A moonlighting metabolic protein influences repair at DNA double-stranded breaks.

Catalytically active proteins with divergent dual functions are often described as 'moonlighting'. In this work we characterize a new, chromatin-based function of Lys20, a moonlighting protein that is well known for its role in metabolism. Lys20 was initially described as homocitrate synthase (HCS), the first enzyme in the lysine biosynthetic pathway in yeast. Its nuclear localization led to the discovery of a key role for Lys20 in DNA damage repair through its interaction with the MYST family histone acetyltransferase Esa1. Overexpression of Lys20 promotes suppression of DNA damage sensitivity of esa1 mutants. In this work, by taking advantage of LYS20 mutants that are active in repair but not in lysine biosynthesis, the mechanism of suppression of esa1 was characterized. First we analyzed the chromatin landscape of esa1 cells, finding impaired histone acetylation and eviction. Lys20 was recruited to sites of DNA damage, and its overexpression promoted enhanced recruitment of the INO80 remodeling complex to restore normal histone eviction at the damage sites. This study improves understanding of the evolutionary, structural and biological relevance of independent activities in a moonlighting protein and links metabolism to DNA damage repair

Resultados de la Investigación sobre los Factores Docentes que Afectan la Actitud de los Estudiantes en el Aula

After some research done inside the Universidad Tecnológica de Tecamachalco, it was reflected that the professor’s behavior has a big impact on students' English learning process. It was seen that students can feel confident if the professor shows them empathy while having classes and, it can have a bigger impact if the professor supports them while facing some learning problem. Also, if there is a rapport after the activity it motivates even more the students’ enhancement. According to a previous paper research students feel alone in the challenge of learning English at the Universidad Tecnológica de Tecamachalco, so a questionnaire about their emotions was applied to obtain information about support, motivation, regulation of emotions, enhancement of mnemonics, and positive rewards to accomplish goals.Después de algunas investigaciones realizadas dentro de la Universidad Tecnológica de Tecamachalco, se ha reflejado que el comportamiento del maestro tiene un gran impacto en el proceso de aprendizaje de una segunda lengua, Inglés. Se observó que los estudiantes pueden sentir confianza sí el profesor muestra empatía durante la clase y puede tener un mayor impacto sí el profesor los apoya en el momento de enfrentar algunas dificultades en el proceso de aprendizaje, también, sí hay una interacción armoniosa después de la actividad motivando aún más la mejora de los estudiantes. De acuerdo a una investigación previa, la cual muestra que los estudiantes se sienten solos ante el reto de aprender inglés en la Universidad Tecnológica de Tecamachalco, por lo que se aplicó un cuestionario sobre sus emociones para obtener información referente a apoyo, motivación, regulación de emociones, potencialización de la mnemotecnia, y recompensas positivas para cumplir metas

New Approach Using the Real-Time PCR Method for Estimation of the Toxic Marine Dinoflagellate Ostreopsis cf. ovata in Marine Environment

Background: We describe the development and validation of a new quantitative real time PCR (qrt-PCR) method for the enumeration of the toxic benthic dinoflagellate Ostreopsis cf. ovata in marine environment. The benthic Ostreopsis sp. has a world-wide distribution and is associated during high biomass proliferation with the production of potent palytoxin-like compounds affecting human health and environment. Species-specific identification, which is relevant for the complex of different toxins production, by traditional methods of microscopy is difficult due to the high morphological variability, and thus different morphotypes can be easily misinterpreted. Methodology/Findings: The method is based on the SYBR I Green real-time PCR technology and combines the use of a plasmid standard curve with a ‘‘gold standard’’ created with pooled crude extracts from environmental samples collected during a bloom event of Ostreopsis cf. ovata in the Mediterranean Sea. Based on their similar PCR efficiencies (95% and 98%, respectively), the exact rDNA copy number per cell was obtained in cultured and environmental samples. Cell lysates were used as the templates to obtain total recovery of DNA. The analytical sensitivity of the PCR was set at two rDNA copy number and 8.061024 cell per reaction for plasmid and gold standards, respectively; the sensitivity of the assay was of cells g21 fw or 121 in macrophyte and seawater samples, respectively. The reproducibility was determined on the total linear quantification range of both curves confirming the accuracy of the technical set-up in the complete ranges of quantification over time. Conclusions/Significance: We developed a qrt-PCR assay specific, robust and high sample throughput for the absolute quantification of the toxic dinoflagellate Ostreopsis cf. ovata in the environmental samples. This molecular approach may be considered alternative to traditional microscopy and applied for the monitoring of benthic toxic microalgal species in the marine ecosystems

Comparative Analysis of the 5S rRNA and Its Associated Proteins Reveals Unique Primitive Rather Than Parasitic Features in Giardia lamblia

BACKGROUND: 5S rRNA is a highly conserved ribosomal component. Eukaryotic 5S rRNA and its associated proteins (5S rRNA system) have become very well understood. Giardia lamblia was thought by some researchers to be the most primitive extant eukaryote while others considered it a highly evolved parasite. Previous reports have indicated that some aspects of its 5S rRNA system are simpler than that of common eukaryotes. We here explore whether this is true to its entire system, and whether this simplicity is a primitive or parasitic feature. METHODOLOGY/PRINCIPAL FINDINGS: By collecting and confirming pre-existing data and identifying new data, we obtained almost complete datasets of the system of three isolates of G. lamblia, two other parasitic excavates (Trichomonas vaginalis, Trypanosoma cruzi), and one free-living one (Naegleria gruberi). After comprehensively comparing each aspect of the system among these excavates and also with those of archaea and common eukaryotes, we found all the three Giardia isolates to harbor a same simplified 5S rRNA system, which is not only much simpler than that of common eukaryotes but also the simplest one among those of these excavates, and is surprisingly very similar to that of archaea; we also found among these excavates the system in parasitic species is not necessarily simpler than that in free-living species, conversely, the system of free-living species is even simpler in some respects than those of parasitic ones. CONCLUSION/SIGNIFICANCE: The simplicity of Giardia 5S rRNA system should be considered a primitive rather than parasitically-degenerated feature. Therefore, Giardia 5S rRNA system might be a primitive system that is intermediate between that of archaea and the common eukaryotic model system, and it may reflect the evolutionary history of the eukaryotic 5S rRNA system from the archaeal form. Our results also imply G. lamblia might be a primitive eukaryote with secondary parasitically-degenerated features

Multiple identification of most important waterborne protozoa in surface water used for irrigation purposes by 18S rRNA amplicon-based metagenomics

[EN] Understanding waterborne protozoan parasites (WPPs) diversity has important implications in public health. In this study, we evaluated a NGS-based method as a detection approach to identify simultaneously most important WPPs using 18S rRNA high-throughput sequencing. A set of primers to target the V4 18S rRNA region of WPPs such as Cryptosporidium spp., Giardia sp., Blastocystis sp., Entamoeba spp, Toxoplasma sp. and free-living amoebae (FLA) was designed. In order to optimize PCR conditions before sequencing, both a mock community with a defined composition of representative WPPs and a real water sample inoculated with specific WPPs DNA were prepared. Using the method proposed in this study, we have detected the presence of Giardia intestinalis, Acanthamoeba castellanii, Toxoplasma gondii, Entamoeba histolytica and Blastocystis sp. at species level in real irrigation water samples. Our results showed that untreated surface irrigation water in open fields can provide an important source of WPPs. Therefore, the methodology proposed in this study can establish a basis for an accurate and effective diagnostic of WPPs to provide a better understanding of the risk associated to irrigation water.This work was supported through the project funded by the Spanish Ministry of Economy and Competitiveness (MINECO) in the frame of the collaborative international consortium JPIW2013-095-C03-02 of the Water Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call. R. Perez acknowledges support from MINECO program "Promocion de Empleo Joven e Implantacion de la Garantia Juvenil en I + D + i".Moreno Trigos, MY.; Moreno-Mesonero, L.; Amoros, I.; Pérez-Santonja, R.; Morillo, J.; Alonso Molina, JL. (2018). Multiple identification of most important waterborne protozoa in surface water used for irrigation purposes by 18S rRNA amplicon-based metagenomics. International Journal of Hygiene and Environmental Health. 221(1):102-111. https://doi.org/10.1016/j.ijheh.2017.10.008S102111221

Obtención de un sistema de análisis para genes transcritos por RNA polimerasa III en Trichomonádidos : estudio del gen del RNAr 5S / tesis que para obtener el grado de Doctor en Ciencias Biomédicas, presenta Ana Lilia Torres Machorro ; asesor María Imelda López Villaseñor

. 103, [46] páginas : ilustraciones. Doctorado en Ciencias Biomédicas UNAM, Instituto de Investigaciones Biomédicas, 201

Homodimeric and Heterodimeric Interactions among Vertebrate Basic Helix–Loop–Helix Transcription Factors

The basic helix–loop–helix transcription factor (bHLH TF) family is involved in tissue development, cell differentiation, and disease. These factors have transcriptionally positive, negative, and inactive functions by combining dimeric interactions among family members. The best known bHLH TFs are the E-protein homodimers and heterodimers with the tissue-specific TFs or ID proteins. These cooperative and dynamic interactions result in a complex transcriptional network that helps define the cell’s fate. Here, the reported dimeric interactions of 67 vertebrate bHLH TFs with other family members are summarized in tables, including specifications of the experimental techniques that defined the dimers. The compilation of these extensive data underscores homodimers of tissue-specific bHLH TFs as a central part of the bHLH regulatory network, with relevant positive and negative transcriptional regulatory roles. Furthermore, some sequence-specific TFs can also form transcriptionally inactive heterodimers with each other. The function, classification, and developmental role for all vertebrate bHLH TFs in four major classes are detailed