2014 – 2019 PhD in Molecular Biology (Madrid, Spain)
UNIVERSIDAD AUTÓNOMA DE MADRID
2013 – 2014 Master in Molecular and Cell Biology (Madrid, Spain)
UNIVERSIDAD AUTÓNOMA DE MADRID
2009 – 2013 Bachelor degree in Biology (Madrid, Spain)
UNIVERSIDAD AUTÓNOMA DE MADRID
11
Scopus Publications
Scopus Publications
Herpes simplex virus type 1 reshapes host chromatin architecture via transcription machinery hijacking Esther González-Almela, Alvaro Castells-Garcia, François Le Dily, Manuel Fernández Merino, Davide Carnevali, Pol Cusco, Luciano Di Croce, Maria Pia Cosma Nature Communications, 2025 Herpes simplex virus type 1 (HSV-1) remodels the host chromatin structure and induces a host-to-virus transcriptional switch during lytic infection. We combine super-resolution imaging and chromosome-capture technologies to identify the mechanism of remodeling. We show that the host chromatin undergoes massive condensation caused by the hijacking of RNA polymerase II (RNAP II) and topoisomerase I (TOP1). In addition, HSV-1 infection results in the rearrangement of topologically associating domains and loops, although the A/B compartments are maintained in the host. The position of viral genomes and their association with RNAP II and cohesin is determined nanometrically. We reveal specific host-HSV-1 genome interactions and enrichment of upregulated human genes in the most contacting regions. Finally, TOP1 inhibition fully blocks HSV-1 infection, suggesting possible antiviral strategies. This viral mechanism of host chromatin rewiring sheds light on the role of transcription in chromatin architecture.
A deep learning method that identifies cellular heterogeneity using nanoscale nuclear features Davide Carnevali, Limei Zhong, Esther González-Almela, Carlotta Viana, Mikhail Rotkevich, Aiping Wang, Daniel Franco-Barranco, Aitor Gonzalez-Marfil, Maria Victoria Neguembor, Alvaro Castells-Garcia, Ignacio Arganda-Carreras, Maria Pia Cosma Nature Machine Intelligence, 2024 Cellular phenotypic heterogeneity is an important hallmark of many biological processes and understanding its origins remains a substantial challenge. This heterogeneity often reflects variations in the chromatin structure, influenced by factors such as viral infections and cancer, which dramatically reshape the cellular landscape. To address the challenge of identifying distinct cell states, we developed artificial intelligence of the nucleus (AINU), a deep learning method that can identify specific nuclear signatures at the nanoscale resolution. AINU can distinguish different cell states based on the spatial arrangement of core histone H3, RNA polymerase II or DNA from super-resolution microscopy images. With only a small number of images as the training data, AINU correctly identifies human somatic cells, human-induced pluripotent stem cells, very early stage infected cells transduced with DNA herpes simplex virus type 1 and even cancer cells after appropriate retraining. Finally, using AI interpretability methods, we find that the RNA polymerase II localizations in the nucleoli aid in distinguishing human-induced pluripotent stem cells from their somatic cells. Overall, AINU coupled with super-resolution microscopy of nuclear structures provides a robust tool for the precise detection of cellular heterogeneity, with considerable potential for advancing diagnostics and therapies in regenerative medicine, virology and cancer biology.
Overlapping promoter library designed for rational heterogenous expression in Cordyceps militaris Mengdi Lyu, Jiapeng Zeng, Yue Zhou, Tongyu Zhang, Aiping Wang, Jiezhao Ma, Ziyi Wu, Alvaro Castells-Garcia, Esther González-Almela, Junfang Lin, Tao Wei Microbial Cell Factories, 2022 Background Cordyceps militaris, a kind of edible and medicinal fungus widely accepted in East Asia, has attracted much attention as a potential cell factory for producing adenosine analogs. Despite the rapid development in gene editing techniques and genome modeling, the diversity of DNA elements in C. militaris was too short to achieve rational heterogeneous expression for metabolic engineering studies. Results In this study, PtrpC, a kind of promoter with a relatively appropriate expression level and small size, was selected as a monomer for promoter library construction. Through in vitro BioBricks assembly, 9 overlapping PtrpC promoters with different copy numbers as well as reporter gene gfp were connected and subsequently integrated into the genome of C. militaris. Both the mRNA transcription level and the expression level of gene gfp gradually increased along with the copy number of the overlapping promoter NPtrpC and peaked at 7. In the meantime, no significant difference was found in either the biomass or morphological characteristic of engineered and wild-type strains. Conclusions This study firstly expanded the overlapping promoter strategy used in model microorganism in C. militaris. It was a proof-of-concept in fungi synthetic biology and provide a general method to pushed the boundary of promoter engineering in edible mushroom.
Static Magnetic Fields Regulate T-Type Calcium Ion Channels and Mediate Mesenchymal Stem Cells Proliferation Haokaifeng Wu, Chuang Li, Muqaddas Masood, Zhen Zhang, Esther González-Almela, Alvaro Castells-Garcia, Gaoyang Zou, Xiaoduo Xu, Luqin Wang, Guoqing Zhao, Shengyong Yu, Ping Zhu, Bo Wang, Dajiang Qin, Jing Liu Cells, 2022 The static magnetic fields (SMFs) impact on biological systems, induce a variety of biological responses, and have been applied to the clinical treatment of diseases. However, the underlying mechanisms remain largely unclear. In this report, by using human mesenchymal stem cells (MSCs) as a model, we investigated the biological effect of SMFs at a molecular and cellular level. We showed that SMF exposure promotes MSC proliferation and activates the expression of transcriptional factors such as FOS (Fos Proto-Oncogene, AP-1 Transcription Factor Subunit) and EGR1 (Early Growth Response 1). In addition, the expression of signal-transduction proteins p-ERK1/2 and p-JNK oscillate periodically with SMF exposure time. Furthermore, we found that the inhibition of the T-type calcium ion channels negates the biological effects of SMFs on MSCs. Together, we revealed that the SMFs regulate T-type calcium ion channels and mediate MSC proliferation via the MAPK signaling pathways.
Super resolution microscopy reveals how elongating RNA polymerase II and nascent RNA interact with nucleosome clutches Alvaro Castells-Garcia, Ilyas Ed-daoui, Esther González-Almela, Chiara Vicario, Jason Ottestrom, Melike Lakadamyali, Maria Victoria Neguembor, Maria Pia Cosma Nucleic Acids Research, 2022 Transcription and genome architecture are interdependent, but it is still unclear how nucleosomes in the chromatin fiber interact with nascent RNA, and which is the relative nuclear distribution of these RNAs and elongating RNA polymerase II (RNAP II). Using super-resolution (SR) microscopy, we visualized the nascent transcriptome, in both nucleoplasm and nucleolus, with nanoscale resolution. We found that nascent RNAs organize in structures we termed RNA nanodomains, whose characteristics are independent of the number of transcripts produced over time. Dual-color SR imaging of nascent RNAs, together with elongating RNAP II and H2B, shows the physical relation between nucleosome clutches, RNAP II, and RNA nanodomains. The distance between nucleosome clutches and RNA nanodomains is larger than the distance measured between elongating RNAP II and RNA nanodomains. Elongating RNAP II stands between nascent RNAs and the small, transcriptionally active, nucleosome clutches. Moreover, RNA factories are small and largely formed by few RNAP II. Finally, we describe a novel approach to quantify the transcriptional activity at an individual gene locus. By measuring local nascent RNA accumulation upon transcriptional activation at single alleles, we confirm the measurements made at the global nuclear level.
System-wide Profiling of RNA-Binding Proteins Uncovers Key Regulators of Virus Infection Manuel Garcia-Moreno, Marko Noerenberg, Shuai Ni, Aino I. Järvelin, Esther González-Almela, Caroline E. Lenz, Marcel Bach-Pages, Victoria Cox, Rosario Avolio, Thomas Davis, Svenja Hester, Thibault J.M. Sohier, Bingnan Li, Gregory Heikel, Gracjan Michlewski, Miguel A. Sanz, Luis Carrasco, Emiliano P. Ricci, Vicent Pelechano, Ilan Davis, Bernd Fischer, Shabaz Mohammed, Alfredo Castello Molecular Cell, 2019 Summary The compendium of RNA-binding proteins (RBPs) has been greatly expanded by the development of RNA-interactome capture (RIC). However, it remained unknown if the complement of RBPs changes in response to environmental perturbations and whether these rearrangements are important. To answer these questions, we developed “comparative RIC” and applied it to cells challenged with an RNA virus called sindbis (SINV). Over 200 RBPs display differential interaction with RNA upon SINV infection. These alterations are mainly driven by the loss of cellular mRNAs and the emergence of viral RNA. RBPs stimulated by the infection redistribute to viral replication factories and regulate the capacity of the virus to infect. For example, ablation of XRN1 causes cells to be refractory to SINV, while GEMIN5 moonlights as a regulator of SINV gene expression. In summary, RNA availability controls RBP localization and function in SINV-infected cells.
A viral RNA motif involved in signaling the initiation of translation on non-AUG codons Miguel Angel Sanz, Esther González Almela, Manuel García-Moreno, Ana Isabel Marina, Luis Carrasco RNA, 2019 Noncanonical translation, and particularly initiation on non-AUG codons, are frequently used by viral and cellular mRNAs during virus infection and disease. The Sindbis virus (SINV) subgenomic mRNA (sgRNA) constitutes a unique model system to analyze the translation of a capped viral mRNA without the participation of several initiation factors. Moreover, sgRNA can initiate translation even when the AUG initiation codon is replaced by other codons. Using SINV replicons, we examined the efficacy of different codons in place of AUG to direct the synthesis of the SINV capsid protein. The substitution of AUG by CUG was particularly efficient in promoting the incorporation of leucine or methionine in similar percentages at the amino terminus of the capsid protein. Additionally, valine could initiate translation when the AUG is replaced by GUG. The ability of sgRNA to initiate translation on non-AUG codons was dependent on the integrity of a downstream stable hairpin (DSH) structure located in the coding region. The structural requirements of this hairpin to signal the initiation site on the sgRNA were examined in detail. Of interest, a virus bearing CUG in place of AUG in the sgRNA was able to infect cells and synthesize significant amounts of capsid protein. This virus infects the human haploid cell line HAP1 and the double knockout variant that lacks eIF2A and eIF2D. Collectively, these findings indicate that leucine-tRNA or valine-tRNA can participate in the initiation of translation of sgRNA by a mechanism dependent on the DSH. This mechanism does not involve the action of eIF2, eIF2A, or eIF2D.
The initiation factors eIF2, eIF2A, eIF2D, eIF4A, and eIF4G are not involved in translation driven by hepatitis C virus IRES in human cells Esther González-Almela, Hugh Williams, Miguel A. Sanz, Luis Carrasco Frontiers in Microbiology, 2018 Animal viruses have evolved a variety of strategies to ensure the efficient translation of their mRNAs. One such strategy is the use of internal ribosome entry site (IRES) elements, which circumvent the requirement for some eukaryotic initiation factors (eIFs). Much effort has been directed to unravel the precise mechanism of translation initiation by hepatitis C virus (HCV) mRNA. In the present study, we examined the involvement of several eIFs in HCV IRES-driven translation in human cells in a comparative analysis with mRNAs bearing the encephalomyocarditis virus or the Cricket paralysis virus IRES element. Consistent with previous findings, several inhibitors of eIF2 activity, including sodium arsenite, thapsigargin, tunicamycin, and salubrinal, had no inhibitory effect on the translation of an mRNA bearing the HCV IRES, and all induced the phosphorylation of eIF2α. In addition, hippuristanol and pateamine A, two known inhibitors of eIF4A, failed to block HCV IRES-directed translation. To test the release of nuclear proteins to the cytoplasm and to analyze the formation of stress granules, the location of the nuclear protein TIA1 was tested by immunocytochemistry. Both arsenite and pateamine A could efficiently induce the formation of stress granules containing TIA1 and eIF4G, whereas eIF3 and eIF2 failed to localize to these cytoplasmic bodies. The finding of eIF4A and eIF4G in stress granules suggests that they do not participate in mRNA translation. Human HAP1 cells depleted for eIF2A, eIF2D, or both factors, were able to synthesize luciferase from an mRNA bearing the HCV IRES even when eIF2α was phosphorylated. Overall, these results demonstrate that neither eIF2A nor eIF2D does not participate in the translation directed by HCV IRES. We conclude that eIF2, eIF4A, eIF2A, and eIF2D do not participate in the initiation of translation of HCV mRNA.
The regulation of translation in alphavirus-infected cells , , and Viruses, 2018 Sindbis virus (SINV) contains an RNA genome of positive polarity with two open reading frames (ORFs). The first ORF is translated from the genomic RNA (gRNA), rendering the viral non-structural proteins, whereas the second ORF is translated from a subgenomic mRNA (sgRNA), which directs the synthesis of viral structural proteins. SINV infection strongly inhibits host cell translation through a variety of different mechanisms, including the phosphorylation of the eukaryotic initiation factor eIF2α and the redistribution of cellular proteins from the nucleus to the cytoplasm. A number of motifs have been identified in SINV sgRNA, including a hairpin downstream of the AUG initiation codon, which is involved in the translatability of the viral sgRNA when eIF2 is inactivated. Moreover, a 3′-UTR motif containing three stem-loop structures is involved in the enhancement of translation in insect cells, but not in mammalian cells. Accordingly, SINV sgRNA has evolved several structures to efficiently compete for the cellular translational machinery. Mechanistically, sgRNA translation involves scanning of the 5′-UTR following a non-canonical mode and without the requirement for several initiation factors. Indeed, sgRNA-directed polypeptide synthesis occurs even after eIF4G cleavage or inactivation of eIF4A by selective inhibitors. Remarkably, eIF2α phosphorylation does not hamper sgRNA translation during the late phase of SINV infection. SINV sgRNA thus constitutes a unique model of a capped viral mRNA that is efficiently translated in the absence of several canonical initiation factors. The present review will mainly focus in the non-canonical mechanism of translation of SINV sgRNA.
Translation of Sindbis Subgenomic mRNA is Independent of eIF2, eIF2A and eIF2D Miguel Angel Sanz, Esther González Almela, Luis Carrasco Scientific Reports, 2017 Translation of Sindbis virus subgenomic mRNA (sgmRNA) can occur after inactivation of eIF2 by phosphorylation in mammalian cells. Several studies have suggested that eIF2 can be replaced by eIF2A or eIF2D. HAP1 human cell lines knocked-out for eIF2A, eIF2D or both by CRISPR/Cas9 genome engineering were compared with wild-type (WT) cells to test the potential role of eIF2A and eIF2D in translation. Sindbis virus infection was comparable between the four cell lines. Moreover, synthesis of viral proteins during late stage infection was similar in all four cell lines despite the fact that eIF2α became phosphorylated. These findings demonstrate that eIF2A and eIF2D are not required for the translation of sgmRNA when eIF2α is phosphorylated. Moreover, silencing of eIF2A or eIF2D by transfection of the corresponding siRNAs in HAP1 WT, HAP1-eIF2A− and HAP1-eIF2D− cells had little effect on the synthesis of viral proteins late in infection. Modification of AUGi to other codons in sgmRNA failed to abrogate translation. Sindbis virus replicons containing these sgmRNA variants could still direct the synthesis of viral proteins. No significant differences were found between the cell lines assayed, suggesting that neither eIF2A nor eIF2D are involved in the translation of this sgmRNA bearing non-AUG codons.
