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1.
Cell Mol Biol Lett ; 29(1): 39, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38504159

RESUMO

BACKGROUND: IGF2BP3 functions as an RNA-binding protein (RBP) and plays a role in the posttranscriptional control of mRNA localization, stability, and translation. Its dysregulation is frequently associated with tumorigenesis across various cancer types. Nonetheless, our understanding of how the expression of the IGF2BP3 gene is regulated remains limited. The specific functions and underlying mechanisms of IGF2BP3, as well as the potential benefits of targeting it for therapeutic purposes in bladder cancer, are not yet well comprehended. METHODS: The mRNA and protein expression were examined by RT-qPCR and western blotting, respectively. The methylation level of CpG sites was detected by Bisulfite sequencing PCR (BSP). The regulation of IGF2BP3 expression by miR-320a-3p was analyzed by luciferase reporter assay. The functional role of IGF2BP3 was determined through proliferation, colony formation, wound healing, invasion assays, and xenograft mouse model. The regulation of HMGB1 by IGF2BP3 was investigated by RNA immunoprecipitation (RIP) and mRNA stability assays. RESULTS: We observed a significant elevation in IGF2BP3 levels within bladder cancer samples, correlating with more advanced stages and grades, as well as an unfavorable prognosis. Subsequent investigations revealed that the upregulation of IGF2BP3 expression is triggered by copy number gain/amplification and promoter hypomethylation in various tumor types, including bladder cancer. Furthermore, miR-320a-3p was identified as another negative regulator in bladder cancer. Functionally, the upregulation of IGF2BP3 expression exacerbated bladder cancer progression, including the proliferation, migration, and invasion of bladder cancer. Conversely, IGF2BP3 silencing produced the opposite effects. Moreover, IGF2BP3 expression positively correlated with inflammation and immune infiltration in bladder cancer. Mechanistically, IGF2BP3 enhanced mRNA stability and promoted the expression of HMGB1 by binding to its mRNA, which is a factor that promotes inflammation and orchestrates tumorigenesis in many cancers. Importantly, pharmacological inhibition of HMGB1 with glycyrrhizin, a specific HMGB1 inhibitor, effectively reversed the cancer-promoting effects of IGF2BP3 overexpression in bladder cancer. Furthermore, the relationship between HMGB1 mRNA and IGF2PB3 is also observed in mammalian embryonic development, with the expression of both genes gradually decreasing as embryonic development progresses. CONCLUSIONS: Our present study sheds light on the genetic and epigenetic mechanisms governing IGF2BP3 expression, underscoring the critical involvement of the IGF2BP3-HMGB1 axis in driving bladder cancer progression. Additionally, it advocates for the investigation of inhibiting IGF2BP3-HMGB1 as a viable therapeutic approach for treating bladder cancer.


Assuntos
Proteína HMGB1 , MicroRNAs , Neoplasias da Bexiga Urinária , Humanos , Animais , Camundongos , MicroRNAs/genética , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Linhagem Celular Tumoral , Carcinogênese/genética , Metilação de DNA , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estabilidade de RNA , Inflamação/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Mamíferos/genética
2.
Methods Mol Biol ; 2760: 95-114, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38468084

RESUMO

We describe a new way to trigger mRNA degradation in Saccharomyces cerevisiae synthetic gene circuits. Our method demands to modify either the 5'- or the 3'-UTR that flanks a target gene with elements from the pre-crRNA of type V Cas12a proteins and expresses a DNase-deficient Cas12a (dCas12a). dCas12a recognizes and cleaves the pre-crRNA motifs on mRNA sequences. Our tool does not require complex engineering operations and permits an efficient control of protein expression via mRNA degradation.


Assuntos
RNA Guia de Sistemas CRISPR-Cas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Genes Sintéticos , Desoxirribonucleases/metabolismo , Estabilidade de RNA , Sistemas CRISPR-Cas
3.
Proc Natl Acad Sci U S A ; 121(14): e2308814121, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38527194

RESUMO

RNA decay is a crucial mechanism for regulating gene expression in response to environmental stresses. In bacteria, RNA-binding proteins (RBPs) are known to be involved in posttranscriptional regulation, but their global impact on RNA half-lives has not been extensively studied. To shed light on the role of the major RBPs ProQ and CspC/E in maintaining RNA stability, we performed RNA sequencing of Salmonella enterica over a time course following treatment with the transcription initiation inhibitor rifampicin (RIF-seq) in the presence and absence of these RBPs. We developed a hierarchical Bayesian model that corrects for confounding factors in rifampicin RNA stability assays and enables us to identify differentially decaying transcripts transcriptome-wide. Our analysis revealed that the median RNA half-life in Salmonella in early stationary phase is less than 1 min, a third of previous estimates. We found that over half of the 500 most long-lived transcripts are bound by at least one major RBP, suggesting a general role for RBPs in shaping the transcriptome. Integrating differential stability estimates with cross-linking and immunoprecipitation followed by RNA sequencing (CLIP-seq) revealed that approximately 30% of transcripts with ProQ binding sites and more than 40% with CspC/E binding sites in coding or 3' untranslated regions decay differentially in the absence of the respective RBP. Analysis of differentially destabilized transcripts identified a role for ProQ in the oxidative stress response. Our findings provide insights into posttranscriptional regulation by ProQ and CspC/E, and the importance of RBPs in regulating gene expression.


Assuntos
Perfilação da Expressão Gênica , Rifampina , Teorema de Bayes , Meia-Vida , Transcriptoma , Proteínas de Ligação a RNA/metabolismo , RNA/metabolismo , Salmonella/metabolismo , Estabilidade de RNA/genética
4.
Plant Mol Biol ; 114(1): 18, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353826

RESUMO

Microalgae represent a promising but yet underexplored production platform for biotechnology. The vast majority of studies on recombinant protein expression in algae have been conducted in a single species, the green alga Chlamydomonas reinhardtii. However, due to epigenetic silencing, transgene expression in Chlamydomonas is often inefficient. Here we have investigated parameters that govern efficient transgene expression in the red microalga Porphyridium purpureum. Porphyridium is unique in that the introduced transformation vectors are episomally maintained as autonomously replicating plasmids in the nucleus. We show that full codon optimization to the preferred codon usage in the Porphyridium genome confers superior transgene expression, not only at the level of protein accumulation, but also at the level of mRNA accumulation, indicating that high translation rates increase mRNA stability. Our optimized expression constructs resulted in YFP accumulation to unprecedented levels of up to 5% of the total soluble protein. We also designed expression cassettes that target foreign proteins to the secretory pathway and lead to efficient protein secretion into the culture medium, thus simplifying recombinant protein harvest and purification. Our study paves the way to the exploration of red microalgae as expression hosts in molecular farming for recombinant proteins and metabolites.


Assuntos
Chlamydomonas reinhardtii , Microalgas , Porphyridium , Porphyridium/genética , Biotecnologia , Estabilidade de RNA , Chlamydomonas reinhardtii/genética , Microalgas/genética , Proteínas Recombinantes/genética
5.
Ecotoxicol Environ Saf ; 272: 116067, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38325270

RESUMO

In order to comprehend the underlying mechanisms contributing to the development and exacerbation of asthma resulting from exposure to fine particulate matter (PM2.5), we established an asthmatic model in fat mass and obesity-associated gene knockdown mice subjected to PM2.5 exposure. Histological analyses using hematoxylin-eosin (HE) and Periodic Acid-Schiff (PAS) staining revealed that the down-regulation of the fat mass and obesity-associated gene (Fto) expression significantly ameliorated the pathophysiological alterations observed in asthmatic mice exposed to PM2.5. Furthermore, the down-regulation of Fto gene expression effectively attenuated damage to the airway epithelial barrier. Additionally, employing in vivo and in vitro models, we elucidated that PM2.5 modulated FTO expression by inducing oxidative stress. Asthmatic mice exposed to PM2.5 exhibited elevated Fto expression, which correlated with increased levels of reactive oxygen species. Similarly, when cells were exposed to PM2.5, FTO expression was up-regulated in a ROS-dependent manner. Notably, the administration of N-acetyl cysteine successfully reversed the PM2.5-induced elevation in FTO expression. Concurrently, we performed transcriptome-wide Methylated RNA immunoprecipitation Sequencing (MeRIP-seq) analysis subsequent to PM2.5 exposure. Through the implementation of Gene Set Enrichment Analysis and m6A-IP-qPCR, we successfully identified inhibitor of nuclear factor kappa B kinase subunit beta (IKBKB) as a target gene regulated by FTO. Interestingly, exposure to PM2.5 led to increased expression of IKBKB, while m6A modification on IKBKB mRNA was reduced. Furthermore, our investigation revealed that PM2.5 also regulated IKBKB through oxidative stress. Significantly, the down-regulation of IKBKB effectively mitigated epithelial barrier damage in cells exposed to PM2.5 by modulating nuclear factor-kappa B (NF-κB) signaling. Importantly, we discovered that decreased m6A modification on IKBKB mRNA facilitated by FTO enhanced its stability, consequently resulting in up-regulation of IKBKB expression. Collectively, our findings propose a novel role for FTO in the regulation of IKBKB through m6A-dependent mRNA stability in the context of PM2.5-induced oxidative stress. Therefore, it is conceivable that the utilization of antioxidants or inhibition of FTO could represent potential therapeutic strategies for the management of asthma exacerbated by PM2.5 exposure.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato , Asma , Quinase I-kappa B , Animais , Camundongos , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Asma/induzido quimicamente , Asma/genética , Quinase I-kappa B/metabolismo , Obesidade , Estresse Oxidativo/genética , Material Particulado/toxicidade , Estabilidade de RNA , RNA Mensageiro/metabolismo
6.
J Cell Biol ; 223(3)2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38349334

RESUMO

The cell cycle is a highly regulated process in which proteins involved in cell cycle progression exhibit periodic expression patterns, controlled by specific mechanisms such as transcription, translation, and degradation. However, the precise mechanisms underlying the oscillations of mRNA levels in cell cycle regulators are not fully understood. In this study, we observed that the stability of cyclin D1 (CCND1) mRNA fluctuates during the cell cycle, with increased stability during interphase and decreased stability during the M phase. Additionally, we identified a key RNA binding protein, positive coactivator 4 (PC4), which plays a crucial role in stabilizing CCND1 mRNA and regulating its periodic expression. Moreover, the binding affinity of PC4 to CCND1 mRNA is modulated by two cell cycle-specific posttranslational modifications: ubiquitination of K68 enhances binding and stabilizes the CCND1 transcript during interphase, while phosphorylation of S17 inhibits binding during the M phase, leading to degradation of CCND1 mRNA. Remarkably, PC4 promotes the transition from G1 to S phase in the cell cycle, and depletion of PC4 enhances the efficacy of CDK4/6 inhibitors in hepatocellular carcinoma, suggesting that PC4 could serve as a potential therapeutic target. These findings provide valuable insights into the intricate regulation of cell cycle dynamics.


Assuntos
Ciclo Celular , Ciclina D1 , Estabilidade de RNA , Proteínas de Ligação a RNA , Ciclo Celular/genética , Divisão Celular , Ciclina D1/genética , Proteínas Inibidoras de Quinase Dependente de Ciclina , Estabilidade de RNA/genética , RNA Mensageiro/genética , Masculino , Animais , Camundongos , Camundongos Endogâmicos BALB C , Humanos , Linhagem Celular Tumoral , Proteínas de Ligação a RNA/genética , Fosforilação , Ubiquitinação
7.
Biochem Soc Trans ; 52(1): 481-490, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38385526

RESUMO

Non-structural protein 1 (Nsp1) is one of the first proteins produced during coronaviral infections. It plays a pivotal role in hijacking and rendering the host gene expression under the service of the virus. With a focus on SARS-CoV-2, this review presents how Nsp1 selectively inhibits host protein synthesis and induces mRNA degradation of host but not viral mRNAs and blocks nuclear mRNA export. The clinical implications of this protein are highlighted by showcasing the pathogenic role of Nsp1 through the repression of interferon expression pathways and the features of viral variants with mutations in the Nsp1 coding sequence. The ability of SARS-CoV-2 Nsp1 to hinder host immune responses at an early step, the absence of homology to any human proteins, and the availability of structural information render this viral protein an ideal drug target with therapeutic potential.


Assuntos
Biossíntese de Proteínas , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estabilidade de RNA
8.
Int J Mol Sci ; 25(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38339002

RESUMO

The ever-increasing applications of metabarcoding analyses for environmental samples demand a well-designed assessment of the stability of DNA and RNA contained in cells that are deposited or buried in marine sediments. We thus conducted a qPCR quantification of the DNA and RNA in the vegetative cells of three microalgae entrapped in facsimile marine sediments and found that >90% of DNA and up to 99% of RNA for all microalgal species were degraded within 60 days at 4 °C. A further examination of the potential interference of the relic DNA of the vegetative cells with resting cyst detection in sediments was performed via a metabarcoding analysis in artificial marine sediments spiked with the vegetative cells of two Kareniaceae dinoflagellates and the resting cysts of another three dinoflagellates. The results demonstrated a dramatic decrease in the relative abundances of the two Kareniaceae dinoflagellates in 120 days, while those of the three resting cysts increased dramatically. Together, our results suggest that a positive detection of microalgae via metabarcoding analysis in DNA or RNA extracted from marine sediments strongly indicates the presence of intact or viable cysts or spores due to the rapid decay of relic DNA/RNA. This study provides a solid basis for the data interpretation of metabarcoding surveys, particularly in resting cyst detection.


Assuntos
Dinoflagelados , Microalgas , Microalgas/genética , DNA , Dinoflagelados/genética , Código de Barras de DNA Taxonômico/métodos , RNA/genética , Estabilidade de RNA , Sedimentos Geológicos
9.
J Mol Biol ; 436(6): 168492, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360088

RESUMO

Many insulin gene variants alter the protein sequence and result in monogenic diabetes due to insulin insufficiency. However, the molecular mechanisms of various disease-causing mutations are unknown. Insulin is synthesized as preproinsulin containing a signal peptide (SP). SPs of secreted proteins are recognized by the signal recognition particle (SRP) or by another factor in a SRP-independent pathway. If preproinsulin uses SRP-dependent or independent pathways is still debatable. We demonstrate by the use of site-specific photocrosslinking that the SRP subunit, SRP54, interacts with the preproinsulin SP. Moreover, SRP54 depletion leads to the decrease of insulin mRNA and protein expression, supporting the involvement of the RAPP protein quality control in insulin biogenesis. RAPP regulates the quality of secretory proteins through degradation of their mRNA. We tested five disease-causing mutations in the preproinsulin SP on recognition by SRP and on their effects on mRNA and protein levels. We demonstrate that the effects of mutations are associated with their position in the SP and their severity. The data support diverse molecular mechanisms involved in the pathogenesis of these mutations. We show for the first time the involvement of the RAPP protein quality control pathway in insulin biogenesis that is implicated in the development of neonatal diabetes caused by the Leu13Arg mutation.


Assuntos
Insulina , Precursores de Proteínas , Estabilidade de RNA , Partícula de Reconhecimento de Sinal , Humanos , Recém-Nascido , Diabetes Mellitus , Insulina/genética , Insulina/metabolismo , Precursores de Proteínas/metabolismo , Sinais Direcionadores de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Partícula de Reconhecimento de Sinal/metabolismo
10.
J Mol Biol ; 436(6): 168496, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38365086

RESUMO

Stalling of ribosomes engaged in protein synthesis can lead to significant defects in the function of newly synthesized proteins and thereby impair protein homeostasis. Consequently, partially synthesized polypeptides resulting from translation stalling are recognized and eliminated by several quality control mechanisms. First, if translation elongation reactions are halted prematurely, a quality control mechanism called ribosome-associated quality control (RQC) initiates the ubiquitination of the nascent polypeptide chain and subsequent proteasomal degradation. Additionally, when ribosomes with defective codon recognition or peptide-bond formation stall during translation, a quality control mechanism known as non-functional ribosomal RNA decay (NRD) leads to the degradation of malfunctioning ribosomes. In both of these quality control mechanisms, E3 ubiquitin ligases selectively recognize ribosomes in distinct translation-stalling states and ubiquitinate specific ribosomal proteins. Significant efforts have been devoted to characterize E3 ubiquitin ligase sensing of ribosome 'collision' or 'stalling' and subsequent ribosome is rescued. This article provides an overview of our current understanding of the molecular mechanisms and physiological functions of ribosome dynamics control and quality control of abnormal translation.


Assuntos
Elongação Traducional da Cadeia Peptídica , Estabilidade de RNA , Ribossomos , Peptídeos/metabolismo , Proteínas Ribossômicas/genética , Ribossomos/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Humanos , Animais , RNA Mensageiro/metabolismo
11.
Oncogene ; 43(13): 976-991, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38361047

RESUMO

Cellular senescence plays a critical role in cancer development, but the underlying mechanisms remain poorly understood. Our recent study uncovered that replicative senescent colorectal cancer (CRC) cells exhibit increased levels of mRNA N6-methyladenosine (m6A) and methyltransferase METTL3. Knockdown of METTL3 can restore the senescence-associated secretory phenotype (SASP) of CRC cells. Our findings, which were confirmed by m6A-sequencing and functional studies, demonstrate that the cyclin-dependent kinase inhibitor 2B (CDKN2B, encoding p15INK4B) is a mediator of METTL3-regulated CRC senescence. Specifically, m6A modification at position A413 in the coding sequence (CDS) of CDKN2B positively regulates its mRNA stability by recruiting IGF2BP3 and preventing binding with the CCR4-NOT complex. Moreover, increased METTL3 methylates and stabilizes the mRNA of E2F1, which binds to the -208 to -198 regions of the CDKN2B promoter to facilitate transcription. Inhibition of METTL3 or specifically targeting CDKN2B methylation can suppress CRC senescence. Finally, the METTL3/CDKN2B axis-induced senescence can facilitate M2 macrophage polarization and is correlated with aging and CRC progression. The involvement of METTL3/CDKN2B in cell senescence provides a new potential therapeutic target for CRC treatment and expands our understanding of mRNA methylation's role in cellular senescence.


Assuntos
Neoplasias Colorretais , Metiltransferases , Humanos , Metiltransferases/metabolismo , Senescência Celular/genética , Neoplasias Colorretais/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estabilidade de RNA/genética
12.
J Cell Biol ; 223(3)2024 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-38393314

RESUMO

The expression of cyclin proteins is tightly regulated during the cell cycle, to allow precise activation of cyclin-dependent kinases. In this issue, Pan et al. (https://doi.org/10.1083/jcb.202308066) identify an RNA-binding protein, PC4, as a regulator of cyclin D1 mRNA stability in hepatocellular carcinoma cells. This study provides a new mechanism regulating the levels of a key cell cycle protein, cyclin D1, in human cells.


Assuntos
Ciclina D1 , Proteínas de Ligação a DNA , Estabilidade de RNA , Fatores de Transcrição , Humanos , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Ciclina D1/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Fosforilação , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Linhagem Celular Tumoral
13.
mBio ; 15(2): e0316823, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38236021

RESUMO

YTH N6-methyladenosine RNA-binding protein F2 (YTHDF2) is a member of the YTH protein family that binds to N6-methyladenosine (m6A)-modified RNA, regulating RNA stability and restricting viral replication, including Epstein-Barr virus (EBV). PIAS1 is an E3 small ubiquitin-like modifier (SUMO) ligase known as an EBV restriction factor, but its role in YTHDF2 SUMOylation remains unclear. In this study, we investigated the functional regulation of YTHDF2 by PIAS1. We found that PIAS1 promotes the SUMOylation of YTHDF2 at three specific lysine residues (K281, K571, and K572). Importantly, PIAS1 synergizes with wild-type YTHDF2, but not a SUMOylation-deficient mutant, to limit EBV lytic replication. Mechanistically, YTHDF2 lacking SUMOylation exhibits reduced binding to EBV transcripts, leading to increased viral mRNA stability. Furthermore, PIAS1 mediates SUMOylation of YTHDF2's paralogs, YTHDF1 and YTHDF3, to restrict EBV replication. These results collectively uncover a unique mechanism whereby YTHDF family proteins control EBV replication through PIAS1-mediated SUMOylation, highlighting the significance of SUMOylation in regulating viral mRNA stability and EBV replication.IMPORTANCEm6A RNA modification pathway plays important roles in diverse cellular processes and viral life cycle. Here, we investigated the relationship between PIAS1 and the m6A reader protein YTHDF2, which is involved in regulating RNA stability by binding to m6A-modified RNA. We found that both the N-terminal and C-terminal regions of YTHDF2 interact with PIAS1. We showed that PIAS1 promotes the SUMOylation of YTHDF2 at three specific lysine residues. We also demonstrated that PIAS1 enhances the anti-EBV activity of YTHDF2. We further revealed that PIAS1 mediates the SUMOylation of other YTHDF family members, namely, YTHDF1 and YTHDF3, to limit EBV replication. These findings together illuminate an important regulatory mechanism of YTHDF proteins in controlling viral RNA decay and EBV replication through PIAS1-mediated SUMOylation.


Assuntos
Adenina/análogos & derivados , Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Humanos , Herpesvirus Humano 4/fisiologia , Sumoilação , RNA Viral/genética , RNA Viral/metabolismo , Lisina/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Estabilidade de RNA , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Proteínas Inibidoras de STAT Ativados/genética , Proteínas Inibidoras de STAT Ativados/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
14.
Nucleic Acids Res ; 52(4): 1558-1574, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38224449

RESUMO

MicroRNAs (miRNAs) guide Argonaute (AGO) proteins to bind mRNA targets. Although most targets are destabilized by miRNA-AGO binding, some targets induce degradation of the miRNA instead. These special targets are also referred to as trigger RNAs. All triggers identified thus far have binding sites with greater complementarity to the miRNA than typical target sites. Target-directed miRNA degradation (TDMD) occurs when trigger RNAs bind the miRNA-AGO complex and recruit the ZSWIM8 E3 ubiquitin ligase, leading to AGO ubiquitination and proteolysis and subsequent miRNA destruction. More than 100 different miRNAs are regulated by ZSWIM8 in bilaterian animals, and hundreds of trigger RNAs have been predicted computationally. Disruption of individual trigger RNAs or ZSWIM8 has uncovered important developmental and physiologic roles for TDMD across a variety of model organisms and cell types. In this review, we highlight recent progress in understanding the mechanistic basis and functions of TDMD, describe common features of trigger RNAs, outline best practices for validating trigger RNAs, and discuss outstanding questions in the field.


Assuntos
MicroRNAs , Estabilidade de RNA , Animais , Proteínas Argonautas/metabolismo , Sítios de Ligação , MicroRNAs/genética , MicroRNAs/metabolismo , Proteólise , Ubiquitinação
15.
J Virol ; 98(1): e0135023, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38169284

RESUMO

Epitranscriptomic RNA modifications can regulate the stability of mRNA and affect cellular and viral RNA functions. The N4-acetylcytidine (ac4C) modification in the RNA viral genome was recently found to promote viral replication; however, the mechanism by which RNA acetylation in the host mRNA regulates viral replication remains unclear. To help elucidate this mechanism, the roles of N-acetyltransferase 10 (NAT10) and ac4C during the infection and replication processes of the alphavirus, Sindbis virus (SINV), were investigated. Cellular NAT10 was upregulated, and ac4C modifications were promoted after alphavirus infection, while the loss of NAT10 or inhibition of its N-acetyltransferase activity reduced alphavirus replication. The NAT10 enhanced alphavirus replication as it helped to maintain the stability of lymphocyte antigen six family member E mRNA, which is a multifunctional interferon-stimulated gene that promotes alphavirus replication. The ac4C modification was thus found to have a non-conventional role in the virus life cycle through regulating host mRNA stability instead of viral mRNA, and its inhibition could be a potential target in the development of new alphavirus antivirals.IMPORTANCEThe role of N4-acetylcytidine (ac4C) modification in host mRNA and virus replication is not yet fully understood. In this study, the role of ac4C in the regulation of Sindbis virus (SINV), a prototype alphavirus infection, was investigated. SINV infection results in increased levels of N-acetyltransferase 10 (NAT10) and increases the ac4C modification level of cellular RNA. The NAT10 was found to positively regulate SINV infection in an N-acetyltransferase activity-dependent manner. Mechanistically, the NAT10 modifies lymphocyte antigen six family member E (LY6E) mRNA-the ac4C modification site within the 3'-untranslated region (UTR) of LY6E mRNA, which is essential for its translation and stability. The findings of this study demonstrate that NAT10 regulated mRNA stability and translation efficiency not only through the 5'-UTR or coding sequence but also via the 3'-UTR region. The ac4C modification of host mRNA stability instead of viral mRNA impacting the viral life cycle was thus identified, indicating that the inhibition of ac4C could be a potential target when developing alphavirus antivirals.


Assuntos
Infecções por Alphavirus , Antígenos de Superfície , Proteínas Ligadas por GPI , Acetiltransferases N-Terminal , Vírus Sindbis , Replicação Viral , Humanos , Infecções por Alphavirus/genética , Antígenos de Superfície/genética , Citidina/análogos & derivados , Proteínas Ligadas por GPI/genética , RNA Mensageiro/genética , Vírus Sindbis/fisiologia , Linhagem Celular , Acetiltransferases N-Terminal/genética , Estabilidade de RNA
16.
Methods Mol Biol ; 2741: 255-272, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38217658

RESUMO

Bacterial small RNAs (sRNAs) can be equipped at the 5' end with triphosphate (5'PPP) or monophosphate (5'P) groups, depending on whether they are primary transcripts, undergo dephosphorylation or originate via processing. Often, 5' groups hallmark RNAs for rapid decay, but whether this also applies to sRNAs is little explored. Moreover, the sRNA 5'P group could activate endoribonuclease RNase E to cleave the base-paired target RNA, but a tool for investigation in vivo was lacking. Here, we describe a two-plasmid system suitable for the generation of 5' monophosphorylated RNAs on demand inside the cell. The sRNA gene of interest is fused to the 3' end of a fragment of sRNA GlmZ and transcribed from a plasmid in an IPTG-inducible manner. The fusion RNA gets cleaved upon arabinose-controlled expression of rapZ, provided on a compatible plasmid. Adaptor protein RapZ binds the GlmZ aptamer and directs RNase E to release the sRNA of choice with 5'P ends. An isogenic plasmid generating the same sRNA with a 5'PPP end allows for direct comparison. The fates of the sRNA variants and target RNA(s) are monitored by Northern blotting. This tool is applicable to E. coli and likely other enteric bacteria.


Assuntos
Proteínas de Escherichia coli , Pequeno RNA não Traduzido , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fosforilação , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , Estabilidade de RNA , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/metabolismo , Regulação Bacteriana da Expressão Gênica
17.
BMC Cancer ; 24(1): 93, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38233795

RESUMO

BACKGROUND: Several publications suggest that UTP11 may be a promising gene engaged for involvement of hepatocellular carcinoma (HCC) pathology. However, there are extremely limited biological, mechanistic and clinical studies of UTP11 in HCC. METHODS: To anayze the UTP11 mRNA expression in HCC and normal clinical samples and further investigate the correlation between UTP11 expression and pathology and clinical prognosis via the Cancer Tissue Gene Atlas (TCGA) database. The protein levels of UTP11 were checked using the Human Protein Atlas (HPA) database. GO-KEGG enrichment was performed from Cancer Cell Line Encyclopedia (CCLE) database and TCGA dataset. The levels of UTP11 were tested with qRT-PCR and western blotting assays. Cell viability, immunofluorescence and flow cytometry assays and animal models were used to explore the potential involvement of UTP11 in regulating HCC growth in vitro and in vivo. The correlation of UTP11 and tumor stemness scores and stemness-associated proteins from TCGA database. The mRNA stability was treated with Actinomycin D, followed by testing the mRNA expression using qRT-PCR assay. RESULTS: UTP11 was highly expressed in HCC samples compared to normal tissues from TCGA database. Similarly, UTP11 protein expression levels were obviously elevated in HCC tissue samples from HPA database. Furthermore, UTP11 levels were correlated with poor prognosis in HCC patient samples in TCGA dataset. In addition, the UTP11 mRNA levels was notably enhanced in different HCC cell lines than in normal liver cells and knocking down UTP11 was obviously reduced the viability and cell death of HCC cells. UTP11 knockdown suppressed the tumor growth of HCC in vivo experiment and extended the mice survival time. GO-KEEG analysis from CCLE and TCGA database suggested that UTP11 might involve in RNA splicing and the stability of mRNA. Further, UTP11 was positively correlated with tumor stemness scores and stemness-associated proteins from TCGA database. Knockdown of UTP11 was reduced the expression of stem cell-related genes and regulated the mRNA stability of Oct4. CONCLUSIONS: UTP11 is potentially a diagnostic molecule and a therapeutic candidate for treatment of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , Prognóstico , Estabilidade de RNA , RNA Mensageiro/genética
18.
Autoimmunity ; 57(1): 2304820, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38269483

RESUMO

Circular RNA (circRNA) has been found to be differentially expressed and involved in regulating the processes of human diseases, including thoracic aortic dissection (TAD). However, the role and mechanism of circNRIP1 in the TAD process are still unclear. GEO database was used to screen the differentially expressed circRNA and mRNA in type A TAD patients and age-matched normal donors. Angiotensin II (Ang II)-induced human aortic vascular smooth muscle cells (HA-VSMCs) were used to construct TAD cell models. The expression levels of circNRIP1, NRIP1, CXC-motif chemokine 5 (CXCL5) and IGF2BP1 were detected by quantitative real-time PCR. Cell proliferation and migration were determined by EdU assay, transwell assay and wound healing assay. The protein levels of synthetic phenotype markers, contractile phenotype markers, CXCL5 and IGF2BP1 were tested by western blot analysis. The interaction between IGF2BP1 and circNRIP1/CXCL5 was confirmed by RIP assay, and CXCL5 mRNA stability was assessed by actinomycin D assay. CircNRIP1 was upregulated in TAD patients and Ang II-induced HA-VSMCs. Knockdown of circNRIP1 suppressed Ang II-induced proliferation, migration and phenotypic switch of HA-VSMCs. Also, high expression of CXCL5 was observed in TAD patients, and its knockdown could inhibit Ang II-induced HA-VSMCs proliferation, migration and phenotypic switch. Moreover, CXCL5 overexpression reversed the regulation of circNRIP1 knockdown on Ang II-induced HA-VSMCs functions. Mechanistically, circNRIP1 could competitively bind to IGF2BP1 and subsequently enhance CXCL5 mRNA stability. CircNRIP1 might contribute to TAD progression by promoting CXCL5 mRNA stability via recruiting IGF2BP1.


Assuntos
Angiotensina II , Músculo Liso Vascular , Humanos , Angiotensina II/farmacologia , Proliferação de Células , Quimiocina CXCL5/genética , Fenótipo , Estabilidade de RNA , RNA Circular/genética
19.
J Reprod Dev ; 70(1): 10-17, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38057116

RESUMO

Poly(A)-binding proteins (PABPs) play roles in mRNA maturation, translational activity, and decay. The functions of PABPs, especially PABPN1 and PABPC1, in somatic cells have been well-studied. However, little is known about the roles of PABPs in oocytes because of the unique mechanisms of mRNA metabolism in oocytes. This study focused on PABPN1L and generated Pabpn1l knockout (KO) mice using the CRISPR/Cas9 system. After mating tests, we found that Pabpn1l KO females were infertile due to the failure of the embryos to develop to the 4-cell stage. RNA-seq analysis revealed aberrant mRNA persistence in Pabpn1l KO-MII oocytes, which indicates impaired mRNA degradation during the germinal vesicle (GV) to MII transition. We also revealed that the exogenous expression of Pabpn1l mRNA in KO-GV oocytes recovered defects of embryonic development. PABPN1L is partly indispensable for female fertility in mice, owing to its necessity for embryonic development, which is supported by mRNA degradation during GV to MII maturation.


Assuntos
Oócitos , RNA Mensageiro Estocado , Gravidez , Feminino , Animais , Camundongos , RNA Mensageiro Estocado/metabolismo , Oócitos/metabolismo , Meiose , RNA Mensageiro/metabolismo , Estabilidade de RNA
20.
Adv Sci (Weinh) ; 11(1): e2305142, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37983610

RESUMO

IGF2BP2 is a new identified N6-methyladenosine (m6A) reader and associated with poor prognosis in many tumors. However, its role and related mechanism in breast cancer, especially in triple-negative breast cancer (TNBC), remains unclear. In this study, it is found that IGF2BP2 is highly expressed in TNBC due to the lower methylation level in its promoter region. Functional and mechanical studies displayed that IGF2BP2 could promote TNBC proliferation and the G1/S phase transition of the cell cycle via directly regulating CDK6 in an m6A-dependent manner. Surprising, the regulation of protein levels of CDK6 by IGF2BP2 is related to the changes in translation rate during translation initiation, rather than mRNA stability. Moreover, EIF4A1 is found to be recruited by IGF2BP2 to promote the translation output of CDK6, providing new evidence for a regulatory role of IGF2BP2 between m6A methylation and translation. Downregulation of IGF2BP2 in TNBC cell could enhance the sensitivity to abemaciclib, a CDK4/6 inhibitor. To sum up, our study revealed IGF2BP2 could facilitate the translation output of CDK6 via recruiting EIF4A1 and also provided a potential therapeutic target for the diagnosis and treatment of TNBC, as well as a new strategy for broadening the drug indications for CDK4/6 inhibitors.


Assuntos
Neoplasias de Mama Triplo Negativas , Humanos , Neoplasias de Mama Triplo Negativas/genética , Ciclo Celular/genética , Regulação para Baixo , Estabilidade de RNA , Proteínas de Ligação a RNA/genética , Quinase 6 Dependente de Ciclina/genética
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