Artículos (Bioquímica Vegetal y Biología Molecular)
URI permanente para esta colecciónhttps://hdl.handle.net/11441/10824
Examinar
Envíos recientes
Artículo A complex and dynamic redox network regulates oxygen reduction at photosystem I in Arabidopsis(Oxford Academic Press, 2024-09-26) Hani, Umama; Naranjo Río-Miranda, Belén; Shimakawa, Ginga; Espinasse, Christophe; Vanacker, Helene; Setif, Pierre; Rintamaki, Eevi; Issakidis-Bourguet, Emmanuelle; Krieger-Liszkay, Anja; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ecole Universitaire de Recherche de Sciences des Plantes de Paris-Saclay (SPS-GSR); Agence Nationale de la Recherche. France; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. EspañaThiol-dependent redox regulation of enzyme activities plays a central role in regulating photosynthesis. Besides the regulation of metabolic pathways, alternative electron transport is subjected to thiol-dependent regulation. We investigated the regulation of O2 reduction at photosystem I. The level of O2 reduction in leaves and isolated thylakoid membranes depends on the photoperiod in which plants are grown. We used a set of Arabidopsis (Arabidopsis thaliana) mutant plants affected in the stromal, membrane, and lumenal thiol network to study the redox protein partners involved in regulating O2 reduction. Light-dependent O2 reduction was determined in leaves and thylakoids of plants grown in short-day and long-day conditions using a spin-trapping electron paramagnetic resonance assay. In wild-type samples from short-day conditions, reactive oxygen species generation was double that of samples from long-day conditions, while this difference was abolished in several redoxin mutants. An in vitro reconstitution assay showed that thioredoxin m, NADPH-thioredoxin reductase C, and NADPH are required for high O2-reduction levels in thylakoids from plants grown in long-day conditions. Using isolated photosystem I, we also showed that reduction of a photosystem I protein is responsible for the increase in O2 reduction. Furthermore, differences in the membrane localization of m-type thioredoxins and 2-Cys peroxiredoxin were detected between thylakoids of short-day and long-day plants. Overall, we propose a model of redox regulation of O2 reduction according to the reduction power of the stroma and the ability of different thiol-containing proteins to form a network of redox interactions.
Artículo The nucleolus: Coordinating Stress Response and Genomic Stability(Elsevier, 2024) González Arzola, Katiuska; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología MolecularThe perception that the nucleoli are merely the organelles where ribosome biogenesis occurs is challenged. Only around 30 % of nucleolar proteins are solely involved in producing ribosomes. Instead, the nucleolus plays a critical role in controlling protein trafficking during stress and, according to its dynamic nature, undergoes continuous protein exchange with nucleoplasm under various cellular stressors. Hence, the concept of nucleolar stress has evolved as cellular insults that disrupt the structure and function of the nucleolus. Considering the emerging role of this organelle in DNA repair and the fact that rDNAs are the most fragile genomic loci, therapies targeting the nucleoli are increasingly being developed. Besides, drugs that target ribosome synthesis and induce nucleolar stress can be used in cancer therapy. In contrast, agents that regulate nucleolar activity may be a potential treatment for neurodegeneration caused by abnormal protein accumulation in the nucleolus. Here, I explore the roles of nucleoli beyond their ribosomal functions, highlighting the factors triggering nucleolar stress and their impact on genomic stability.Artículo Persulfidome of Sweet Pepper Fruits during Ripening: The Case Study of Leucine Aminopeptidase That Is Positively Modulated by H2S(Multidisciplinary Digital Publishing Institute (MDPI), 2024-06-13) Muñoz-Vargas, María A.; González-Gordo, Salvador; Aroca Aguilar, Ángeles; Romero, Luis C.; Gotor, Cecilia; Palma, José M.; Corpas, Francisco J.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Agencia Estatal de Investigación (AEI)Protein persulfidation is a thiol-based oxidative posttranslational modification (oxiPTM) that involves the modification of susceptible cysteine thiol groups present in peptides and proteins through hydrogen sulfide (H2S), thus affecting their function. Using sweet pepper (Capsicum annuum L.) fruits as a model material at different stages of ripening (immature green and ripe red), endogenous persulfidated proteins (persulfidome) were labeled using the dimedone switch method and identified using liquid chromatography and mass spectrometry analysis (LC-MS/MS). A total of 891 persulfidated proteins were found in pepper fruits, either immature green or ripe red. Among these, 370 proteins were exclusively present in green pepper, 237 proteins were exclusively present in red pepper, and 284 proteins were shared between both stages of ripening. A comparative analysis of the pepper persulfidome with that described in Arabidopsis leaves allowed the identification of 25% of common proteins. Among these proteins, glutathione reductase (GR) and leucine aminopeptidase (LAP) were selected to evaluate the effect of persulfidation using an in vitro approach. GR activity was unaffected, whereas LAP activity increased by 3-fold after persulfidation. Furthermore, this effect was reverted through treatment with dithiothreitol (DTT). To our knowledge, this is the first persulfidome described in fruits, which opens new avenues to study H2S metabolism. Additionally, the results obtained lead us to hypothesize that LAP could be involved in glutathione (GSH) recycling in pepper fruits.Artículo Persulfidome of Sweet Pepper Fruits during Ripening: The Case Study of Leucine Aminopeptidase That Is Positively Modulated by H2S(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Muñoz Vargas, M. A.; González Gordo, S.; Aroca Aguilar, Ángeles; Romero, L. C.; Gotor, C.; Palma, J. M.; Corpas, F. J.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. EspañaProtein persulfidation is a thiol-based oxidative posttranslational modification (oxiPTM) that involves the modification of susceptible cysteine thiol groups present in peptides and proteins through hydrogen sulfide (H2S), thus affecting their function. Using sweet pepper (Capsicum annuum L.) fruits as a model material at different stages of ripening (immature green and ripe red), endogenous persulfidated proteins (persulfidome) were labeled using the dimedone switch method and identified using liquid chromatography and mass spectrometry analysis (LC-MS/MS). A total of 891 persulfidated proteins were found in pepper fruits, either immature green or ripe red. Among these, 370 proteins were exclusively present in green pepper, 237 proteins were exclusively present in red pepper, and 284 proteins were shared between both stages of ripening. A comparative analysis of the pepper persulfidome with that described in Arabidopsis leaves allowed the identification of 25% of common proteins. Among these proteins, glutathione reductase (GR) and leucine aminopeptidase (LAP) were selected to evaluate the effect of persulfidation using an in vitro approach. GR activity was unaffected, whereas LAP activity increased by 3-fold after persulfidation. Furthermore, this effect was reverted through treatment with dithiothreitol (DTT). To our knowledge, this is the first persulfidome described in fruits, which opens new avenues to study H2S metabolism. Additionally, the results obtained lead us to hypothesize that LAP could be involved in glutathione (GSH) recycling in pepper fruits.Artículo Antisense RNA Regulates Glutamine Synthetase in a Heterocyst-forming Cyanobacterium(American Society of Plant Biologists, 2024) Álvarez Escribano, Isidro; Suárez Murillo, Belén; Brenes Álvarez, Manuel; Vioque Peña, Agustín; Muro Pastor, Alicia M.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Junta de AndalucíaGlutamine synthetase (GS) is a key enzyme involved in nitrogen assimilation and the maintenance of C/N balance, and it is strictly regulated in all bacteria. In cyanobacteria, GS expression is controlled by nitrogen control A (NtcA) transcription factor, which operates global nitrogen regulation in these photosynthetic organisms. Furthermore, posttranslational regulation of GS is operated by protein–protein interaction with GS inactivating factors (IFs). In this study, we describe an additional regulatory mechanism involving an antisense RNA. In Nostoc sp. PCC 7120, the gifA gene (encoding GS inactivating factor IF7) is transcribed downstream of the GS (glnA) gene, from the opposite strand, and the gifA mRNA extends into the glnA coding sequence in antisense orientation. Therefore, the dual RNA transcript that encodes gifA constitutes two functional regions: a 5′ protein-coding region, encoding IF7, and a 3′ untranslated region that acts as an antisense to glnA. By increasing the levels of such antisense RNA either in cis or in trans, we demonstrate that the amount of GS activity can be modulated by the presence of the antisense RNA. The tail-to-tail disposition of the glnA and gifA genes observed in many cyanobacterial strains from the Nostocales clade suggests the prevalence of such antisense RNA-mediated regulation of GS in this group of cyanobacteria.Artículo CONSTANS alters the circadian clock in Arabidopsis thaliana(Elsevier, 2024-06-17) Reyes, Pedro de los; Serrano Bueno, Gloria; Romero Campero, Francisco José; Gao, He; Romero Rodríguez, José María; Valverde, Federico; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Universidad de Sevilla. Departamento de Ciencias de la Computación e Inteligencia Artificial; Ministerio de Ciencia, Innovación y Universidades (MICINN). EspañaPlants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment. Among these processes, the floral transition is essential to ensure reproductive success and is finely regulated by several internal and external genetic networks. The photoperiodic pathway, which controls plant response to day length, is one of the most important pathways controlling flowering. In Arabidopsis photoperiodic flowering, CONSTANS (CO) is the central gene activating the expression of the florigen FLOWERING LOCUS T (FT) in the leaves at the end of a long day. The circadian clock strongly regulates CO expression. However, to date, no evidence has been reported regarding a feedback loop from the photoperiod pathway back to the circadian clock. Using transcriptional networks, we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway. Gene expression, chromatin immunoprecipitation experiments, and phenotypic analysis allowed us to elucidate the role of CO over the circadian clock. Plants with altered CO expression showed a different internal clock period, measured by daily leaf rhythmic movements. We showed that CO upregulates the expression of key genes related to the circadian clock, such as CCA1, LHY, PRR5, and GI, at the end of a long day by binding to specific sites on their promoters. Moreover, a high number of PRR5-repressed target genes are upregulated by CO, and this could explain the phase transition promoted by CO. The CO-PRR5 complex interacts with the bZIP transcription factor HY5 and helps to localize the complex in the promoters of clock genes. Taken together, our results indicate that there may be a feedback loop in which CO communicates back to the circadian clock, providing seasonal information to the circadian system.Artículo Properties of polyplexes formed between a cationic polymer derived from l-arabinitol and nucleic acids(Royal Society of Chemistry, 2021-05-14) Pérez Alfonso, David; López López, Manuel; López-Cornejo, María del Pilar; Romero Azogil, Lucía; Benito Hernández, Elena María; García Martín, María de Gracia; García Calderón, Clara Beatriz; Valle Rosado, Iván; Romero Balestra, Fernando; Huertas Sánchez, Pablo; García Calderón, Margarita; Moyá Morán, María Luisa; Universidad de Sevilla. Departamento de Química Física; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Universidad de Sevilla. Departamento de Química Orgánica y Farmacéutica; Universidad de Sevilla. Departamento de Genética; Junta de Andalucía; Universidad de Sevilla; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; European Union (UE)In this work a sugar-based cationic polymer derived from L-arabinitol, PUArab, was prepared and its interactions with the linear calf thymus DNA and with the circular plasmid pEGFP-C1 were investigated at different N/P ratios. The polyplexes were characterized by using several techniques. For both nucleic acids, a charge inversion was observed, together with a conformational change from a coiled structure to a more compacted one. However, the N/P ratio required to observe the DNA condensation depended on the nucleic acid architecture. PUArab presents low toxicity in several cell lines. The transfection efficiency, TE, of the PUArab/pEGFP-C1 polyplexes was investigated at several N/P ratios in order to study their potential as vectors in gene transfection.Artículo Phosphorylation of cytochrome c at tyrosine 48 finely regulates its binding to the histone chaperone SET/TAF-Iβ in the nucleus(Wiley, 2024-11-16) Tamargo Azpilicueta, Joaquín; Casado Combreras, Miguel Ángel; Giner Arroyo, Rafael Luis; Velázquez Campoy, Adrián; Márquez Escudero, Inmaculada; Olloqui Sariego, José Luis; Rosa Acosta, Miguel Ángel de la; Díaz Moreno, Irene; Universidad de Sevilla. Departamento de Química Física; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; European Union (UE); Junta de AndalucíaPost-translational modifications (PTMs) of proteins are ubiquitous processes present in all life kingdoms, involved in the regulation of protein stability, subcellular location and activity. In this context, cytochrome c (Cc) is an excellent case study to analyze the structural and functional changes induced by PTMS as Cc is a small, moonlighting protein playing different roles in different cell compartments at different cell-cycle stages. Cc is actually a key component of the mitochondrial electron transport chain (ETC) under homeostatic conditions but is translocated to the cytoplasm and even the nucleus under apoptotic conditions and/or DNA damage. Phosphorylation does specifically alter the Cc redox activity in the mitochondria and the Cc non-redox interaction with apoptosis-related targets in the cytoplasm. However, little is known on how phosphorylation alters the interaction of Cc with histone chaperones in the nucleus. Here, we report the effect of Cc Tyr48 phosphorylation by examining the protein interaction with SET/TAF-Iβ in the nuclear compartment using a combination of molecular dynamics simulations, biophysical and structural approaches such as isothermal titration calorimetry (ITC) and nuclear magnetic resonance (NMR) and in cell proximity ligation assays. From these experiments, we infer that Tyr48 phosphorylation allows a fine-tuning of the Cc-mediated inhibition of SET/TAF-Iβ histone chaperone activity in vitro. Our findings likewise reveal that phosphorylation impacts the nuclear, stress-responsive functions of Cc, and provide an experimental framework to explore novel aspects of Cc post-translational regulation in the nucleus.Artículo Use of a Biostimulant Obtained from Slaughterhouse Sludge in a Greenhouse Tomato Crop(MDPI, 2022) Ávila Pozo, Paloma; Parrado Rubio, Juan; Caballero Jiménez, Pablo; Tejada Moral, Manuel; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola; Junta de Andalucía; European Union (UE). H2020; Ministerio de Ciencia, Innovación y Universidades (MICINN). EspañaCurrently, the use of biostimulants is widespread in sustainable agriculture because they represent an alternative to chemical fertilizers. In this manuscript, we investigate the response of a greenhouse tomato crop grown in pots to a biostimulant obtained from slaughterhouse sludge applied continuously to the substrate under which the tomato crop was grown or applied directly via the foliar route. Two doses of biostimulant (0.7 and 1.4 g L−1), applied four times throughout the crop growth period (120 days), were used. During this period, the height of the plants, number of flowers and number of fruits obtained were measured. After 90 days of the growth period, the nutrient contents in leaves as well as the chlorophyll a and b contents were analyzed. For fruits, nutrient and lycopene contents were determined, and the equatorial diameter and average fresh and dry weight were measured. The results indicate a higher content of nutrients and chlorophyll a and b in the leaves of plants treated with the highest dose of biostimulant and applied continuously to the substrate. This higher content of photosynthesis pigments in the plant is possibly responsible for a greater absorption of N by the plant and, consequently, for better growth.Artículo Persulfidation of ATG18a regulates autophagy underER stress in Arabidopsis(National Academy of Sciences, 2021-05) Aroca Aguilar, Ángeles; Yruela Guerrero, Inmaculada; Gotor Martínez, Cecilia; Bassham, Diane C.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; European Union (UE). H2020; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Agencia Estatal de Investigación. España; National Institutes of Health. United StatesHydrogen sulfide (H2S) is an endogenously generated gaseous signaling molecule, which recently has been implicated in autophagy regulation in both plants and mammals through persulfidation of specific targets. Persulfidation has been suggested as the molecular mechanism through which sulfide regulates autophagy in plant cells. ATG18a is a core autophagy component that is required for bulk autophagy and also for reticulophagy during endoplasmic reticulum (ER) stress. In this research, we revealed the role of sulfide in plant ER stress responses as a negative regulator of autophagy. We demonstrate that sulfide regulates ATG18a phospholipid-binding activity by reversible persulfidation at Cys103, and that this modification activates ATG18a binding capacity to specific phospholipids in a reversible manner. Our findings strongly suggest that persulfidation of ATG18a at C103 regulates autophagy under ER stress, and that the impairment of persulfidation affects both the number and size of autophagosomes.Artículo PCNA molecular recognition of different PIP motifs: Role of Tyr211 phosphorylation(Elsevier, 2024-07) Ruiz Albor, Antonio; Chaves Arquero, Belén; Martín Barros, Inés; Guerra Castellano, Alejandra; González-Magaña, Amaia; Ibáñez de Okapua, Alain; Merino, Nekane; Ferreras Gutiérrez, Mariola; Berra, Edurne; Díaz Moreno, Irene; Blanco, Francisco J.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Junta de Andalucía; Consejo Superior de Investigaciones Científicas (CSIC)The coordination of enzymes and regulatory proteins for eukaryotic DNA replication and repair is largely achieved by Proliferating Cell Nuclear Antigen (PCNA), a toroidal homotrimeric protein that embraces the DNA duplex. Many proteins bind PCNA through a conserved sequence known as the PCNA interacting protein motif (PIP). PCNA is further regulated by different post-translational modifications. Phosphorylation at residue Y211 facilitates unlocking stalled replication forks to bypass DNA damage repair processes but increasing nucleotide misincorporation. We explore here how phosphorylation at Y211 affects PCNA recognition of the canonical PIP sequences of the regulatory proteins p21 and p15, which bind with nM and μM affinity, respectively. For that purpose, we have prepared PCNA with p-carboxymethyl-L-phenylalanine (pCMF, a mimetic of phosphorylated tyrosine) at position 211. We have also characterized PCNA binding to the non-canonical PIP sequence of the catalytic subunit of DNA polymerase δ (p125), and to the canonical PIP sequence of the enzyme ubiquitin specific peptidase 29 (USP29) which deubiquitinates PCNA. Our results show that Tyr211 phosphorylation has little effect on the molecular recognition of p21 and p15, and that the PIP sequences of p125 and USP29 bind to the same site on PCNA as other PIP sequences, but with very low affinity.Artículo A splice-altering homozygous variant in COX18 causes severe sensory-motor neuropathy with oculofacial apraxia(Elsevier B.V., 2024-10) Mavillard, Fabiola; Guerra Castellano, Alejandra; Guerrero Gómez, David; Rivas, Eloy; Cantero, Gloria; Servián Morilla, Emilia; Folland, Chiara; Ravenscroft, Gianina; Martín, Miguel A.; Miranda Vizuete, Antonio; Cabrera Serrano, Macarena; Díaz Moreno, Irene; Paradas, Carmen; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Instituto de Salud Carlos III; Junta de Andalucía; European Union (UE); Ministerio de Ciencia e Innovación (MICIN). EspañaCytochrome-c oxidase (COX) is part of the mitochondrial complex IV (CIV). COX deficiency is usually associated with tRNA variants, and less frequently with variants in COX assembly factors. Mutations in COX subunits encoded by mitochondrial DNA and nuclear DNA are rare, likely because most of them are associated to very severe phenotypes with early lethality. COX18, an assembly factor of CIV, has long been analyzed as a potential cause of mitochondrial disease. To date, only one patient has been identified carrying a homozygous missense variant in COX18, associated with neonatal encephalo-cardiomyopathy and axonal sensory neuropathy. Here, we describe a 40-year-old patient, asymptomatic until 7 months of age, who presented with progressive muscle weakness resembling spinal muscle atrophy type-2, associated with oculofacial apraxia and dysarthric speech. Electrophysiology analysis highlighted a severe sensory-motor neuropathy. Muscle biopsy showed striking and diffuse decreases of COX staining and a substantial reduction of CIV activity. Muscle biopsy showed no raggedred fibers, although ultrastructural mitochondrial alterations were evident. A novel homozygous variant (c.598G>A), located in the last nucleotide of exon 3, was detected in COX18 by whole-exome sequencing, which affected the splicing donor site, as demonstrated by cDNA-seq. The patient fibroblasts express a truncated form of COX18 (COX18Δ112-240) capable of assembling CIV and CIV-involving supercomplexes. However, CIV activity was decreased. COX18 full-length (COX18-fl) overexpression partially rescued CIV activity in the patient fibroblasts. The rescue of the null CIV activity in COX18-KO-HEK293 cells by overexpressing of COX18Δ112-240 was significantly lower than in cells with COX18-fl. In addition, cox-18 downregulation in C. elegans resulted in slow growth and, diminished reduced motility phenotypes and as well as severe fragmentation of the mitochondrial network. Our case expands the phenotypes associated with COX18 variants and supports the pathogenic role of COX18 as the cause of a severe encephaloneuropathy syndrome.Artículo Phosphorylation at the disordered N-end makes HuR accumulate and dimerize in the cytoplasm.(Oxford University Press, 2024-07-05) Baños Jaime, Blanca; Corrales Guerrero, Laura; Pérez Mejías, Gonzalo; Rejano Gordillo, Claudia M.; Velázquez Campoy, Adrián; Martínez Cruz, Luis Alfonso; Rosa Acosta, Miguel Ángel de la; Díaz Moreno, Irene; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Agencia Estatal de Investigación. España; Ministerio de Ciencia e Innovación (MICIN). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Junta de Andalucía; Universidad de Sevilla; Ministerio de Educación, Cultura y Deporte (MECD). EspañaHuman antigen R (HuR) is an RNA binding protein mainly involved in maintaining the stability and controlling the translation of mRNAs, critical for immune response, cell survival, proliferation and apoptosis. Although HuR is a nuclear protein, its mRNA translational-related function occurs at the cytoplasm, where the oligomeric form of HuR is more abundant. However, the regulation of nucleo-cytoplasmic transport of HuR and its connection with protein oligomerization remain unclear. In this work, we describe the phosphorylation of Tyr5 as a new hallmark for HuR activation. Our biophysical, structural and computational assays using phosphorylated and phosphomimetic HuR proteins demonstrate that phosphorylation of Tyr5 at the disordered N-end stretch induces global changes on HuR dynamics and conformation, modifying the solvent accessible surface of the HuR nucleo-cytoplasmic shuttling (HNS) sequence and releasing regions implicated in HuR dimerization. These findings explain the preferential cytoplasmic accumulation of phosphorylated HuR in HeLa cells, aiding to comprehend the mechanisms underlying HuR nucleus-cytoplasm shuttling and its later dimerization, both of which are relevant in HuR-related pathogenesis.Artículo Comparative Genomics of Synechococcus elongatus Explains the Phenotypic Diversity of the Strains(American Society for Microbiology, 2022) Adomako, Marie; Ernst, Dustin; Simkovsky, Ryan; Chao, Yi Yun; Wang, Jingtong; Fang, Mingxu; Bouchier, Christiane; López Igual, Rocío; Mazel, Didier; Gugger, Muriel; Golden, Susan S.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; National Institutes of Health. United StatesStrains of the freshwater cyanobacterium Synechococcus elongatus were first isolated approximately 60 years ago, and PCC 7942 is well established as a model for photosynthesis, circadian biology, and biotechnology research. The recent isolation of UTEX 3055 and subsequent discoveries in biofilm and phototaxis phenotypes suggest that lab strains of S. elongatus are highly domesticated. We performed a comprehensive genome comparison among the available genomes of S. elongatus and sequenced two additional laboratory strains to trace the loss of native phenotypes from the standard lab strains and determine the genetic basis of useful phenotypes. The genome comparison analysis provides a pangenome description of S. elongatus, as well as correction of extensive errors in the published sequence for the type strain PCC 6301. The comparison of gene sets and single nucleotide polymorphisms (SNPs) among strains clarifies strain isolation histories and, together with large-scale genome differences, supports a hypothesis of laboratory domestication. Prophage genes in laboratory strains, but not UTEX 3055, affect pigmentation, while unique genes in UTEX 3055 are necessary for phototaxis. The genomic differences identified in this study include previously reported SNPs that are, in reality, sequencing errors, as well as SNPs and genome differences that have phenotypic consequences. One SNP in the circadian response regulator rpaA that has caused confusion is clarified here as belonging to an aberrant clone of PCC 7942, used for the published genome sequence, that has confounded the interpretation of circadian fitness research.Artículo An Actin Remodeling Role for Arabidopsis Processing Bodies Revealed by their Proximity Interactome(WILEY, 2023) Liu, Chen; Mentzelopoulou, Andriani; Muhammad, Amna; Volkov, Andriy; Weijers, Dolf; Gutiérrez Beltrán, Emilio; Moschou, Panagiotis N.; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Carl Tryggers Foundation; European Union (UE); Vetenskapsradet (VR) research council; FORMAS research council; Helge Ax:son Johnsons stiftelse; Hellenic Foundation of Research and Innovation (HFRI); European Research Council (ERC); Ministerio de Ciencia e Innovación (MICIN). EspañaCellular condensates can comprise membrane-less ribonucleoprotein assemblies with liquid-like properties. These cellular condensates influence various biological outcomes, but their liquidity hampers their isolation and characterization. Here, we investigated the composition of the condensates known as processing bodies (PBs) in the model plant Arabidopsis thaliana through a proximity-biotinylation proteomics approach. Using in situ protein–protein interaction approaches, genetics and high-resolution dynamic imaging, we show that processing bodies comprise networks that interface with membranes. Surprisingly, the conserved component of PBs, DECAPPING PROTEIN 1 (DCP1), can localize to unique plasma membrane subdomains including cell edges and vertices. We characterized these plasma membrane interfaces and discovered a developmental module that can control cell shape. This module is regulated by DCP1, independently from its role in decapping, and the actin-nucleating SCAR–WAVE complex, whereby the DCP1–SCAR–WAVE interaction confines and enhances actin nucleation. This study reveals an unexpected function for a conserved condensate at unique membrane interfaces.Artículo Glycogen synthesis prevents metabolic imbalance and disruption of photosynthetic electron transport from photosystem II during transition to photomixotrophy in Synechocystis sp. PCC 6803(John Wiley & Sons, 2024-05-06) Ortega Martínez, Pablo; Nikkanen, Lauri; Wey, Laura T.; Florencio Bellido, Francisco Javier; Allahverdiyeva, Yagut; Díaz Troya, Sandra; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Junta de Andalucía; NordForsk Nordic Center of Excellence; Novo Nordisk Foundation; Ministerio de Universidades. EspañaSome cyanobacteria can grow photoautotrophically or photomixotrophically by using simultaneously CO2 and glucose. The switch between these trophic modes and the role of glycogen, their main carbon storage macromolecule, was investigated. We analysed the effect of glucose addition on the physiology, metabolic and photosynthetic state of Synechocystis sp. PCC 6803 and mutants lacking phosphoglucomutase and ADP-glucose pyrophosphorylase, with limitations in glycogen synthesis. Glycogen acted as a metabolic buffer: glucose addition increased growth and glycogen reserves in the wild-type (WT), but arrested growth in the glycogen synthesis mutants. Already 30 min after glucose addition, metabolites from the Calvin–Benson–Bassham cycle and the oxidative pentose phosphate shunt increased threefold more in the glycogen synthesis mutants than the WT. These alterations substantially affected the photosynthetic performance of the glycogen synthesis mutants, as O2 evolution and CO2 uptake were both impaired. We conclude that glycogen synthesis is essential during transitions to photomixotrophy to avoid metabolic imbalance that induces inhibition of electron transfer from PSII and subsequently accumulation of reactive oxygen species, loss of PSII core proteins, and cell death. Our study lays foundations for optimising photomixotrophy-based biotechnologies through understanding the coordination of the crosstalk between photosynthetic electron transport and metabolism.Artículo Double blocking of carbon metabolism causes a large increase of Calvin–Benson cycle compounds in cyanobacteria(AMER SOC PLANT BIOLOGISTS; OXFORD UNIV PRESS INC, 2024) Domínguez Lobo, María Teresa; Roldán, Miguel; Gutiérrez Diánez, Alba María; Florencio Bellido, Francisco Javier; Muro Pastor, María Isabel; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Agencia Estatal de Investigación. España; Junta de Andalucía; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)Carbon-flow-regulator A (CfrA) adapts carbon flux to nitrogen conditions in nondiazotrophic cyanobacteria. Under nitrogen deficiency, CfrA leads to the storage of excess carbon, which cannot combine with nitrogen, mainly as glycogen. cfrA overexpression from the arsenite-inducible, nitrogen-independent ParsB promoter allows analysis of the metabolic effects of CfrA accumulation. Considering that the main consequence of cfrA overexpression is glycogen accumulation, we examined carbon distribution in response to cfrA expression in Synechocystis sp. PCC 6803 strains impaired in synthesizing this polymer. We carried out a comparative phenotypic analysis to evaluate cfrA overexpression in the wild-type strain and in a mutant of ADP-glucose pyrophosphorylase (ΔglgC), which is unable to synthesize glycogen. The accumulation of CfrA in the wildtype background caused a photosynthetic readjustment although growth was not affected. However, in a ΔglgC strain, growth decreased depending on CfrA accumulation and photosynthesis was severely affected. An elemental analysis of the H, C, and N content of cells revealed that cfrA expression in the wild-type caused an increase in the C/N ratio, due to decreased nitrogen assimilation. Metabolomic study indicated that these cells store sucrose and glycosylglycerol, in addition to the previously described glycogen accumulation. However, cells deficient in glycogen synthesis accumulated large amounts of Calvin–Benson cycle intermediates as cfrA was expressed. These cells also showed increased levels of some amino acids, mainly alanine, serine, valine, isoleucine, and leucine. The findings suggest that by controlling cfrA expression, in different conditions and strains, we could change the distribution of fixed carbon, with potential biotechnological benefits.Artículo CONSTANS, a HUB for all seasons: How photoperiod pervades plant physiology regulatory circuits(AMER SOC PLANT BIOLOGISTS; OXFORD UNIV PRESS INC, 2024) Romero Rodríguez, José María; Serrano Bueno, Gloria; Camacho-Fernández, Carolina; Henrique Vicente, Mateus; Ruiz, María Teresa; Pérez Castiñeira, José Román; Pérez Hormaeche, Javier; Nogueira, Fabio; Valverde, Federico; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE)How does a plant detect the changing seasons and make important developmental decisions accordingly? How do they incorporate daylength information into their routine physiological processes?Photoperiodism, or the capacity to measure the daylength, is a crucial aspect of plant development that helps plants determine the best time of the year to make vital decisions, such as flowering. The protein CONSTANS (CO) constitutes the central regulator of this sensing mechanism, not only activating florigen production in the leaves but also participating in many physiological aspects in which seasonality is important. Recent discoveries place CO in the center of a gene network that can determine the length of the day and confer seasonal input to aspects of plant development and physiology as important as senescence, seed size, or circadian rhythms. In this review, we discuss the importance of CO protein structure, function, and evolutionary mechanisms that embryophytes have developed to incorporate annual information into their physiology.Artículo Cancer-Stem-Cell Phenotype-Guided Discovery of a Microbiota- Inspired Synthetic Compound Targeting NPM1 for Leukemia(AMER CHEMICAL SOC, 2023) Algar, Sergio; Vázquez-Villa, Henar; Aguilar-Garrido, Pedro; Navarro-Aguadero, Miguel Ángel; Velasco-Estévez, María; Sánchez-Merino, Anabel; Giner Arroyo, Rafael Luis; Tamargo Azpilicueta, Joaquín; Díaz Moreno, Irene; Benhamú, Bellinda; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); European Union (UE); Instituto de Salud Carlos III; Junta de AndalucíaThe human microbiota plays an important role in human health and disease, through the secretion of metabolites that regulate key biological functions. We propose that microbiota metabolites represent an unexplored chemical space of small druglike molecules in the search of new hits for drug discovery. Here, we describe the generation of a set of complex chemotypes inspired on selected microbiota metabolites, which have been synthesized using asymmetric organocatalytic reactions. Following a primary screening in CSC models, we identified the novel compound UCM-13369 (4b) whose cytotoxicity was mediated by NPM1. This protein is one of the most frequent mutations of AML, and NPM1-mutated AML is recognized by the WHO as a distinct hematopoietic malignancy. UCM-13369 inhibits NPM1 expression, downregulates the pathway associated with mutant NPM1 C+, and specifically recognizes the C-end DNA-binding domain of NPM1 C+, avoiding the nucleus-cytoplasm translocation involved in the AML tumorological process. The new NPM1 inhibitor triggers apoptosis in AML cell lines and primary cells from AML patients and reduces tumor infiltration in a mouse model of AML with NPM1 C+ mutation. The disclosed phenotype-guided discovery of UCM-13369, a novel small molecule inspired on microbiota metabolites, confirms that CSC death induced by NPM1 inhibition represents a promising therapeutic opportunity for NPM1-mutated AML, a high-mortality disease.Artículo 2-Cys peroxiredoxins contribute to thylakoid lipid unsaturation by affecting ω-3 fatty acid desaturase 8(AMER SOC PLANT BIOLOGISTS; OXFORD UNIV PRESS INC, 2024-02-22) Hernández Jiménez, María Luisa; Jiménez López, Julia; Cejudo Fernández, Francisco Javier; Pérez Ruiz, Juan Manuel; Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular; National Institutes of Health. United States; USDA National Institute of Food and AgricultureFatty acid unsaturation levels affect chloroplast function and plant acclimation to environmental cues. However, the regulatory mechanism(s) controlling fatty acid unsaturation in thylakoid lipids is poorly understood. Here, we have investigated the connection between chloroplast redox homeostasis and lipid metabolism by focusing on 2-Cys peroxiredoxins (Prxs), which play a central role in balancing the redox state within the organelle. The chloroplast redox network relies on NADPH-dependent thioredoxin reductase C (NTRC), which controls the redox balance of 2-Cys Prxs to maintain the reductive activity of redox-regulated enzymes. Our results show that Arabidopsis (Arabidopsis thaliana) mutants deficient in 2-Cys Prxs contain decreased levels of trienoic fatty acids, mainly in chloroplast lipids, indicating that these enzymes contribute to thylakoid membrane lipids unsaturation. This function of 2-Cys Prxs is independent of NTRC, the main reductant of these enzymes, hence 2-Cys Prxs operates beyond the classic chloroplast regulatory redox system. Moreover, the effect of 2-Cys Prxs on lipid metabolism is primarily exerted through the prokaryotic pathway of glycerolipid biosynthesis and fatty acid desaturase 8 (FAD8). While 2-Cys Prxs and FAD8 interact in leaf membranes as components of a large protein complex, the levels of FAD8 were markedly decreased when FAD8 is overexpressed in 2-Cys Prxs- deficient mutant backgrounds. These findings reveal a function for 2-Cys Prxs, possibly acting as a scaffold protein, affecting the unsaturation degree of chloroplast membranes.