Publications by authors named "Alessandro Grottesi"

Epitranscriptomic mRNA modifications affect gene expression, with their altered balance detected in various cancers. YTHDF proteins contain the YTH reader domain recognizing the mA mark on mRNA and represent valuable drug targets. Crystallographic structures have been determined for all three family members; however, discrepancies are present in the organization of the mA-binding pocket.

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  • Argonaute (Ago) proteins help miRNA bind to mRNA by recognizing complementary sequences, mainly in the seed region, but also through additional base pairing that enhances their interaction.
  • Researchers used molecular dynamics simulations to investigate the binding behavior of human Ago2 with a miRNA-mRNA duplex in different solvent environments, specifically a water/methanol mixture alongside pure water.
  • The study found that the mixed solvent enhances the interaction between the Ago protein and RNA, stabilizes the supplementary duplex, and restricts its flexibility, while having little effect on the conformation of the seed duplex.
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Thanks to the considerable research which has been undertaken in the last few years to improve our understanding of the biology and mechanism of action of SARS-CoV-2, we know how the virus uses its surface spike protein to infect host cells. The transmembrane prosthesis, serine 2 (TMPRSS2) protein, located on the surface of human cells, recognizes the cleavage site in the spike protein, leading to the release of the fusion peptide and entry of the virus into the host cells. Because of its role, TMPRSS2 has been proposed as a drug target to prevent infection by the virus.

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Peptidomimetic antimicrobials exhibit a selective interaction with bacterial cells over mammalian cells once they have achieved an optimum amphiphilic balance (hydrophobicity/hydrophilicity) in the molecular architecture. To date, hydrophobicity and cationic charge have been considered the crucial parameters to attain such amphiphilic balance. However, optimization of these properties is not enough to circumvent unwanted toxicity towards mammalian cells.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the pandemic that broke out in 2020 and continues to be the cause of massive global upheaval. Coronaviruses are positive-strand RNA viruses with a genome of ~30 kb. The genome is replicated and transcribed by RNA-dependent RNA polymerase together with accessory factors.

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  • The study investigates how the surrounding boundary lipids affect the behavior of integral membrane proteins, specifically focusing on the Lck kinase and its regulation by the CD45 phosphatase.
  • Using advanced techniques like super-resolution microscopy and flow cytometry, researchers found that Lck is generated at the plasma membrane and maintained in a dynamic balance with its unphosphorylated form through a process called trans-autophosphorylation.
  • The findings suggest that fluctuations in the lipid bilayer rather than previously assumed phase-separated domains are key to understanding Lck formation and its interactions with CD45, highlighting the role of boundary lipids in this process.
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The COVID-19 pandemic is caused by SARS-CoV-2. Currently, most of the research efforts towards the development of vaccines and antibodies against SARS-CoV-2 were mainly focused on the spike (S) protein, which mediates virus entry into the host cell by binding to ACE2. As the virus SARS-CoV-2 continues to spread globally, variants have emerged, characterized by multiple mutations of the S glycoprotein.

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The conformational state of the activation loop (A-loop) is pivotal for the activity of most protein kinases. Hence, the characterization of the conformational dynamics of the A-loop is important to increase our understanding of the molecular processes related to diseases and to support the discovery of small molecule kinase inhibitors. Here, we carry out a combination of molecular dynamics (MD) and essential dynamics (ED) analyses to fully map the effects of phosphorylation, ADP, and conformation disrupting (CD) inhibitors (i.

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Given the enormous social and health impact of the pandemic triggered by severe acute respiratory syndrome 2 (SARS-CoV-2), the scientific community made a huge effort to provide an immediate response to the challenges posed by Coronavirus disease 2019 (COVID-19). One of the most important proteins of the virus is an enzyme, called 3CLpro or main protease, already identified as an important pharmacological target also in SARS and Middle East respiratory syndrome virus (MERS) viruses. This protein triggers the production of a whole series of enzymes necessary for the virus to carry out its replicating and infectious activities.

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PPARγ represents a key target for the treatment of type 2 diabetes and metabolic syndrome. Synthetic antidiabetic drugs activating PPARγ are accompanied by serious undesirable side effects related to their agonism. In the search for new PPARγ regulators, inhibitors of PPARγ phosphorylation on S245 mediated by CDK5 represent an opportunity for the development of an improved generation of antidiabetic drugs acting through this nuclear receptor.

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  • The primary method for predicting protein structure is homology modeling, with the 3D model-building phase being crucial for accuracy, often employing the software MODELLER.
  • This study suggests two modifications to enhance MODELLER's performance: improving the accuracy of structural variability estimates (σ values) for better predictions and incorporating statistical potential terms to boost modeling quality.
  • The authors demonstrate significant potential for improving 3D modeling outcomes using these strategies and provide Python modules for implementing the second approach, available on GitHub.
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Histidine decarboxylase is a pyridoxal 5'-phosphate enzyme catalyzing the conversion of histidine to histamine, a bioactive molecule exerting its role in many modulatory processes. The human enzyme is involved in many physiological functions, such as neurotransmission, gastrointestinal track function, cell growth, and differentiation. Here, we studied the functional properties of the human enzyme and, in particular, the effects exerted at the protein level by two cysteine residues: Cys-180 and Cys-418.

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A 2-yr-old boy presented profound developmental delay, failure to thrive, ataxia, hypotonia, and tonic-clonic seizures that caused the death of the patient. Targeted and whole exome sequencing revealed two heterozygous missense variants: a novel mutation in the gene that encodes for the inward-rectifying K channel Kir4.1 and another previously characterized mutation in that encodes for the Na-activated K channel known as Slo2.

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Molecular dynamics (MD) simulation allows one to predict the time evolution of a system of interacting particles. It is widely used in physics, chemistry and biology to address specific questions about the structural properties and dynamical mechanisms of model systems. MD earned a great success in genome research, as it proved to be beneficial in sorting pathogenic from neutral genomic mutations.

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  • Globular denatured proteins behave like random coils, and increasing temperature can lead to thermal compaction, shrinking their size significantly (5% to 35% reduction in radius of gyration).
  • The study focuses on the protein tau, which compacts by 18% when temperature rises from 293 K to 333 K, using atomistic simulations alongside experimental methods to analyze changes.
  • Key findings highlight contributions to compaction from factors such as entropy, hydrophobic interactions, and alterations in secondary structures like α-helices and β-sheets as the temperature increases.
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Dysfunction of the inwardly-rectifying potassium channels Kir4.1 (KCNJ10) represents a pathogenic mechanism contributing to Autism-Epilepsy comorbidity. To define the role of Kir4.

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The conformational behavior of the wild-type endonucleases I-DmoI and two of its mutants has been studied in the presence and in the absence of DNA target sequences by means of extended molecular dynamics simulations. Our results show that in the absence of DNA, the three protein forms explore a similar essential conformational space, whereas when bound to the same DNA target sequence of 25 base pairs, they diversify and restrain the subspace explored. In addition, the differences in the essential subspaces explored by the residues near the catalytic site for both the bound and unbound forms are discussed in background of the experimental protein activity.

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An autosomal dominant protein aggregate myopathy, characterized by high plasma creatine kinase and calsequestrin-1 (CASQ1) accumulation in skeletal muscle, has been recently associated with a missense mutation in CASQ1 gene. The mutation replaces an evolutionarily-conserved aspartic acid with glycine at position 244 (p.D244G) of CASQ1, the main sarcoplasmic reticulum (SR) Ca2+ binding and storage protein localized at the terminal cisternae of skeletal muscle cells.

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Marine ladder-shaped polyether toxins are implicated in neurological symptoms of fish-borne food poisonings. The toxin gambierol, produced by the marine dinoflagellate Gambierdiscus toxicus, belongs to the group of ladder-shaped polyether toxins and inhibits Kv3.1 channels with nanomolar affinity through a mechanism of gating modification.

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Episodic ataxia type 1 (EA1) is an autosomal dominant K(+) channelopathy which manifests with short attacks of cerebellar ataxia and dysarthria, and may also show interictal myokymia. Episodes can be triggered by emotional or physical stress, startle response, sudden postural change or fever. Here we describe a 31-year-old man displaying markedly atypical symptoms, including long-lasting attacks of jerking muscle contractions associated with hyperthermia, severe migraine, and a relatively short-sleep phenotype.

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Protein kinases work because their flexibility allows to continuously switch from inactive to active form. Despite the large number of structures experimentally determined in such states, the mechanism of their conformational transitions as well as the transition pathways are not easily to capture. In this regard, computational methods can help to shed light on such an issue.

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Short QT3 syndrome (SQT3S) is a cardiac disorder characterized by a high risk of mortality and associated with mutations in Kir2.1 (KCNJ2) channels. The molecular mechanisms leading to channel dysfunction, cardiac rhythm disturbances and neurodevelopmental disorders, potentially associated with SQT3S, remain incompletely understood.

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ATP-sensitive K(+) (K(ATP)) channels, comprised of pore-forming Kir6.x and regulatory SURx subunits, play important roles in many cellular functions; because of their sensitivity to inhibition by intracellular ATP, K(ATP) channels provide a link between cell metabolism and membrane electrical activity. We constructed structural homology models of Kir6.

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  • - The 37/67-kDa human laminin receptor (LamR) is a protein on cell surfaces that plays a crucial role in cell adhesion and various biological processes by interacting with extracellular matrix molecules, especially laminins.
  • - The specific way that laminin-1 binds to LamR is still not completely understood, but it's believed to involve regions of the protein called peptide G and the C-terminal helix.
  • - Recent molecular dynamics simulations reveal that a flexible loop in LamR undergoes a conformational change that could expose a key residue (R180) for binding to laminin-1, suggesting important structural factors in their interaction.
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The inwardly-rectifying potassium channel Kir4.1 is a major player in the astrocyte-mediated regulation of [K(+)](o) in the brain, which is essential for normal neuronal activity and synaptic functioning. KCNJ10, encoding Kir4.

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