Transcription Factors Tec1 and Tec2 Play Key Roles in the Hyphal Growth and Virulence of Mucor lusitanicus Through Increased Mitochondrial Oxidative Metabolism

Alejandre-Castañeda Viridiana,Patiño-Medina J. Alberto,Valle-Maldonado Marco I.,García Alexis,Ortiz-Alvarado Rafael,Ruíz-Herrera León F.,Castro-Cerritos Karla Viridiana,Ramírez-Emiliano Joel,Ramírez-D 한국미생물학회 2023 The journal of microbiology Vol.61 No.12

Mucormycosis is a lethal and difficult-to-treat fungal infection caused by fungi of the order Mucorales. Mucor lusitanicus, a member of Mucorales, is commonly used as a model to understand disease pathogenesis. However, transcriptional control of hyphal growth and virulence in Mucorales is poorly understood. This study aimed to investigate the role of Tec proteins, which belong to the TEA/ATTS transcription factor family, in the hyphal development and virulence of M. lusitanicus. Unlike in the genome of Ascomycetes and Basidiomycetes, which have a single Tec homologue, in the genome of Mucorales, two Tec homologues, Tec1 and Tec2, were found, except in that of Phycomyces blakesleeanus, with only one Tec homologue. tec1 and tec2 overexpression in M. lusitanicus increased mycelial growth, mitochondrial content and activity, expression of the rhizoferrin synthetase-encoding gene rfs, and virulence in nematodes and wax moth larvae but decreased cAMP levels and protein kinase A (PKA) activity. Furthermore, tec1- and tec2-overexpressing strains required adequate mitochondrial metabolism to promote the virulent phenotype. The heterotrimeric G beta subunit 1-encoding gene deletant strain (Δgpb1) increased cAMP-PKA activity, downregulation of both tec genes, decreased both virulence and hyphal development, but tec1 and tec2 overexpression restored these defects. Overexpression of allele-mutated variants of Tec1(S332A) and Tec2(S168A) in the putative phosphorylation sites for PKA increased both virulence and hyphal growth of Δgpb1. These findings suggest that Tec homologues promote mycelial development and virulence by enhancing mitochondrial metabolism and rhizoferrin accumulation, providing new information for the rational control of the virulent phenotype of M. lusitanicus.

La Dinàmica de la Cooperación Triangular

Carlos Uscanga,Lesly Viridiana Melo Campos 한국라틴아메리카학회 2012 라틴아메리카연구 Vol.25 No.3

This article aims to outline the importance of international cooperation-specifically triangular cooperation- as this new cooperative form has been gaining popularity in the last few years. Triangular cooperation endeavors to improve aid programs" effectiveness and provide a new method for cooperation among traditional actors. We develop programs and projects for International Cooperation for Development and for Official Development Assistance. We describe how these can be used as tools to facilitate growth in developing countries and how donors and receptors can carry out programs and projects in a triangular method that produce mutual benefits. In this paper, we explore how a net donor country provides technical or financial resources to a relatively less developed country, typically a middle-income country. This latter country then acts as a mediator or bridge to conduct programs, projects, or actions in another receptor country. This scenario is known as triangular cooperation, and in order to identify its advantage and disadvantages, we analyze the performance of South Korea as a donor country and Mexico as a mediator or bridge country. In the field of international cooperation, both Mexico and South Korea perform highly and complementarily, and if they work together in a triangular cooperation form, both can play a better and more meaningful role in international scenarios. Both countries can deploy actions -under the principle of co-responsibility- in different fields, sharing experiences related to issues in small and medium enterprises, rehabilitation and administration of water resources, and disaster relief. All these topics and others can be benefited in third countries that are mainly located in Central America and the Caribbean region. This region is an important area as well: for Mexico, it contains historic and traditional partnerships, and for Korea, the region represents a new area where Korea can find allies for its international plans and also fortify the relationships that it already has. Finally, we suggest that Mexico in the international cooperation field will be a net receptor country and an emerging donor with substantial experience in triangular cooperation.

(−)-Epicatechin Ameliorates Cardiac Fibrosis in a Female Rat Model of Pre-Heart Failure with Preserved Ejection Fraction

Moises Bustamante-Pozo,Israel Ramirez-Sanchez,Alejandra Garate-Carrillo,Bruce Ito,Viridiana Navarrete,Moises Haro,Ricardo Garcia,Nancy Carson,Guillermo Ceballos,Francisco Villarreal 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.8

One of the most abundant flavonoids present in cacao is (−)-epicatechin (Epi) and this flavanol has been linked to the cardiovascular health promoting actions of cocoa products. We previously demonstrated that Epi reduces infarct size in rodent models of ischemia/reperfusion and permanent coronary occlusion. Reduced infarct size was associated with decreased left ventricular (LV) oxidative stress (OS) and indicators of inflammation factors, which foster myocardial fibrosis. In this study, we examine the antifibrotic actions of Epi in an aging female rat model of pre-heart failure with preserved ejection fraction (pre-HFpEF) as well as its potential to mitigate plasma levels of OS, proinflammatory/profibrotic cytokines, and improve passive and active LV function. Epi treatment [1 mg/(kg·d)] was provided daily by gavage from 21 to 22 months of age, whereas controls received water. A Millar catheter was used to assess hemodynamic function. Subsequently, hearts were arrested in diastole, a balloon inserted into the LV and passive pressure–volume curves generated. Fixed LV sections were processed for collagen area fraction quantification using Sirius Red staining. Treatment with Epi did not lead to detectable changes in LV contractile function. However, passive LV pressure volume curves were significantly right shifted with Epi. Collagen area fraction values indicated that Epi treatment significantly reduces LV fibrosis. Epi also significantly reduced plasma OS markers and levels of profibrotic and proinflammatory cytokines. In conclusion, Epi reduces cardiac fibrosis in an aged, female rat model of pre-HFpEF, which correlates with significant reductions in OS and cytokine levels in the absence of changes in LV contractile function.

Two new species from the Mexican Pacific Slope and new distributional records of Onthophagus Latreille, 1802 (Coleoptera, Scarabaeidae)

Moctezuma Victor,Hernández Benjamín,Sánchez-Huerta José Luis,Lizardo Viridiana,Quiroz-Rocha Georgina Adriana,Navarrete-Heredia José Luis 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.1

Two new species of Onthophagus Latreille, 1802 from the Pacific Slope of Mexico are described and illustrated: Onthophagus gonzaloi Moctezuma, Hernández & Sánchez-Huerta, sp. nov., and Onthophagus yescaensis Moctezuma, Hernández & Sánchez-Huerta, sp. nov. New records for Onthophagus browni Howden & Cartwright, 1963 from the Mexican states of Jalisco (the southernmost locality known to date) and Zacatecas are provided. urn:lsid:zoobank.org:pub:51AA52C6-41BF-4A8B-9BC9-D78600EDB32E.

Alcohol dehydrogenase 1 participates in the Crabtree effect and connects fermentative and oxidative metabolism in the Zygomycete Mucor circinelloides

Rosa Angélica Rangel-Porras,Sharel P. Díaz-Pérez,Juan Manuel Mendoza-Hernández,Pamela Romo-Rodríguez,Viridiana Alejandre-Castañeda,Marco I Valle-Maldonado,Juan Carlos Torres-Guzmán,Gloria Angélica Gon 한국미생물학회 2019 The journal of microbiology Vol.57 No.7

Mucor circinelloides is a dimorphic Zygomycete fungus that produces ethanol under aerobic conditions in the presence of glucose, which indicates that it is a Crabtree-positive fungus. To determine the physiological role of the alcohol dehydrogenase (ADH) activity elicited under these conditions, we obtained and characterized an allyl alcohol-resistant mutant that was defective in ADH activity, and examined the effect of adh mutation on physiological parameters related to carbon and energy metabolism. Compared to the Adh+ strain R7B, the ADH-defective (Adh-) strain M5 was unable to grow under anaerobic conditions, exhibited a considerable reduction in ethanol production in aerobic cultures when incubated with glucose, had markedly reduced growth capacity in the presence of oxygen when ethanol was the sole carbon source, and exhibited very low levels of NAD+-dependent alcohol dehydrogenase activity in the cytosolic fraction. Further characterization of the M5 strain showed that it contains a 10-bp deletion that interrupts the coding region of the adh1 gene. Complementation with the wild-type allele adh1+ by transformation of M5 remedied all the defects caused by the adh1 mutation. These findings indicate that in M. circinelloides, the product of the adh1 gene mediates the Crabtree effect, and can act as either a fermentative or an oxidative enzyme, depending on the nutritional conditions, thereby participating in the association between fermentative and oxidative metabolism. It was found that the spores of M. circinelloides possess low mRNA levels of the ethanol assimilation genes (adl2 and acs2), which could explain their inability to grow in the alcohol.

Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV

( Araceli Hernández-sánchez ),( Edgar D. Páez-pérez ),( Elvia Alfaro-saldaña ),( Vanesa Olivares-illana ),( J. Viridiana García-meza ) 한국미생물생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.3

Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.