Coxsackie B1 virus-like particle vaccine modified to exclude a highly conserved immunoreactive region from the capsid induces potent neutralizing antibodies and protects against infection in mice.

Background: Enteroviruses, including Coxsackie B (CVB) viruses, can cause severe diseases such as myocarditis, pancreatitis, and meningitis. Vaccines can prevent these complications, but conserved non-neutralizing epitopes in the viral capsid may limit their effectiveness. The immunodominant PALXAXETG motif, located in the VP1 N-terminus, is a highly conserved region in enteroviruses that elicits non-neutralizing antibody responses.

Molecular basis of JAK kinase regulation guiding therapeutic approaches: Evaluating the JAK3 pseudokinase domain as a drug target.

Janus kinases (JAK1-3, TYK2) are critical mediators of cytokine signaling and their role in hematological and inflammatory and autoimmune diseases has sparked widespread interest in their therapeutic targeting. JAKs have unique tandem kinase structure consisting of an active tyrosine kinase domain adjacent to a pseudokinase domain that is a hotspot for pathogenic mutations. The development of JAK inhibitors has focused on the active kinase domain and the developed drugs have demonstrated good clinical efficacy but due to off-target inhibition cause also side-effects and carry a black box warning limiting their use.

Molecular basis of JAK2 activation in erythropoietin receptor and pathogenic JAK2 signaling.

Janus kinase 2 (JAK2) mediates type I/II cytokine receptor signaling, but JAK2 is also activated by somatic mutations that cause hematological malignancies by mechanisms that are still incompletely understood. Quantitative superresolution microscopy (qSMLM) showed that erythropoietin receptor (EpoR) exists as monomers and dimerizes upon Epo stimulation or through the predominant JAK2 pseudokinase domain mutations (V617F, K539L, and R683S). Crystallographic analysis complemented by kinase activity analysis and atomic-level simulations revealed distinct pseudokinase dimer interfaces and activation mechanisms for the mutants: JAK V617F activity is driven by dimerization, K539L involves both increased receptor dimerization and kinase activity, and R683S prevents autoinhibition and increases catalytic activity and drives JAK2 equilibrium toward activation state through a wild-type dimer interface.

The RNA-binding protein Snd1/Tudor-SN regulates hypoxia-responsive gene expression.

Snd1 is an evolutionarily conserved RNA-binding protein implicated in several regulatory processes in gene expression including activation of transcription, mRNA splicing, and microRNA decay. Here, we have investigated the outcome of gene deletion in the mouse. The knockout mice are viable showing no gross abnormalities apart from decreased fertility, organ and body size, and decreased number of myeloid cells concomitant with decreased expression of granule protein genes.

Development of an enzyme-coupled activity assay for Janus kinase 2 inhibitor screening.

JAK2 transmits signals of several important cytokines, such as growth hormone and erythropoietin. The interest toward the therapeutic targeting of JAK2 was boosted in 2005, when the somatic JAK2 V617F mutation, responsible for the majority of myeloproliferative neoplasms (MPNs) was discovered. JAK2 inhibitors have been approved for MPN therapy and they are effective in alleviating symptoms and improving the quality of life of the patients, but they do not lead to molecular remission.

Identification of Novel Small Molecule Ligands for JAK2 Pseudokinase Domain.

Hyperactive mutation V617F in the JAK2 regulatory pseudokinase domain (JH2) is prevalent in patients with myeloproliferative neoplasms. Here, we identified novel small molecules that target JH2 of JAK2 V617F and characterized binding via biochemical and structural approaches. Screening of 107,600 small molecules resulted in identification of 55 binders to the ATP-binding pocket of recombinant JAK2 JH2 V617F protein at a low hit rate of 0.

Inhibition of RNA Binding in SND1 Increases the Levels of miR-1-3p and Sensitizes Cancer Cells to Navitoclax.

SND1 is an RNA-binding protein overexpressed in large variety of cancers. SND1 has been proposed to enhance stress tolerance in cancer cells, but the molecular mechanisms are still poorly understood. We analyzed the expression of 372 miRNAs in the colon carcinoma cell line and show that SND1 silencing increases the expression levels of several tumor suppressor miRNAs.

Janus Kinases in Leukemia.

Janus kinases (JAKs) transduce signals from dozens of extracellular cytokines and function as critical regulators of cell growth, differentiation, gene expression, and immune responses. Deregulation of JAK/STAT signaling is a central component in several human diseases including various types of leukemia and other malignancies and autoimmune diseases. Different types of leukemia harbor genomic aberrations in all four JAKs (JAK1, JAK2, JAK3, and TYK2), most of which are activating somatic mutations and less frequently translocations resulting in constitutively active JAK fusion proteins.

Characterization of JAK1 Pseudokinase Domain in Cytokine Signaling.

The Janus kinase-signal transducer and activator of transcription protein (JAK-STAT) pathway mediates essential biological functions from immune responses to haematopoiesis. Deregulated JAK-STAT signaling causes myeloproliferative neoplasms, leukaemia, and lymphomas, as well as autoimmune diseases. Thereby JAKs have gained significant relevance as therapeutic targets.

Selective JAKinibs: Prospects in Inflammatory and Autoimmune Diseases.

Cytokines, many of which signal through the JAK-STAT (Janus kinase-Signal Transducers and Activators of Transcription) pathway, play a central role in the pathogenesis of inflammatory and autoimmune diseases. Currently three JAK inhibitors have been approved for clinical use in USA and/or Europe: tofacitinib for rheumatoid arthritis, psoriatic arthritis and ulcerative colitis, baricitinib for rheumatoid arthritis, and ruxolitinib for myeloproliferative neoplasms. The clinical JAK inhibitors target multiple JAKs at high potency and current research has focused on more selective JAK inhibitors, almost a dozen of which currently are being evaluated in clinical trials.

Structural basis for DNA break recognition by ARTD2/PARP2.

Human ARTD2 (or PARP2) is an ADP-ribosyltransferase, which is catalytically activated by binding to damaged DNA. ARTD2 subsequently ADP-ribosylates itself and other proteins, initiating a cascade of events leading to DNA repair. In contrast to ARTD1, the founding member of the enzyme family, ARTD2 does not have specialized zinc-fingers for detecting DNA damage.

Small-Molecule Screening Assay for Mono-ADP-Ribosyltransferases.

Mono-ADP-ribosyltransferases of the PARP/ARTD enzyme family are enzymes catalyzing the transfer of a single ADP-ribose unit to target proteins. The enzymes have various roles in vital cellular processes such as DNA repair and transcription, and many of the enzymes are linked to cancer-relevant functions. Thus inhibition of the enzymes is a potential way to discover and develop new drugs against cancer.

2-Phenylquinazolinones as dual-activity tankyrase-kinase inhibitors.

Tankyrases (TNKSs) are enzymes specialized in catalyzing poly-ADP-ribosylation of target proteins. Several studies have validated TNKSs as anti-cancer drug targets due to their regulatory role in Wnt/β-catenin pathway. Recently a lot of effort has been put into developing more potent and selective TNKS inhibitors and optimizing them towards anti-cancer agents.

Development of an Inhibitor Screening Assay for Mono-ADP-Ribosyl Hydrolyzing Macrodomains Using AlphaScreen Technology.

Protein mono-ADP-ribosylation is a posttranslational modification involved in the regulation of several cellular signaling pathways. Cellular ADP-ribosylation is regulated by ADP-ribose hydrolases via a hydrolysis of the protein-linked ADP-ribose. Most of the ADP-ribose hydrolases share a macrodomain fold.

Structural and Biochemical Characterization of Poly-ADP-ribose Polymerase from Trypanosoma brucei.

Trypanosoma brucei is a unicellular parasite responsible for African trypanosomiasis or sleeping sickness. It contains a single PARP enzyme opposed to many higher eukaryotes, which have numerous PARPs. PARPs are responsible for a post-translational modification, ADP-ribosylation, regulating a multitude of cellular events.

Highly Potent and Isoform Selective Dual Site Binding Tankyrase/Wnt Signaling Inhibitors That Increase Cellular Glucose Uptake and Have Antiproliferative Activity.

Compounds 13 and 14 were evaluated against 11 PARP isoforms to reveal that both 13 and 14 were more potent and isoform selective toward inhibiting tankyrases (TNKSs) than the "standard" inhibitor 1 (XAV939), i.e., IC = 100 pM vs TNKS2 and IC = 6.

Small-Molecule Chemical Probe Rescues Cells from Mono-ADP-Ribosyltransferase ARTD10/PARP10-Induced Apoptosis and Sensitizes Cancer Cells to DNA Damage.

Members of the human diphtheria toxin-like ADP-ribosyltransferase (ARTD or PARP) family play important roles in regulating biological activities by mediating either a mono-ADP-ribosylation (MARylation) of a substrate or a poly-ADP-ribosylation (PARylation). ARTD10/PARP10 belongs to the MARylating ARTDs (mARTDs) subfamily, and plays important roles in biological processes that range from cellular signaling, DNA repair, and cell proliferation to immune response. Despite their biological and disease relevance, no selective inhibitors for mARTDs are available.

Characterization of the DNA dependent activation of human ARTD2/PARP2.

Human ADP-ribosyltransferase 2 (ARTD2/PARP2) is an enzyme catalyzing a post-translational modification, ADP-ribosylation. It is one of the three DNA dependent ARTDs in the 17 member enzyme family. ADP-ribosylation catalyzed by ARTD2 is involved in the regulation of multiple cellular processes such as control of chromatin remodeling, transcription and DNA repair.

Structure-activity relationships of 2-arylquinazolin-4-ones as highly selective and potent inhibitors of the tankyrases.

Tankyrases (TNKSs), members of the PARP (Poly(ADP-ribose)polymerases) superfamily of enzymes, have gained interest as therapeutic drug targets, especially as they are involved in the regulation of Wnt signalling. A series of 2-arylquinazolin-4-ones with varying substituents at the 8-position was synthesised. An 8-methyl group (compared to 8-H, 8-OMe, 8-OH), together with a 4'-hydrophobic or electron-withdrawing group, provided the most potency and selectivity towards TNKSs.

Proximal ADP-ribose Hydrolysis in Trypanosomatids is Catalyzed by a Macrodomain.

ADP-ribosylation is a ubiquitous protein modification utilized by both prokaryotes and eukaryotes for several cellular functions, such as DNA repair, proliferation, and cell signaling. Higher eukaryotes, such as humans, utilize various enzymes to reverse the modification and to regulate ADP-ribose dependent signaling. In contrast, some lower eukaryotes, including trypanosomatids, lack many of these enzymes and therefore have a much more simplified ADP-ribose metabolism.

Disrupted ADP-ribose metabolism with nuclear Poly (ADP-ribose) accumulation leads to different cell death pathways in presence of hydrogen peroxide in procyclic Trypanosoma brucei.

Background: Poly(ADP-ribose) (PAR) metabolism participates in several biological processes such as DNA damage signaling and repair, which is a thoroughly studied function. PAR is synthesized by Poly(ADP-ribose) polymerase (PARP) and hydrolyzed by Poly(ADP-ribose) glycohydrolase (PARG). In contrast to human and other higher eukaryotes, Trypanosoma brucei contains only one PARP and PARG.

Development and structural analysis of adenosine site binding tankyrase inhibitors.

Tankyrases 1 and 2, the specialized members of the ARTD protein family, are druggable biotargets whose inhibition may have therapeutic potential against cancer, metabolic disease, fibrotic disease, fibrotic wound healing and HSV viral infections. We have previously identified a novel tankyrase inhibitor scaffold, JW55, and showed that it reduces mouse colon adenoma formation in vivo. Here we expanded the scaffold and profiled the selectivity of the compounds against a panel of human ARTDs.