Papers by Bernardo F Franco
Frontiers in Bioengineering and Biotechnology
JÓVENES EN LA CIENCIA, Sep 7, 2021
JÓVENES EN LA CIENCIA, Sep 7, 2021
Journal of Applied Microbiology, 2021
As options to treat recalcitrant bacterial infections which are increasingly limited due to multi... more As options to treat recalcitrant bacterial infections which are increasingly limited due to multidrug‐resistant strains, searching for new, effective antibacterial compounds is necessary. One strategy is to generate treatment alternatives by drug repurposing.
<i>Escherichia coli</i> - Recent Advances on Physiology, Pathogenesis and Biotechnological Applications, 2017
Colloids and Surfaces B: Biointerfaces, 2020
Journal of Fungi, 2020
The secretory pathway in Candida albicans involves the protein translocation into the lumen of th... more The secretory pathway in Candida albicans involves the protein translocation into the lumen of the endoplasmic reticulum and transport to the Golgi complex, where proteins undergo posttranslational modifications, including glycosylation and proteolysis. The Golgi-resident Kex2 protease is involved in such processing and disruption of its encoding gene affected virulence and dimorphism. These previous studies were performed using cells without URA3 or with URA3 ectopically placed into the KEX2 locus. Since these conditions are known to affect the cellular fitness and the host–fungus interaction, here we generated a kex2Δ null mutant strain with URA3 placed into the neutral locus RPS1. The characterization of this strain showed defects in the cell wall composition, with a reduction in the N-linked mannan content, and the increment in the levels of O-linked mannans, chitin, and β-glucans. The defects in the mannan content are likely linked to changes in Golgi-resident enzymes, as the α...
Journal of Experimental Biology, 2019
In invertebrates, it has been recently reported that secondary sexual characteristics (SSC) refle... more In invertebrates, it has been recently reported that secondary sexual characteristics (SSC) reflect the antioxidant defense of their bearers, but it is not known what physiological link maintains the honesty of those signals. Here, we use the damselfly Hetaerina americana to test whether Juvenile Hormone plays such a role. First, we analyzed whether oxidative damage is a real threat in natural damselfly populations by examining the accumulation of oxidized guanines as a function of age in males. Then, we injected paraquat (a pro-oxidant agent) and added the Juvenile Hormone analog Methoprene (JHa) to the experimental group and the JHa vehicle (acetone) to the control group, to determine whether JHa increases the levels of pro-oxidants and antioxidants. We found that DNA oxidation increased with age, and levels of hydrogen peroxide and superoxide dismutase, but not catalase or glutathione, were elevated in the JHa group compared to the control group. We propose that Juvenile Hormone ...
Infection and Drug Resistance, 2018
PLoS neglected tropical diseases, Mar 9, 2018
Sporotrichosis is a subcutaneous mycosis caused by pathogenic species of the Sporothrix genus. A ... more Sporotrichosis is a subcutaneous mycosis caused by pathogenic species of the Sporothrix genus. A new emerging species, Sporothrix brasiliensis, is related to cat-transmitted sporotrichosis and has severe clinical manifestations. The cell wall of pathogenic fungi is a unique structure and impacts directly on the host immune response. We reveal and compare the cell wall structures of Sporothrix schenckii and S. brasiliensis using high-pressure freezing electron microscopy to study the cell wall organization of both species. To analyze the components of the cell wall, we also used infrared and 13C and 1H NMR spectroscopy and the sugar composition was determined by quantitative high-performance anion-exchange chromatography. Our ultrastructural data revealed a bi-layered cell wall structure for both species, including an external microfibrillar layer and an inner electron-dense layer. The inner and outer layers of the S. brasiliensis cell wall were thicker than those of S. schenckii s. ...
Ecological Entomology, 2016
1. Immune priming refers to improved protection of the host after a second encounter with the sam... more 1. Immune priming refers to improved protection of the host after a second encounter with the same parasite or pathogen. This phenomenon is similar to that of adaptive immunity in vertebrates.2. There is evidence to suggest that this improved protection can be species/strain‐specific and can protect organisms for a lifetime. These two attributes, along with a biphasic immune response, are essential characteristics of immune priming and form the basis for the effectiveness of resistance to parasites and pathogens.3. This paper considers the effect of immune priming within and across generations, the influence of a heterologous challenge during immune priming and the importance of testing the immune response with natural pathogens.4. The analysis presented takes into account the multifaceted nature of the invertebrate immune response. The lack of evidence suggesting that the bacterial microbiome plays a complementary role in the immune priming outcome is discussed.5. Finally, the cost...
Archives of microbiology, 2003
The cytoplasmic pyrophosphatase from Rhodobacter sphaeroides was purified and characterized. The ... more The cytoplasmic pyrophosphatase from Rhodobacter sphaeroides was purified and characterized. The enzyme is a homodimer of 64 kDa. The N-terminus was sequenced and used to obtain the complete pyrophosphatase sequence from the preliminary genome sequence of Rba. sphaeroides, showing extensive sequence similarity to family II or class C pyrophosphatases. The enzyme hydrolyzes only Mg-PP(i) and Mn-PP(i) with a K(m) of 0.35 mM for both substrates. It is not activated by free Mg (2+), in contrast to the cytoplasmic pyrophosphatase from Rhodospirillum rubrum, and it is not inhibited by NaF, methylendiphosphate, or imidodiphosphate. This work shows that Rba. sphaeroides and Rhodobacter capsulatus cytoplasmic pyrophosphatases belong to family II, in contrast to Rsp. rubrum, Rhodopseudomonas palustris, Rhodopseudomonas gelatinosa, and Rhodomicrobium vannielii cytoplasmic pyrophosphatases which should be classified as members of family I. This is the first report of family II cytoplasmic pyrop...
Plasmid, 2003
The functionality of direct and inverted repeat sequences inside the cis acting locus of transfer... more The functionality of direct and inverted repeat sequences inside the cis acting locus of transfer (clt) of the Streptomyces plasmid pJV1 was determined by testing the effect of different deletions on plasmid transfer. The results show that the single most important element for pJV1 clt function is a series of evenly spaced 9 bp long direct repeats which match the consensus CCGCACA(C/G)(C/G), since their deletion caused a dramatic reduction in plasmid transfer. The presence of these repeats in the absence of any other clt sequences allowed plasmid transfer to occur at a frequency that was at least two orders of magnitude higher than that obtained in the complete absence of clt. A database search revealed regions with a similar organization, and in the same position, in Streptomyces plasmids pSN22 and pSLS, which have transfer proteins homologous to those of pJV1.
Molecular and Biochemical Parasitology, 2012
Experimental parasitology, Jan 22, 2018
Amoebiasis is a worldwide health problem caused by the pathogen Entamoeba histolytica. Several vi... more Amoebiasis is a worldwide health problem caused by the pathogen Entamoeba histolytica. Several virulence factors have been implicated in host invasion, immune evasion, and tissue damage. There are still new factors that remain to be elucidated and characterized. In this work, we obtained amoebic transfectants overexpressing three of the neutral sphingomyelinase enzymes encoded in the E. histolytica genome. The EhnSM3 overexpression induced an increase in hemolytic and cytotoxic activities, besides an increase in gene expression of amoebapore A, B, and C. Meanwhile the EhnSM1 and EhnSM2 overexpression caused an increase in cytopathic activity. In all the neutral sphingomyelinases overexpressing strains, the gene expression levels for cysteine proteinase 5, adhesin 112 and, heavy and light Gal/GalNAc lectin subunits were not affected. We propose that the increase of cytotoxic and lytic effect of EhnSM3 overexpressed strain can be related to the sum of the effect of EhnSM3 plus amoebap...
Academia Molecular Biology and Genomics, Jan 31, 2025
Using genomic and proteomic data, many researchers have uncovered novel proteins associated with ... more Using genomic and proteomic data, many researchers have uncovered novel proteins associated with the cell walls of pathogenic fungi. The literature proposes examples of detected proteins in the cell wall, such as moonlight proteins, with dual activity. They are associated with the pathogenic process, immune recognition, and cell wall structure. Some examples are glycolytic enzymes, elongation factors, redox-related proteins, chaperones, adhesins, and other proteins found in fungal pathogens' cell walls. The secondary function mainly focuses on binding plasminogen and innate immune cell surface receptors. Since the first structure of pathogenic fungi that encounters immune cells is the cell wall, structural studies are needed to address the differences between enzymes that mostly have a cytoplasmic role and those found in the cell wall. In this review, we analyze the possible structural features of cell wall proteins identified from pathogenic fungi, their role in the architecture of the cell wall, and their interaction with immune cells. Special focus is given to the GP70 protein, a 3-carboxy-cis, cis-muconate lactonizing enzyme present in the cell wall of S. shenckii. We present a case for the novel AlphaFold3 software that can predict post-translational modifications in the research of moonlighting proteins. The knowledge of proteins that have a relevant role in the cell wall of fungi, and its relevance under adverse conditions improving pathogenic traits, may render novel targets for the control of these pathogens.
Molecules, Jun 28, 2023
The signal transduction paradigm in bacteria involves two-component systems (TCSs). Asgardarchaeo... more The signal transduction paradigm in bacteria involves two-component systems (TCSs). Asgardarchaeota are archaea that may have originated the current eukaryotic lifeforms. Most research on these archaea has focused on eukaryotic-like features, such as genes involved in phagocytosis, cytoskeleton structure, and vesicle trafficking. However, little attention has been given to specific prokaryotic features. Here, the sequence and predicted structural features of TCS sensor kinases analyzed from two metagenome assemblies and a genomic assembly from cultured Asgardian archaea are presented. The homology of the sensor kinases suggests the grouping of Lokiarchaeum closer to bacterial homologs. In contrast, one group from a Lokiarchaeum and a meta-genome assembly from Candidatus Heimdallarchaeum suggest the presence of a set of kinases separated from the typical bacterial TCS sensor kinases. AtoS and ArcB homologs were found in meta-genome assemblies along with defined domains for other well-characterized sensor kinases, suggesting the close link between these organisms and bacteria that may have resulted in the metabolic link to the establishment of symbiosis. Several kinases are predicted to be cytoplasmic; some contain several PAS domains. The data shown here suggest that TCS kinases in Asgardian bacteria are witnesses to the transition from bacteria to eukaryotic organisms.
Las infecciones intrahospitalarias (IIH) son un problema de salud publica que afecta a la poblaci... more Las infecciones intrahospitalarias (IIH) son un problema de salud publica que afecta a la poblacion y que ocasiona la muerte del 5% de los pacientes. Las IIH son causadas principalmente por bacterias multirresistentes a los antibioticos convencionales. Las manos y los uniformes usados por el personal medico son unos de los vehiculos mas relevantes de transmision. Las nanoparticulas (NPs) metalicas con propiedades antimicrobianas son una alternativa para ayudar a disminuir las IIH. El uso de las NPs de Cu se ha incrementado por su alta actividad antibacteriana y su bajo costo. Se evaluo la actividad antibacteriana de dos NPs de Cu, las cuales presentaron alta actividad sobre Staphylococcus aureus y Pseudomona aeruginosa. Hilos de PET y Nylon conteniendo NPs de Cu presentaron buena actividad, siendo esta mayor en los hilos de Nylon. Las telas conteniendo NPs de Cu presentaron una actividad antibacteriana moderada, la cual se incremento para S. aureus despues de varios tratamientos. La concentracion de NPs de Cu en las telas falta por ser determinada. Lo anterior sugiere que las NPs de Cu con propiedades antibacterianas son una buena alternativa para disenar y crear materiales antimicrobianos con utilidad para el sector salud.
Protein and Peptide Letters, Dec 10, 2019
Background: Marine sessile organisms display a color palette that is the result of the expression... more Background: Marine sessile organisms display a color palette that is the result of the expression of fluorescent and non-fluorescent proteins. Fluorescent proteins have uncovered transcriptional regulation, subcellular localization of proteins, and the fate of cells during development. Chromoproteins have received less attention until recent years as bioreporters. Here, we studied the properties of aeBlue, a a 25.91 kDa protein from the anemone Actinia equina. Objective: To assess the properties of aeBlue chromoprotein under different physicochemical conditions. Methods: In this article, during the purification of aeBlue we uncovered that it suffered a color shift when frozen. We studied the color shift by different temperature incubation and physicochemical conditions and light spectroscopy. To assess the possible structural changes in the protein, circular dichroism analysis, size exclusion chromatography and native PAGE was performed. We uncover that aeBlue chromoprotein, when expressed from a synthetic construct in Escherichia coli, showed a temperature dependent color shift. Protein purified at 4 °C by metal affinity chromatography exhibited a pinkish color and shifts back at higher temperatures to its intense blue color. Circular dichroism analysis revealed that the structure in the pink form of the protein has reduced secondary structure at 4 °C, but at 35 °C and higher, the structure shifts to a native conformation and Far UV-vis CD spectra revealed the shift in an aromatic residue of the chromophore. Also, the chromophore retains its properties in a wide range of conditions (pH, denaturants, reducing and oxidants agents). Quaternary structure is also maintained as a tetrameric conformation as shown by native gel and size exclusion chromatography. Our results suggest that the chromophore position in aeBlue is shifted from its native position rendering the pink color and the process to return it to its native blue conformation is temperature dependent.
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Papers by Bernardo F Franco