Crystal structure of Zika virus NS2B-NS3 protease in complex with a boronate inhibitor.

The ongoing Zika virus (ZIKV) outbreak is linked to severe neurological disorders. ZIKV relies on its NS2B/NS3 protease for polyprotein processing; hence, this enzyme is an attractive drug target. The 2.

A HIF-1α-driven feed-forward loop augments HIF signalling in Hep3B cells by upregulation of ARNT.

Oxygen-deprived (hypoxic) areas are commonly found within neoplasms caused by excessive cell proliferation. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) is part of the hypoxia-inducible factor (HIF) pathway, which mediates adaptive responses to ensure cellular survival under hypoxic conditions. HIF signalling leads to metabolic alterations, invasion/metastasis and the induction of angiogenesis in addition to radio-chemoresistance of tumour cells.

Structural and mutational analysis of the interaction between the Middle-East respiratory syndrome coronavirus (MERS-CoV) papain-like protease and human ubiquitin.

The papain-like protease (PL(pro)) of Middle-East respiratory syndrome coronavirus (MERS-CoV) has proteolytic, deubiquitinating, and deISGylating activities. The latter two are involved in the suppression of the antiviral innate immune response of the host cell. To contribute to an understanding of this process, we present here the X-ray crystal structure of a complex between MERS-CoV PL(pro) and human ubiquitin (Ub) that is devoid of any covalent linkage between the two proteins.

Unraveling the Conformational Landscape of Ligand Binding to Glucose/Galactose-Binding Protein by Paramagnetic NMR and MD Simulations.

Protein dynamics related to function can nowadays be structurally well characterized (i.e., instances obtained by high resolution structures), but they are still ill-defined energetically, and the energy landscapes are only accessible computationally.

Two variants of the major serine protease inhibitor from the sea anemone Stichodactyla helianthus, expressed in Pichia pastoris.

The major protease inhibitor from the sea anemone Stichodactyla helianthus (ShPI-1) is a non-specific inhibitor that binds trypsin and other trypsin-like enzymes, as well as chymotrypsin, and human neutrophil elastase. We performed site-directed mutagenesis of ShPI-1 to produce two variants (rShPI-1/K13L and rShPI/Y15S) that were expressed in Pichia pastoris, purified, and characterized. After a single purification step, 65 mg and 15 mg of protein per liter of culture supernatant were obtained for rShPI-1/K13L and rShPI/Y15S, respectively.

The role of microfibrillar-associated protein 4 (MFAP4) in the formation and function of splenic compartments during embryonic and adult life.

Microfibrillar-associated protein 4 (MFAP4) is an extracellular protein belonging to the fibrinogen-related protein superfamily and is recognized as an integrin ligand with suggested functions in pulmonary and vascular tissue homeostasis. MFAP4 expression in the spleen is increased during infections; however, the significance of MFAP4 for the function of the spleen is unknown. Immunohistochemistry, morphometry and real-time RT-PCR were used to analyze wild-type and MFAP4-deficient spleens.

The brain renin-angiotensin system plays a crucial role in regulating body weight in diet-induced obesity in rats.

Background And Purpose: Reduced weight gain after treatment with AT1 receptor antagonists may involve a brain-related mechanism. Here, we investigated the role of the brain renin-angiotensin system on weight regulation and food behaviour, with or without additional treatment with telmisartan.

Methods: Transgenic rats with a brain-specific deficiency in angiotensinogen (TGR(ASrAOGEN)) and the corresponding wild-type, Sprague Dawley (SD) rats were fed (3 months) with a high-calorie cafeteria diet (CD) or standard chow.

Real-time investigation of dynamic protein crystallization in living cells.

X-ray crystallography requires sufficiently large crystals to obtain structural insights at atomic resolution, routinely obtained in vitro by time-consuming screening. Recently, successful data collection was reported from protein microcrystals grown within living cells using highly brilliant free-electron laser and third-generation synchrotron radiation. Here, we analyzed in vivo crystal growth of firefly luciferase and Green Fluorescent Protein-tagged reovirus μNS by live-cell imaging, showing that dimensions of living cells did not limit crystal size.

Impact of caspase-8 and PKA in regulating neutrophil-derived microparticle generation.

The morbidity and mortality from sepsis continues to remain high despite extensive research into understanding this complex immunologic process. Further, while source control and antibiotic therapy have improved patient outcomes, many immunologically based therapies have fallen short. Microparticles (MPs) are intact vesicles that serve as mediators of intercellular communication as well as markers of inflammation in various disease processes.

A unique GCN5-related glucosamine N-acetyltransferase region exist in the fungal multi-domain glycoside hydrolase family 3 β-N-acetylglucosaminidase.

Glycoside hydrolase (GH) family 3 β-N-acetylglucosaminidases widely exist in the filamentous fungi, which may play a key role in chitin metabolism of fungi. A multi-domain GH family 3 β-N-acetylglucosaminidase from Rhizomucor miehei (RmNag), exhibiting a potential N-acetyltransferase region, has been recently reported to show great potential in industrial applications. In this study, the crystal structure of RmNag was determined at 2.

Production, crystallization and X-ray diffraction analysis of the protease CT441 from Chlamydia trachomatis.

The prokaryotic obligate intracellular pathogen Chlamydia trachomatis is the most prevalent cause of preventable blindness, affecting approximately six million people worldwide. In addition, C. trachomatis is the most commonly reported sexually transmitted pathogen in Europe and the US, causing pelvic inflammation, ectopic pregnancy and infertility.

Structural basis for the binding of tryptophan-based motifs by δ-COP.

Coatomer consists of two subcomplexes: the membrane-targeting, ADP ribosylation factor 1 (Arf1):GTP-binding βγδζ-COP F-subcomplex, which is related to the adaptor protein (AP) clathrin adaptors, and the cargo-binding αβ'ε-COP B-subcomplex. We present the structure of the C-terminal μ-homology domain of the yeast δ-COP subunit in complex with the WxW motif from its binding partner, the endoplasmic reticulum-localized Dsl1 tether. The motif binds at a site distinct from that used by the homologous AP μ subunits to bind YxxΦ cargo motifs with its two tryptophan residues sitting in compatible pockets.

The expression level of the transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT) determines cellular survival after radiation treatment.

Background: Tumour hypoxia promotes radioresistance and is associated with poor prognosis. The transcription factor Aryl hydrocarbon receptor nuclear translocator (ARNT), also designated as Hypoxia-inducible factor (HIF)-1β, is part of the HIF pathway which mediates cellular adaptations to oxygen deprivation and facilitates tumour progression. The subunits HIF-1α and ARNT are key players within this pathway.

A rigid lanthanide binding tag to aid NMR studies of a 70 kDa homodimeric coat protein of human norovirus.

Attachment of human noroviruses to histo blood group antigens is thought to be essential for infection of host cells. Molecular details of the attachment process can be studied in vitro using a variety of NMR experiments. The use of protein NMR based experiments requires assignments of backbone NMR signals.

The murine cytomegalovirus immunoevasin gp40 binds MHC class I molecules to retain them in the early secretory pathway.

In the presence of the murine cytomegalovirus (mCMV) gp40 (m152) protein, murine major histocompatibility complex (MHC) class I molecules do not reach the cell surface but are retained in an early compartment of the secretory pathway. We find that gp40 does not impair the folding or high-affinity peptide binding of the class I molecules but binds to them, leading to their retention in the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment (ERGIC) and the cis-Golgi, most likely by retrieval from the cis-Golgi to the ER. We identify a sequence in gp40 that is required for both its own retention in the early secretory pathway and for that of class I molecules.

Antiviral Activity of Broad-Spectrum and Enterovirus-Specific Inhibitors against Clinical Isolates of Enterovirus D68.

We investigated the susceptibility of 10 enterovirus D68 (EV-D68) isolates (belonging to clusters A, B, and C) to (entero)virus inhibitors with different mechanisms of action. The 3C-protease inhibitors proved to be more efficient than enviroxime and pleconaril, which in turn were more effective than vapendavir and pirodavir. Favipiravir proved to be a weak inhibitor.

Sex differences in H7N9 influenza A virus pathogenesis.

Sex, gender and age have an impact on incidence and severity of several infectious diseases. Here, we analyzed reported human cases of avian H7N9 influenza A virus infections for potential sex-dependent incidence and mortality. We report that females in their reproductive years display an increased tendency to die of H7N9 influenza than males (female-to-male ratio=1.

Structures of DegQ from Legionella pneumophila Define Distinct ON and OFF States.

HtrA (high-temperature requirement A) family proteins play important roles in protein-quality control processes in the bacterial periplasm. A common feature of all members of this family is their modular organization comprising a chymotrypsin-like protease domain and at least one PDZ (postsynaptic density of 95 kDa, disks large homolog 1 and zonula occludens 1) domain. All characterized HtrA proteins assemble into complex oligomers consisting of typically 3-24 monomers, which allow a tight regulation of proteolytic activity.

Importin-β facilitates nuclear import of human GW proteins and balances cytoplasmic gene silencing protein levels.

MicroRNAs (miRNAs) guide Argonaute (Ago) proteins to distinct target mRNAs leading to translational repression and mRNA decay. Ago proteins interact with a member of the GW protein family, referred to as TNRC6A-C in mammals, which coordinate downstream gene-silencing processes. The cytoplasmic functions of TNRC6 and Ago proteins are reasonably well established.

A G-quadruplex-binding macrodomain within the "SARS-unique domain" is essential for the activity of the SARS-coronavirus replication-transcription complex.

The multi-domain non-structural protein 3 of SARS-coronavirus is a component of the viral replication/transcription complex (RTC). Among other domains, it contains three sequentially arranged macrodomains: the X domain and subdomains SUD-N as well as SUD-M within the "SARS-unique domain". The X domain was proposed to be an ADP-ribose-1"-phosphatase or a poly(ADP-ribose)-binding protein, whereas SUD-NM binds oligo(G)-nucleotides capable of forming G-quadruplexes.

Drebrin-like protein DBN-1 is a sarcomere component that stabilizes actin filaments during muscle contraction.

Actin filament organization and stability in the sarcomeres of muscle cells are critical for force generation. Here we identify and functionally characterize a Caenorhabditis elegans drebrin-like protein DBN-1 as a novel constituent of the muscle contraction machinery. In vitro, DBN-1 exhibits actin filament binding and bundling activity.

Introduction to selected articles from the 15th ICCBM.

Selected papers from ICCBM15 have been published in the July 2015 issue of .

The enterovirus 3C protease inhibitor SG85 efficiently blocks rhinovirus replication and is not cross-resistant with rupintrivir.

The novel enterovirus protease inhibitor (PI) SG85 effectively inhibits the in vitro replication of 14 rhinoviruses representative of species A and B (median 50% effective concentration, 0.04 μM). A low-level SG85-resistant variant was selected that carried amino acid substitutions S127G and T143A in the 3C protease.

Ribonuclease-neutralized pancreatic microsomal membranes from livestock for in vitro co-translational protein translocation.

Here, we demonstrate that pancreatic microsomal membranes from pigs, sheep, or cattle destined for human consumption can be used as a valuable and ethically correct alternative to dog microsomes for cell-free protein translocation. By adding adequate ribonuclease (RNase) inhibitors to the membrane fraction, successful in vitro co-translational translocation of wild-type and chimeric pre-prolactin into the lumen of rough microsomes was obtained. In addition, the human type I integral membrane proteins CD4 and VCAM-1 were efficiently glycosylated in RNase-treated microsomes.

Lack of weight gain after angiotensin AT1 receptor blockade in diet-induced obesity is partly mediated by an angiotensin-(1-7)/Mas-dependent pathway.

Background And Purpose: Angiotensin AT1 receptor antagonists induce weight loss; however, the mechanism underlying this phenomenon is unknown. The Mas receptor agonist angiotensin-(1-7) is a metabolite of angiotensin I and of angiotensin II . As an agonist of Mas receptors, angiotensin-(1-7) has beneficial cardiovascular and metabolic effects.