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1.
Mol Cell ; 81(16): 3356-3367.e6, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34297910

RESUMO

RNA polymerase II (RNAP II) pausing is essential to precisely control gene expression and is critical for development of metazoans. Here, we show that the m6A RNA modification regulates promoter-proximal RNAP II pausing in Drosophila cells. The m6A methyltransferase complex (MTC) and the nuclear reader Ythdc1 are recruited to gene promoters. Depleting the m6A MTC leads to a decrease in RNAP II pause release and in Ser2P occupancy on the gene body and affects nascent RNA transcription. Tethering Mettl3 to a heterologous gene promoter is sufficient to increase RNAP II pause release, an effect that relies on its m6A catalytic domain. Collectively, our data reveal an important link between RNAP II pausing and the m6A RNA modification, thus adding another layer to m6A-mediated gene regulation.


Assuntos
Proteínas de Drosophila/genética , Complexos Multiproteicos/genética , Proteínas Nucleares/genética , RNA Polimerase II/genética , Transcrição Genética , Animais , Drosophila melanogaster/genética , Metiltransferases/genética , Regiões Promotoras Genéticas/genética
2.
Nat Commun ; 12(1): 3778, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145251

RESUMO

N6-methyladenosine (m6A) is the most abundant internal modification on mRNA which influences most steps of mRNA metabolism and is involved in several biological functions. The E3 ubiquitin ligase Hakai was previously found in complex with components of the m6A methylation machinery in plants and mammalian cells but its precise function remained to be investigated. Here we show that Hakai is a conserved component of the methyltransferase complex in Drosophila and human cells. In Drosophila, its depletion results in reduced m6A levels and altered m6A-dependent functions including sex determination. We show that its ubiquitination domain is required for dimerization and interaction with other members of the m6A machinery, while its catalytic activity is dispensable. Finally, we demonstrate that the loss of Hakai destabilizes several subunits of the methyltransferase complex, resulting in impaired m6A deposition. Our work adds functional and molecular insights into the mechanism of the m6A mRNA writer complex.


Assuntos
Adenosina/análogos & derivados , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Metiltransferases/metabolismo , RNA Mensageiro/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Adenosina/metabolismo , Animais , Linhagem Celular , Drosophila melanogaster , Células HeLa , Humanos , Metilação , Metiltransferases/genética , Processamento Pós-Transcricional do RNA/genética , Splicing de RNA/genética
3.
EMBO J ; 40(4): e104975, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33428246

RESUMO

N6-methyladenosine (m6 A) regulates a variety of physiological processes through modulation of RNA metabolism. This modification is particularly enriched in the nervous system of several species, and its dysregulation has been associated with neurodevelopmental defects and neural dysfunctions. In Drosophila, loss of m6 A alters fly behavior, albeit the underlying molecular mechanism and the role of m6 A during nervous system development have remained elusive. Here we find that impairment of the m6 A pathway leads to axonal overgrowth and misguidance at larval neuromuscular junctions as well as in the adult mushroom bodies. We identify Ythdf as the main m6 A reader in the nervous system, being required to limit axonal growth. Mechanistically, we show that the m6 A reader Ythdf directly interacts with Fmr1, the fly homolog of Fragile X mental retardation RNA binding protein (FMRP), to inhibit the translation of key transcripts involved in axonal growth regulation. Altogether, this study demonstrates that the m6 A pathway controls development of the nervous system and modulates Fmr1 target transcript selection.

4.
Trends Genet ; 37(4): 355-372, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33203572

RESUMO

Splicing of precursor mRNAs (pre-mRNA) is an important step during eukaryotic gene expression. The identification of the actual splice sites and the proper removal of introns are essential for the production of the desired mRNA isoforms and their encoded proteins. While the basic mechanisms of splicing regulation are well understood, recent work has uncovered a growing number of noncanonical splicing mechanisms that play key roles in the regulation of gene expression. In this review, we summarize the current principles of splicing regulation, including the impact of cis and trans regulatory elements, as well as the influence of chromatin structure, transcription, and RNA modifications. We further discuss the recent development of emerging splicing mechanisms, such as recursive and back splicing, and their impact on gene expression.

5.
Nucleic Acids Res ; 49(4): e23, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33313868

RESUMO

Methods for the detection of m6A by RNA-Seq technologies are increasingly sought after. We here present NOseq, a method to detect m6A residues in defined amplicons by virtue of their resistance to chemical deamination, effected by nitrous acid. Partial deamination in NOseq affects all exocyclic amino groups present in nucleobases and thus also changes sequence information. The method uses a mapping algorithm specifically adapted to the sequence degeneration caused by deamination events. Thus, m6A sites with partial modification levels of ∼50% were detected in defined amplicons, and this threshold can be lowered to ∼10% by combination with m6A immunoprecipitation. NOseq faithfully detected known m6A sites in human rRNA, and the long non-coding RNA MALAT1, and positively validated several m6A candidate sites, drawn from miCLIP data with an m6A antibody, in the transcriptome of Drosophila melanogaster. Conceptually related to bisulfite sequencing, NOseq presents a novel amplicon-based sequencing approach for the validation of m6A sites in defined sequences.


Assuntos
Adenosina/análogos & derivados , Sequenciamento de Nucleotídeos em Larga Escala/métodos , RNA/química , Análise de Sequência de RNA/métodos , Adenosina/análise , Algoritmos , Animais , Cromatografia Líquida , Desaminação , Drosophila melanogaster/genética , Células HEK293 , Células HeLa , Humanos , RNA Longo não Codificante/química , RNA Mensageiro/química , RNA Ribossômico 18S/química , Alinhamento de Sequência , Espectrometria de Massas em Tandem
6.
RNA ; 26(12): 1935-1956, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32963109

RESUMO

The NineTeen Complex (NTC), also known as pre-mRNA-processing factor 19 (Prp19) complex, regulates distinct spliceosome conformational changes necessary for splicing. During Drosophila midblastula transition, splicing is particularly sensitive to mutations in NTC-subunit Fandango, which suggests differential requirements of NTC during development. We show that NTC-subunit Salsa, the Drosophila ortholog of human RNA helicase Aquarius, is rate-limiting for splicing of a subset of small first introns during oogenesis, including the first intron of gurken Germline depletion of Salsa and splice site mutations within gurken first intron impair both adult female fertility and oocyte dorsal-ventral patterning, due to an abnormal expression of Gurken. Supporting causality, the fertility and dorsal-ventral patterning defects observed after Salsa depletion could be suppressed by the expression of a gurken construct without its first intron. Altogether, our results suggest that one of the key rate-limiting functions of Salsa during oogenesis is to ensure the correct expression and efficient splicing of the first intron of gurken mRNA. Retention of gurken first intron compromises the function of this gene most likely because it undermines the correct structure and function of the transcript 5'UTR.


Assuntos
Padronização Corporal/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Íntrons/genética , Splicing de RNA , Fator de Crescimento Transformador alfa/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/genética , Feminino , Infertilidade Feminina/etiologia , Infertilidade Feminina/metabolismo , Infertilidade Feminina/patologia , Spliceossomos/genética , Spliceossomos/metabolismo , Fator de Crescimento Transformador alfa/genética
7.
EMBO Rep ; 21(7): e49443, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32350990

RESUMO

RNA modifications have recently emerged as an important layer of gene regulation. N6-methyladenosine (m6 A) is the most prominent modification on eukaryotic messenger RNA and has also been found on noncoding RNA, including ribosomal and small nuclear RNA. Recently, several m6 A methyltransferases were identified, uncovering the specificity of m6 A deposition by structurally distinct enzymes. In order to discover additional m6 A enzymes, we performed an RNAi screen to deplete annotated orthologs of human methyltransferase-like proteins (METTLs) in Drosophila cells and identified CG9666, the ortholog of human METTL5. We show that CG9666 is required for specific deposition of m6 A on 18S ribosomal RNA via direct interaction with the Drosophila ortholog of human TRMT112, CG12975. Depletion of CG9666 yields a subsequent loss of the 18S rRNA m6 A modification, which lies in the vicinity of the ribosome decoding center; however, this does not compromise rRNA maturation. Instead, a loss of CG9666-mediated m6 A impacts fly behavior, providing an underlying molecular mechanism for the reported human phenotype in intellectual disability. Thus, our work expands the repertoire of m6 A methyltransferases, demonstrates the specialization of these enzymes, and further addresses the significance of ribosomal RNA modifications in gene expression and animal behavior.


Assuntos
Drosophila , Metiltransferases , Adenosina , Animais , Drosophila/genética , Humanos , Metiltransferases/genética , RNA Ribossômico , RNA Ribossômico 18S/genética , Caminhada
8.
PLoS Genet ; 16(1): e1008581, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31978041

RESUMO

Makorins are evolutionary conserved proteins that contain C3H-type zinc finger modules and a RING E3 ubiquitin ligase domain. In Drosophila, maternal Makorin 1 (Mkrn1) has been linked to embryonic patterning but the mechanism remained unsolved. Here, we show that Mkrn1 is essential for axis specification and pole plasm assembly by translational activation of oskar (osk). We demonstrate that Mkrn1 interacts with poly(A) binding protein (pAbp) and binds specifically to osk 3' UTR in a region adjacent to A-rich sequences. Using Drosophila S2R+ cultured cells we show that this binding site overlaps with a Bruno1 (Bru1) responsive element (BREs) that regulates osk translation. We observe increased association of the translational repressor Bru1 with osk mRNA upon depletion of Mkrn1, indicating that both proteins compete for osk binding. Consistently, reducing Bru1 dosage partially rescues viability and Osk protein level in ovaries from Mkrn1 females. We conclude that Mkrn1 controls embryonic patterning and germ cell formation by specifically activating osk translation, most likely by competing with Bru1 to bind to osk 3' UTR.


Assuntos
Padronização Corporal , Proteínas de Drosophila/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Ligação a RNA/metabolismo , Regiões 3' não Traduzidas , Animais , Linhagem Celular , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Ovário/metabolismo , Ligação Proteica
9.
Nucleic Acids Res ; 48(4): 2050-2072, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31943105

RESUMO

2'-O-Methylation (Nm) represents one of the most common RNA modifications. Nm affects RNA structure and function with crucial roles in various RNA-mediated processes ranging from RNA silencing, translation, self versus non-self recognition to viral defense mechanisms. Here, we identify two Nm methyltransferases (Nm-MTases) in Drosophila melanogaster (CG7009 and CG5220) as functional orthologs of yeast TRM7 and human FTSJ1. Genetic knockout studies together with MALDI-TOF mass spectrometry and RiboMethSeq mapping revealed that CG7009 is responsible for methylating the wobble position in tRNAPhe, tRNATrp and tRNALeu, while CG5220 methylates position C32 in the same tRNAs and also targets additional tRNAs. CG7009 or CG5220 mutant animals were viable and fertile but exhibited various phenotypes such as lifespan reduction, small RNA pathways dysfunction and increased sensitivity to RNA virus infections. Our results provide the first detailed characterization of two TRM7 family members in Drosophila and uncover a molecular link between enzymes catalyzing Nm at specific tRNAs and small RNA-induced gene silencing pathways.


Assuntos
Drosophila melanogaster/genética , Inativação Gênica , RNA de Transferência/genética , tRNA Metiltransferases/genética , Animais , Regulação da Expressão Gênica/genética , Humanos , Metilação , Metiltransferases/genética , Proteínas Nucleares/genética , Interferência de RNA , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
10.
Genome Biol ; 20(1): 216, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640799

RESUMO

BACKGROUND: Cells have evolved quality control mechanisms to ensure protein homeostasis by detecting and degrading aberrant mRNAs and proteins. A common source of aberrant mRNAs is premature polyadenylation, which can result in non-functional protein products. Translating ribosomes that encounter poly(A) sequences are terminally stalled, followed by ribosome recycling and decay of the truncated nascent polypeptide via ribosome-associated quality control. RESULTS: Here, we demonstrate that the conserved RNA-binding E3 ubiquitin ligase Makorin Ring Finger Protein 1 (MKRN1) promotes ribosome stalling at poly(A) sequences during ribosome-associated quality control. We show that MKRN1 directly binds to the cytoplasmic poly(A)-binding protein (PABPC1) and associates with polysomes. MKRN1 is positioned upstream of poly(A) tails in mRNAs in a PABPC1-dependent manner. Ubiquitin remnant profiling and in vitro ubiquitylation assays uncover PABPC1 and ribosomal protein RPS10 as direct ubiquitylation substrates of MKRN1. CONCLUSIONS: We propose that MKRN1 mediates the recognition of poly(A) tails to prevent the production of erroneous proteins from prematurely polyadenylated transcripts, thereby maintaining proteome integrity.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Biossíntese de Proteínas , Ribonucleoproteínas/metabolismo , Regiões 3' não Traduzidas , Células HEK293 , Humanos , Proteína I de Ligação a Poli(A)/metabolismo , RNA Mensageiro/metabolismo , Ubiquitinação
11.
Angew Chem Int Ed Engl ; 58(28): 9565-9569, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-30892798

RESUMO

Accurate quantification of the copy numbers of noncoding RNA has recently emerged as an urgent problem, with impact on fields such as RNA modification research, tissue differentiation, and others. Herein, we present a hybridization-based approach that uses microscale thermophoresis (MST) as a very fast and highly precise readout to quantify, for example, single tRNA species with a turnaround time of about one hour. We developed MST to quantify the effect of tRNA toxins and of heat stress and RNA modification on single tRNA species. A comparative analysis also revealed significant differences to RNA-Seq-based quantification approaches, strongly suggesting a bias due to tRNA modifications in the latter. Further applications include the quantification of rRNA as well as of polyA levels in cellular RNA.


Assuntos
RNA não Traduzido/química , Fluorescência
12.
Nat Commun ; 10(1): 521, 2019 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-30705266

RESUMO

Promoter-proximal pausing of RNA polymerase II (Pol II) is a widespread transcriptional regulatory step across metazoans. Here we find that the nuclear exon junction complex (pre-EJC) is a critical and conserved regulator of this process. Depletion of pre-EJC subunits leads to a global decrease in Pol II pausing and to premature entry into elongation. This effect occurs, at least in part, via non-canonical recruitment of pre-EJC components at promoters. Failure to recruit the pre-EJC at promoters results in increased binding of the positive transcription elongation complex (P-TEFb) and in enhanced Pol II release. Notably, restoring pausing is sufficient to rescue exon skipping and the photoreceptor differentiation defect associated with depletion of pre-EJC components in vivo. We propose that the pre-EJC serves as an early transcriptional checkpoint to prevent premature entry into elongation, ensuring proper recruitment of RNA processing components that are necessary for exon definition.


Assuntos
Éxons/genética , Animais , Núcleo Celular/genética , Núcleo Celular/metabolismo , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/fisiologia , Células HeLa , Humanos , Regiões Promotoras Genéticas/genética , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Splicing de RNA/genética
13.
Proc Natl Acad Sci U S A ; 116(9): 3805-3810, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30808766

RESUMO

Adrenergic signaling profoundly modulates animal behavior. For example, the invertebrate counterpart of norepinephrine, octopamine, and its biological precursor and functional antagonist, tyramine, adjust motor behavior to different nutritional states. In Drosophila larvae, food deprivation increases locomotor speed via octopamine-mediated structural plasticity of neuromuscular synapses, whereas tyramine reduces locomotor speed, but the underlying cellular and molecular mechanisms remain unknown. We show that tyramine is released into the CNS to reduce motoneuron intrinsic excitability and responses to excitatory cholinergic input, both by tyraminehonoka receptor activation and by downstream decrease of L-type calcium current. This central effect of tyramine on motoneurons is required for the adaptive reduction of locomotor activity after feeding. Similarly, peripheral octopamine action on motoneurons has been reported to be required for increasing locomotion upon starvation. We further show that the level of tyramine-ß-hydroxylase (TBH), the enzyme that converts tyramine into octopamine in aminergic neurons, is increased by food deprivation, thus selecting between antagonistic amine actions on motoneurons. Therefore, octopamine and tyramine provide global but distinctly different mechanisms to regulate motoneuron excitability and behavioral plasticity, and their antagonistic actions are balanced within a dynamic range by nutritional effects on TBH.


Assuntos
Oxigenases de Função Mista/genética , Neurônios Motores/metabolismo , Octopamina/genética , Receptores de Amina Biogênica/genética , Tiramina/metabolismo , Animais , Comportamento Animal/fisiologia , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Drosophila melanogaster/fisiologia , Privação de Alimentos/fisiologia , Larva/metabolismo , Larva/fisiologia , Locomoção/genética , Locomoção/fisiologia , Oxigenases de Função Mista/metabolismo , Neurônios Motores/fisiologia , Estado Nutricional/genética , Estado Nutricional/fisiologia , Octopamina/metabolismo , Receptores de Amina Biogênica/metabolismo , Sinapses/metabolismo , Sinapses/fisiologia
14.
Methods Mol Biol ; 1870: 89-106, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30539549

RESUMO

m6A is the most abundant internal modification on mRNA. Recent improvements of high-throughput sequencing techniques enables its detection at the transcriptome level, even at the nucleotide resolution. However most current techniques require large amounts of starting material to detect the modification. Here, we describe a complementary technique of standard meRIP-seq/miCLIP-seq approaches to identify methylated RNA using a low amount of material. We believe this approach can be applied in vivo to identify methylated targets in specific tissues or subpopulations of cells.


Assuntos
Biologia Computacional/métodos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Clonagem Molecular , Edição de Genes , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Metilação , Processamento Pós-Transcricional do RNA , RNA Mensageiro/isolamento & purificação , Software , Transcriptoma
15.
Biochim Biophys Acta Gene Regul Mech ; 1862(3): 222-229, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30395944

RESUMO

The field of RNA modifications, so-called epitranscriptomics, has flourished over the past years owing to improvements of detection methods and the identification of important regulatory players. N6-methyladenosine (m6A) is the most abundant internal modification in messenger (mRNA) and long non-coding (lncRNA), and controls most steps of RNA metabolism. Its physiological roles range from gametogenesis, stem cell differentiation to immunity, neuronal development and functions, while its alterations are associated with cancer development and progression. In this review we focus on the proteins that catalyze formation of m6A (also called writers) on RNA. Interestingly, distinct proteins deposit m6A on different classes of RNA, indicating that specific RNA features dictate recognition mechanisms. Associated factors and post-translational modifications can also alter m6A enzyme activity. A better understanding of the underlying regulation involved in m6A deposition is the first step towards developing tools for cancer therapy and for treatment of other m6A-associated diseases.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/química , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo , Adenosina/química , Adenosina/metabolismo , Animais , Domínio Catalítico , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Metiltransferases/metabolismo , RNA Mensageiro/química
16.
Am J Hum Genet ; 103(6): 1045-1052, 2018 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-30526862

RESUMO

We describe six persons from three families with three homozygous protein truncating variants in PUS7: c.89_90del (p.Thr30Lysfs∗20), c.1348C>T (p.Arg450∗), and a deletion of the penultimate exon 15. All these individuals have intellectual disability with speech delay, short stature, microcephaly, and aggressive behavior. PUS7 encodes the RNA-independent pseudouridylate synthase 7. Pseudouridylation is the most abundant post-transcriptional modification in RNA, which is primarily thought to stabilize secondary structures of RNA. We show that the disease-related variants lead to abolishment of PUS7 activity on both tRNA and mRNA substrates. Moreover, pus7 knockout in Drosophila melanogaster results in a number of behavioral defects, including increased activity, disorientation, and aggressiveness supporting that neurological defects are caused by PUS7 variants. Our findings demonstrate that RNA pseudouridylation by PUS7 is essential for proper neuronal development and function.


Assuntos
Agressão/fisiologia , Nanismo/genética , Variação Genética/genética , Deficiência Intelectual/genética , Transtornos do Desenvolvimento da Linguagem/genética , Microcefalia/genética , Adolescente , Animais , Criança , Drosophila melanogaster/genética , Éxons/genética , Feminino , Técnicas de Inativação de Genes/métodos , Homozigoto , Humanos , Masculino , Linhagem , Fenótipo , RNA Mensageiro/genética , RNA de Transferência/genética
17.
Nat Commun ; 9(1): 4970, 2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30478415

RESUMO

Even though proteins are produced from mRNA, the correlation between mRNA levels and protein abundances is moderate in most studies, occasionally attributed to complex post-transcriptional regulation. To address this, we generate a paired transcriptome/proteome time course dataset with 14 time points during Drosophila embryogenesis. Despite a limited mRNA-protein correlation (ρ = 0.54), mathematical models describing protein translation and degradation explain 84% of protein time-courses based on the measured mRNA dynamics without assuming complex post transcriptional regulation, and allow for classification of most proteins into four distinct regulatory scenarios. By performing an in-depth characterization of the putatively post-transcriptionally regulated genes, we postulate that the RNA-binding protein Hrb98DE is involved in post-transcriptional control of sugar metabolism in early embryogenesis and partially validate this hypothesis using Hrb98DE knockdown. In summary, we present a systems biology framework for the identification of post-transcriptional gene regulation from large-scale, time-resolved transcriptome and proteome data.


Assuntos
Drosophila melanogaster/genética , Regulação da Expressão Gênica , Transcrição Genética , Animais , Sequência de Bases , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Desenvolvimento Embrionário/genética , Glucose/metabolismo , Cinética , Proteoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma/genética
18.
Artigo em Inglês | MEDLINE | ID: mdl-29707539

RESUMO

Analogous to DNA methylation and histone modifications, RNA modifications represent a novel layer of regulation of gene expression. The dynamic nature and increasing number of RNA modifications offer new possibilities to rapidly alter gene expression upon specific environmental changes. Recent lines of evidence indicate that modified RNA molecules and associated complexes regulating and "reading" RNA modifications play key roles in the nervous system of several organisms, controlling both, its development and function. Mutations in several human genes that modify transfer RNA (tRNA) have been linked to neurological disorders, in particular to intellectual disability. Loss of RNA modifications alters the stability of tRNA, resulting in reduced translation efficiency and generation of tRNA fragments, which can interfere with neuronal functions. Modifications present on messenger RNAs (mRNAs) also play important roles during brain development. They contribute to neuronal growth and regeneration as well as to the local regulation of synaptic functions. Hence, potential combinatorial effects of RNA modifications on different classes of RNA may represent a novel code to dynamically fine tune gene expression during brain function. Here we discuss the recent findings demonstrating the impact of modified RNAs on neuronal processes and disorders.

19.
RNA Biol ; 15(6): 829-831, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29671387

RESUMO

The genetic alphabet consists of the four letters: C, A, G, and T in DNA and C,A,G, and U in RNA. Triplets of these four letters jointly encode 20 different amino acids out of which proteins of all organisms are built. This system is universal and is found in all kingdoms of life. However, bases in DNA and RNA can be chemically modified. In DNA, around 10 different modifications are known, and those have been studied intensively over the past 20 years. Scientific studies on DNA modifications and proteins that recognize them gave rise to the large field of epigenetic and epigenomic research. The outcome of this intense research field is the discovery that development, ageing, and stem-cell dependent regeneration but also several diseases including cancer are largely controlled by the epigenetic state of cells. Consequently, this research has already led to the first FDA approved drugs that exploit the gained knowledge to combat disease. In recent years, the ~150 modifications found in RNA have come to the focus of intense research. Here we provide a perspective on necessary and expected developments in the fast expanding area of RNA modifications, termed epitranscriptomics.


Assuntos
DNA de Neoplasias , Epigênese Genética , Epigenômica/normas , Perfilação da Expressão Gênica/normas , Regulação Neoplásica da Expressão Gênica , Neoplasias , RNA Neoplásico , Transcriptoma , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Europa (Continente) , Perfilação da Expressão Gênica/métodos , Humanos , Neoplasias/genética , Neoplasias/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo
20.
Genes Dev ; 32(5-6): 415-429, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29535189

RESUMO

N6-methyladenosine (m6A) is the most abundant mRNA modification in eukaryotes, playing crucial roles in multiple biological processes. m6A is catalyzed by the activity of methyltransferase-like 3 (Mettl3), which depends on additional proteins whose precise functions remain poorly understood. Here we identified Zc3h13 (zinc finger CCCH domain-containing protein 13)/Flacc [Fl(2)d-associated complex component] as a novel interactor of m6A methyltransferase complex components in Drosophila and mice. Like other components of this complex, Flacc controls m6A levels and is involved in sex determination in Drosophila We demonstrate that Flacc promotes m6A deposition by bridging Fl(2)d to the mRNA-binding factor Nito. Altogether, our work advances the molecular understanding of conservation and regulation of the m6A machinery.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/metabolismo , Drosophila melanogaster/fisiologia , Metiltransferases/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Adenosina/metabolismo , Animais , Proteínas de Ciclo Celular , Linhagem Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimologia , Regulação da Expressão Gênica no Desenvolvimento , Metilação , Camundongos , Células-Tronco Embrionárias Murinas , Transporte Proteico , Precursores de RNA/genética , Splicing de RNA , Fatores de Processamento de RNA , Processos de Determinação Sexual/genética
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