Writing a wrong: Coupled RNA polymerase II transcription and RNA quality control

Processing and maturation of precursor RNA species is coupled to RNA polymerase II transcription. Co-transcriptional RNA processing helps to ensure efficient and proper capping, splicing, and 3' end processing of different RNA species to help ensure quality control of the transcriptome. Many improperly processed transcripts are not exported from the nucleus, are restricted to the site of transcription, and are in some cases degraded, which helps to limit any possibility of aberrant RNA causing harm to cellular health. These critical quality control pathways are regulated by the highly dynamic protein-protein interaction network at the site of transcription. Recent work has further revealed the extent to which the processes of transcription and RNA processing and quality control are integrated, and how critically their coupling relies upon the dynamic protein interactions that take place co-transcriptionally. This review focuses specifically on the intricate balance between 3' end processing and RNA decay during transcription termination. This article is categorized under: RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Processing > 3' End Processing RNA Processing > Splicing Mechanisms RNA Processing > Capping and 5' End Modifications

Ssu72 and Rtr1 Serine 5 Phosphates and Their Role in NNS and CPF Transcription Termination

Indiana University-Purdue University Indianapolis (IUPUI)Polyadenylation dependent transcription termination is dependent on the Cleavage and Polyadenylation Factor complex (CPF) which is essential for the termination and processing of mature RNA. Polyadenylation (PolyA) independent transcription termination is carried out by the NNS (Nrd1-Nab3-Sen1) termination pathway, which helps regulate termination and processing of non-coding RNA (ncRNA). The disruption of these pathways can impact expression of nearby genes, both protein coding and noncoding. Recruitment of termination pathway components is achieved through a domain unique to the largest subunit of RNA Polymerase II (RNAPII) referred to as the Cterminal domain (CTD), which contains a repeating heptad sequence, Y1S2P3T4S5P6S7, and acts as a docking site for transcription regulatory proteins. Ssu72 is a serine 5 phosphatase and an essential member of the CPF complex. Rtr1 is also a serine 5 phosphatase, but its mechanism of action is less well characterized. Both Rtr1 and Ssu72 regulate transcription machinery recruitment through control of the phosphorylation status of the CTD. My studies have focused on Rtr1 and Ssu72 mutants in yeast which show evidence of transcription termination related phenotypes. Chromatin immunoprecipitation of RNAPII followed by exonuclease treatment (ChIP-exo) studies provide evidence of RNAPII transcription continuing through termination sites at ncRNA genes as a result of a hyperactive Ssu72-L84F mutant, while an RTR1 knockout results in increased premature RNAPII transcription termination. Northern blots and RNA sequencing confirm premature transcription termination and decreased total RNA expression in the RTR1 knockout and increased length of ncRNA transcripts as well as total RNA expression in the Ssu72-L84F mutant. Mass spectrometry analysis has identified changes in the protein-protein interactions (PPI) within the CPF complex in the Ssu72-L84F mutant and decreased PPIs between different transcription machinery in RTR1 knockout cells. My results show that the CTD phosphatases Rtr1 and Ssu72 play unique roles in the regulation of RNAPII termination in eukaryotes.2020-11-1

Disruption of thymic central tolerance by infection with murine roseolovirus induces autoimmune gastritis

Infections with herpesviruses, including human roseoloviruses, have been proposed to cause autoimmune disease, but defining a causal relationship and mechanism has been difficult due to the ubiquitous nature of infection and development of autoimmunity long after acute infection. Murine roseolovirus (MRV) is highly related to human roseoloviruses. Herein we show that neonatal MRV infection induced autoimmune gastritis (AIG) in adult mice in the absence of ongoing infection. MRV-induced AIG was dependent on replication during the neonatal period and was CD4+ T cell and IL-17 dependent. Moreover, neonatal MRV infection was associated with development of a wide array of autoantibodies in adult mice. Finally, neonatal MRV infection reduced medullary thymic epithelial cell numbers, thymic dendritic cell numbers, and thymic expression of AIRE and tissue-restricted antigens, in addition to increasing thymocyte apoptosis at the stage of negative selection. These findings strongly suggest that infection with a roseolovirus early in life results in disruption of central tolerance and development of autoimmune disease

Generadores de vapor y diseno de un secador para los subproductos del aceite en Agro Industrial-Miraflores

120 p.El trabajo de tesis, realizado en Agro Industria Miraflores, además de ser requisito para optar al titulo de Ingeniero en Ejecución Mecánica, juega un papel fundamental en nuestra formación como futuros profesionales. La primera parte de este trabajo esta asignado al estudio de generadores a vapor, con lo cual nos ayuda a solidificar nuestros conocimientos adquiridos en la Universidad de Talca ya que consideramos que en la actualidad los generadores de vapor son la parte medular para el normal desarrollo de los procesos productivos en las industria y por consiguiente como futuros profesionales, nos vemos en la necesidad de acumular conocimientos para desenvolvernos normalmente en nuestro campo ocupacional . La segunda parte de la tesis esta asignada al diseño de un secador para los subproductos del aceite en Agro Industria Miraflores. Es un trabajo teórico-practico destinado a mejorar el proceso de secado en la industria

Educational Trajectories in the Agricultural High School, Universidad Autónoma Chapingo: a Theoretical View of Five Key Studies to Generate Strategies to Support Students

Conocer la trayectoria o recorrido escolar de todo estudiante y lograr que se concluya con éxito, debiera ser una obligación y preocupación institucional. La presente investigación es un estudio documental con visión panorámica, su objetivo es proponer una discusión teórica de cinco documentos que abordan el estudio de las trayectorias escolares en la Preparatoria Agrícola de la Universidad Autónoma Chapingo; El contenido del artículo aborda cada investigación por separado mostrando los hallazgos y propuestas más relevantes de cada autor, posteriormente se enlista la discusión destacando las coincidencias y diferencias entre los documentos, para concluir con la propuesta de implementar los estudios de trayectorias escolares en la Preparatoria Agrícola de la Universidad Autónoma Chapingo como una política universitaria que se incluya en el Plan de Desarrollo Institucional 2009-2025; Además de, incorporar como políticas institucionales en la estructura académica y de apoyo a la tutoría académica de pares, acompañamiento académico institucional a grupos vulnerables, afiliación de grupos vulnerables en acompañamiento personal y la implementación de un programa de atención psico-pedagógica para estudiantes, que atiendan la problemática de abandono escolar en el Nivel Medio Superior de Unuversidad Autonoma Chapingo; Se propone continuar generando investigación educativa en el tema de trayectorias escolares donde sean contempladas las condiciones institucionales actuales  de la Preparatoria Agricola.It should be an institutional obligation and concern to know how each student progresses through school, in order to ensure that they have a successful graduation. This research is a documentary study with a panoramic view, its objective is to propose a theoretical discussion of five documents dealing with the study of academic trajectories in the Agricultural High School of the Universidad Autónoma Chapingo. Afterwards, it discusses and points out similarities and differences between them, and finally, it proposes to implement studies on educational pathways in the Agricultural High School of the Autonomous University of Chapingo as a university policy to include in its Institutional Development Plan 2009-2025. Furthermore, it is proposed to incorporate as institutional policies into the academic structure and support for academic tutors, institutional academic support for vulnerable groups, the inclusion of vulnerable groups into personal support and the implementation of a psycho-educational care program for students to address the problem of dropping out of high school at the Chapingo Autonomous University. We suggest continuing the generation of educational research on the subject of educational pathways, taking into account the current institutional conditions of the Agricultural High School

Serum endocan levels associated with hypertension and loss of renal function in pediatric patients after two years from renal transplant

Endocan is an important biomarker of inflammation and endothelial dysfunction that increases in association with several chronic diseases. Few published data have described the role of endocan in pediatric renal transplant (RT) patients. We evaluated the endocan concentrations in 62 children who underwent renal transplantation and assessed their relationships with the patients' blood pressure and loss of renal function. The endocan levels were significantly elevated in the pediatric RT patients who had hypertension and a loss of renal function. We determined positive correlations between the endocan concentrations and the hemodynamic variables (systolic blood pressure: r = 0.416P = 0.001pulse pressure: r = 0.412P = 0.003). The endocan levels were inversely correlated with the estimated glomerular filtration rate (r = -0.388P = 0.003). An endocan cutoff concentration of 7.0 ng/mL identified pediatric RT patients who had hypertension and a loss of renal function with 100% sensitivity and 75% specificity. In conclusion, the endocan concentrations were significantly elevated in pediatric RT patients who had both hypertension and a loss of renal function. The correlations between the endocan levels and the hemodynamic variables and the markers of renal function strengthen the hypothesis that it is an important marker of cardiorenal risk.FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo, Brazil) [2013/03139-0]CNPq (Conselho-Nacional de Desenvolvimento Cientifico e Tecnologico) [443248/2014-1]Nephrology Division, School of Medicine, Federal University of São Paulo, São Paulo, SP, BrazilPediatrics Department, School of Medicine, Federal University of São Paulo, São Paulo, SP, BrazilNephrology Division, School of Medicine, Federal University of São Paulo, São Paulo, SP, BrazilPediatrics Department, School of Medicine, Federal University of São Paulo, São Paulo, SP, BrazilFAPESP: 2013/03139-0CNPq: 443248/2014-1Web of Scienc

Contribution of the time domain electromagnetic method to the study of the Kalahari transboundary multilayered aquifer systems in Southern Angola

ABSTRACT: The Cunene Province (Southern Angola) is facing recurrent and pluriannual droughts. Surface water supply could be reinforced using the groundwater resources of the multilayered aquifer systems (MAS) hosted in the siliciclastic sediments of the Kalahari Group. The MAS were first identified in the early 2000s in Northern Namibia and recently in the Cunene Province, by studies of the PLANAGEO project based on modern processing and reinterpretation of legacy data from the 1960s and 1970s (electrical resistivity data and deep boreholes). This article presents the results of a time domain electromagnetic (TDEM) survey conducted in the Cunene Province to: (i) contribute to the design of the hydrogeological conceptual model of the transboundary MAS, namely their geometry and extension; (ii) validate the reprocessing of the legacy data; and (iii) guide the future location of boreholes. Results depict the geometry of the sedimentary basin and the characterization of the MAS, with particular emphasis on the intermediate and deep aquifers. The borehole siting, based on the interpretation of the new TDEM data and the legacy data (clay markers in borehole logs), was successful, with a good agreement between estimated and observed horizons of the deep aquifers. However, the presence of clayey layers, a clay-rich matrix in the detrital deposits and saline/brackish groundwater led to uncertainties in the interpretation of the electrical transects. As such, recommendations are made to improve future data collection and mapping of the MAS.info:eu-repo/semantics/publishedVersio

Selective inhibition of pancreatic ductal adenocarcinoma cell growth by the mitotic MPS1 kinase inhibitor NMS-P715

Most solid tumors, including pancreatic ductal adenocarcinoma (PDAC), exhibit structural and numerical chromosome instability (CIN). Although often implicated as a driver of tumor progression and drug resistance, CIN also reduces cell fitness and poses a vulnerability that can be exploited therapeutically. The spindle assembly checkpoint (SAC) ensures correct chromosome-microtubule attachment, thereby minimizing chromosome segregation errors. Many tumors exhibit upregulation of SAC components such as MPS1, which may help contain CIN within survivable limits. Prior studies showed that MPS1 inhibition with the small molecule NMS-P715 limits tumor growth in xenograft models. In cancer cell lines, NMS-P715 causes cell death associated with impaired SAC function and increased chromosome missegregation. Although normal cells appeared more resistant, effects on stem cells, which are the dose-limiting toxicity of most chemotherapeutics, were not examined. Elevated expression of 70 genes (CIN70), including MPS1, provides a surrogate measure of CIN and predicts poor patient survival in multiple tumor types. Our new findings show that the degree of CIN70 upregulation varies considerably among PDAC tumors, with higher CIN70 gene expression predictive of poor outcome. We identified a 25 gene subset (PDAC CIN25) whose overexpression was most strongly correlated with poor survival and included MPS1. In vitro, growth of human and murine PDAC cells is inhibited by NMS-P715 treatment, whereas adipose-derived human mesenchymal stem cells are relatively resistant and maintain chromosome stability upon exposure to NMS-P715. These studies suggest that NMS-P715 could have a favorable therapeutic index and warrant further investigation of MPS1 inhibition as a new PDAC treatment strategy

RNA Polymerase II CTD phosphatase Rtr1 fine-tunes transcription termination

RNA Polymerase II (RNAPII) transcription termination is regulated by the phosphorylation status of the C-terminal domain (CTD). The phosphatase Rtr1 has been shown to regulate serine 5 phosphorylation on the CTD; however, its role in the regulation of RNAPII termination has not been explored. As a consequence of RTR1 deletion, interactions within the termination machinery and between the termination machinery and RNAPII were altered as quantified by Disruption-Compensation (DisCo) network analysis. Of note, interactions between RNAPII and the cleavage factor IA (CF1A) subunit Pcf11 were reduced in rtr1Δ, whereas interactions with the CTD and RNA-binding termination factor Nrd1 were increased. Globally, rtr1Δ leads to decreases in numerous noncoding RNAs that are linked to the Nrd1, Nab3 and Sen1 (NNS) -dependent RNAPII termination pathway. Genome-wide analysis of RNAPII and Nrd1 occupancy suggests that loss of RTR1 leads to increased termination at noncoding genes. Additionally, premature RNAPII termination increases globally at protein-coding genes with a decrease in RNAPII occupancy occurring just after the peak of Nrd1 recruitment during early elongation. The effects of rtr1Δ on RNA expression levels were lost following deletion of the exosome subunit Rrp6, which works with the NNS complex to rapidly degrade a number of noncoding RNAs following termination. Overall, these data suggest that Rtr1 restricts the NNS-dependent termination pathway in WT cells to prevent premature termination of mRNAs and ncRNAs. Rtr1 facilitates low-level elongation of noncoding transcripts that impact RNAPII interference thereby shaping the transcriptome

Pluripotency factors regulate the onset of Hox cluster activation in the early embryo

Pluripotent cells are a transient population of the mammalian embryo dependent on transcription factors, such as OCT4 and NANOG, which maintain pluripotency while suppressing lineage specification. However, these factors are also expressed during early phases of differentiation, and their role in the transition from pluripotency to lineage specification is largely unknown. We found that pluripotency factors play a dual role in regulating key lineage specifiers, initially repressing their expression and later being required for their proper activation. We show that Oct4 is necessary for activation of HoxB genes during differentiation of embryonic stem cells and in the embryo. In addition, we show that the HoxB cluster is coordinately regulated by OCT4 binding sites located at the 3′ end of the cluster. Our results show that core pluripotency factors are not limited to maintaining the precommitted epiblast but are also necessary for the proper deployment of subsequent developmental programs