Biology subjects

Franco, G. R.

Publications and source records attributed to Franco, G. R..

11 recordsLinked to original sources

bioRxiv2026

Structural and functional insights into yeast Rqc1p, a protein required for thermotolerance with potential nuclear localization

Protein homeostasis - i.e., proteostasis - is the biological process by which the qualitative and quantitative balance of the proteome is conducted, either by preserving functionally relevant proteins or by degrading unnecessary ones. Stress conditions can modulate cellular proteostasis in order to promote cytoprotection and preserve the viability of living organisms. Among the cellular pathways already described that can play an important role in preserving biological functions by modulating proteostasis are the heat shock response and the ribosome quality control pathways. In this work, we show that the Rqc1p protein is necessary for the thermoadaptation of S. cerevisiae to heat shock, as RQC1-deficient yeast is sensitive to elevated temperatures. In silico approaches - such as multiple sequence alignment, structural analysis, and molecular dynamics simulations - confirmed earlier predictions that Rqc1p shares characteristics with the bHLH family of proteins. We also verified, through computational prediction of sub-cellular localization, that S. cerevisiae Rqc1p contains nuclear localization signals, suggesting that this protein can potentially be translocated toward the nucleus, thereby broadening its current range of recognized biological functions in this organism. Also, analysis of yeast transcriptomes subjected to heat shock showed that Rqc1p mRNA levels do not fluctuate in response to heat shock, suggesting that cellular concentrations of Rqc1p are already at optimal levels to elicit a rapid and effective response during thermal stress in S. cerevisiae.

biochemistry↗

bioRxiv2025

The peptide LyeTx I mnΔK induces transcriptomic reprogramming in a novel Multidrug-resistant Acinetobacter baumannii

Acinetobacter baumannii is a critical pathogen in healthcare-associated infections, and treatment is challenging due to the emergence of multidrug-resistant strains. Antimicrobial peptides, such as LyeTx I mn{Delta}K, a synthetic peptide derived of a toxin from the spider Lycosa erythrognatha, represent a promising alternative due to their broad-spectrum activity and synergistic potential with antibiotics like meropenem. This study aimed to compare the genomes of several A. baumannii strains, including a novel multidrug-resistant A. baumannii isolate (AC37), and to evaluate the antimicrobial effects of LyeTx I mn{Delta}K-alone and in combination with meropenem-through transcriptomic analysis. Genome assembly and annotation of AC37 revealed 31 antibiotic resistance genes, and phylogenetic analysis comprising 123 A. baumannii genomes, including the reference strain, identified three unique resistant genes in the AC37 strain. Mobilome analysis showed 13 genes associated with mobile genetic elements, including two of the unique genes, highlighting horizontal gene transfer events. Transcriptomic profiling revealed that treatment with LyeTx I mn{Delta}K peptide alone induced several differentially expressed genes, including two efflux pump operons. Additionally, pathways related to protein synthesis, export, and secretion were activated, indicating a broader cellular response to the peptide. The treatment with LyeTx I mn{Delta}K in combination with meropenem disrupted oxidative phosphorylation, further revealing the metabolic plasticity of the bacterial response to external stresses. This study characterizes a new A. baumannii isolate and provides new insights into the bacterial response to a potential novel therapeutic molecule.

bioinformatics↗

bioRxiv2025

Long Non-Coding RNAs in Response to Ebola Virus Vaccine-Induced Immunity

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of gene expression, yet their role in shaping human responses to vaccination remains largely uncharacterized. Here, we analyzed RNA-sequencing data from three independent human cohorts vaccinated with the rVSV{Delta}G-ZEBOV-GP Ebola vaccine to profile lncRNA expression dynamics. Using differential expression analysis and correlation meta-analysis across cohorts, we identified an expression signature with several lncRNAs, including LEF1-AS1 and DOCK8-AS1, that exhibit conserved transcriptional activation following vaccination. Correlation of lncRNA expression with gene targets and IgG titers revealed putative roles for lncRNAs in regulating and/or participate in both innate immune responses and adaptive antibody production. Functional enrichment of lncRNA co-expressed protein-coding genes highlighted involvement in T-cell differentiation, interferon signaling, and leukocyte activation. Integrating global run-on sequencing data and comparative transcriptomic analysis across other vaccine studies suggests that LEF1-AS1 modulation is distinctively associated with Ebola vaccination. Our findings demonstrate that lncRNAs are potential integral components of the human vaccine response and provide a foundation for future mechanistic studies targeting noncoding RNA regulation of immunity SignificanceEbola virus remains a significant global health threat due to its high mortality rate and potential for widespread outbreaks, underscoring the urgent need for effective and durable vaccines to control future epidemics. Understanding the transcriptional mechanisms underlying immune responses to vaccination is important to improving vaccine design and efficacy. While protein-coding genes have been extensively studied, the role of long noncoding RNAs (lncRNAs) in vaccine-induced immunity remains poorly understood. Here, we characterize the dynamics of lncRNA expression following administration of the rVSV{Delta}G-ZEBOV-GP Ebola vaccine across multiple human cohorts and identify conserved lncRNA signatures associated with both innate and adaptive immunity. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=154 SRC="FIGDIR/small/671152v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@25581aorg.highwire.dtl.DTLVardef@1bb31cforg.highwire.dtl.DTLVardef@c3299eorg.highwire.dtl.DTLVardef@e176b9_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

bioRxiv2023

SARS-CoV-2 selectively induces the expression of unproductive splicing isoforms of interferon, class I MHC and splicing machinery genes

Splicing is a highly conserved, intricate mechanism intimately linked to transcription elongation, serving as a pivotal regulator of gene expression. Alternative splicing may generate specific transcripts incapable of undergoing translation into proteins, designated as unproductive. A plethora of respiratory viruses, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), strategically manipulate the hosts splicing machinery to circumvent antiviral responses. During the infection, SARS-CoV-2 effectively suppresses interferon (IFN) expression, leading to B cell and CD8+ T cell leukopenia, while simultaneously increasing the presence of macrophages and neutrophils in patients with severe COVID-19. In this study, we integrated publicly available omics datasets to systematically analyze transcripts at the isoform level and delineate the nascent-peptide translatome landscapes of SARS-CoV-2-infected human cells. Our findings reveal a hitherto uncharacterized mechanism whereby SARS-CoV-2 infection induces the predominant expression of unproductive splicing isoforms in key IFN signaling genes, interferon-stimulated genes (ISGs), class I MHC genes, and splicing machinery genes, including IRF7, OAS3, HLA-B, and HNRNPH1. In stark contrast, cytokine and chemokine genes, such as IL6, CXCL8, and TNF, predominantly express productive (protein-coding) splicing isoforms in response to SARS-CoV-2 infection. We postulate that SARS-CoV-2 employs a previously unreported tactic of exploiting the host splicing machinery to bolster viral replication and subvert the immune response by selectively upregulating unproductive splicing isoforms from antigen presentation and antiviral response genes. Our study sheds new light on the molecular interplay between SARS-CoV-2 and the host immune system, offering a foundation for the development of novel therapeutic strategies to combat COVID-19.

bioinformatics↗

bioRxiv2022

Vitamin B12 attenuates leukocyte inflammatory signature in COVID-19 via methyl-dependent changes in epigenetic marks

COVID-19 induces chromatin remodeling in host immune cells, and it had previously been shown that vitamin B12 downregulates some inflammatory genes via methyl-dependent epigenetic mechanisms. In this work, whole blood cultures from moderate or severe COVID-19 patients were used to assess the potential of B12 as adjuvant drug. The vitamin normalized the expression of a panel of inflammatory genes still dysregulated in the leukocytes despite glucocorticoid therapy during hospitalization. B12 also increased the flux of the sulfur amino acid pathway, raising the bioavailability of methyl. Accordingly, B12-induced downregulation of CCL3 strongly and negatively correlated with the hypermethylation of CpGs in its regulatory regions. Transcriptome analysis revealed that B12 attenuates the effects of COVID-19 on most inflammation-related pathways affected by the disease. As far as we are aware, this is the first study to demonstrate that pharmacological modulation of epigenetic marks in leukocytes favorably regulates central components of COVID-19 physiopathology. TeaserB12 has great potential as an adjuvant drug for alleviating inflammation in COVID-19.

immunology↗

bioRxiv2021

Network analysis of ten thousand genomes shed light on Pseudomonas diversity and classification

The growth of sequenced bacterial genomes has revolutionized the assessment of microbial diversity. Pseudomonas is a widely diverse genus, containing more than 254 species. Although type strains have been employed to estimate Pseudomonas diversity, they represent a small fraction of the genomic diversity at a genus level. We used 10,035 available Pseudomonas genomes, including 210 type strains, to build a genomic distance network to estimate the number of species through community identification. We identified taxonomic inconsistencies with several type strains and found that 25.65% of the Pseudomonas genomes deposited on Genbank are misclassified. The phylogenetic tree using single-copy genes from representative genomes in each species cluster in the distance network revealed at least 14 Pseudomonas groups, including P. alcaligenes group proposed here. We show that Pseudomonas is likely an admixture of different genera and should be further divided. This study provides an overview of Pseudomonas diversity from a network and phylogenomic perspective that may help reduce the propagation of mislabeled Pseudomonas genomes.

microbiology↗

bioRxiv2020

Phylogenetic and population structure analyses uncover pervasive misclassification and help assessing the biosafety of Pseudomonas putida for biotechnological applications

The Pseudomonas putida group comprises strains with biotechnological and clinical relevance. P. alloputida was proposed as a new species and highlighted the misclassification of P. putida. Nevertheless, the population structure of P. alloputida remained unexplored. We retrieved 11,025 Pseudomonas genomes and used P. alloputida Kh7T to delineate the species. The P. alloputida population structure comprises at least 7 clonal complexes (CCs). Clinical isolates are mainly found in CC4 and acquired resistance genes are present at low frequency in plasmids. Virulence profiles support the potential of CC7 members to outcompete other plant or human pathogens through a type VI secretion system. Finally, we found that horizontal gene transfer had an important role in shaping the ability of P. alloputida to bioremediate aromatic compounds such as toluene. Our results provide the grounds to understand P. alloputida genetic diversity and safety for environmental applications.

microbiology↗

bioRxiv2020

Subcellular relocalization and nuclear redistribution of the RNA methyltransferases TRMT1 and TRMT1L upon neuronal activation

RNA modifications are dynamic chemical entities that regulate RNA fate, and an avenue for environmental response in neuronal function. However, which RNA modifications may be playing a role in neuronal plasticity and environmental responses is largely unknown. Here we characterize the biochemical function and cellular dynamics of two human RNA methyltransferases previously associated with neurological dysfunction, TRMT1 and its homolog, TRMT1-like (TRMT1L). Using a combination of next-generation sequencing, LC-MS/MS, patient-derived cell lines and knockout mouse models, we confirm the previously reported dimethylguanosine (m 2,2 G) activity of TRMT1 in tRNAs, as well as reveal that TRMT1L, whose activity was unknown, is responsible for methylating a subset of cytosolic tRNA Ala (AGC) isoacceptors at position 26. Using a cellular in vitro model that mimics neuronal activation and long term potentiation, we find that both TRMT1 and TRMT1L change their subcellular localization upon neuronal activation. Specifically, we observe a major subcellular relocalization from mitochondria and other cytoplasmic domains (TRMT1) and nucleoli (TRMT1L) to different small punctate compartments in the nucleus, which are as yet uncharacterized. This phenomenon does not occur upon heat shock, suggesting that the relocalization of TRMT1 and TRMT1L is not a general reaction to stress, but rather a specific response to neuronal activation. Our results suggest that subcellular relocalization of RNA modification enzymes play a role in neuronal plasticity and transmission of information, presumably by addressing new targets.

molecular biology↗

bioRxiv2020

Transcriptional landscape of PTEN loss in primary prostate cancer

PTEN is the most frequently lost tumor suppressor in primary prostate cancer (PCa) and its loss is associated with aggressive disease. However, the transcriptional changes associated with PTEN loss in PCa have not been described in detail. Here, we applied a meta-analysis approach, leveraging two large PCa cohorts with experimentally validated PTEN and ERG status, to derive a transcriptomic signature of PTEN loss, while also accounting for potential confounders due to ERG rearrangements. Strikingly, the signature indicates a strong activation of both innate and adaptive immune systems upon PTEN loss, as well as an expected activation of cell-cycle genes. Moreover, we made use of our recently developed FC-R2 expression atlas to expand this signature to include many non-coding RNAs recently annotated by the FANTOM consortium. With this resource, we analyzed the TCGA-PRAD cohort, creating a comprehensive transcriptomic landscape of PTEN loss in PCa that comprises both the coding and an extensive non-coding counterpart.

cancer biology↗

bioRxiv2019

Recounting the FANTOM Cage Associated Transcriptome

Long non-coding RNAs (lncRNAs) have emerged as key coordinators of biological and cellular processes. Characterizing lncRNA expression across cells and tissues is key to understanding their role in determining phenotypes including human diseases. We present here FC-R2, a comprehensive expression atlas across a broadly-defined human transcriptome, inclusive of over 109,000 coding and non-coding genes, as described in the FANTOM CAGE-Associated Transcriptome (FANTOM-CAT) study. This atlas greatly extends the gene annotation used in the original recount2 resource. We demonstrate the utility of the FC-R2 atlas by reproducing key findings from published large studies and by generating new results across normal and diseased human samples. In particular, we (a) identify tissue specific transcription profiles for distinct classes of coding and non-coding genes, (b) perform differential expression analyses across thirteen cancer types, providing new insights linking promoter and enhancer lncRNAs expression to tumor pathogenesis, and (c) confirm the prognostic value of several enhancers in cancer. Comprised of over 70,000 samples, the FC-R2 atlas will empower other researchers to investigate functions and biological roles of both known coding genes and novel lncRNAs. Most importantly, access to the FC-R2 atlas is available from https://jhubiostatistics.shinyapps.io/recount/, the recount Bioconductor package, and http://marchionnilab.org/fcr2.html.

genomics↗

bioRxiv2019

Differential modulation of mouse heart gene expression by infection with two Trypanosoma cruzi strains: a transcriptome analysis

The protozoan Trypanosoma cruzi (T. cruzi) is a well-adapted parasite to mammalian hosts and the pathogen of Chagas disease in humans. As both host and T. cruzi are highly genetically diverse, many variables come into play during infection, making disease outcomes difficult to predict. One important challenge in the field of Chagas disease research is determining the main factors leading to parasite establishment in the chronic stage in some organs, mainly the heart and/or digestive system. Our group previously showed that distinct strains of T. cruzi (JG and Col1.7G2) acquired differential tissue distribution in the chronic stage in dually-infected BALB/c mice. To investigate changes in the host triggered by the two distinct T. cruzi strains, we assessed the gene expression profile of BALB/c mouse hearts infected with either JG, Col1.7G2 or an equivalent mixture of both parasites during the initial phase of infection. This study demonstrates a clear distinction in host gene expression modulation by both parasites. Col1.7G2 strongly activated Th1-polarized immune signature genes, whereas JG showed only minor activation of the host immune response. Moreover, JG strongly reduced the expression of genes for ribosomal proteins and mitochondrial proteins related to the electron transport chain. Interestingly, evaluation of gene expression in mice inoculated with the mixture of parasites showed expression profiles for both up- and down-regulated genes, indicating the coexistence of both parasite strains in the heart during the acute phase. This study suggests that different strains of T. cruzi may be distinguished by their efficiency in activating the immune system, modulating host energy and reactive oxygen species production and decreasing protein synthesis during early infection, which may be crucial in defining parasite persistence in specific organs.\n\nAuthor SummaryThe causative agent of Chagas disease, Trypanosoma cruzi, retains high genetic diversity, and its populations vary greatly across geographic locations. The T. cruzi mammalian hosts, including humans, also have high genetic variation, making it difficult to predict the disease outcome. Accordingly, this variability must be taken into account in several studies aiming to interrogate the effect of polyparasitism in drug trials, vaccines, diagnosis or basic research. Therefore, there is a growing need to consider the interaction between the pathogen and the host immune system in mixed infections. In the present work, we present an in-depth analysis of the gene expression of hearts from BALB/c mice infected with Col1.7G2 and JG alone or a mixture of both strains. Col1.7G2 induced a higher Th1 inflammatory response, while JG exhibited a weaker activation of immune response genes. Furthermore, JG-infected mice showed a notable reduction in the expression of genes responsible for mitochondrial oxidative phosphorylation and protein synthesis. Interestingly, the mixture-infected group displayed changes in gene expression as caused by both strains. Overall, we provided new insights into the host-pathogen interaction in the context of single and dual infection, showing remarkable differences in host gene expression modulation by two T. cruzi strains.

bioinformatics↗