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1.
RNA ; 30(3): 271-280, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38164604

RESUMEN

The human U1 snRNA is encoded by a multigene family consisting of transcribed variants and defective pseudogenes. Many variant U1 (vU1) snRNAs have been demonstrated to not only be transcribed but also processed by the addition of a trimethylated guanosine cap, packaged into snRNPs, and assembled into spliceosomes; however, their capacity to facilitate pre-mRNA splicing has, so far, not been tested. A recent systematic analysis of the human snRNA genes identified 178 U1 snRNA genes that are present in the genome as either tandem arrays or single genes on multiple chromosomes. Of these, 15 were found to be expressed in human tissues and cell lines, although at significantly low levels from their endogenous loci, <0.001% of the canonical U1 snRNA. In this study, we found that placing the variants in the context of the regulatory elements of the RNU1-1 gene improves the expression of many variants to levels comparable to the canonical U1 snRNA. Application of a previously established HeLa cell-based minigene reporter assay to examine the capacity of the vU1 snRNAs to support pre-mRNA splicing revealed that even though the exogenously expressed variant snRNAs were enriched in the nucleus, only a few had a measurable effect on splicing.


Asunto(s)
Precursores del ARN , Empalme del ARN , Humanos , Precursores del ARN/genética , Precursores del ARN/metabolismo , Células HeLa , ARN Nuclear Pequeño/genética , ARN Nuclear Pequeño/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35101980

RESUMEN

In mammals, the structural basis for the interaction between U1 and U2 small nuclear ribonucleoproteins (snRNPs) during the early steps of splicing is still elusive. The binding of the ubiquitin-like (UBL) domain of SF3A1 to the stem-loop 4 of U1 snRNP (U1-SL4) contributes to this interaction. Here, we determined the 3D structure of the complex between the UBL of SF3A1 and U1-SL4 RNA. Our crystallography, NMR spectroscopy, and cross-linking mass spectrometry data show that SF3A1-UBL recognizes, sequence specifically, the GCG/CGC RNA stem and the apical UUCG tetraloop of U1-SL4. In vitro and in vivo mutational analyses support the observed intermolecular contacts and demonstrate that the carboxyl-terminal arginine-glycine-glycine-arginine (RGGR) motif of SF3A1-UBL binds sequence specifically by inserting into the RNA major groove. Thus, the characterization of the SF3A1-UBL/U1-SL4 complex expands the repertoire of RNA binding domains and reveals the capacity of RGG/RG motifs to bind RNA in a sequence-specific manner.


Asunto(s)
Factores de Empalme de ARN/química , Ribonucleoproteína Nuclear Pequeña U1/química , Ribonucleoproteína Nuclear Pequeña U2/química , Cristalografía por Rayos X , Humanos , Resonancia Magnética Nuclear Biomolecular , Motivos de Nucleótidos , Factores de Empalme de ARN/genética , Ribonucleoproteína Nuclear Pequeña U1/genética , Ribonucleoproteína Nuclear Pequeña U2/genética
3.
J Med Virol ; 96(4): e29555, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38546037

RESUMEN

In this study, we demonstrated the antiviral efficacy of hesperetin against multiple poxviruses, including buffalopox virus (BPXV), vaccinia virus (VACV), and lumpy skin disease virus (LSDV). The time-of-addition and virus step-specific assays indicated that hesperetin reduces the levels of viral DNA, mRNA, and proteins in the target cells. Further, by immunoprecipitation (IP) of the viral RNA from BPXV-infected Vero cells and a cell-free RNA-IP assay, we demonstrated that hesperetin-induced reduction in BPXV protein synthesis is also consistent with diminished interaction between eukaryotic translation initiation factor eIF4E and the 5' cap of viral mRNA. Molecular docking and MD simulation studies were also consistent with the binding of hesperetin to the cap-binding pocket of eIF4E, adopting a conformation similar to m7GTP binding. Furthermore, in a BPXV egg infection model, hesperetin was shown to suppress the development of pock lesions on the chorioallantoic membrane and associated mortality in the chicken embryos. Most importantly, long-term culture of BPXV in the presence of hesperetin did not induce the generation of drug-resistant viral mutants. In conclusion, we, for the first time, demonstrated the antiviral activity of hesperetin against multiple poxviruses, besides providing some insights into its potential mechanisms of action.


Asunto(s)
Factor 4E Eucariótico de Iniciación , Hesperidina , Virus Vaccinia , Animales , Bovinos , Chlorocebus aethiops , Embrión de Pollo , Células Vero , Simulación del Acoplamiento Molecular , Virus Vaccinia/genética , Antivirales/farmacología , ARN Mensajero , Replicación Viral
4.
Trop Anim Health Prod ; 56(7): 226, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39093442

RESUMEN

Since 2019, Lumpy skin disease (LSD) has suddenly spread in many Asian countries, including India. LSD primarily occurs in cattle. However, recent LSD outbreaks in India have also revealed significant morbidity and production losses in buffaloes. This has raised concerns about the role of buffaloes in the epidemiology and transmission of LSD and necessitates the inclusion of buffaloes in the mass vaccination program for the prevention and control of the disease in the country. However, there is no significant data on the immune response in buffaloes following vaccination with the LSD vaccine. In this study, we evaluated antibody- and cell-mediated immune responses following vaccination with a newly developed live-attenuated LSD vaccine (Lumpi-ProVacInd). The detectable amount of anti-LSDV antibodies was observed at 1-2 months following vaccination, with a peak antibody titer at 3 months. Upon stimulation of the peripheral blood mononuclear cells (PBMCs) with the UV-inactivated LSDV antigen, there was a significant increase in CD8 + T cell counts in vaccinated animals as compared to the unvaccinated animals. Besides, vaccinated animals also showed a significant increase in IFN-γ levels upon antigenic stimulation of their PBMCs with LSDV antigen. In conclusion, the buffaloes also mount a potent antibody- and cell-mediated immune response following vaccination with Lumpi-ProVacInd.


Asunto(s)
Búfalos , Dermatosis Nodular Contagiosa , Virus de la Dermatosis Nodular Contagiosa , Vacunas Atenuadas , Vacunas Virales , Animales , Búfalos/inmunología , Dermatosis Nodular Contagiosa/prevención & control , Dermatosis Nodular Contagiosa/inmunología , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/inmunología , Virus de la Dermatosis Nodular Contagiosa/inmunología , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología , India , Inmunidad Celular , Anticuerpos Antivirales/sangre , Vacunación/veterinaria , Leucocitos Mononucleares/inmunología , Femenino
5.
Mol Biol Evol ; 39(9)2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35975687

RESUMEN

Host-dependency factors have increasingly been targeted to minimize antiviral drug resistance. In this study, we have demonstrated that inhibition of p38 mitogen-activated protein kinase (a cellular protein) suppresses buffalopox virus (BPXV) protein synthesis by targeting p38-MNK1-eIF4E signaling pathway. In order to provide insights into the evolution of drug resistance, we selected resistant mutants by long-term sequential passages (P; n = 60) in the presence of p38 inhibitor (SB239063). The P60-SB239063 virus exhibited significant resistance to SB239063 as compared to the P60-Control virus. To provide mechanistic insights on the acquisition of resistance by BPXV-P60-SB239063, we generated p38-α and p38-ϒ (isoforms of p38) knockout Vero cells by CRISPR/Cas9-mediated genome editing. It was demonstrated that unlike the wild type (WT) virus which is dependent on p38-α isoform, the resistant virus (BPXV-P60-SB239063) switches over to use p38-ϒ so as to efficiently replicate in the target cells. This is a rare evidence wherein a virus was shown to bypass the dependency on a critical cellular factor under selective pressure of a drug.


Asunto(s)
Antivirales , Virus Vaccinia , Animales , Antivirales/farmacología , Chlorocebus aethiops , Farmacorresistencia Viral/genética , Virus Vaccinia/metabolismo , Células Vero , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
6.
Nature ; 547(7661): 89-93, 2017 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-28636592

RESUMEN

T cells are defined by a heterodimeric surface receptor, the T cell receptor (TCR), that mediates recognition of pathogen-associated epitopes through interactions with peptide and major histocompatibility complexes (pMHCs). TCRs are generated by genomic rearrangement of the germline TCR locus, a process termed V(D)J recombination, that has the potential to generate marked diversity of TCRs (estimated to range from 1015 (ref. 1) to as high as 1061 (ref. 2) possible receptors). Despite this potential diversity, TCRs from T cells that recognize the same pMHC epitope often share conserved sequence features, suggesting that it may be possible to predictively model epitope specificity. Here we report the in-depth characterization of ten epitope-specific TCR repertoires of CD8+ T cells from mice and humans, representing over 4,600 in-frame single-cell-derived TCRαß sequence pairs from 110 subjects. We developed analytical tools to characterize these epitope-specific repertoires: a distance measure on the space of TCRs that permits clustering and visualization, a robust repertoire diversity metric that accommodates the low number of paired public receptors observed when compared to single-chain analyses, and a distance-based classifier that can assign previously unobserved TCRs to characterized repertoires with robust sensitivity and specificity. Our analyses demonstrate that each epitope-specific repertoire contains a clustered group of receptors that share core sequence similarities, together with a dispersed set of diverse 'outlier' sequences. By identifying shared motifs in core sequences, we were able to highlight key conserved residues driving essential elements of TCR recognition. These analyses provide insights into the generalizable, underlying features of epitope-specific repertoires and adaptive immune recognition.


Asunto(s)
Epítopos de Linfocito T/química , Epítopos de Linfocito T/inmunología , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/inmunología , Algoritmos , Animales , Linfocitos T CD8-positivos/química , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Análisis por Conglomerados , Femenino , Humanos , Masculino , Ratones Endogámicos C57BL , Receptores de Antígenos de Linfocitos T alfa-beta/química , Receptores de Antígenos de Linfocitos T alfa-beta/inmunología , Especificidad por Sustrato , Recombinación V(D)J
7.
Somatosens Mot Res ; 40(1): 8-24, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36576096

RESUMEN

BACKGROUND: Knee osteoarthritis (KOA) is commonly associated with multiple musculoskeletal impairments. OBJECTIVE: The purpose of this review was (1) to investigate the effectiveness of LLLT plus ET on pain, ROM, muscle strength, and function in KOA immediately after therapy and (2) whether the effectiveness of LLLT plus ET could be sustained at follow-up (4 - 32 weeks). METHODS: Six databases were systematically searched upto December 2021 to find relevant articles. Included studies were RCTs written in English, which compared LLLT plus ET with placebo LLLT plus ET in KOA. Three independent reviewers extracted data and assessed the quality of included studies. Standard mean difference (SMD) was used in meta-analysis using random effect model. RESULT: Of the 6307 articles, 14 RCTs (820 patients) met the inclusion criteria. The results demonstrated that there was a significant difference in pain immediately after therapy (SMD: -0.58, p = 0.001) and at follow-up (SMD: -1.35, p = 0.05) in LLLT plus ET group. There were no significant differences in knee ROM, muscle strength, and knee function outcomes immediately and at follow-up. CONCLUSION: Our findings indicate that LLLT plus ET could be considered to alleviate pain in the KOA. LLLT reduces pain at 4-8J with a wavelength of 640-905nm per point applied for 10-16 sessions at a frequency of 2 sessions/week. An exercise therapy program at prescribed dosage involving major muscle groups might help. However, LLLT plus ET is no more effective than placebo LLLT plus ET in improving ROM, muscle strength, and function in KOA.


Asunto(s)
Terapia por Luz de Baja Intensidad , Osteoartritis de la Rodilla , Humanos , Osteoartritis de la Rodilla/terapia , Terapia por Luz de Baja Intensidad/métodos , Dolor , Terapia por Ejercicio , Rango del Movimiento Articular , Fuerza Muscular
8.
Somatosens Mot Res ; : 1-18, 2023 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-36825612

RESUMEN

BACKGROUND: The benefits of Blood Flow Restriction Therapy (BFRT) have gained attention in recent times. OBJECTIVE: This review aimed to evaluate the immediate (up to 24 hours), intermediate (up to 6 weeks), and long term (6-10 weeks) effects of BFRT plus exercises (EX) compared to EX only on athletic performance (sprint and jump performance), muscle strength, and hypertrophy in athletes and physically active population. METHODS: A literature search was conducted to select randomized controlled trials across four electronic databases from inception till April 2021. The search yielded twenty-seven studies in total. RESULTS: Based on eligibility criteria, twenty-one studies were analyzed. No differences were found between both groups for immediate (standardized mean difference [SMD] -0.02, 95% confidence interval [CI] -0.31, 0.27) and long-term effects (SMD -0.30, 95%CI -0.90, 0.30) on sprint performance. For jump performance, no significant effect was observed immediately (SMD -0.02 (95% CI -1.06, 1.02) and long term (SMD -0.40 (95% CI -1.46, 0.67). Similarly, muscle torque at intermediate (SMD 0.90 (95% CI -1.01, 2.81) and long term (SMD -0.54 (95% CI -1.19, 0.12), muscle strength at intermediate (SMD 1.12 (95% CI 0.20, 2.04) , and long term (SMD -0.07 (95% CI -0.56, 0.42) also showed non-significant effects. Muscle hypertrophy at intermediate (SMD 0.16 (95% CI -0.31, 0.63) and long term (SMD -0.20 (95% CI -0.90, 0.50) were not statistically significant. CONCLUSIONS: There was no significant difference observed in BFRT plus EX group compared to the EX-group on athletic performance, muscle strength, and muscle hypertrophy.

9.
Luminescence ; 38(7): 999-1010, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35997211

RESUMEN

Nanomaterials are gaining enormous interests due to their novel applications that have been explored nearly in every field of our contemporary society. In this scenario, preparations of nanomaterials following green routes have attracted widespread attention in terms of sustainable, reliable, and environmentally friendly practices to produce diverse nanostructures. In this review, we summarize the fundamental processes and mechanisms of green synthesis approaches of TiO2 nanoparticles (NPs). We explore the role of plants and microbes as natural bioresources to prepare TiO2 NPs. Particularly, focus has been made to explore the potential of TiO2 -based nanomaterials to design a variety of sensing platforms by exploiting the photocatalysis efficiency under the influence of a light source. These types of sensing are of massive importance for monitoring environmental pollution and therefore for inventing advanced strategies to remediate hazardous pollutants and offer a clean environment.


Asunto(s)
Nanopartículas , Nanoestructuras , Nanotecnología , Nanoestructuras/química , Contaminación Ambiental
10.
Neuroradiology ; 64(9): 1801-1818, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35435463

RESUMEN

PURPOSE: Primary objective of this study was to retrospectively evaluate the potential of a range of qualitative and quantitative multiparametric features assessed on T2, post-contrast T1, DWI, DCE-MRI, and susceptibility-weighted-imaging (SWI) in differentiating evenly sampled cohort of primary-central-nervous-system-lymphoma (PCNSL) vs glioblastoma (GB) with pathological validation. METHODS: The study included MRI-data of histopathologically confirmed ninety-five GB and PCNSL patients scanned at 3.0 T MRI. A total of six qualitative features (three from T2 and post-contrast T1, three from SWI: thin-linear-uninterrupted-intra-tumoral-vasculature, broken-intra-tumoral-microvasculature, hemorrhage) were analyzed by three independent radiologists. Ten quantitative features from DWI and DCE-MRI were computed using in-house-developed algorithms. For qualitative features, Cohen's Kappa-interrater-variability-analysis was performed. Z-test and independent t-tests were performed to find significant qualitative and quantitative features respectively. Logistic-regression (LR) classifiers were implemented for evaluating performance of individual and various combinations of features in differentiating PCNSL vs GB. Performance evaluation was done via ROC-analysis. Pathological validation was performed to verify disintegration of vessel walls in GB and rim of viable neoplastic lymphoid cells with angiocentric-pattern in PCNSL. RESULTS: Three qualitative SWI features and four quantitative DCE-MRI features (rCBVcorr, Kep, Ve, and necrosis-volume-percentage) were significantly different (p < 0.05) between PCNSL and GB. Best diagnostic performance was observed with LR classifier using SWI features (AUC-0.99). The inclusion of quantitative features with SWI feature did not improve the differentiation accuracy. CONCLUSIONS: The combination of three qualitative SWI features using LR provided the highest accuracy in differentiating PCNSL and GB. Thin-linear-uninterrupted-intra-tumoral-vasculature in PCNSL and broken-intra-tumoral-microvasculature with hemorrhage in GB are the major contributors to the differentiation.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Linfoma , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/patología , Sistema Nervioso Central/patología , Diagnóstico Diferencial , Glioblastoma/diagnóstico por imagen , Glioblastoma/patología , Humanos , Linfoma/diagnóstico por imagen , Linfoma/patología , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos
11.
J Sports Sci ; 40(21): 2444-2460, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36604650

RESUMEN

This review sought to assess the dose-response, i.e., low (<300 mg/day) and high (>300 mg/day), and temporal effects of ginseng, i.e., immediate, short-term (up to 4 weeks) and long-term (>4 weeks) in comparison to placebo on physical performance [visual analogue scale (VAS) level, vertical jump(VJ), rating of perceived exertion (RPE), peak power output (PPO)] and physiological measures [VO2 max, creatine kinase(CK), heart rate(HR)], in athletes and active participants. Search in four databases with English language constraints yielded 492 studies. Fourteen studies were shortlisted through PEDro scale by methodological quality evaluation. Ginseng exhibited significant short-term effect at high dosage for VJ improvement (SMD: -8.17, 95% CI: -16.28 to -0.06, p= 0.05). Ginseng had no effect on VAS (SMD: -0.65, 95% CI: -1.35 to 0.06, p= 0.07), RPE (SMD: -1.11, 95% CI: -2.57 to 0.35, p= 0.14), PPO (SMD: -0.70, 95% CI: -1.78 to 0.38, p= 0.20), HR (SMD: -0.54, 95% CI: -2.05 to 0.96, p= 0.48), CK (SMD: 0.33, 95% CI: -0.18 to 0.84, p= 0.21) and VO2 max (SMD: 0.08, 95% CI: -0.69 to 0.85, p= 0.08).The ginseng supplementation was found to have significant short-term effect at high dose only for VJ in athletic and active participants. Methodologically strong research is warranted to further consolidate these findings.


Asunto(s)
Panax , Sustancias para Mejorar el Rendimiento , Deportes , Humanos , Atletas , Creatina Quinasa , Suplementos Dietéticos
12.
Emerg Radiol ; 29(4): 791-799, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35482173

RESUMEN

Infectious diseases affecting the central nervous system remain an important cause of morbidity and mortality in developing countries and in immunocompromised patients. Cerebritis refers to pyogenic inflammation of the brain parenchyma that may lead to abscess formation if left untreated. Cerebritis is an uncommon diagnosis as patients are usually diagnosed at the stage of abscess formation. We present three cases of bacterial cerebritis with different clinical manifestations and varied appearances on MRI. To our knowledge, only few case reports of bacterial cerebritis have been published in the literature, and imaging findings are not fully elucidated. These cases of bacterial cerebritis add valuable information to the existing literature and would be helpful in making the appropriate diagnosis of this uncommon condition that can be medically managed if diagnosed appropriately. We recommend that cerebritis should be considered in the differential diagnosis of such lesions.


Asunto(s)
Absceso Encefálico , Encéfalo/patología , Absceso Encefálico/diagnóstico por imagen , Absceso Encefálico/tratamiento farmacológico , Diagnóstico Diferencial , Humanos , Imagen por Resonancia Magnética
13.
Genes Dev ; 28(22): 2518-31, 2014 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-25403181

RESUMEN

The pairing of 5' and 3' splice sites across an intron is a critical step in spliceosome formation and its regulation. Interactions that bring the two splice sites together during spliceosome assembly must occur with a high degree of specificity and fidelity to allow expression of functional mRNAs and make particular alternative splicing choices. Here, we report a new interaction between stem-loop 4 (SL4) of the U1 snRNA, which recognizes the 5' splice site, and a component of the U2 small nuclear ribonucleoprotein particle (snRNP) complex, which assembles across the intron at the 3' splice site. Using a U1 snRNP complementation assay, we found that SL4 is essential for splicing in vivo. The addition of free U1-SL4 to a splicing reaction in vitro inhibits splicing and blocks complex assembly prior to formation of the prespliceosomal A complex, indicating a requirement for a SL4 contact in spliceosome assembly. To characterize the interactions of this RNA structure, we used a combination of stable isotope labeling by amino acids in cell culture (SILAC), biotin/Neutravidin affinity pull-down, and mass spectrometry. We show that U1-SL4 interacts with the SF3A1 protein of the U2 snRNP. We found that this interaction between the U1 snRNA and SF3A1 occurs within prespliceosomal complexes assembled on the pre-mRNA. Thus, SL4 of the U1 snRNA is important for splicing, and its interaction with SF3A1 mediates contact between the 5' and 3' splice site complexes within the assembling spliceosome.


Asunto(s)
Empalme del ARN/fisiología , ARN Nuclear Pequeño/metabolismo , Ribonucleoproteína Nuclear Pequeña U2/metabolismo , Empalmosomas/metabolismo , Células HeLa , Humanos , Secuencias Invertidas Repetidas/genética , Mutación , Unión Proteica/genética , Sitios de Empalme de ARN , Empalme del ARN/genética , Factores de Empalme de ARN , ARN Nuclear Pequeño/genética
14.
Clin Microbiol Rev ; 33(3)2020 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-32404434

RESUMEN

Antiviral drugs have traditionally been developed by directly targeting essential viral components. However, this strategy often fails due to the rapid generation of drug-resistant viruses. Recent genome-wide approaches, such as those employing small interfering RNA (siRNA) or clustered regularly interspaced short palindromic repeats (CRISPR) or those using small molecule chemical inhibitors targeting the cellular "kinome," have been used successfully to identify cellular factors that can support virus replication. Since some of these cellular factors are critical for virus replication, but are dispensable for the host, they can serve as novel targets for antiviral drug development. In addition, potentiation of immune responses, regulation of cytokine storms, and modulation of epigenetic changes upon virus infections are also feasible approaches to control infections. Because it is less likely that viruses will mutate to replace missing cellular functions, the chance of generating drug-resistant mutants with host-targeted inhibitor approaches is minimized. However, drug resistance against some host-directed agents can, in fact, occur under certain circumstances, such as long-term selection pressure of a host-directed antiviral agent that can allow the virus the opportunity to adapt to use an alternate host factor or to alter its affinity toward the target that confers resistance. This review describes novel approaches for antiviral drug development with a focus on host-directed therapies and the potential mechanisms that may account for the acquisition of antiviral drug resistance against host-directed agents.


Asunto(s)
Sistemas CRISPR-Cas , Desarrollo de Medicamentos , Factores Celulares Derivados del Huésped/antagonistas & inhibidores , ARN Interferente Pequeño , Replicación Viral/genética , Animales , Marcación de Gen , Factores Celulares Derivados del Huésped/genética , Interacciones Huésped-Patógeno/genética , Humanos , Ratones , Virus/genética
15.
RNA ; 25(11): 1509-1521, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31383795

RESUMEN

During splicing of pre-mRNA, 5' and 3' splice sites are brought within proximity by interactions between the pre-mRNA bound U1 and U2 snRNPs, followed by recruitment of the tri-snRNP for assembly of the mature spliceosome. Previously, we identified an interaction between the U2 snRNP-specific protein SF3A1 and the stem-loop 4 (SL4) of the U1 snRNA that occurs during the early steps of spliceosome assembly. Although harboring many annotated domains, SF3A1 lacks a canonical RNA binding domain. To identify the U1-SL4 binding region in SF3A1, we expressed amino- and carboxy-terminal deletion constructs using a HeLa cell-based cell free expression system. UV-crosslinking of the truncated proteins with 32P-U1-SL4 RNA identified the carboxy-terminal ubiquitin-like (UBL) domain of SF3A1 as the RNA binding region. Characterization of the interaction between SF3A1-UBL and U1-SL4 by electrophoretic mobility shift assay and surface plasmon resonance determined high binding affinity (KD = ∼97 nM), and revealed the double-stranded G-C rich stem of U1-SL4 as an important feature for binding to the UBL domain. Further, mutations of two conserved tyrosine residues, Y772 and Y773, were found to cause a two- and fivefold decrease in the binding affinity for U1-SL4, respectively. Finally, we found that SF3A1-UBL can specifically pull down the U1 snRNP from HeLa nuclear extract, demonstrating its capacity to bind U1-SL4 in the context of the intact snRNP. Thus, the data show that the UBL domain of SF3A1 can function as an RNA binding domain and that mutations in this region may interfere with U1-SL4 binding.


Asunto(s)
Factores de Empalme de ARN/metabolismo , ARN/metabolismo , Sitios de Unión , Ensayo de Cambio de Movilidad Electroforética , Células HeLa , Humanos , Unión Proteica , ARN Nuclear Pequeño/metabolismo , Ubiquitina/metabolismo
16.
PLoS Pathog ; 15(5): e1007789, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31095644

RESUMEN

The highly conserved proteins of the 14-3-3 family are universal adaptors known to regulate an enormous range of cellular processes in eukaryotes. However, their biological functions remain largely uncharacterized in pathogenic protists comprising of several 14-3-3 protein isoforms. In this study, we report the role of 14-3-3 in coordinating cytoskeletal dynamics during phagocytosis in a professional phagocytic protist Entamoeba histolytica, the etiological agent of human amebiasis. There are three isoforms of 14-3-3 protein in amoeba and here we have investigated Eh14-3-3 Protein 3 (EhP3). Live and fixed cell imaging studies revealed the presence of this protein throughout the parasite phagocytosis process, with high rate of accumulation at the phagocytic cups and closed phagosomes. Conditional suppression of EhP3 expression caused significant defects in phagocytosis accompanied by extensive diminution of F-actin at the site of cup formation. Downregulated cells also exhibited defective recruitment of an F-actin stabilizing protein, EhCoactosin at the phagocytic cups. In addition, mass spectrometry based analysis further revealed a large group of EhP3-associated proteins, many of these proteins are known to regulate cytoskeletal architecture in E histolytica. The dynamics of these proteins may also be controlled by EhP3. Taken together, our findings strongly suggest that EhP3 is a novel and a key regulatory element of actin dynamics and phagocytosis in E. histolytica.


Asunto(s)
Proteínas 14-3-3/metabolismo , Actinas/metabolismo , Citoesqueleto/metabolismo , Entamebiasis/parasitología , Eritrocitos/parasitología , Fagocitosis , Proteínas Protozoarias/metabolismo , Proteínas 14-3-3/genética , Secuencia de Aminoácidos , Animales , Entamoeba histolytica/fisiología , Entamebiasis/metabolismo , Eritrocitos/metabolismo , Femenino , Humanos , Inmunización , Ratones , Ratones Endogámicos BALB C , Filogenia , Proteínas Protozoarias/genética , Homología de Secuencia
17.
RNA Biol ; 18(12): 2576-2593, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34105434

RESUMEN

During spliceosome assembly, interactions that bring the 5' and 3' ends of an intron in proximity are critical for the production of mature mRNA. Here, we report synergistic roles for the stem-loops 3 (SL3) and 4 (SL4) of the human U1 small nuclear RNA (snRNA) in maintaining the optimal U1 snRNP function, and formation of cross-intron contact with the U2 snRNP. We find that SL3 and SL4 bind distinct spliceosomal proteins and combining a U1 snRNA activity assay with siRNA-mediated knockdown, we demonstrate that SL3 and SL4 act through the RNA helicase UAP56 and the U2 protein SF3A1, respectively. In vitro analysis using UV crosslinking and splicing assays indicated that SL3 likely promotes the SL4-SF3A1 interaction leading to enhancement of A complex formation and pre-mRNA splicing. Overall, these results highlight the vital role of the distinct contacts of SL3 and SL4 in bridging the pre-mRNA bound U1 and U2 snRNPs during the early steps of human spliceosome assembly.


Asunto(s)
Conformación de Ácido Nucleico , Precursores del ARN/genética , Empalme del ARN , ARN Mensajero/genética , ARN Nuclear Pequeño/genética , Secuencia de Bases , Humanos , Intrones , Precursores del ARN/química , ARN Mensajero/química , ARN Nuclear Pequeño/química
18.
Reprod Domest Anim ; 56(5): 736-743, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33559234

RESUMEN

In cattle production systems, an intense selection pressure for production traits has resulted in the decline of fertility traits. To optimize an efficient reproduction system, the inclusion of both male and female fertility traits in the selection process is very much essential. RAPD (Random Amplified Polymorphic DNA) was developed as a molecular biology tool and has been extensively used, to study intra- and interspecific genetic diversity. The present study was undertaken to utilize RAPD primers to investigate the association between DNA markers and semen quality traits viz. Sperm concentration, total sperm count ejaculate and initial sperm motility and thereby to identify good/poor semen producers. DNA isolated from the blood samples of healthy bulls was subjected to RAPD-PCR. The multiple regression analysis followed by independent t test was carried out to identify suitable markers. Based on the results, only 12 bands were identified as marker suitable for any of the quality trait. This includes, OPA2 ~ 760, OPA2 ~ 700, OPA6 ~ 1,200, OPA9 ~ 400, OPA9 ~ 380, OPA12 ~ 970, OPA14 ~ 715, OPA14 ~ 605, OPA16 ~ 485, OPA17 ~ 860 and OPA18 ~ 480. Multiple regression analysis selected, OPA2 ~ 760 and OPA2 ~ 1,750 for sperm concentration and OPA2 ~ 760, OPA2 ~ 700, OPA9 ~ 620, OPA4 ~ 670 and OPA18 ~ 1,015 for total sperm count/ejaculate. But the t test revealed a significant association between OPA2 ~ 760 and total sperm count. Further, discriminant function analysis also identified this marker in the first step itself. The results of the present study can be exploited as a low-cost alternative strategy for identification of good /poor semen producers in crossbred bulls at an early age.


Asunto(s)
Bovinos/genética , Técnica del ADN Polimorfo Amplificado Aleatorio/veterinaria , Análisis de Semen/veterinaria , Animales , ADN/sangre , Masculino , Técnica del ADN Polimorfo Amplificado Aleatorio/métodos , Recuento de Espermatozoides/veterinaria , Motilidad Espermática/genética
19.
Genomics ; 112(2): 1598-1610, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31521711

RESUMEN

Understanding male gametophyte development is essential to augment hybrid production in sorghum. Although small RNAs are known to critically influence anther/pollen development, their roles in sorghum reproduction have not been deciphered yet. Here, we report small RNA profiling and high-confidence annotation of microRNAs (miRNAs) from meiotic and post-meiotic anthers in sorghum. We identified 262 miRNAs (82 known and 180 novel), out of which 58 (35 known and 23 novel) exhibited differential expression between two stages. Out of 35 differentially expressed known miRNAs, 13 are known to regulate anther/pollen development in other plant species. We also demonstrated conserved spatiotemporal patterns of 21- and 24-nt phasiRNAs and their respective triggers, miR2118 and miR2275, in sorghum anthers as evidenced in other monocots. miRNA target identification yielded 5622 modules, of which 46 modules comprising 16 known and 8 novel miRNA families with 38 target genes are prospective candidates for engineering male fertility in grasses.


Asunto(s)
Redes Reguladoras de Genes , Meiosis , MicroARNs/genética , Infertilidad Vegetal/genética , Polen/genética , Sorghum/genética , Gametogénesis en la Planta , Regulación de la Expresión Génica de las Plantas , MicroARNs/metabolismo , Polen/citología , Sorghum/fisiología , Transcriptoma
20.
Int J Mol Sci ; 22(18)2021 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-34575900

RESUMEN

Viruses are major contributors to the annual 1.3 million deaths associated with the global burden of diarrheal disease morbidity and mortality. While household-level water treatment technologies reduce diarrheal illness, the majority of filtration technologies are ineffective in removing viruses due to their small size relative to filter pore size. In order to meet the WHO health-based tolerable risk target of 10-6 Disability Adjusted Life Years per person per year, a drinking water filter must achieve a 5 Log10 virus reduction. Ceramic pot water filters manufactured in developing countries typically achieve less than 1 Log10 virus reductions. In order to overcome the shortfall in virus removal efficiency in household water treatment filtration, we (1) evaluated the capacity of chitosan acetate and chitosan lactate, as a cationic coagulant pretreatment combined with ceramic water filtration to remove lab cultured and sewage derived viruses and bacteria in drinking waters, (2) optimized treatment conditions in waters of varying quality and (3) evaluated long-term continuous treatment over a 10-week experiment in surface waters. For each test condition, bacteria and virus concentrations were enumerated by culture methods for influent, controls, and treated effluent after chitosan pretreatment and ceramic water filtration. A > 5 Log10 reduction was achieved in treated effluent for E.coli, C. perfringens, sewage derived E. coli and total coliforms, MS2 coliphage, Qß coliphage, ΦX174 coliphage, and sewage derived F+ and somatic coliphages.


Asunto(s)
Cerámica/química , Quitosano/química , Filtración , Purificación del Agua , Carga Bacteriana , Filtración/métodos , Microbiología del Agua , Purificación del Agua/métodos
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