pathogenesis.


Subject(s)
Amyotrophic Lateral Sclerosis , DNA-Binding Proteins , Genetics , Metabolism , Frontotemporal Dementia , Humans , Mutation , RNA Processing, Post-Transcriptional , RNA-Binding Protein FUS , Genetics , Metabolism
12.
Article in English | IMSEAR | ID: sea-148892

ABSTRACT

Background: The quantitative assays are important tests in the management of patients with HIV-1/AIDS. The important step in developing the assay is the availability of the standard HIV-1 RNA. For this purpose, we optimized in vitro HIV-1 RNA transcription to produce the standard HIV-1 RNA. Methods: The HIV-1 DNA was amplified from pNL43 by PCR using a primer pair that was specific for conserved region of HIV-1 Gag gene. The PCR product was further cloned into pBluescript II KS. The recombinant plasmid was restricted with EcoRI enzyme. Then, the linearized plasmid was used as template for RNA transcription. RT-PCR and PCR were performed simultaneously for confirmation of synthesized RNA fragment. Results: A 115 bp DNA of HIV-1 Gag gene has been cloned into pBluescript II SK with the exact true orientation. The reaction of the RNA transcription was also successfully performed. The RNA transcripts have been confirmed and showed the accuracy of the transcripts. Conclusion: We successfuly constructed the recombinant plasmid containing a conserved region of HIV-1 Gag gene, and the HIV-1 RNA has been transcribed in vitro as well.


Subject(s)
HIV Infections , RNA Processing, Post-Transcriptional
13.
Mem. Inst. Oswaldo Cruz ; 106(3): 257-266, May 2011. ilus
Article in English | LILACS | ID: lil-589032

ABSTRACT

Trypanosoma cruzi, a protozoan parasite that causes Chagas disease, exhibits unique mechanisms for gene expression such as constitutive polycistronic transcription of protein-coding genes, RNA editing and trans-splicing. In the absence of mechanism controlling transcription initiation, organized subsets of T. cruzi genes must be post-transcriptionally co-regulated in response to extracellular signals. The mechanisms that regulate stage-specific gene expression in this parasite have become much clearer through sequencing its whole genome as well as performing various proteomic and microarray analyses, which have demonstrated that at least half of the T. cruzi genes are differentially regulated during its life cycle. In this review, we attempt to highlight the recent advances in characterising cis and trans-acting elements in the T. cruzi genome that are involved in its post-transcriptional regulatory machinery.


Subject(s)
Gene Expression Regulation, Developmental , RNA Processing, Post-Transcriptional , RNA, Messenger , Transcription, Genetic , Trypanosoma cruzi , Genome, Protozoan , Oligonucleotide Array Sequence Analysis , RNA, Protozoan , Trans-Splicing , Trypanosoma cruzi/growth & development
14.
Article in English | IMSEAR | ID: sea-143516

ABSTRACT

The discovery of the mechanism of RNA interference by ds RNA by Prof. Andrew Fire and Prof. Craig Mello in 1998, gave them the Nobel Prize in 2006. This discovery revealed a new mechanism for gene regulation through “gene silencing” at the transcriptional level (TGS) or at the post-transcriptional level (PTGS), which play a key role in many essential cellular processes. Today dsRNA is used as a powerful tool to experimentally elucidate the function of essentially any gene in a cell. The immense impact of the discovery of RNA interference (RNAi) on biomedical research and its novel medical applications in the future are reviewed in this article, with particular stress on therapeutic applications of radio-labeled antisense oligonucleotides (RASONs) for diagnosis and treatment of various cancers and neurodegenerative diseases by “gene silencing”. Antisense oligonucleotides (ASONs) can also modulate alternative splicing which 74% of all human genes undergo. The most effective targeting strategy employs simultaneous blocking SnRNP binding sites and splice junctions. Correction of splicing by ASONs can be used to silence mutations causing aberrant splicing as in thalassemia, Duchenne muscular dystrophy and cystic fibrosis. ©


Subject(s)
Alternative Splicing , Epigenesis, Genetic , Gene Expression , Gene Silencing , Humans , Neurodegenerative Diseases/therapy , Oligonucleotides, Antisense/therapeutic use , RNA Interference , RNA Processing, Post-Transcriptional , RNA Splicing , Respiratory Tract Diseases/therapy
15.
J Genet ; 2008 Dec; 87(5): 505-11
Article in English | IMSEAR | ID: sea-114228

ABSTRACT

MicroRNA (miRNA) is a recently discovered new class of small RNA molecules that have a significant role in regulating gene and protein expression. These small RNAs (approximately 22 nt) bind to 3' untranslated regions (3'UTRs) and induce degradation or repression of translation of their mRNA targets. Hundreds of miRNAs have been identified in various organisms and have been shown to play a significant role in development and normal cell functioning. Recently, a few studies have suggested that miRNAs may be an important regulators of circadian rhythmicity, providing a new dimension (posttranscriptional) of our understanding of biological clocks. Here, we describe the mechanisms of miRNA regulation, and recent studies attempting to identify clock miRNAs and their function in the circadian system.


Subject(s)
Animals , Base Sequence , Biological Clocks/genetics , Circadian Rhythm/genetics , Humans , MicroRNAs/genetics , Models, Biological , Molecular Sequence Data , Nucleic Acid Conformation , Protein Biosynthesis/physiology , RNA Processing, Post-Transcriptional/physiology
16.
Genet. mol. biol ; 28(3,suppl): 496-500, Nov. 2005. ilus, tab, graf
Article in English | LILACS | ID: lil-440461

ABSTRACT

Post-transcriptional gene silencing (PTGS) is a conserved surveillance mechanism that identifies and cleaves double-stranded RNA molecules and their cellular cognate transcripts. The RNA silencing response is actually used as a powerful technique (named RNA interference) for potent and specific inhibition of gene expression in several organisms. To identify gene products in Eucalyptus sharing similarities with enzymes involved in the PTGS pathway, we queried the expressed sequence tag database of the Brazilian Eucalyptus Genome Sequence Project Consortium (FORESTs) with the amino acid sequences of known PTGS-related proteins. Among twenty-six prospected genes, our search detected fifteen assembled sequences encoding products presenting high level of similarity (E value < 10-40) to proteins involved in PTGS in plants and other organisms. We conclude that most of the genes known to be involved in the PTGS pathway are represented in the FORESTs database


Subject(s)
Eucalyptus/genetics , Gene Silencing , Plants/genetics , Databases, Genetic , Expressed Sequence Tags , Genetic Code , RNA Processing, Post-Transcriptional , Sequence Analysis, Protein
17.
Chinese Journal of Hepatology ; (12): 808-810, 2005.
Article in Chinese | WPRIM | ID: wpr-276345

ABSTRACT

<p><b>OBJECTIVE</b>To synthesize highly pure HBV post-transcriptional regulatory element (HPRE) via transcription in vitro by T7 RNA polymerase.</p><p><b>METHODS</b>HPRE gene was amplified by PCR from a template containing HBV complete genomic DNA and cloned into plasmid pGEM-11zf. The cloned DNA sequence was transcribed by T7 RNA polymerase.</p><p><b>RESULTS</b>The construction of HPRE gene recombinant plasmid and production of HPRE via transcription in vitro was successful.</p><p><b>CONCLUSION</b>In vitro transcription by T7 RNA polymerase can be used to synthesize highly pure HPRE.</p>


Subject(s)
DNA-Directed DNA Polymerase , DNA-Directed RNA Polymerases , Hepatitis B virus , Genetics , RNA Processing, Post-Transcriptional , RNA Splicing , RNA-Binding Proteins , Physiology , Transcription, Genetic , Viral Proteins
18.
Chinese Journal of Hepatology ; (12): 156-158, 2003.
Article in Chinese | WPRIM | ID: wpr-344477

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the cleavage activity of two deoxyribozymes targeting at hepatitis C virus (HCV) RNA in vitro and evaluate their prospects of antiviral therapy.</p><p><b>METHODS</b>Two specific sequences containing 5' ...A / U... 3' in HCV 5'-noncoding region and 5'-fragment of C region (5'-NCR-C) were selected as the target sites, and with the active region of 5'GGCTAGCTACAACGA3', two phosphorothioate deoxyribozymes (TDRz) named as TDRz-127 and TDRz1 were synthesized. HCV RNA 5'-NCR-C was transcribed in vitro from plasmid pHCV-neo which was completely linearized with restriction endonuclease Nar I, and its 5'-end phosphoric acid was deleted by calf intestinal alkaline phosphatase (CIP), then radiolabelled with T4 polynucleotide kinase and gamma-32P-ATP. Under the conditions such as pH 7.5 and a 10 mmol/L Mg2+ concentration, TDRz-127 and TDRz1 were separately (a 5 micromol/L final concentration) or combinedly (each 2.5 micromol/L) mixed with the substrate RNA (200 nmol/L). After denaturation and then renaturation, the reaction systems were incubated in 37 degrees C, and aliquots were removed to terminate the reaction at intended time points. The cleavage products were separated with 8% denaturated polyacrylamide gel electrophoresis and displayed by autoradiography. Finally, the optical density of each product band was measured with Gel Documentation-Analyzing Systems for calculating the percentages of cleaved HCV 5'-NCR-C.</p><p><b>RESULTS</b>After reaction for 15, 30, 45, 60, 75 and 90 min under the adopted conditions, about 8.3%, 16.1%, 24.3%, 26.2%, 29.4% and 31.1% of HCV 5'-NCR-C was cleaved by TDRz-127 respectively; 7.4%, 13.0%, 15.6%, 18.7%, 19.4% and 20.3% by TDRz1; and 15.1%, 29.6%, 37.8%, 39.1%, 41.5%, 42.6% by combining the two TDRzs.</p><p><b>CONCLUSIONS</b>Cleavage percentage of both TDRz-127 and TDRz1 increases with the time, and the effect of combining the two TDRzs is better than that of anyone.</p>


Subject(s)
5' Untranslated Regions , Metabolism , Base Sequence , DNA, Catalytic , Genetics , Metabolism , Hepacivirus , Genetics , Humans , Molecular Sequence Data , RNA Processing, Post-Transcriptional , RNA, Catalytic , Metabolism , RNA, Viral , Metabolism , mRNA Cleavage and Polyadenylation Factors , Genetics , Metabolism
19.
Article in English | WPRIM | ID: wpr-290494

ABSTRACT

The relationship between 3 polymorphisms sites [interleulin-4 (IL-4), IL-4 receptor (IL-4R) alpha chain and activation-induced cytidine deaminase (AICDA)] and adult allergic asthma in China was studied. By using case-control method, DNA and clinical data were obtained from allergic asthmatic patients and compared with those in the control subjects. The subjects were genotyped for the IL-4 C-589T promoter polymorphism, the IL-4R alpha chain Q576R and the AICDA C8408T by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results showed that the IL-4 C-589T was not associated with adult allergic asthma in China. However, the IL-4R alpha chain 576R/R and AICDA 8408T/T frequency was significantly increased in allergic asthma group as compared with that in the control group [odd ratio (OR) = 3.797 and 9.127, respectively; P < 0.01)] and was correlated with the increased plasma total IgE. These data suggested that the IL-4R alpha chain 576R/R and AICDA 8408T/T genotypes confer genetic susceptibility to adult allergic asthma in China.


Subject(s)
Adult , Alleles , Asthma , Genetics , Cytidine Deaminase , Genetics , Humans , Immunoglobulin E , Blood , Interleukin-4 , Genetics , Phenotype , Polymorphism, Restriction Fragment Length , RNA Processing, Post-Transcriptional , Receptors, Interleukin-4 , Genetics
20.
Article in English | WPRIM | ID: wpr-634059

ABSTRACT

The relationship between 3 polymorphisms sites [interleulin-4 (IL-4), IL-4 receptor (IL-4R) alpha chain and activation-induced cytidine deaminase (AICDA)] and adult allergic asthma in China was studied. By using case-control method, DNA and clinical data were obtained from allergic asthmatic patients and compared with those in the control subjects. The subjects were genotyped for the IL-4 C-589T promoter polymorphism, the IL-4R alpha chain Q576R and the AICDA C8408T by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results showed that the IL-4 C-589T was not associated with adult allergic asthma in China. However, the IL-4R alpha chain 576R/R and AICDA 8408T/T frequency was significantly increased in allergic asthma group as compared with that in the control group [odd ratio (OR) = 3.797 and 9.127, respectively; P < 0.01)] and was correlated with the increased plasma total IgE. These data suggested that the IL-4R alpha chain 576R/R and AICDA 8408T/T genotypes confer genetic susceptibility to adult allergic asthma in China.


Subject(s)
Alleles , Asthma/etiology , Asthma/genetics , Cytidine Deaminase/genetics , Immunoglobulin E/blood , Interleukin-4/genetics , Phenotype , Polymorphism, Restriction Fragment Length , RNA Processing, Post-Transcriptional , Receptors, Interleukin-4/genetics
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