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2.
Nucleic Acids Res ; 48(5): 2518-2530, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-31950173

RESUMO

Recruitment of the human ribonucleolytic RNA exosome to nuclear polyadenylated (pA+) RNA is facilitated by the Poly(A) Tail eXosome Targeting (PAXT) connection. Besides its core dimer, formed by the exosome co-factor MTR4 and the ZFC3H1 protein, the PAXT connection remains poorly defined. By characterizing nuclear pA+-RNA bound proteomes as well as MTR4-ZFC3H1 containing complexes in conditions favoring PAXT assembly, we here uncover three additional proteins required for PAXT function: ZC3H3, RBM26 and RBM27 along with the known PAXT-associated protein, PABPN1. The zinc-finger protein ZC3H3 interacts directly with MTR4-ZFC3H1 and loss of any of the newly identified PAXT components results in the accumulation of PAXT substrates. Collectively, our results establish new factors involved in the turnover of nuclear pA+ RNA and suggest that these are limiting for PAXT activity.


Assuntos
Exossomos/metabolismo , Poli A/metabolismo , Estabilidade de RNA , RNA Nuclear/metabolismo , Proteínas de Ligação a RNA/metabolismo , Células HEK293 , Células HeLa , Humanos , Ligação Proteica , Proteoma/metabolismo , Ribonucleoproteínas/metabolismo
3.
Science ; 367(6477): 580-586, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-31949099

RESUMO

N 6-methyladenosine (m6A) regulates stability and translation of messenger RNA (mRNA) in various biological processes. In this work, we show that knockout of the m6A writer Mettl3 or the nuclear reader Ythdc1 in mouse embryonic stem cells increases chromatin accessibility and activates transcription in an m6A-dependent manner. We found that METTL3 deposits m6A modifications on chromosome-associated regulatory RNAs (carRNAs), including promoter-associated RNAs, enhancer RNAs, and repeat RNAs. YTHDC1 facilitates the decay of a subset of these m6A-modified RNAs, especially elements of the long interspersed element-1 family, through the nuclear exosome targeting-mediated nuclear degradation. Reducing m6A methylation by METTL3 depletion or site-specific m6A demethylation of selected carRNAs elevates the levels of carRNAs and promotes open chromatin state and downstream transcription. Collectively, our results reveal that m6A on carRNAs can globally tune chromatin state and transcription.


Assuntos
Adenosina/análogos & derivados , Cromatina/metabolismo , Metiltransferases/metabolismo , RNA Nuclear/metabolismo , Transcrição Genética , Adenosina/metabolismo , Animais , Células-Tronco Embrionárias/metabolismo , Elementos Facilitadores Genéticos , Metilação , Metiltransferases/genética , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo
4.
Adv Exp Med Biol ; 1203: 113-132, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31811632

RESUMO

The RNA exosome is a highly conserved ribonuclease endowed with 3'-5' exonuclease and endonuclease activities. The multisubunit complex resides in both the nucleus and the cytoplasm, with varying compositions and activities between the two compartments. While the cytoplasmic exosome functions mostly in mRNA quality control pathways, the nuclear RNA exosome partakes in the 3'-end processing and complete decay of a wide variety of substrates, including virtually all types of noncoding (nc) RNAs. To handle these diverse tasks, the nuclear exosome engages with dedicated cofactors, some of which serve as activators by stimulating decay through oligoA addition and/or RNA helicase activities or, as adaptors, by recruiting RNA substrates through their RNA-binding capacities. Most nuclear exosome cofactors contain the essential RNA helicase Mtr4 (MTR4 in humans). However, apart from Mtr4, nuclear exosome cofactors have undergone significant evolutionary divergence. Here, we summarize biochemical and functional knowledge about the nuclear exosome and exemplify its cofactor variety by discussing the best understood model organisms-the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe, and human cells.


Assuntos
Coenzimas , Complexo Multienzimático de Ribonucleases do Exossomo , RNA Nuclear , Coenzimas/metabolismo , RNA Helicases DEAD-box/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Humanos , RNA/metabolismo , RNA Nuclear/metabolismo , RNA não Traduzido/metabolismo , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/metabolismo
5.
J Parasitol ; 105(5): 821-826, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31670613

RESUMO

Codonocephalus is a monotypic genus of diplostomid digeneans and is the only genus in the sub-family Codonocephalinae. The type-species Codonocephalus urniger has an unusual progenetic metacercaria that uses frogs as intermediate hosts and can use snakes as paratenic hosts. Adult C. urniger parasitize ardeid wading birds in the Palearctic. Despite the broad distribution of Codonocephalus, no DNA sequence data are currently available for the genus. In this study, we generated sequence data for nuclear ribosomal and mitochondrial DNA from progenetic metacercaria of the type-species C. urniger from marsh frog, Pelophylax ridibundus, collected in Ukraine. We used partial sequences of the nuclear ribosomal 28S gene to examine for the first time the phylogenetic position of Codonocephalus among the Diplostomoidea.


Assuntos
Filogenia , Ranidae/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Teorema de Bayes , DNA de Helmintos/química , DNA de Helmintos/isolamento & purificação , DNA Ribossômico/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Estágios do Ciclo de Vida , Metacercárias/classificação , Metacercárias/genética , Microscopia Eletrônica de Varredura/veterinária , Mitocôndrias/enzimologia , RNA de Helmintos/genética , RNA Nuclear/genética , RNA Ribossômico 28S/genética , Trematódeos/genética , Trematódeos/ultraestrutura , Infecções por Trematódeos/parasitologia
6.
Commun Biol ; 2: 211, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31240249

RESUMO

Cell cycle progression depends on phase-specific gene expression. Here we show that the nuclear RNA degradation machinery plays a lead role in promoting cell cycle-dependent gene expression by triggering promoter-dependent co-transcriptional RNA degradation. Single molecule quantification of RNA abundance in different phases of the cell cycle indicates that relative curtailment of gene expression in certain phases is attained even when transcription is not completely inhibited. When nuclear ribonucleases are deleted, transcription of the Saccharomyces cerevisiae G1-specific axial budding gene AXL2 is detected throughout the cell cycle and its phase-specific expression is lost. Promoter replacement abolished cell cycle-dependent RNA degradation and rendered the RNA insensitive to the deletion of nuclear ribonucleases. Together the data reveal a model of gene regulation whereby RNA abundance is controlled by promoter-dependent induction of RNA degradation.


Assuntos
Ciclo Celular , Regiões Promotoras Genéticas , RNA Nuclear/metabolismo , Regulação Fúngica da Expressão Gênica , Humanos , Glicoproteínas de Membrana/genética , RNA Mensageiro/metabolismo , Ribonuclease III/fisiologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/fisiologia , Fator de Transcrição TFIIA/genética
7.
Curr Opin Cell Biol ; 58: 120-125, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31009871

RESUMO

The importance of three-dimensional chromatin organisation in genome regulation has never been clearer. But in spite of the enormous technological advances to probe chromatin organisation in vivo, there is still a lack of mechanistic understanding of how such an arrangement is achieved. Here we review emerging evidence pointing to an intriguing role of nuclear RNA in shaping large-scale chromatin structure and regulating genome function. We suggest this role may be achieved through the formation of a dynamic nuclear mesh that can exploit ATP-driven processes and phase separation of RNA-binding proteins to tune its assembly and material properties.


Assuntos
Cromatina/química , RNA Nuclear/fisiologia , Transcrição Genética , Animais , Núcleo Celular/química , Núcleo Celular/fisiologia , Montagem e Desmontagem da Cromatina , Regulação da Expressão Gênica , Genoma , Humanos , Proteínas de Ligação a RNA/metabolismo
8.
PLoS Pathog ; 15(2): e1007596, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30785952

RESUMO

Nuclear RNAs are subject to a number of RNA decay pathways that serve quality control and regulatory functions. As a result, any virus that expresses its genes in the nucleus must have evolved mechanisms that avoid these pathways, but the how viruses evade nuclear RNA decay remains largely unknown. The multifunctional Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 (Mta) protein is required for the nuclear stability of viral transcripts. In the absence of ORF57, we show that viral transcripts are subject to degradation by two specific nuclear RNA decay pathways, PABPN1 and PAPα/γ-mediated RNA decay (PPD) in which decay factors are recruited through poly(A) tails, and an ARS2-mediated RNA decay pathway dependent on the 5' RNA cap. In transcription pulse chase assays, ORF57 appears to act primarily by inhibiting the ARS2-mediated RNA decay pathway. In the context of viral infection in cultured cells, inactivation of both decay pathways by RNAi is necessary for the restoration of ORF57-dependent viral genes produced from an ORF57-null bacmid. Mechanistically, we demonstrate that ORF57 protects viral transcripts by preventing the recruitment of the exosome co-factor hMTR4. In addition, our data suggest that ORF57 recruitment of ALYREF inhibits hMTR4 association with some viral RNAs, whereas other KSHV transcripts are stabilized by ORF57 in an ALYREF-independent fashion. In conclusion, our studies show that KSHV RNAs are subject to nuclear degradation by two specific host pathways, PPD and ARS2-mediated decay, and ORF57 protects viral transcripts from decay by inhibiting hMTR4 recruitment.


Assuntos
RNA Helicases/metabolismo , Estabilidade de RNA/fisiologia , Proteínas Virais Reguladoras e Acessórias/metabolismo , Linhagem Celular , Núcleo Celular , Proteínas Ativadoras de GTPase/metabolismo , Proteínas Ativadoras de GTPase/fisiologia , Regulação Viral da Expressão Gênica/genética , Genes Virais/genética , Células HEK293 , Herpesvirus Humano 8/metabolismo , Herpesvirus Humano 8/patogenicidade , Humanos , Proteínas Nucleares , Proteína I de Ligação a Poli(A)/metabolismo , Proteína I de Ligação a Poli(A)/fisiologia , Ligação Proteica , RNA Helicases/fisiologia , Estabilidade de RNA/genética , RNA Nuclear/fisiologia , RNA Viral , Proteínas de Ligação a RNA , Fatores de Transcrição , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteínas Virais Reguladoras e Acessórias/fisiologia , Replicação Viral
10.
RNA Biol ; 16(6): 770-784, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30806147

RESUMO

miR-1246 is considered an oncomiR in various cancer types. However, the origin and biogenesis of miR-1246 remain controversial which often leads to misinterpretation of its detection and biological function, and inevitably masking its mechanisms of action. Using next generation small RNA sequencing, CRISPR-Cas9 knockout, siRNA knockdown and the poly-A tailing SYBR qRT-PCR, we examined the biogenesis of exosomal miR-1246 in human cancer cell model systems. We found that miR-1246 is highly enriched in exosomes derived from human cancer cells and that it originates from RNU2-1, a small nuclear RNA and essential component of the U2 complex of the spliceosome. Knockdown of Drosha and Dicer did not reduce exosomal miR-1246 levels, indicating that exosomal miR-1246 is generated in a Drosha- and Dicer-independent manner. Direct digestion of cellular lysate by RNase A and knockdown of the RNU2-1 binding protein SmB/B' demonstrated that exosomal miR-1246 is a RNU2-1 degradation product. Furthermore, the GCAG motif present in the RUN2-1 transcript was shown to mediate miR-1246 enrichment in cancer exosomes. We conclude that exosome miR-1246 is derived from RNU2-1 degradation through a non-canonical microRNA biogenesis process. These findings reveal the origin of an oncomiR in human cancer cells, providing guidance in understanding miR-1246 detection and biological function. Abbreviations: CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats; miRNA, microRNA; PDAC, pancreatic ductal adenocarcinoma; RNU2-1, U2 small nuclear RNA; RT-PCR, Reverse transcription polymerase chain reaction; sgRNA, single-guide RNA.


Assuntos
Exossomos/genética , MicroRNAs/metabolismo , Neoplasias/genética , Linhagem Celular , Linhagem Celular Tumoral , Humanos , MicroRNAs/química , MicroRNAs/genética , Neoplasias/metabolismo , Motivos de Nucleotídeos , RNA Nuclear/metabolismo
11.
Int J Biochem Cell Biol ; 108: 1-6, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30593955

RESUMO

RBMX is a ubiquitously expressed nuclear RNA binding protein that is encoded by a gene on the X chromosome. RBMX belongs to a small protein family with additional members encoded by paralogs on the mammalian Y chromosome and other chromosomes. These RNA binding proteins are important for normal development, and also implicated in cancer and viral infection. At the molecular level RBMX family proteins contribute to splicing control, transcription and genome integrity. Establishing what endogenous genes and pathways are controlled by RBMX and its paralogs will have important implications for understanding chromosome biology, DNA repair and mammalian development. Here we review what is known about this family of RNA binding proteins, and identify important current questions about their functions.


Assuntos
Doença , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , RNA Nuclear/genética , Cromossomos Sexuais/genética , Animais , Humanos , Sistema Nervoso/crescimento & desenvolvimento , Transcrição Genética
12.
PLoS Pathog ; 14(11): e1007389, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30383841

RESUMO

During lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV), a nuclear viral long noncoding RNA known as PAN RNA becomes the most abundant polyadenylated transcript in the cell. Knockout or knockdown of KSHV PAN RNA results in loss of late lytic viral gene expression and, consequently, reduction of progeny virion release from the cell. Here, we demonstrate that knockdown of PAN RNA from the related Rhesus macaque rhadinovirus (RRV) phenocopies that of KSHV PAN RNA. These two PAN RNA homologs, although lacking significant nucleotide sequence conservation, can functionally substitute for each other to rescue phenotypes associated with the absence of PAN RNA expression. Because PAN RNA is exclusively nuclear, previous studies suggested that it directly interacts with host and viral chromatin to modulate gene expression. We studied KSHV and RRV PAN RNA homologs using capture hybridization analysis of RNA targets (CHART) and observed their association with host chromatin, but the loci differ between PAN RNA homologs. Accordingly, we find that KSHV PAN RNA is undetectable in chromatin following cell fractionation. Thus, modulation of gene expression at specific chromatin loci appears not to be the primary, nor the pertinent function of this viral long noncoding RNA. PAN RNA represents a cautionary tale for the investigation of RNA association with chromatin whereby cross-linking of DNA spatially adjacent to an abundant nuclear RNA gives the appearance of specific interactions. Similarly, PAN RNA expression does not affect viral transcription factor complex expression or activity, which is required for generation of the late lytic viral mRNAs. Rather, we provide evidence for an alternative model of PAN RNA function whereby knockdown of KSHV or RRV PAN RNA results in compromised nuclear mRNA export thereby reducing the cytoplasmic levels of viral mRNAs available for production of late lytic viral proteins.


Assuntos
RNA Longo não Codificante/genética , Rhadinovirus/genética , Animais , Linhagem Celular , Núcleo Celular/metabolismo , Cromatina/metabolismo , Regulação Viral da Expressão Gênica/genética , Técnicas de Silenciamento de Genes/métodos , Células HEK293 , Herpesviridae/genética , Infecções por Herpesviridae/genética , Herpesvirus Humano 8/genética , Interações Hospedeiro-Patógeno , Humanos , Macaca mulatta/virologia , RNA Mensageiro/genética , RNA Nuclear/genética , RNA Viral/genética , Infecções Tumorais por Vírus , Proteínas Virais/metabolismo , Replicação Viral
13.
Artigo em Inglês | MEDLINE | ID: mdl-30397105

RESUMO

A polyA (pA) tail is an essential modification added to the 3' ends of a wide range of RNAs at different stages of their metabolism. Here, we describe the main sources of polyadenylation and outline their underlying biochemical interactions within the nuclei of budding yeast Saccharomyces cerevisiae, human cells and, when relevant, the fission yeast Schizosaccharomyces pombe Polyadenylation mediated by the S. cerevisiae Trf4/5 enzymes, and their human homologues PAPD5/7, typically leads to the 3'-end trimming or complete decay of non-coding RNAs. By contrast, the primary function of canonical pA polymerases (PAPs) is to produce stable and nuclear export-competent mRNAs. However, this dichotomy is becoming increasingly blurred, at least in S. pombe and human cells, where polyadenylation mediated by canonical PAPs may also result in transcript decay.This article is part of the theme issue '5' and 3' modifications controlling RNA degradation'.


Assuntos
Poliadenilação , RNA Nuclear/metabolismo , Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/metabolismo , Humanos , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo
14.
Nat Commun ; 9(1): 3225, 2018 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-30104565

RESUMO

Recent studies have suggested that genes longer than 100 kb are more likely to be misregulated in neurological diseases associated with synaptic dysfunction, such as autism and Rett syndrome. These length-dependent transcriptional changes are modest in MeCP2-mutant samples, but, given the low sensitivity of high-throughput transcriptome profiling technology, here we re-evaluate the statistical significance of these results. We find that the apparent length-dependent trends previously observed in MeCP2 microarray and RNA-sequencing datasets disappear after estimating baseline variability from randomized control samples. This is particularly true for genes with low fold changes. We find no bias with NanoString technology, so this long gene bias seems to be particular to polymerase chain reaction amplification-based platforms. In contrast, authentic long gene effects, such as those caused by topoisomerase inhibition, can be detected even after adjustment for baseline variability. We conclude that accurate characterization of length-dependent (or other) trends requires establishing a baseline from randomized control samples.


Assuntos
Pareamento de Bases/genética , Regulação da Expressão Gênica , Proteína 2 de Ligação a Metil-CpG/genética , Animais , Viés , Bases de Dados Genéticas , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Análise de Componente Principal , RNA Nuclear/genética , Síndrome de Rett/genética , Análise de Sequência de RNA , Síndrome , Topotecan/farmacologia
15.
Curr Opin Chem Biol ; 45: 179-186, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30007213

RESUMO

Chemical modifications to rRNA, tRNA and mRNA provide a new regulatory layer of gene expression, which is termed as the `epitranscriptome'. N1-methyladenosine (m1A), first characterized more than 50 years ago, is a well-known modification in rRNA and tRNA. m1A in these abundant non-coding RNAs plays important roles in maintaining their biological functions. Recent studies also reveal that m1A is present in both nuclear-encoded and mitochondrial-encoded mRNA and is dynamically regulated by environmental and developmental conditions; m1A is found in a subset of nuclear-encoded long non-coding RNAs as well. Finally, we also discuss the potential challenges of identifying m1A modification in the human transcriptome.


Assuntos
Adenosina/análogos & derivados , Epigênese Genética , RNA Longo não Codificante/genética , RNA Mensageiro/genética , RNA Mitocondrial/genética , RNA Nuclear/genética , Transcriptoma , Adenosina/análise , Adenosina/genética , Animais , Humanos , Metilação , RNA Longo não Codificante/química , RNA Mensageiro/química , RNA Mitocondrial/química , RNA Nuclear/química
16.
EMBO J ; 37(13)2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29880601

RESUMO

Cytoplasmic mRNA degradation controls gene expression to help eliminate pathogens during infection. However, it has remained unclear whether such regulation also extends to nuclear RNA decay. Here, we show that 145 unstable nuclear RNAs, including enhancer RNAs (eRNAs) and long noncoding RNAs (lncRNAs) such as NEAT1v2, are stabilized upon Salmonella infection in HeLa cells. In uninfected cells, the RNA exosome, aided by the Nuclear EXosome Targeting (NEXT) complex, degrades these labile transcripts. Upon infection, the levels of the exosome/NEXT components, RRP6 and MTR4, dramatically decrease, resulting in transcript stabilization. Depletion of lncRNAs, NEAT1v2, or eRNA07573 in HeLa cells triggers increased susceptibility to Salmonella infection concomitant with the deregulated expression of a distinct class of immunity-related genes, indicating that the accumulation of unstable nuclear RNAs contributes to antibacterial defense. Our results highlight a fundamental role for regulated degradation of nuclear RNA in the response to pathogenic infection.


Assuntos
RNA Nuclear , RNA não Traduzido , Infecções por Salmonella/genética , Sobrevivência Celular , Células HeLa , Humanos , Salmonella enterica/genética , Regulação para Cima
18.
Mol Cell Biol ; 38(18)2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29941491

RESUMO

Accurate chromosome segregation is a fundamental process in cell biology. During mitosis, chromosomes are segregated into daughter cells through interactions between centromeres and microtubules in the mitotic spindle. Centromere domains have evolved to nucleate formation of the kinetochore, which is essential for establishing connections between chromosomal DNA and microtubules during mitosis. Centromeres are typically formed on highly repetitive DNA that is not conserved in sequence or size among organisms and can differ substantially between individuals within the same organism. However, transcription of repetitive DNA has emerged as a highly conserved property of the centromere. Recent work has shown that both the topological effect of transcription on chromatin and the nascent noncoding RNAs contribute to multiple aspects of centromere function. In this review, we discuss the fundamental aspects of centromere transcription, i.e., its dual role in chromatin remodeling/CENP-A deposition and kinetochore assembly during mitosis, from a cell cycle perspective.


Assuntos
Centrômero/genética , Centrômero/metabolismo , Transcrição Genética , Animais , Aurora Quinase B/metabolismo , Proteína Centromérica A/metabolismo , Montagem e Desmontagem da Cromatina , Segregação de Cromossomos , DNA/genética , DNA/metabolismo , Humanos , Cinetocoros/metabolismo , Mitose , Modelos Genéticos , RNA Polimerase II/metabolismo , RNA Nuclear/genética , RNA Nuclear/metabolismo
19.
Mycologia ; 110(1): 93-103, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29864000

RESUMO

Amanita cf. lavendula collections in eastern North America, Mexico, and Costa Rica were found to consist of four cryptic taxa, one of which exhibited consistently unreadable nuclear rDNA ITS1-5.8S-ITS2 (fungal barcode) sequences after ITS1 base 130. This taxon is designated here as Amanita cf. lavendula taxon 1. ITS sequences from dikaryotic basidiomata were cloned, but sequences recovered from cloning did not segregate into distinct haplotypes. Rather, there was a mix of haplotypes that varied among themselves predominantly at 28 ITS positions. Analysis of each of these 28 variable bases showed predominantly two alternate bases at each position. Based on these findings and additional sequence data from the nuclear rDNA 28S, RNA polymerase II subunit 2 (RPB2) and mitochondrial rDNA small subunit (SSU) and 23S genes, we speculate that taxon 1 represents an initial hybridization event between two divergent taxa followed by failure of the ribosomal repeat to homogenize. Homogenization failure may be a result of repeated hybridization between divergent internal transcribed spacer (ITS) types with inadequate time for concerted evolution of the ribosomal repeat or, alternately, a complete failure of the ribosomal homogenization process. To our knowledge, this finding represents the first report of a geographically widespread taxon (Canada, eastern USA, Costa Rica) with apparent homogenization failure across all collections. Findings such as these have implications for fungal barcoding efforts and the application of fungal barcodes in identifying environmental sequences.


Assuntos
Amanita/classificação , Amanita/genética , Variação Genética , RNA Fúngico/genética , RNA Nuclear/genética , Análise por Conglomerados , Costa Rica , DNA Fúngico/química , DNA Fúngico/genética , DNA Mitocondrial/química , DNA Mitocondrial/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , México , América do Norte , Filogenia , RNA Polimerase II/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA
20.
Nat Rev Genet ; 19(8): 518-529, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29748575

RESUMO

RNA turnover is an integral part of cellular RNA homeostasis and gene expression regulation. Whereas the cytoplasmic control of protein-coding mRNA is often the focus of study, we discuss here the less appreciated role of nuclear RNA decay systems in controlling RNA polymerase II (RNAPII)-derived transcripts. Historically, nuclear RNA degradation was found to be essential for the functionalization of transcripts through their proper maturation. Later, it was discovered to also be an important caretaker of nuclear hygiene by removing aberrant and unwanted transcripts. Recent years have now seen a set of new protein complexes handling a variety of new substrates, revealing functions beyond RNA processing and the decay of non-functional transcripts. This includes an active contribution of nuclear RNA metabolism to the overall cellular control of RNA levels, with mechanistic implications during cellular transitions.


Assuntos
Núcleo Celular/metabolismo , Regulação da Expressão Gênica/fisiologia , RNA Polimerase II/metabolismo , Estabilidade de RNA/fisiologia , RNA Nuclear/biossíntese , Transcrição Genética/fisiologia , Animais , Núcleo Celular/genética , Humanos , RNA Polimerase II/genética , RNA Nuclear/genética
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