Allosteric inhibition of Aurora-A kinase by a synthetic vNAR domain

The vast majority of clinically-approved protein kinase inhibitors target the ATP binding pocket directly. Consequently, many inhibitors have broad selectivity profiles and most have significant off-target effects. Allosteric inhibitors are generally more selective, but are difficult to identify because allosteric binding sites are often unknown or poorly characterized. Aurora-A is activated through binding of TPX2 to an allosteric site on the kinase catalytic domain, and this knowledge could be exploited to generate an inhibitor. Here, we generated an allosteric inhibitor of Aurora-A kinase based on a synthetic, vNAR single domain scaffold, vNAR-D01. Biochemical studies and a crystal structure of the Aurora-A/vNAR-D01 complex show that the vNAR domain stabilizes an inactive conformation, in which the αC-helix is distorted, the canonical Lys-Glu salt bridge is broken, and the regulatory (R-) spine is disrupted by an additional hydrophobic side chain from the activation loop. These studies illustrate how single domain antibodies can be used to characterize the regulatory mechanisms of kinases and provide a rational basis for structure-guided design of allosteric Aurora-A kinase inhibitors

Aneuploidy in human eggs: contributions of the meiotic spindle

Human eggs frequently contain an incorrect number of chromosomes, a condition termed aneuploidy. Aneuploidy affects ∼10–25% of eggs in women in their early 30s, and more than 50% of eggs from women over 40. Most aneuploid eggs cannot develop to term upon fertilization, making aneuploidy in eggs a leading cause of miscarriages and infertility. The cellular origins of aneuploidy in human eggs are incompletely understood. Aneuploidy arises from chromosome segregation errors during the two meiotic divisions of the oocyte, the progenitor cell of the egg. Chromosome segregation is driven by a microtubule spindle, which captures and separates the paired chromosomes during meiosis I, and sister chromatids during meiosis II. Recent studies reveal that defects in the organization of the acentrosomal meiotic spindle contribute to human egg aneuploidy. The microtubules of the human oocyte spindle are very frequently incorrectly attached to meiotic kinetochores, the multi-protein complexes on chromosomes to which microtubules bind. Multiple features of human oocyte spindles favour incorrect attachments. These include spindle instability and many age-related changes in chromosome and kinetochore architecture. Here, we review how the unusual spindle assembly mechanism in human oocytes contributes to the remarkably high levels of aneuploidy in young human eggs, and how age-related changes in chromosome and kinetochore architecture cause aneuploidy levels to rise even higher as women approach their forties

Satellite gravity fields and the identification of accreted microplates

Small-scale lithospheric terranes (microplates) are important building-blocks of continental accretion but their presence is often obscured by subsequent plate-margin deformation events and by younger volcano-sedimentary covers. The geological fabric of the eastern Anatolian-Caucasian region results from the sequential accretion of lithospheric terranes against the southwestern continental margin of the Eurasian plate. Widespread sedimentary and volcanic covers conceal some of the principal tectonic boundaries in the region, and major uncertainties persist as to the number and extent of the various terranes. We determine whether the topographic height fits the expectance from crustal thickness, complying to the isostatic equilibrium. The input data of the study are the topography, the satellite derived gravity field, the geologic knowledge defining magmatic intrusions and tectonic terranes, arcs and sedimentary basins, the seismic Moho depth, and a seismic tomography model. We accomplish a topography-gravity regression analysis controlled by a seismic Moho model, which produces well defined positive and negative anomalies. Allowing for varying density contrast in lower crust, the topography is greatly in isostatic equilibrium and controlled by the crustal thickness, that is topographic uplift has evolved proportionally to crustal thickening. The average density contrast in lower crust is between 200 and 300 kg/m3 for the orogenic belt, with local exceptions. The inversion of the prominent positive linear anomalies of the regional gravity field defines discrete crustal density inhomogeneities, which can be interpreted as related to specific tectonic events, thus placing cogent constraints on the accretionary history and the overall anatomy of the eastern Anatolian-Caucasian lithospheric agglomerate. Three linear belts of intracrustal increased density are found along (i) the Greater Caucasus, (ii) the Lesser Caucasus, and (iii) a previously unidentified parallel belt ca. 80 km south of the Lesser Caucasus. The latter gravity anomaly clearly delineates for the first time the southwestern margin of the South Armenian Block, a lithospheric element (microplate) whose existence has long been a matter of debate

Satellite gravity fields and the identification of accreted microplates

Small-scale lithospheric terranes (microplates) are important building-blocks of continental accretion but their presence is often obscured by subsequent plate-margin deformation events and by younger volcano-sedimentary covers. The geological fabric of the eastern Anatolian-Caucasian region results from the sequential accretion of lithospheric terranes against the southwestern continental margin of the Eurasian plate. Widespread sedimentary and volcanic covers conceal some of the principal tectonic boundaries in the region, and major uncertainties persist as to the number and extent of the various ter-ranes. We determine whether the topographic height fits the expectance from crustal thickness, complying to the isostatic equilibrium. The input data of the study are the topography, the satellite derived gravity field, the geologic knowledge defining magmatic intrusions and tectonic terranes, arcs and sedimentary basins, the seismic Moho depth, and a seismic tomography model. We accomplish a topography-gravity regression analysis controlled by a seismic Moho model, which produces well defined positive and neg-ative anomalies. Allowing for varying density contrast in lower crust, the topography is greatly in iso-static equilibrium and controlled by the crustal thickness, that is topographic uplift has evolved proportionally to crustal thickening. The average density contrast in lower crust is between 200 and 300 kg/m3 for the orogenic belt, with local exceptions. The inversion of the prominent positive linear anomalies of the regional gravity field defines discrete crustal density inhomogeneities, which can be interpreted as related to specific tectonic events, thus placing cogent constraints on the accretionary history and the overall anatomy of the eastern Anatolian-Caucasian lithospheric agglomerate. Three linear belts of intracrustal increased density are found along (i) the Greater Caucasus, (ii) the Lesser Caucasus, and (iii) a previously unidentified parallel belt ca. 80 km south of the Lesser Caucasus. The latter gravity anomaly clearly delineates for the first time the southwestern margin of the South Armenian Block, a lithospheric element (microplate) whose existence has long been a matter of debate

Two mechanisms drive pronuclear migration in mouse zygotes

A new life begins with the unification of the maternal and paternal chromosomes upon fertilization. The parental chromosomes first become enclosed in two separate pronuclei near the surface of the fertilized egg. The mechanisms that then move the pronuclei inwards for their unification are only poorly understood in mammals. Here, we report two mechanisms that act in concert to unite the parental genomes in fertilized mouse eggs. The male pronucleus assembles within the fertilization cone and is rapidly moved inwards by the flattening cone. Rab11a recruits the actin nucleation factors Spire and Formin-2 into the fertilization cone, where they locally nucleate actin and further accelerate the pronucleus inwards. In parallel, a dynamic network of microtubules assembles that slowly moves the male and female pronuclei towards the cell centre in a dynein-dependent manner. Both mechanisms are partially redundant and act in concert to unite the parental pronuclei in the zygote’s centre

Complexes With Biologically Active Ligands. Part 111. Synthesis and Carbonic Anhydrase Inhibitory Activity of Metal Complexes of 4,5-Disubstituted-3-Mercapto-1,2,4-Triazole Derivatives

Complexes containing five 4,5-disubstituted-3-mercapto-1,2,4-triazoles and Zn(II), Hg(II) and Cu(I) were synthesized and characterized by standard procedures (elemental analysis; IR, electronic and NMR spectroscopy, conductimetry and TG analysis). Both the thione as well as the thiolate forms of the ligands were evidenced to interact with the metal ions in the prepared complexes. The original mercaptans and their metal complexes behave as inhibitors of three carbonic anhydrase (CA) isozymes, CA I, II and IV, but did not lower intraocular pressure in rabbits in animal models of glaucoma

The cost of severe haemophilia in Europe: the CHESS study

Background Severe haemophilia is associated with major psychological and economic burden for patients, caregivers, and the wider health care system. This burden has been quantified and documented for a number of European countries in recent years. However, few studies have taken a standardised methodology across multiple countries simultaneously, and sought to amalgamate all three levels of burden for severe disease. The overall aim of the ‘Cost of Haemophilia in Europe: a Socioeconomic Survey’ (CHESS) study was to capture the annualised economic and psychosocial burden of severe haemophilia in five European countries. A cross-section of haemophilia specialists (surveyed between January and April 2015) provided demographic and clinical information and 12-month ambulatory and secondary care activity for patients via an online survey. In turn, patients provided corresponding direct and indirect non-medical cost information, including work loss and out-of-pocket expenses, as well as information on quality of life and adherence. The direct and indirect costs for the patient sample were calculated and extrapolated to population level. Results Clinical reports for a total of 1,285 patients were received. Five hundred and fifty-two patients (43% of the sample) provided information on indirect costs and health-related quality of life via the PSC. The total annual cost of severe haemophilia across the five countries for 2014 was estimated at EUR 1.4 billion, or just under EUR 200,000 per patient. The highest per-patient costs were in Germany (mean EUR 319,024) and the lowest were in the United Kingdom (mean EUR 129,365), with a study average of EUR 199,541. As expected, consumption of clotting factor replacement therapy represented the vast majority of costs (up to 99%). Indirect costs are driven by patient and caregiver work loss. Conclusions The results of the CHESS study reflect previous research findings suggesting that costs of factor replacement therapy account for the vast majority of the cost burden in severe haemophilia. However, the importance of the indirect impact of haemophilia on the patient and family should not be overlooked. The CHESS study highlights the benefits of observational study methodologies in capturing a ‘snapshot’ of information for patients with rare diseases

<i>Mycobacterium haemophilum</i>as the Initial Presentation of a B-Cell Lymphoma in a Liver Transplant Patient

A 66-year-old woman presented with pustular lesions of her face, trunk, and limbs and an acute arthritis of the knees and elbows. She had a complex medical background and had been on immunosuppressants for three years after a liver transplant. Tissue samples from her skin lesions and synovial fluid showed acid-fast bacilli.Mycobacterium haemophilum, an atypical mycobacteria, was later grown on culture. During her treatment with combination antibiotic therapy, she developed a pronounced generalised lymphadenopathy. Histology showed features of a diffuse B-cell lymphoma, a posttransplant lymphoproliferative disorder (PTLD).</jats:p