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1.
Cell Rep ; 43(3): 113855, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38427563

RESUMEN

SWI/SNF complexes are evolutionarily conserved, ATP-dependent chromatin remodeling machines. Here, we characterize the features of SWI/SNF-dependent genes using BRM014, an inhibitor of the ATPase activity of the complexes. We find that SWI/SNF activity is required to maintain chromatin accessibility and nucleosome occupancy for most enhancers but not for most promoters. SWI/SNF activity is needed for expression of genes with low to medium levels of expression that have promoters with (1) low chromatin accessibility, (2) low levels of active histone marks, (3) high H3K4me1/H3K4me3 ratio, (4) low nucleosomal phasing, and (5) enrichment in TATA-box motifs. These promoters are mostly occupied by the canonical Brahma-related gene 1/Brahma-associated factor (BAF) complex. These genes are surrounded by SWI/SNF-dependent enhancers and mainly encode signal transduction, developmental, and cell identity genes (with almost no housekeeping genes). Machine-learning models trained with different chromatin characteristics of promoters and their surrounding regulatory regions indicate that the chromatin landscape is a determinant for establishing SWI/SNF dependency.


Asunto(s)
Cromatina , Factores de Transcripción , Cromatina/genética , Factores de Transcripción/metabolismo , Nucleosomas/genética , Ensamble y Desensamble de Cromatina
2.
Materials (Basel) ; 17(4)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38399098

RESUMEN

This paper presents the preparation of heterogeneous catalysts for the direct hydrogenation process of CO2 to methanol. The development of the modern chemical industry is inextricably linked to the use of catalytic processes. As a result, currently over 80% of new technologies introduced in the chemical industry incorporate catalytic processes. Since the basic factor of catalytic processes is the catalysts, the studies for the deepening of the knowledge regarding the nature of the action of the catalysts, for the development of new catalysts and catalytic systems, as well as for their improvement, represent a research priority of a fundamental or applied nature. The Cu/ZnO/Al2O3 catalyst for the synthesis of green methanol, using precursors of an inorganic (copper nitrate, denoted by Cu/ZnO/Al2O3-1) and organic (copper acetate, denoted by Cu/ZnO/Al2O3-2) nature, are obtained by chemical impregnation that includes two stages: preparation and one of calcination. The preparation methods and conditions, as well as the physico-chemical properties of the catalyst precursor, play a major role in the behavior of the catalysts. The prepared catalysts were characterized using atomic adsorption analysis, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, specific surface area and pore size analyses, adsorption, and the chemisorption of vapor (BET).

3.
J Public Health Manag Pract ; 30(1): 89-98, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37350621

RESUMEN

OBJECTIVE: To assess the impact of a multicomponent intervention in women with cervical dysplasia who were treated with loop electrosurgical excision procedure (LEEP), as well as the time between colposcopy and treatment. DESIGN: Retrospective cohort study. INTERVENTION: Clinic participation in a multicomponent cervical cancer prevention program that included community outreach, patient in-reach, and navigation, as well as provider capacity building with in-person training and ongoing telementoring through Project ECHO. MAIN OUTCOME MEASURES: Medical records were reviewed to evaluate women with cervical dysplasia undergoing treatment with LEEP within 90 days of colposcopy, as well as time between colposcopy and treatment. Baseline data from year 1 were compared with each subsequent year of implementation. Additional variables examined included patient's age, history of abnormal screening results, and percentage of families living below poverty line based on county of residence, parity, and clinic site. We performed logistic regression and multiple linear regression analyses to assess the programmatic impact in the outcomes of interest by year of program implementation. RESULTS: A total of 290 women were included in the study. The proportion of women undergoing treatment within 90 days of colposcopy increased from 76.2% at baseline to 91.3% in year 3 and 92.9% in year 4 of program implementation. The odds of undergoing treatment within 90 days were 5.11 times higher in year 4 of program implementation than at baseline. The mean time between colposcopy and LEEP decreased from 62 days at baseline to 45 days by year 4 of program implementation. CONCLUSIONS: Implementation of our multicomponent cervical cancer prevention program increased the proportion of women undergoing LEEP within 90 days of colposcopy and decreased the time between colposcopy and LEEP. This program has the potential to support cervical cancer prevention efforts and could be implemented in other low-resource settings.


Asunto(s)
Lesiones Precancerosas , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Embarazo , Femenino , Humanos , Neoplasias del Cuello Uterino/cirugía , Neoplasias del Cuello Uterino/diagnóstico , Estudios Retrospectivos , Texas/epidemiología , Electrocirugia/métodos , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/cirugía , Lesiones Precancerosas/cirugía
4.
Nat Commun ; 14(1): 7224, 2023 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-37940686

RESUMEN

Planctopirus limnophila belongs to the bacterial phylum Planctomycetes, a relatively understudied lineage with remarkable cell biology features. Here, we report a genome-wide analysis of essential gene content in P. limnophila. We show that certain genes involved in peptidoglycan synthesis or cell division, which are essential in most other studied bacteria, are not essential for growth under laboratory conditions in this species. We identify essential genes likely involved in lipopolysaccharide biosynthesis, consistent with the view of Planctomycetes as diderm bacteria, and highlight other essential genes of unknown functions. Furthermore, we explore potential stages of evolution of the essential gene repertoire in Planctomycetes and the related phyla Verrucomicrobia and Chlamydiae. Our results provide insights into the divergent molecular and cellular biology of Planctomycetes.


Asunto(s)
Genes Esenciales , Planctomycetales , Planctomycetales/genética , Verrucomicrobia/genética
5.
Pharmaceutics ; 15(8)2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37631349

RESUMEN

Treatment with second-generation antipsychotics (SGAs) can cause obesity and other cardiometabolic disorders linked to D2 receptor (DRD2) and to genotypes affecting dopaminergic (DA) activity, within reward circuits. We explored the relationship of cardiometabolic alterations with single genetic polymorphisms DRD2 rs1799732 (NG_008841.1:g.4750dup -> C), DRD2 rs6277 (NG_008841.1:g.67543C>T), COMT rs4680 (NG_011526.1:g.27009G>A), and VNTR in both DRD4 NC_000011.10 (637269-640706) and DAT1 NC_000005.10 (1392794-1445440), as well as with a multilocus genetic profile score (MLGP). A total of 285 psychiatric patients treated with SGAs for at least three months were selected. Cardiometabolic parameters were classified according to ATP-III and WHO criteria. Blood samples were taken for routinely biochemical assays and PCR genotyping. Obesity (BMI, waist (W)), high diastolic blood pressure (DBP), and hypertriglyceridemia (HTG) were present in those genetic variants related to low dopaminergic activity: InsIns genotype in rs1799732 (BMI: OR: 2.91 [1.42-5.94]), DRD4-VNTR-L allele (W: OR: 1.73 [1.04-2.87]) and 9R9R variant in DAT1-VNTR (W: OR: 2.73 [1.16-6.40]; high DBP: OR: 3.33 [1.54-7.31]; HTG: OR: 4.38 [1.85-10.36]). A low MLGP score indicated a higher risk of suffering cardiometabolic disorders (BMI: OR: 1.23 [1.05-1.45]; W: OR: 1.18 [1.03-1.34]; high DBP: OR: 1.22 [1.06-1.41]; HTG: OR: 1.20 [1.04-1.39]). The MLGP score was more sensitive for detecting the risk of suffering these alterations. Low dopaminergic system function would contribute to increased obesity, BDP, and HTG following long-term SGA treatment.

6.
Int Ophthalmol ; 43(8): 2731-2736, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37185774

RESUMEN

PURPOSE: To analyze using Pentacam®, the corneal and anterior chamber changes following periocular botulinum toxin injection in patients with facial dystonia. METHODS: Prospective study that included patients with facial dystonia that were going to receive a periocular botulinum toxin injection for the first time or six months or more after the previous injection. A Pentacam® examination was carried out in all patients before and 4 weeks after the injection. RESULTS: Thirty-one eyes were included. Twenty-two had a diagnosis of blepharospasm and nine of hemifacial spasm. Analysis of corneal and anterior chamber parameters revealed a significant decrease in iridocorneal angle after botulinum toxin injection (from 35 ± 10º to 33.8 ± 9.7º, p = 0.022). No other corneal or anterior chamber parameters changed significantly after the injection. CONCLUSIONS: Periocular botulinum toxin injection causes narrowing of the iridocorneal angle.


Asunto(s)
Blefaroespasmo , Toxinas Botulínicas Tipo A , Toxinas Botulínicas , Distonía , Espasmo Hemifacial , Humanos , Blefaroespasmo/tratamiento farmacológico , Toxinas Botulínicas/efectos adversos , Espasmo Hemifacial/tratamiento farmacológico , Estudios Prospectivos , Distonía/tratamiento farmacológico , Cámara Anterior , Inyecciones Intraoculares , Toxinas Botulínicas Tipo A/efectos adversos
8.
Proc Natl Acad Sci U S A ; 119(52): e2210081119, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36534808

RESUMEN

Carotenoids are isoprenoid lipids found across the tree of life with important implications in oxidative stress adaptations, photosynthetic metabolisms, as well as in membrane dynamics. The canonical view is that C40 carotenoids are synthesized from phytoene and C30 carotenoids from diapophytoene. Squalene is mostly associated with the biosynthesis of polycyclic triterpenes, although there have been suggestions that it could also be involved in the biosynthesis of C30 carotenoids. However, demonstration of the existence of this pathway in nature is lacking. Here, we demonstrate that C30 carotenoids are synthesized from squalene in the Planctomycetes bacteria and that this squalene route to C30 carotenoids is the most widespread in prokaryotes. Using the evolutionary history of carotenoid and squalene amino oxidases, we propose an evolutionary scenario to explain the origin and diversification of the different carotenoid and squalene-related pathways. We show that carotenoid biosynthetic pathways have been constantly transferred and neofunctionalized during prokaryotic evolution. One possible origin of the squalene pathway connects it with the one of C40 carotenoid synthesis of Cyanobacteria. The widespread occurrence of the squalene route to C30 carotenoids in Bacteria increases the functional repertoire of squalene, establishing it as a general hub of carotenoids and polycyclic triterpenes synthesis.


Asunto(s)
Cianobacterias , Triterpenos , Escualeno , Vías Biosintéticas , Carotenoides
9.
Nucleic Acids Res ; 50(17): 9838-9857, 2022 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-36124662

RESUMEN

High mobility group (HMG) proteins are chromatin regulators with essential functions in development, cell differentiation and cell proliferation. The protein HMG20A is predicted by the AlphaFold2 software to contain three distinct structural elements, which we have functionally characterized: i) an amino-terminal, intrinsically disordered domain with transactivation activity; ii) an HMG box with higher binding affinity for double-stranded, four-way-junction DNA than for linear DNA; and iii) a long coiled-coil domain. Our proteomic study followed by a deletion analysis and structural modeling demonstrates that HMG20A forms a complex with the histone reader PHF14, via the establishment of a two-stranded alpha-helical coiled-coil structure. siRNA-mediated knockdown of either PHF14 or HMG20A in MDA-MB-231 cells causes similar defects in cell migration, invasion and homotypic cell-cell adhesion ability, but neither affects proliferation. Transcriptomic analyses demonstrate that PHF14 and HMG20A share a large subset of targets. We show that the PHF14-HMG20A complex modulates the Hippo pathway through a direct interaction with the TEAD1 transcription factor. PHF14 or HMG20A deficiency increases epithelial markers, including E-cadherin and the epithelial master regulator TP63 and impaired normal TGFß-trigged epithelial-to-mesenchymal transition. Taken together, these data indicate that PHF14 and HMG20A cooperate in regulating several pathways involved in epithelial-mesenchymal plasticity.


Asunto(s)
Proteínas del Grupo de Alta Movilidad/metabolismo , Histonas , Proteínas Nucleares/metabolismo , Factores de Transcripción/metabolismo , Factor de Crecimiento Transformador beta , Cadherinas/genética , Cadherinas/metabolismo , Línea Celular Tumoral , Cromatina , Vía de Señalización Hippo , Histonas/metabolismo , Humanos , Proteómica , ARN Interferente Pequeño , Factores de Transcripción/genética , Factor de Crecimiento Transformador beta/genética
10.
Children (Basel) ; 9(6)2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35740766

RESUMEN

Social interaction skills are related to successful academic performance and mental health. One of the key elements of socio-emotional competence is self-regulation. The main aim of this study was to analyze the effect of a self-regulation program at a primary school on the social interactions of neurotypical children and children with special educational needs, from the teachers' and parents' perspectives. A pre-post study was conducted. The children (n = 107) followed 10 sessions, each one of 50 min, for ten weeks, between January and April 2021. To assess the changes in children's social interaction, the Peer Social Maturity Scale was administered to the teachers. After the intervention, parents completed a questionnaire designed ad hoc to understand the effectiveness of children's emotional self-regulation. The results showed a statistically significant improvement in peer interaction skills. The families were satisfied with the program, due to the improvement in their children's knowledge about their own emotions and those of the other people, and the learning strategies to regulate their emotions. Likewise, parents indicated that it would be necessary to complement the program with teaching and emotional regulation strategies for them. The "Exciting School" program could help improve the social skills of school-aged children.

11.
JCO Oncol Pract ; 18(5): e805-e813, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35544645

RESUMEN

PURPOSE: Racial and ethnic disparities have included a lack of access to both genetic testing and research, resulting in poor understanding of the genomic architecture in under-represented populations. The South Texas population is primarily of Hispanic background and has been largely devoid of genetic services. We extended access to this underserved population and uncovered genetic variants previously not observed, emphasizing the need to continually improve both genomic databases and clarification of variant significance to provide meaningful patient counseling. METHODS: This study consisted of a retrospective cohort review of patients seen through a cancer genetics education and service program across 24 counties in South Texas. In total, 1,595 individuals were identified as appropriate for cancer genetic counseling and 1,377 completed genetic testing. RESULTS: Eighty percent of those receiving genetic counseling self-identified as Hispanic, 16% as non-Hispanic White (NHW), 3% as African American, and 1% as other race/ethnicity. Of reported variants, 18.8% were pathogenic and 13.7% were reported as a variant of uncertain significance (VUS). VUS was reported in 17.2% of the Hispanic individuals compared with 9% NHW (P = .005). CONCLUSION: Individuals of Hispanic ethnicity were significantly more likely to harbor a VUS compared with NHW. The extended reach into our regional communities revealed a gap in the ability to accurately interpret genomic variation with implications for advising patients on screening, prevention, and management strategies. A higher percentage of VUS also emphasizes the challenge of continued follow-up amid existing barriers that led to disparities in access. As understanding of the variants develops, hopefully gaps in knowledge of the genomic landscape will be lessened with increased clarity to provide accurate cancer risk assessment and recommendations for implementing prevention initiatives.


Asunto(s)
Hispánicos o Latinos , Neoplasias , Pruebas Genéticas/métodos , Hispánicos o Latinos/genética , Humanos , Neoplasias/genética , Estudios Retrospectivos , Texas/epidemiología
13.
World J Psychiatry ; 11(9): 530-542, 2021 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-34631458

RESUMEN

Attachment style, which has been theorized to be rooted in childhood bonding experiences, influences adult cognitive, emotional and interpersonal functioning. Despite its relationship with early experiences, research indicates that the continuity of attachment style across childhood and adulthood is only partial, being a malleable tendency that is shaped throughout development, with an increasing influence of genetics, as it occurs in other cognitive and behavioral phenotypes. Genetic research indicates that up to 45% of the variability in anxious and 39% in avoidant adult attachment style could be explained by genetic causes, but the precise mechanisms remain unclear. A narrative review is conducted analyzing the existing literature regarding the implication of candidate genes related to oxytocin, dopaminergic pathways, serotonergic pathways and brain-derived neurotrophic factor in adult attachment, with both vulnerability and differential susceptibility approaches, yielding mixed results. We highlight the lack of genome-wide studies and the scarcity of epigenetic investigation. Based on the existing data, we conclude that the genetics of adult attachment is an area that requires further research to clarify its etiological role and that it should be preferably approached as an interaction between nature and nurture.

14.
Rev Esp Cardiol (Engl Ed) ; 74(5): 402-413, 2021 May.
Artículo en Inglés, Español | MEDLINE | ID: mdl-32917565

RESUMEN

INTRODUCTION AND OBJECTIVES: Sudden cardiac death (SCD) in young people often has a genetic cause. Consequently, the results of "molecular autopsy" may have important implications for their relatives. Our objective was to evaluate the diagnostic yield of a molecular autopsy program using next-generation sequencing. METHODS: We performed a prospective study of a cohort of consecutive patients who died from nonviolent SCD, aged ≤ 50 years, and who underwent molecular autopsy using large panels of next-generation sequencing, with subsequent clinical and genetic family screening. We analyzed demographic, clinical, toxicological, and genetic data. RESULTS: We studied 123 consecutive cases of SCD in persons aged ≤ 50 years. The incidence of SCD was 5.8 cases/100 000 individuals/y, mean age was 36.15±12.7 years, and 95 were men (77%). The cause was cardiac in 53%, unexplained SCD in 24%, toxic in 10.6%, and infant SCD in 4%. Among cardiac causes, ischemic heart disease accounted for 38% of deaths, arrhythmogenic cardiomyopathy for 7%, hypertrophic cardiomyopathy for 5%, and idiopathic left ventricular hypertrophy for 11%. Genetic analysis was performed in 62 cases (50.4%). Genetic variants were found in 42 cases (67.7%), with a mean of 3.4±4 genetic variants/patient, and the variant found was considered to be pathogenic or probably pathogenic in 30.6%. In unexplained SCD, 70% showed some genetic variant. Family screening diagnosed 21 carriers or affected individuals, 5 of whom were at risk, indicating an implantable cardiac defibrillator. CONCLUSIONS: Protocol-based and exhaustive study of SCD from cardiac causes in persons aged ≤ 50 years is feasible and necessary. In a high percentage of cases, the cause is genetic, indicating the existence of relatives at risk who could benefit from early diagnosis and treatment to avoid complications.


Asunto(s)
Cardiomiopatía Hipertrófica , Muerte Súbita Cardíaca , Adolescente , Adulto , Autopsia , Cardiomiopatía Hipertrófica/genética , Muerte Súbita Cardíaca/epidemiología , Muerte Súbita Cardíaca/etiología , Femenino , Pruebas Genéticas , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto Joven
15.
Thorax ; 75(9): 754-763, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32709610

RESUMEN

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease which presents a grave prognosis for diagnosed patients. Nintedanib (a triple tyrosine kinase inhibitor) and pirfenidone (unclear mechanism of action) are the only approved therapies for IPF, but have limited efficacy. The pathogenic mechanisms of this disease are not fully elucidated; however, a role for mast cells (MCs) has been postulated. OBJECTIVES: The aim of this work was to investigate a role for MCs in IPF and to understand whether nintedanib or pirfenidone could impact MC function. METHODS AND RESULTS: MCs were significantly elevated in human IPF lung and negatively correlated with baseline lung function (FVC). Importantly, MCs were positively associated with the number of fibroblast foci, which has been linked to increased mortality. Furthermore, MCs were increased in the region immediately surrounding the fibroblast foci, and co-culture studies confirmed a role for MC-fibroblast crosstalk in fibrosis. Nintedanib but not pirfenidone inhibited recombinant stem cell factor (SCF)-induced MC survival. Further evaluation of nintedanib determined that it also inhibited human fibroblast-mediated MC survival. This was likely via a direct effect on ckit (SCF receptor) since nintedanib blocked SCF-stimulated ckit phosphorylation, as well as downstream effects on MC proliferation and cytokine release. In addition, nintedanib ablated the increase in lung MCs and impacted high tissue density frequency (HDFm) in a rat bleomycin model of lung fibrosis. CONCLUSION: Nintedanib inhibits MC survival and activation and thus provides a novel additional mechanism by which this drug may exert anti-fibrotic effects in patients with IPF.


Asunto(s)
Supervivencia Celular/efectos de los fármacos , Fibroblastos/fisiología , Fibrosis Pulmonar Idiopática/patología , Indoles/farmacología , Mastocitos/fisiología , Inhibidores de Proteínas Quinasas/farmacología , Anciano , Animales , Antiinflamatorios no Esteroideos/farmacología , Bleomicina , Proliferación Celular/efectos de los fármacos , Quimiocina CCL2/metabolismo , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Femenino , Fibroblastos/patología , Fibrosis , Humanos , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Fibrosis Pulmonar Idiopática/fisiopatología , Pulmón/patología , Masculino , Mastocitos/patología , Persona de Mediana Edad , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-kit/metabolismo , Piridonas/farmacología , Ratas , Proteínas Recombinantes/farmacología , Transducción de Señal/efectos de los fármacos , Factor de Células Madre/farmacología , Capacidad Vital
16.
Antonie Van Leeuwenhoek ; 113(12): 1915-1926, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32583191

RESUMEN

Access to axenic cultures is crucial to extend the knowledge of the biology, lifestyle or metabolic capabilities of bacteria from different phyla. The phylum Planctomycetes is an excellent example since its members display an unusual cell biology and complex lifestyles. As a contribution to the current collection of axenic planctomycete cultures, here we describe strain Mal48T isolated from phytoplankton material sampled at the coast of S'Arenal close to Palma de Mallorca (Spain). The isolated strain shows optimal growth at pH 7.0-7.5 and 30 °C and exhibits typical features of Planctomycetes. Cells of the strain are spherical to pear-shaped, divide by polar budding with daughter cells showing the same shape as the mother cell, tend to aggregate, display a stalk and produce matrix or fimbriae. Strain Mal48T showed 95.8% 16S rRNA gene sequence similarity with the recently described Thalassoglobus neptunius KOR42T. The genome sequence of the novel isolate has a size of 6,357,355 bp with a G+C content of 50.3%. A total of 4874 protein-coding genes, 41 tRNA genes and 2 copies of the 16S rRNA gene are encoded in the genome. Based on phylogenetic, morphological and physiological analyses, we conclude that strain Mal48T (= DSM 100737T = LMG 29019T) should be classified as the type strain of a new species in the genus Thalassoglobus, for which the name Thalassoglobus polymorphus sp. nov. is proposed.


Asunto(s)
Ácidos Grasos , ADN Bacteriano/genética , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , España
17.
Antonie Van Leeuwenhoek ; 113(12): 1901-1913, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32583192

RESUMEN

Planctomycetes are ubiquitous bacteria with environmental and biotechnological relevance. Axenic cultures of planctomycetal strains are the basis to analyse their unusual biology and largely uncharacterised metabolism in more detail. Here, we describe strain Mal4T isolated from marine sediments close to Palma de Mallorca, Spain. Strain Mal4T displays common planctomycetal features, such as division by polar budding and the presence of fimbriae and crateriform structures on the cell surface. Cell growth was observed at ranges of 10-39 °C (optimum at 31 °C) and pH 6.5-9.0 (optimum at 7.5). The novel strain shows as pear-shaped cells of 2.0 ± 0.2 × 1.4 ± 0.1 µm and is one of the rare examples of orange colony-forming Planctomycetes. Its genome has a size of 7.7 Mb with a G+C content of 63.4%. Phylogenetically, we conclude that strain Mal4T (= DSM 100296T = LMG 29133T) is the type strain representing the type species of a novel genus, for which we propose the name Maioricimonas rarisocia gen. nov., sp. nov.


Asunto(s)
Ácidos Grasos , Sedimentos Geológicos , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , España
18.
Sci Rep ; 10(1): 5177, 2020 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-32198475

RESUMEN

Under ever-changing environmental conditions, the General Stress Response (GSR) represents a lifesaver for bacteria in order to withstand hostile situations. In α-proteobacteria, the EcfG-type extracytoplasmic function (ECF) σ factors are the key activators of this response at the transcriptional level. In this work, we address the hierarchical function of the ECF σ factor paralogs EcfG1 and EcfG2 in triggering the GSR in Sphingopyxis granuli TFA and describe the role of EcfG2 as global switch of this response. In addition, we define a GSR regulon for TFA and use in vitro transcription analysis to study the relative contribution of each EcfG paralog to the expression of selected genes. We show that the features of each promoter ultimately dictate this contribution, though EcfG2 always produced more transcripts than EcfG1 regardless of the promoter. These first steps in the characterisation of the GSR in TFA suggest a tight regulation to orchestrate an adequate protective response in order to survive in conditions otherwise lethal.


Asunto(s)
Factor sigma/metabolismo , Sphingomonadaceae/metabolismo , Estrés Fisiológico/fisiología , Alphaproteobacteria/metabolismo , Proteínas Bacterianas/metabolismo , Fenómenos Biológicos/genética , Regulación Bacteriana de la Expresión Génica/genética , Factor sigma/fisiología , Transducción de Señal/genética , Sphingomonadaceae/genética , Estrés Fisiológico/genética
19.
Mol Biol Evol ; 37(7): 1925-1941, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32125435

RESUMEN

Polycyclic triterpenes are members of the terpene family produced by the cyclization of squalene. The most representative polycyclic triterpenes are hopanoids and sterols, the former are mostly found in bacteria, whereas the latter are largely limited to eukaryotes, albeit with a growing number of bacterial exceptions. Given their important role and omnipresence in most eukaryotes, contrasting with their scant representation in bacteria, sterol biosynthesis was long thought to be a eukaryotic innovation. Thus, their presence in some bacteria was deemed to be the result of lateral gene transfer from eukaryotes. Elucidating the origin and evolution of the polycyclic triterpene synthetic pathways is important to understand the role of these compounds in eukaryogenesis and their geobiological value as biomarkers in fossil records. Here, we have revisited the phylogenies of the main enzymes involved in triterpene synthesis, performing gene neighborhood analysis and phylogenetic profiling. Squalene can be biosynthesized by two different pathways containing the HpnCDE or Sqs proteins. Our results suggest that the HpnCDE enzymes are derived from carotenoid biosynthesis ones and that they assembled in an ancestral squalene pathway in bacteria, while remaining metabolically versatile. Conversely, the Sqs enzyme is prone to be involved in lateral gene transfer, and its emergence is possibly related to the specialization of squalene biosynthesis. The biosynthesis of hopanoids seems to be ancestral in the Bacteria domain. Moreover, no triterpene cyclases are found in Archaea, invoking a potential scenario in which eukaryotic genes for sterol biosynthesis assembled from ancestral bacterial contributions in early eukaryotic lineages.


Asunto(s)
Carotenoides/metabolismo , Evolución Molecular , Farnesil Difosfato Farnesil Transferasa/genética , Filogenia , Escualeno/metabolismo , Eucariontes/metabolismo , Farnesil Difosfato Farnesil Transferasa/metabolismo , Genes Bacterianos , Esteroles/biosíntesis
20.
Sci Rep ; 10(1): 66, 2020 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-31919386

RESUMEN

Most bacteria divide by binary fission using an FtsZ-based mechanism that relies on a multi-protein complex, the divisome. In the majority of non-spherical bacteria another multi-protein complex, the elongasome, is also required for the maintenance of cell shape. Components of these multi-protein assemblies are conserved and essential in most bacteria. Here, we provide evidence that at least three proteins of these two complexes are not essential in the FtsZ-less ovoid planctomycete bacterium Planctopirus limnophila which divides by budding. We attempted to construct P. limnophila knock-out mutants of the genes coding for the divisome proteins FtsI, FtsK, FtsW and the elongasome protein MreB. Surprisingly, ftsI, ftsW and mreB could be deleted without affecting the growth rate. On the other hand, the conserved ftsK appeared to be essential in this bacterium. In conclusion, the canonical bacterial cell division machinery is not essential in P. limnophila and this bacterium divides via budding using an unknown mechanism.


Asunto(s)
Proteínas Bacterianas/genética , Planctomycetales/genética , Actinas/genética , Mutación , Proteínas de Unión a las Penicilinas/genética , Fenotipo , Planctomycetales/crecimiento & desarrollo
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