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1.
Elife ; 112022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36355419

RESUMO

Alternative splicing expands the transcriptome and proteome complexity and plays essential roles in tissue development and human diseases. However, how alternative splicing regulates spermatogenesis remains largely unknown. Here, using a germ cell-specific knockout mouse model, we demonstrated that the splicing factor Srsf10 is essential for spermatogenesis and male fertility. In the absence of SRSF10, spermatogonial stem cells can be formed, but the expansion of Promyelocytic Leukemia Zinc Finger (PLZF)-positive undifferentiated progenitors was impaired, followed by the failure of spermatogonia differentiation (marked by KIT expression) and meiosis initiation. This was further evidenced by the decreased expression of progenitor cell markers in bulk RNA-seq, and much less progenitor and differentiating spermatogonia in single-cell RNA-seq data. Notably, SRSF10 directly binds thousands of genes in isolated THY+ spermatogonia, and Srsf10 depletion disturbed the alternative splicing of genes that are preferentially associated with germ cell development, cell cycle, and chromosome segregation, including Nasp, Bclaf1, Rif1, Dazl, Kit, Ret, and Sycp1. These data suggest that SRSF10 is critical for the expansion of undifferentiated progenitors by regulating alternative splicing, expanding our understanding of the mechanism underlying spermatogenesis.


Assuntos
Processamento Alternativo , Espermatogônias , Camundongos , Animais , Masculino , Humanos , Espermatogênese/genética , Diferenciação Celular/genética , Meiose , Camundongos Knockout , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Ciclo Celular/metabolismo
2.
Cell Death Dis ; 13(11): 933, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36344491

RESUMO

Serine/arginine-rich splicing factor 3 (SRSF3) is an RNA binding protein that most often regulates gene expression at the splicing level. Although the role of SRSF3 in mRNA splicing in the nucleus is well known, its splicing-independent role outside of the nucleus is poorly understood. Here, we found that SRSF3 exerts a translational control of p21 mRNA. Depletion of SRSF3 induces cellular senescence and increases the expression of p21 independent of p53. Consistent with the expression patterns of SRSF3 and p21 mRNA in the TCGA database, SRSF3 knockdown increases the p21 mRNA level and its translation efficiency as well. SRSF3 physically associates with the 3'UTR region of p21 mRNA and the translational initiation factor, eIF4A1. Our study proposes a model in which SRSF3 regulates translation by interacting with eIF4A1 at the 3'UTR region of p21 mRNA. We also found that SRSF3 localizes to the cytoplasmic RNA granule along with eIF4A1, which may assist in translational repression therein. Thus, our results provide a new mode of regulation for p21 expression, a crucial regulator of the cell cycle and senescence, which occurs at the translational level and involves SRSF3.


Assuntos
Splicing de RNA , Proteínas de Ligação a RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regiões 3' não Traduzidas/genética , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Proteínas de Ligação a RNA/metabolismo
3.
Contrast Media Mol Imaging ; 2022: 8497078, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36237584

RESUMO

Objective: To investigate the effect of SRSF3 on the viability and metastasis of cervical cancer (CC) SiHa and Hela cells. Methods: In vitro, HeLa cells and SiHa cells were cultured. In cervical cancer cells, RNA interference technology was utilized to lessen the SRSF3 level, and via RT-PCR utilization, the SRSF3 level in every group of cells was revealed. By employing the CCK-8 method, the OD value was revealed in every group at 24, 48, 72, and 96 h. On the migration of cervical cancer SiHa and HeLa cells via transwell utilizing, the consequence of SRSF3 was surveyed. Through western blotting utilizing, the PI3K/AKT/mTOR signaling pathway-connected proteins levels was revealed. Results: In SiHa cells, contrasted to the NC-SiHa group, the SRSF3 level, the number of invasive cells per unit area, the p-PI3K/PI3K level, the p-AKT/AKT level, and the p-mTOR/mTOR level in the si-SRSF3 group were substantially lessened. The OD value at 490 nm of the si-SRSF3 group had no impressive divergence, contrasted to the NC-SiHa group at 24 h. At 48 h, the OD value of the si-SRSF3 group was impressively lessened than that of the NC-SiHa group. This connection was time-dependent. In HeLa cells, the SRSF3 level, the number of invasive cells per unit area, the level of p-PI3K/PI3K, the level of p-AKT/AKT, and the level of p-mTOR/mTOR in the cells of the si-SRSF3 group in the NC-HeLa group were impressively lessened than those in the NC-Hela group. Between the NC-HeLa group and the si-SRSF3 group at 24 h, there was no impressive divergence in the OD value at 490 nm. At 48 h, the OD value of the si-SRSF3 group was impressively lessened than that of the NC-SiHa group. This connection is time-dependent. Conclusion: Reducing the SRSF3 level can restrain the viability and metastasis of cervical cancer cells via restraining the PI3K/AKT/mTOR signaling pathway.


Assuntos
Neoplasias do Colo do Útero , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Feminino , Células HeLa , Humanos , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Neoplasias do Colo do Útero/patologia
4.
Front Immunol ; 13: 906355, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36189299

RESUMO

Cytotoxic CD8 T cells are crucial for the host antigen-specific immune response to viral pathogens. Here we report the identification of an essential role for the serine/arginine-rich splicing factor (SRSF) 1 in CD8 T cell homeostasis and function. Specifically, SRSF1 is necessary for the maintenance of normal CD8 T lymphocyte numbers in the lymphoid compartment, and for the proliferative capacity and cytotoxic function of CD8 T cells. Furthermore, SRSF1 is required for antigen-specific IFN-γ cytokine responses in a viral infection challenge in mice. Transcriptomics analyses of Srsf1-deficient T cells reveal that SRSF1 controls proliferation, MAP kinase signaling and IFN signaling pathways. Mechanistically, SRSF1 controls the expression and activity of the Mnk2/p38-MAPK axis at the molecular level. Our findings reveal previously unrecognized roles for SRSF1 in the physiology and function of cytotoxic CD8 T lymphocytes and a potential molecular mechanism in viral immunopathogenesis.


Assuntos
Linfócitos T CD8-Positivos , Citocinas , Fatores de Processamento de Serina-Arginina/imunologia , Animais , Arginina , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Imunidade , Camundongos , Fatores de Processamento de RNA , Serina , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
5.
Cell Rep ; 40(13): 111404, 2022 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-36170835

RESUMO

Dysregulation of alternative splicing in prostate cancer is linked to transcriptional programs activated by AR, ERG, FOXA1, and MYC. Here, we show that FOXA1 functions as the primary orchestrator of alternative splicing dysregulation across 500 primary and metastatic prostate cancer transcriptomes. We demonstrate that FOXA1 binds to the regulatory regions of splicing-related genes, including HNRNPK and SRSF1. By controlling trans-acting factor expression, FOXA1 exploits an "exon definition" mechanism calibrating alternative splicing toward dominant isoform production. This regulation especially impacts splicing factors themselves and leads to a reduction of nonsense-mediated decay (NMD)-targeted isoforms. Inclusion of the NMD-determinant FLNA exon 30 by FOXA1-controlled oncogene SRSF1 promotes cell growth in vitro and predicts disease recurrence. Overall, we report a role for FOXA1 in rewiring the alternative splicing landscape in prostate cancer through a cascade of events from chromatin access, to splicing factor regulation, and, finally, to alternative splicing of exons influencing patient survival.


Assuntos
Processamento Alternativo , Neoplasias da Próstata , Processamento Alternativo/genética , Cromatina , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Humanos , Masculino , Recidiva Local de Neoplasia , Neoplasias da Próstata/genética , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Transativadores/metabolismo
6.
Oxid Med Cell Longev ; 2022: 8645830, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36062189

RESUMO

Background: Covalently closed circular RNAs (circRNAs) play critical oncogenic or anticancer roles in various cancers including renal cell carcinoma (RCC), pointing to their regulation as a promising strategy against development of RCC. We, thus, studied the tumor-suppressive role of circ_000829 in RCC through in vitro and in vivo experiments. Methods: The expression of circ_000829 was validated in clinical RCC tissues and RCC cell lines. Based on ectopic expression and knockdown experiments, we examined the interactions among circ_000829, serine and arginine rich splicing factor 1 (SRSF1), and solute carrier family 39 member 14 (SLC39A14, zinc transporter). Then, the effects of circ_000829, SRSF1, and SLC39A14 on cell cycle distribution and proliferation in vitro and on tumor growth in vivo were evaluated in RCC cells. Results: Circ_000829 was poorly expressed in RCC tissues and cells, while SRSF1 was highly expressed. Restoration of circ_000829 reduced the levels of SRSF1 and SLC39A14B, thereby repressing the RCC cell proliferation in vitro and tumor growth in vivo. Meanwhile, overexpression of SRSF1 and SLC39A14B promoted the proliferation and cell cycle entry of RCC cells. Mechanistically, circ_000829 directly bound to SRSF1, and SRSF1 enhanced the expression of SLC39A14B by mediating the alternative splicing of SLC39A14. SLC39A14B upregulation negated the effect of SLC39A14 knockdown on RCC cell proliferation. Conclusion: Hence, this study suggests the antiproliferative role of circ_000829 in RCC growth and further elucidates the underlying mechanism involving the inhibited SRSF1-mediated alternative splicing of SLC39A14 mRNA.


Assuntos
Carcinoma de Células Renais , Proteínas de Transporte de Cátions , Neoplasias Renais , RNA Circular , Fatores de Processamento de Serina-Arginina , Processamento Alternativo , Carcinoma de Células Renais/patologia , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Renais/patologia , RNA Circular/genética , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
7.
Int J Mol Sci ; 23(17)2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36077545

RESUMO

Serine/arginine-rich (SR) proteins are a type of splicing factor. They play significant roles in constitutive and alternative pre-mRNA splicing, and are involved in post-splicing activities, such as mRNA nuclear export, nonsense-mediated mRNA decay, mRNA translation, and miRNA biogenesis. In plants, SR proteins function under a complex regulatory network by protein-protein and RNA-protein interactions between SR proteins, other splicing factors, other proteins, or even RNAs. The regulatory networks of SR proteins are complex-they are regulated by the SR proteins themselves, they are phosphorylated and dephosphorylated through interactions with kinase, and they participate in signal transduction pathways, whereby signaling cascades can link the splicing machinery to the exterior environment. In a complex network, SR proteins are involved in plant growth and development, signal transduction, responses to abiotic and biotic stresses, and metabolism. Here, I review the current status of research on plant SR proteins, construct a model of SR proteins function, and ask many questions about SR proteins in plants.


Assuntos
Arginina , Serina , Processamento Alternativo , Arginina/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Precursores de RNA/genética , Splicing de RNA , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Serina/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
8.
Genes (Basel) ; 13(9)2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36140826

RESUMO

Substantial emerging evidence supports that dysregulated RNA metabolism is associated with tumor initiation and development. Serine/Arginine-Rich proteins (SR) are a number of ultraconserved and structurally related proteins that contain a characteristic RS domain rich in arginine and serine residues. SR proteins perform a critical role in spliceosome assembling and conformational transformation, contributing to precise alternative RNA splicing. Moreover, SR proteins have been reported to participate in multiple other RNA-processing-related mechanisms than RNA splicing, such as genome stability, RNA export, and translation. The dysregulation of SR proteins has been reported to contribute to tumorigenesis through multiple mechanisms. Here we reviewed the different biological roles of SR proteins and strategies for functional rectification of SR proteins that may serve as potential therapeutic approaches for cancer.


Assuntos
Neoplasias , Proteínas de Ligação a RNA , Arginina/metabolismo , Humanos , Neoplasias/genética , RNA , Fatores de Processamento de RNA/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Serina , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
9.
Commun Biol ; 5(1): 908, 2022 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-36064747

RESUMO

The blood-tumor barrier (BTB) contributes to poor therapeutic efficacy by limiting drug uptake; therefore, elevating BTB permeability is essential for glioma treatment. Here, we prepared astrocyte microvascular endothelial cells (ECs) and glioma microvascular ECs (GECs) as in vitro blood-brain barrier (BBB) and BTB models. Upregulation of METTL3 and IGF2BP3 in GECs increased the stability of CPEB2 mRNA through its m6A methylation. CPEB2 bound to and increased SRSF5 mRNA stability, which promoted the ETS1 exon inclusion. P51-ETS1 promoted the expression of ZO-1, occludin, and claudin-5 transcriptionally, thus regulating BTB permeability. Subsequent in vivo knockdown of these molecules in glioblastoma xenograft mice elevated BTB permeability, promoted doxorubicin penetration, and improved glioma-specific chemotherapeutic effects. These results provide a theoretical and experimental basis for epigenetic regulation of the BTB, as well as insight into comprehensive glioma treatment.


Assuntos
Neoplasias Encefálicas , Glioma , Metiltransferases , Proteínas de Ligação a RNA , Fatores de Processamento de Serina-Arginina , Animais , Astrócitos/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Células Endoteliais/metabolismo , Epigênese Genética , Glioma/tratamento farmacológico , Glioma/genética , Glioma/metabolismo , Humanos , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Microvasos/metabolismo , Permeabilidade , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo
10.
J Proteome Res ; 21(9): 2211-2223, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-35980772

RESUMO

IQGAP1 (IQ motif-containing GTPase-activating protein 1) scaffolds several signaling pathways in mammalian cells that are implicated in carcinogenesis, including the RAS and PI3K pathways that involve multiple protein kinases. IQGAP1 has been shown to promote head and neck squamous cell carcinoma (HNSCC); however, the underlying mechanism(s) remains unclear. Here, we report a mass spectrometry-based analysis identifying differences in phosphorylation of cellular proteins in vivo and in vitro in the presence or absence of IQGAP1. By comparing the esophageal phosphoproteome profiles between Iqgap1+/+ and Iqgap1-/- mice, we identified RNA splicing as one of the most altered cellular processes. Serine/arginine-rich splicing factor 6 (SRSF6) was the protein with the most downregulated levels of phosphorylation in Iqgap1-/- tissue. We confirmed that the absence of IQGAP1 reduced SRSF6 phosphorylation both in vivo and in vitro. We then expanded our analysis to human normal oral keratinocytes. Again, we found factors involved in RNA splicing to be highly altered in the phosphoproteome profile upon genetic disruption of IQGAP1. Both the Clinical Proteomic Tumor Analysis Consortium (CPTAC) and the Cancer Genome Atlas (TCGA) data sets indicate that phosphorylation of splicing-related proteins is important in HNSCC prognosis. The Biological General Repository for Interaction Datasets (BioGRID) repository also suggested multiple interactions between IQGAP1 and splicing-related proteins. Based on these collective observations, we propose that IQGAP1 regulates the phosphorylation of splicing proteins, which potentially affects their splicing activities and, therefore, contributes to HNSCC. Raw data are available from the MassIVE database with identifier MSV000087770.


Assuntos
Neoplasias de Cabeça e Pescoço , Fosfatidilinositol 3-Quinases , Animais , Neoplasias de Cabeça e Pescoço/genética , Humanos , Mamíferos/metabolismo , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteômica , Splicing de RNA/genética , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/metabolismo
11.
Comput Math Methods Med ; 2022: 3299336, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35959349

RESUMO

Method: Using the tumor database (TCGA) and analysis platform (GEPIA), NUTM2A-AS1 expression in breast cancer cases was compared with the normal cases. In addition, Kaplan-Meier curve of overall survival according to the various levels of NUTM2A-AS1 was assessed. Then, we constructed a knockdown plasmid of NUTM2A-AS1 and successfully reduced the expression function of NUTM2A-AS1 in BC cells. Results: We found NUTM2A-AS1 could promote the malignant phenotype of proliferation and invasion of BC. In terms of mechanism research, NUTM2A-AS1 was mainly located in the cytoplasm of BC cells, which indicated that NUTM2A-AS1 may achieve its function through transcriptional or posttranscriptional regulation pathways. While knocking down NUTM2A-AS1, we detected several major molecules of the trim family. The results showed that only trim37 mRNA was significantly affected, and protein detection also showed that knockdown NUTM2A-AS1 expression could reduce the expression of trim37. The results of RIP experiments suggested that NUTM2A-AS1 played a key role by combining with SRSF1 and affecting the interaction between SRSF1 and trim37 mRNA. The stability test of mRNA also confirmed that during the knockdown of NUTM2A-AS1, the mRNA stability of trim37 decreased significantly, but this downward trend could be reversed by overexpressed SRSF1. The above results suggested that NUTM2A-AS1 could maintain the stability and expression of trim37 through SRSF1 pathway. The results of rescue experiment showed the overexpression of trim37, while knocking down NUTM2A-AS1 could reverse the decrease of proliferation and invasiveness of BC cells induced by NUTM2A-AS1 knockdown. Conclusion: Therefore, trim37 is seen as a necessary target for NUTM2A-AS1 to exert the biological function of BC. Additionally, NUTM2A-AS1 is to regulate the malignant phenotype of BC through NUTM2A-AS1/trim37 pathway.


Assuntos
MicroRNAs , RNA Longo não Codificante , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , RNA Mensageiro/genética , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Transdução de Sinais , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
12.
RNA ; 28(10): 1298-1314, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35863866

RESUMO

Serine/arginine-rich (SR) proteins comprise a family of proteins that is predominantly found in eukaryotes and plays a prominent role in RNA splicing. A characteristic feature of SR proteins is the presence of an S/R-rich low-complexity domain (RS domain), often in conjunction with spatially distinct RNA recognition motifs (RRMs). To date, 52 human proteins have been classified as SR or SR-related proteins. Here, using an unbiased series of composition criteria together with enrichment for known RNA binding activity, we identified >100 putative SR-related proteins in the human proteome. This method recovers known SR and SR-related proteins with high sensitivity (∼94%), yet identifies a number of additional proteins with many of the hallmark features of true SR-related proteins. Newly identified SR-related proteins display slightly different amino acid compositions yet similar levels of post-translational modification, suggesting that these new SR-related candidates are regulated in vivo and functionally important. Furthermore, candidate SR-related proteins with known RNA-binding activity (but not currently recognized as SR-related proteins) are nevertheless strongly associated with a variety of functions related to mRNA splicing and nuclear speckles. Finally, we applied our SR search method to all available reference proteomes, and provide maps of RS domains and Pfam annotations for all putative SR-related proteins as a resource. Together, these results expand the set of SR-related proteins in humans, and identify the most common functions associated with SR-related proteins across all domains of life.


Assuntos
Proteoma , Proteínas de Ligação a RNA , Animais , Arginina/metabolismo , Humanos , Proteínas Nucleares/genética , Proteoma/genética , RNA/metabolismo , Precursores de RNA/genética , Splicing de RNA , RNA Mensageiro/genética , Proteínas de Ligação a RNA/metabolismo , Serina/genética , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
13.
Biochem Biophys Res Commun ; 620: 92-97, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35780586

RESUMO

Excess nutrients are stored as triglycerides, mostly as lipid droplets found in adipose tissue. Previous studies have characterized a group of splicing factors called serine/arginine rich (SR) proteins that function to identify intron/exon borders in regulating metabolic homeostasis in the Drosophila fat body. Decreasing the function of one SR protein, 9G8, causes an increase in triglyceride storage; however, the full complement of genes regulated by 9G8 to control metabolism is unknown. To address this question, we performed RNA sequencing on Drosophila fat bodies with 9G8 levels reduced by RNAi. Differential expression and differential exon usage analyses revealed several genes involved in the immune response, xenobiotic biology, protein translation, sleep, and lipid and carbohydrate metabolism whose expression or splicing is altered in 9G8-RNAi fat bodies. One gene that was both downregulated and had altered splicing in 9G8-RNAi fat bodies was Zwischenferment (Zw), the Drosophila homolog of human glucose 6-phosphate dehydrogenase (G6PD). G6PD regulates flux of glucose 6-phosphate (G6P) into the pentose phosphate pathway, which generates NADPH, a coenzyme for lipid synthesis. Interestingly, the other NADPH-producing enzyme genes in Drosophila (phosphogluconate dehydrogenase, isocitrate dehydrogenase and malic enzyme) were also decreased in 9G8-RNAi flies. Together, these findings suggest that 9G8 regulates several classes of genes and may regulate NADPH-producing enzyme genes to maintain metabolic homeostasis.


Assuntos
Drosophila , Lipídeos , Fatores de Processamento de Serina-Arginina/metabolismo , Animais , Drosophila/metabolismo , Glucose , Glucosefosfato Desidrogenase/metabolismo , Humanos , NADP/metabolismo , Fosfatos/metabolismo , Fatores de Processamento de RNA/metabolismo
14.
Stem Cell Res Ther ; 13(1): 297, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35841017

RESUMO

BACKGROUND: Human urine-derived stem cells (USCs)-derived exosomes (USC-Exo) could improve kidney ischemia/reperfusion injury (IRI), while the underlying mechanisms of this protective effect remain unclear. METHODS: Human USCs and USC-Exo were isolated and verified by morphology and specific biomarkers. The effects of USC-Exo on ferroptosis and kidney injury were detected in the IRI-induced acute kidney injury (AKI) model in C57BL/6 mice. The effects of USC-Exo on ferroptosis and lncRNA taurine-upregulated gene 1 (TUG1) were detected in hypoxia/reoxygenation (H/R)-treated human proximal tubular epithelial cells (HK-2). The interaction of SRSF1 and TUG1, ACSL4 was checked via RNA pull-down/RIP and RNA stability assays. The effects of LncRNA TUG1 on SRSF1/ACSL4-mediated ferroptosis were verified in H/R-treated HK-2 cells and the IRI-induced AKI mouse models. RESULTS: USC-Exo treatment improved kidney injury and ameliorated ferroptosis in IRI-induced AKI mouse models. USC-Exo were rich in lncRNA TUG1, which suppressed ferroptosis in HK-2 cells exposed to H/R. Mechanistically, lncRNA TUG1 regulates the stability of ACSL4 mRNA by interacting with RNA-binding protein SRSF1. In addition, SRSF1 upregulation or ACSL4 downregulation partially reversed the protective effect of lncRNA TUG1 on ferroptosis in H/R-treated HK-2 cells. Further, ACSL4 upregulation partially reversed TUG1's repression on kidney injury and ferroptosis in IRI-induced AKI mice. CONCLUSION: Collectively, lncRNA TUG1 carried by USC-Exo regulated ASCL4-mediated ferroptosis by interacting with SRSF1 and then protected IRI-induced AKI. Potentially, USC-Exo rich in lncRNA TUG1 can serve as a promising therapeutic method for IRI-AKI.


Assuntos
Injúria Renal Aguda , Ferroptose , RNA Longo não Codificante , Traumatismo por Reperfusão , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/terapia , Animais , Ferroptose/genética , Humanos , Hipóxia/metabolismo , Isquemia/metabolismo , Rim/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/terapia , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Células-Tronco/metabolismo , Taurina/metabolismo
15.
Bioorg Med Chem ; 70: 116921, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35863237

RESUMO

>90% of genes in the human body undergo alternative splicing (AS) after transcription, which enriches protein species and regulates protein levels. However, there is growing evidence that various genetic isoforms resulting from dysregulated alternative splicing are prevalent in various types of cancers. Dysregulated alternative splicing leads to cancer generation and maintenance of cancer properties such as proliferation differentiation, apoptosis inhibition, invasion metastasis, and angiogenesis. Serine/arginine-rich proteins and SR protein-associated kinases mediate splice site recognition and splice complex assembly during variable splicing. Based on the impact of dysregulated alternative splicing on disease onset and progression, the search for small molecule inhibitors targeting alternative splicing is imminent. In this review, we discuss the structure and specific biological functions of SR proteins and describe the regulation of SR protein function by SR protein related kinases meticulously, which are closely related to the occurrence and development of various types of cancers. On this basis, we summarize the reported small molecule inhibitors targeting SR proteins and SR protein related kinases from the perspective of medicinal chemistry. We mainly categorize small molecule inhibitors from four aspects, including targeting SR proteins, targeting Serine/arginine-rich protein-specific kinases (SRPKs), targeting Cdc2-like kinases (CLKs) and targeting dual-specificity tyrosine-regulated kinases (DYRKs), in terms of structure, inhibition target, specific mechanism of action, biological activity, and applicable diseases. With this review, we are expected to provide a timely summary of recent advances in alternative splicing regulated by kinases and a preliminary introduction to relevant small molecule inhibitors.


Assuntos
Processamento Alternativo , Serina , Arginina/metabolismo , Humanos , Proteínas Nucleares/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases , Proteínas Tirosina Quinases , Serina/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
16.
J Mol Biol ; 434(18): 167705, 2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-35760371

RESUMO

MicroRNAs (miRNAs) are small, noncoding RNAs that mediate post-transcriptional downregulation of specific target genes. These transcripts are the products of a two-step processing pathway; primary miRNAs (pri-miRNAs) are processed by Drosha into individual precursor miRNA (pre-miRNA) hairpins, which are subsequently processed by Dicer into mature miRNAs. Single nucleotide polymorphisms (SNPs) that occur in pri-miRNAs, pre-miRNAs and mature miRNAs have been shown to affect the processing of specific target genes by modulating Drosha and Dicer processing or interactions with RNA binding proteins (RBPs). Using NMR and single-molecule optical tweezer experiments, we have investigated the conformational effects of a cancer-linked G/A mutation in the terminal loop of pri-miR-30c RNA, and how this influences binding by the SRSF3 and hnRNP A1 RBPs, which are implicated in its processing. Our results reveal that the wildtype and G/A variant pri-miR-30c RNAs adopt very similar elongated stem-loop structures, both of which are bound by SRSF3. However, while both wildtype and G/A pri-miR-30c RNAs can form dimeric kissing hairpin structures, the G to A mutation results in partial destabilization of the dimer in the variant transcript. This promotes recognition and binding by hnRNP A1, an RBP that enhances pri-miR-30c processing. Our data provide structural insight into the conformational effects of a G/A mutation in pri-miR-30c RNA and how this could affect processing and promote cancer.


Assuntos
Ribonucleoproteína Nuclear Heterogênea A1 , MicroRNAs , Neoplasias , Processamento Pós-Transcricional do RNA , Ribonucleoproteína Nuclear Heterogênea A1/metabolismo , Humanos , MicroRNAs/química , MicroRNAs/genética , MicroRNAs/metabolismo , Mutação , Neoplasias/genética , Ressonância Magnética Nuclear Biomolecular , Conformação de Ácido Nucleico , Pinças Ópticas , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Imagem Individual de Molécula
17.
Nat Commun ; 13(1): 3588, 2022 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-35739118

RESUMO

Coordinated regulation of alternative pre-mRNA splicing is essential for germ cell development. However, the underlying molecular mechanism that controls alternative mRNA expression during germ cell development remains elusive. Herein, we show that hnRNPH1 is highly expressed in the reproductive system and recruits the PTBP2 and SRSF3 to modulate the alternative splicing in germ cells. Conditional knockout Hnrnph1 in spermatogenic cells causes many abnormal splicing events, thus affecting the genes related to meiosis and communication between germ cells and Sertoli cells. This is characterized by asynapsis of chromosomes and impairment of germ-Sertoli communications, which ultimately leads to male sterility. Markedly, Hnrnph1 germline-specific mutant female mice are also infertile, and Hnrnph1-deficient oocytes exhibit a similar defective synapsis and cell-cell junction as seen in Hnrnph1-deficient male germ cells. Collectively, our data support a molecular model wherein hnRNPH1 governs a network of alternative splicing events in germ cells via recruitment of PTBP2 and SRSF3.


Assuntos
Processamento Alternativo , Ribonucleoproteínas Nucleares Heterogêneas , Proteínas do Tecido Nervoso , Proteína de Ligação a Regiões Ricas em Polipirimidinas , Fatores de Processamento de Serina-Arginina , Animais , Feminino , Células Germinativas/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/genética , Masculino , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Splicing de RNA , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Células de Sertoli/metabolismo
18.
Cell Rep ; 39(12): 110985, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35732114

RESUMO

Non-core spliceosome components are essential, conserved regulators of alternative splicing. They provide concentration-dependent control of diverse pre-mRNAs. Many splicing factors direct unproductive splicing of their own pre-mRNAs through negative autoregulation. However, the impact of such feedback loops on splicing dynamics at the single-cell level remains unclear. Here, we developed a system to quantitatively analyze negative autoregulatory splicing dynamics by splicing factor SRSF1 in response to perturbations in single HEK293 cells. We show that negative autoregulatory splicing provides critical functions for gene regulation, establishing a ceiling of SRSF1 protein concentration, reducing cell-cell heterogeneity in SRSF1 levels, and buffering variation in transcription. Most important, it adapts SRSF1 splicing activity to variations in demand from other pre-mRNA substrates. A minimal mathematical model of autoregulatory splicing explains these experimentally observed features and provides values for effective biochemical parameters. These results reveal the unique functional roles that splicing negative autoregulation plays in homeostatically regulating transcriptional programs.


Assuntos
Processamento Alternativo , Precursores de RNA , Processamento Alternativo/genética , Células HEK293 , Homeostase , Humanos , Precursores de RNA/genética , Precursores de RNA/metabolismo , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
19.
Nat Commun ; 13(1): 2791, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589755

RESUMO

Tumour cell plasticity is a major barrier to the efficacy of targeted cancer therapies but the mechanisms that mediate it are poorly understood. Here, we identify dysregulated RNA splicing as a key driver of tumour cell dedifferentiation in colorectal cancer (CRC). We find that Apc-deficient CRC cells have dysregulated RNA splicing machinery and exhibit global rewiring of RNA splicing. We show that the splicing factor SRSF1 controls the plasticity of tumour cells by controlling Kras splicing and is required for CRC invasion in a mouse model of carcinogenesis. SRSF1 expression maintains stemness in human CRC organoids and correlates with cancer stem cell marker expression in human tumours. Crucially, partial genetic downregulation of Srsf1 does not detrimentally affect normal tissue homeostasis, demonstrating that tumour cell plasticity can be differentially targeted. Thus, our findings link dysregulation of the RNA splicing machinery and control of tumour cell plasticity.


Assuntos
Plasticidade Celular , Neoplasias Colorretais , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Plasticidade Celular/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Camundongos , Splicing de RNA/genética , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
20.
Cells ; 11(9)2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35563766

RESUMO

N6-methyladenosine (m6A) is a well-known RNA modification and has various functions with its binding proteins. Nuclear m6A reader protein YTHDC1 plays a significant role in RNA metabolism including some non-coding RNA such as LINE or circRNA. It is also known to regulate mRNA splicing through recruiting SRSF3 to the targeted mRNAs, which then mediates export of YTHDC1-bound RNA to the cytoplasm. Additionally, it has been indicated that SRSF3 binding to YHTDC1 may be mediated by its dephosphorylated status. However, their binding mechanism, including the positions of dephosphorylated residues of SRSF3, has not been sufficiently investigated. Thus, we explored the mechanism of interaction between SRSF3 and YTHDC1 in human cells. We used co-immunoprecipitation to examine the binding of YTHDC1/SRSF3 through their N- and C-terminal amino-acid residues. Furthermore, dephosphorylation-mimic serine to alanine mutants of SRSF3 indicated the position of phosphorylated residues. Cumulatively, our results demonstrate that YTHDC1 binding to SRSF3 is regulated by not only hypo-phosphorylated residues of arginine/serine-rich (RS) domain of SRSF3 but also other parts of SRSF3 via YTHDC1 N- or C-terminal residues. Our results contribute to the understanding of the complex mechanism of binding between SR protein SRSF3 and the m6A reader YTHDC1 to regulate the expression of mRNA and non-coding RNAs.


Assuntos
Splicing de RNA , Serina , Humanos , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Fatores de Processamento de RNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Serina/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo
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