The ALS drug riluzole binds to the C-terminal domain of SARS-CoV-2 nucleocapsid protein and has antiviral activity.

Nucleoproteins (N) play an essential role in virus assembly and are less prone to mutation than other viral structural proteins, making them attractive targets for drug discovery. Using an NMR fragment-based drug discovery approach, we identified the 1,3-benzothiazol-2-amine (BZT) group as a scaffold to develop potential antivirals for SARS-CoV-2 nucleocapsid (N) protein. A thorough characterization of BZT derivatives using NMR, X-ray crystallography, antiviral activity assays, and intrinsic fluorescence measurements revealed their binding in the C-terminal domain (CTD) domain of the N protein, to residues Arg 259, Trp 330, and Lys 338, coinciding with the nucleotide binding site.

Development of anti-membrane type 1-matrix metalloproteinase nanobodies as immunoPET probes for triple negative breast cancer imaging.

Triple-negative breast cancer (TNBC) is characterized by aggressiveness and high rates of metastasis. The identification of relevant biomarkers is crucial to improve outcomes for TNBC patients. Membrane type 1-matrix metalloproteinase (MT1-MMP) could be a good candidate because its expression has been reported to correlate with tumor malignancy, progression and metastasis.

The MASTL/PP2A cell cycle kinase-phosphatase module restrains PI3K-Akt activity in an mTORC1-dependent manner.

The AKT-mTOR pathway is a central regulator of cell growth and metabolism. Upon sustained mTOR activity, AKT activity is attenuated by a feedback loop that restrains upstream signaling. However, how cells control the signals that limit AKT activity is not fully understood.

Structure of the RAF1-HSP90-CDC37 complex reveals the basis of RAF1 regulation.

RAF kinases are RAS-activated enzymes that initiate signaling through the MAPK cascade to control cellular proliferation, differentiation, and survival. Here, we describe the structure of the full-length RAF1 protein in complex with HSP90 and CDC37 obtained by cryoelectron microscopy. The reconstruction reveals a RAF1 kinase with an unfolded N-lobe separated from its C-lobe.

Structural basis of Nrd1-Nab3 heterodimerization.

Heterodimerization of RNA binding proteins Nrd1 and Nab3 is essential to communicate the RNA recognition in the nascent transcript with the Nrd1 recognition of the Ser-phosphorylated Rbp1 C-terminal domain in RNA polymerase II. The structure of a Nrd1-Nab3 chimera reveals the basis of heterodimerization, filling a missing gap in knowledge of this system. The free form of the Nrd1 interaction domain of Nab3 (NRID) forms a multi-state three-helix bundle that is clamped in a single conformation upon complex formation with the Nab3 interaction domain of Nrd1 (NAID).

Histone acetylation of bile acid transporter genes plays a critical role in cirrhosis.

Background & Aims: Owing to the lack of genetic animal models that adequately recreate key clinical characteristics of cirrhosis, the molecular pathogenesis of cirrhosis has been poorly characterized, and treatments remain limited. Hence, we aimed to better elucidate the pathological mechanisms of cirrhosis using a novel murine model.

Methods: We report on the first murine genetic model mimicking human cirrhosis induced by hepatocyte-specific elimination of microspherule protein 1 (MCRS1), a member of non-specific lethal (NSL) and INO80 chromatin-modifier complexes.

Limited survival and impaired hepatic fasting metabolism in mice with constitutive Rag GTPase signaling.

The mechanistic target of rapamycin complex 1 (mTORC1) integrates cellular nutrient signaling and hormonal cues to control metabolism. We have previously shown that constitutive nutrient signaling to mTORC1 by means of genetic activation of RagA (expression of GTP-locked RagA, or RagA) in mice resulted in a fatal energetic crisis at birth. Herein, we rescue neonatal lethality in RagA mice and find morphometric and metabolic alterations that span glucose, lipid, ketone, bile acid and amino acid homeostasis in adults, and a median lifespan of nine months.

Urine NMR-based TB metabolic fingerprinting for the diagnosis of TB in children.

Tuberculosis (TB) is a major cause of morbidity and mortality in children, and early diagnosis and treatment are crucial to reduce long-term morbidity and mortality. In this study, we explore whether urine nuclear magnetic resonance (NMR)-based metabolomics could be used to identify differences in the metabolic response of children with different diagnostic certainty of TB. We included 62 children with signs and symptoms of TB and 55 apparently healthy children.

Discovery and validation of an NMR-based metabolomic profile in urine as TB biomarker.

Despite efforts to improve tuberculosis (TB) detection, limitations in access, quality and timeliness of diagnostic services in low- and middle-income countries are challenging for current TB diagnostics. This study aimed to identify and characterise a metabolic profile of TB in urine by high-field nuclear magnetic resonance (NMR) spectrometry and assess whether the TB metabolic profile is also detected by a low-field benchtop NMR spectrometer. We included 189 patients with tuberculosis, 42 patients with pneumococcal pneumonia, 61 individuals infected with latent tuberculosis and 40 uninfected individuals.

The structure of transcription termination factor Nrd1 reveals an original mode for GUAA recognition.

Transcription termination of non-coding RNAs is regulated in yeast by a complex of three RNA binding proteins: Nrd1, Nab3 and Sen1. Nrd1 is central in this process by interacting with Rbp1 of RNA polymerase II, Trf4 of TRAMP and GUAA/G terminator sequences. We lack structural data for the last of these binding events.

Structural basis for interdomain communication in SHIP2 providing high phosphatase activity.

SH2-containing-inositol-5-phosphatases (SHIPs) dephosphorylate the 5-phosphate of phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P) and play important roles in regulating the PI3K/Akt pathway in physiology and disease. Aiming to uncover interdomain regulatory mechanisms in SHIP2, we determined crystal structures containing the 5-phosphatase and a proximal region adopting a C2 fold. This reveals an extensive interface between the two domains, which results in significant structural changes in the phosphatase domain.

Discovery of first-in-class reversible dual small molecule inhibitors against G9a and DNMTs in hematological malignancies.

The indisputable role of epigenetics in cancer and the fact that epigenetic alterations can be reversed have favoured development of epigenetic drugs. In this study, we design and synthesize potent novel, selective and reversible chemical probes that simultaneously inhibit the G9a and DNMTs methyltransferase activity. In vitro treatment of haematological neoplasia (acute myeloid leukaemia-AML, acute lymphoblastic leukaemia-ALL and diffuse large B-cell lymphoma-DLBCL) with the lead compound CM-272, inhibits cell proliferation and promotes apoptosis, inducing interferon-stimulated genes and immunogenic cell death.

Liver carcinogenesis by FOS-dependent inflammation and cholesterol dysregulation.

Human hepatocellular carcinomas (HCCs), which arise on a background of chronic liver damage and inflammation, express c-Fos, a component of the AP-1 transcription factor. Using mouse models, we show that hepatocyte-specific deletion of c-Fos protects against diethylnitrosamine (DEN)-induced HCCs, whereas liver-specific c-Fos expression leads to reversible premalignant hepatocyte transformation and enhanced DEN-carcinogenesis. c-Fos-expressing livers display necrotic foci, immune cell infiltration, and altered hepatocyte morphology.

p21 plays a critical role in the physiological adaptation to fasting through activation of PPARα.

Fasting is a physiological stress that elicits well-known metabolic adaptations, however, little is known about the role of stress-responsive tumor suppressors in fasting. Here, we have examined the expression of several tumor suppressors upon fasting in mice. Interestingly, p21 mRNA is uniquely induced in all the tissues tested, particularly in liver and muscle (>10 fold), and this upregulation is independent of p53.

Regulation of OGT by URI in Response to Glucose Confers c-MYC-Dependent Survival Mechanisms.

Cancer cells can adapt and survive under low nutrient conditions, but underlying mechanisms remain poorly explored. We demonstrate here that glucose maintains a functional complex between the co-chaperone URI, PP1γ, and OGT, the enzyme catalyzing O-GlcNAcylation. Glucose deprivation induces the activation of PKA, which phosphorylates URI at Ser-371, resulting in PP1γ release and URI-mediated OGT inhibition.

Stabilization of i-motif structures by 2'-β-fluorination of DNA.

i-Motifs are four-stranded DNA structures consisting of two parallel DNA duplexes held together by hemi-protonated and intercalated cytosine base pairs (C:CH(+)). They have attracted considerable research interest for their potential role in gene regulation and their use as pH responsive switches and building blocks in macromolecular assemblies. At neutral and basic pH values, the cytosine bases deprotonate and the structure unfolds into single strands.

Conformational Selection and Induced Fit Mechanisms in the Binding of an Anticancer Drug to the c-Src Kinase.

Understanding the conformational changes associated with the binding of small ligands to their biological targets is a fascinating and meaningful question in chemistry, biology and drug discovery. One of the most studied and important is the so-called "DFG-flip" of tyrosine kinases. The conserved three amino-acid DFG motif undergoes an "in to out" movement resulting in a particular inactive conformation to which "type II" kinase inhibitors, such as the anti-cancer drug Imatinib, bind.

Combined Use of Oligopeptides, Fragment Libraries, and Natural Compounds: A Comprehensive Approach To Sample the Druggability of Vascular Endothelial Growth Factor.

The modulation of protein-protein interactions (PPIs) is emerging as a highly promising tool to fight diseases. However, whereas an increasing number of compounds are able to disrupt peptide-mediated PPIs efficiently, the inhibition of domain-domain PPIs appears to be much more challenging. Herein, we report our results related to the interaction between vascular endothelial growth factor (VEGF) and its receptor (VEGFR).

MYC/PGC-1α Balance Determines the Metabolic Phenotype and Plasticity of Pancreatic Cancer Stem Cells.

The anti-diabetic drug metformin targets pancreatic cancer stem cells (CSCs), but not their differentiated progenies (non-CSCs), which may be related to distinct metabolic phenotypes. Here we conclusively demonstrate that while non-CSCs were highly glycolytic, CSCs were dependent on oxidative metabolism (OXPHOS) with very limited metabolic plasticity. Thus, mitochondrial inhibition, e.

AMPK and PFKFB3 mediate glycolysis and survival in response to mitophagy during mitotic arrest.

Blocking mitotic progression has been proposed as an attractive therapeutic strategy to impair proliferation of tumour cells. However, how cells survive during prolonged mitotic arrest is not well understood. We show here that survival during mitotic arrest is affected by the special energetic requirements of mitotic cells.

Alternative Activation Mechanisms of Protein Kinase B Trigger Distinct Downstream Signaling Responses.

Protein kinase B (PKB/Akt) is an important mediator of signals that control various cellular processes including cell survival, growth, proliferation, and metabolism. PKB promotes these processes by phosphorylating many cellular targets, which trigger distinct downstream signaling events. However, how PKB is able to selectively target its substrates to induce specific cellular functions remains elusive.

The N-terminal domain of MuB protein has striking structural similarity to DNA-binding domains and mediates MuB filament-filament interactions.

MuB is an ATP-dependent DNA-binding protein that regulates the activity of MuA transposase and delivers the target DNA for transposition of phage Mu. Mechanistic insight into MuB function is limited to its AAA+ ATPase module, which upon ATP binding assembles into helical filaments around the DNA. However, the structure and function of the flexible N-terminal domain (NTD) appended to the AAA+ module remains uncharacterized.

A switch from white to brown fat increases energy expenditure in cancer-associated cachexia.

Cancer-associated cachexia (CAC) is a wasting syndrome characterized by systemic inflammation, body weight loss, atrophy of white adipose tissue (WAT) and skeletal muscle. Limited therapeutic options are available and the underlying mechanisms are poorly defined. Here we show that a phenotypic switch from WAT to brown fat, a phenomenon termed WAT browning, takes place in the initial stages of CAC, before skeletal muscle atrophy.

BuD, a helix-loop-helix DNA-binding domain for genome modification.

DNA editing offers new possibilities in synthetic biology and biomedicine for modulation or modification of cellular functions to organisms. However, inaccuracy in this process may lead to genome damage. To address this important problem, a strategy allowing specific gene modification has been achieved through the addition, removal or exchange of DNA sequences using customized proteins and the endogenous DNA-repair machinery.