Explore the vast range of titles available.

Activation of cyclin B1-cyclin-dependent kinase 1 (Cdk1), triggered by a positive feedback loop at the end of G2, is the key event that initiates mitotic entry. In metaphase, anaphase-promoting complex/cyclosome-dependent destruction of cyclin B1 inactivates Cdk1 again, allowing mitotic exit and cell division. Several models describe Cdk1 activation kinetics in mitosis, but experimental data on how the activation proceeds in mitotic cells have largely been lacking. We use a novel approach to determine the temporal development of cyclin B1-Cdk1 activity in single cells. By quantifying both dephosphorylation of Cdk1 and phosphorylation of the Cdk1 target anaphase-promoting complex/cyclosome 3, we disclose how cyclin B1-Cdk1 continues to be activated after centrosome separation. Importantly, we discovered that cytoplasmic cyclin B1-Cdk1 activity can be maintained even when cyclin B1 translocates to the nucleus in prophase. These experimental data are fitted into a model describing cyclin B1-Cdk1 activation in human cells, revealing a striking resemblance to a bistable circuit. In line with the observed kinetics, cyclin B1-Cdk1 levels required to enter mitosis are lower than the amount of cyclin B1-Cdk1 needed for mitotic progression. We propose that gradually increasing cyclin B1-Cdk1 activity after centrosome separation is critical to coordinate mitotic progression.

Cohesion between sister chromatids is essential for faithful chromosome segregation. In budding yeast, the acetyltransferase Eco1/Ctf7 establishes cohesion during DNA replication in S phase and in response to DNA double strand breaks in G2/M phase. In humans two Eco1 orthologs exist: ESCO1 and ESCO2. Both proteins are required for proper sister chromatid cohesion, but their exact function is unclear at present. Since ESCO2 has been identified as the gene defective in the rare autosomal recessive cohesinopathy Roberts syndrome (RBS), cells from RBS patients can be used to elucidate the role of ESCO2. We investigated for the first time RBS cells in comparison to isogenic controls that stably express V5- or GFP-tagged ESCO2. We show that the sister chromatid cohesion defect in the transfected cell lines is rescued and suggest that ESCO2 is regulated by proteasomal degradation in a cell cycle-dependent manner. In comparison to the corrected cells RBS cells were hypersensitive to the DNA-damaging agents mitomycin C, camptothecin and etoposide, while no particular sensitivity to UV, ionizing radiation, hydroxyurea or aphidicolin was found. The cohesion defect of RBS cells and their hypersensitivity to DNA-damaging agents were not corrected by a patient-derived ESCO2 acetyltransferase mutant (W539G), indicating that the acetyltransferase activity of ESCO2 is essential for its function. In contrast to a previous study on cells from patients with Cornelia de Lange syndrome, another cohesinopathy, RBS cells failed to exhibit excessive chromosome aberrations after irradiation in G2 phase of the cell cycle. Our results point at an S phase-specific role for ESCO2 in the maintenance of genome stability.

The Regulation establishing a framework for screening of Foreign Direct Investments (FDI) into the European Union (EU) represents a new chapter for the EU’s foreign policy. FDI is a divisive topic within the EU, particularly FDI originating from China. This article seeks to add to the existing literature by assessing the effectiveness of the Screening Regulation towards this Chinese FDI. This assessment shall elucidate the interplay of this Regulation with the internal market, the free movement of capital, freedom of establishment, and the duty of sincere cooperation in response to Chinese FDI. Whilst the Regulation has proven its effectiveness, several deficiencies still exist, brought to light by recent developments such as the COVID-19 pandemic and the Belt and Road Initiative (BRI). By framing this article against the backdrop of the golden shares case law, these deficiencies are highlighted and addressed. Allowing EU Member States (MS) to safeguard their public order and security considerations in screening through national measures would allow for a better control over their markets in conjunction with the Regulation, although further development is needed. Foreign direct investment, Chinese State-Owned Enterprises, Chinese economic statecraft, European External Trade Policy, EU trade policy, EU foreign policy, Bilateral Investment Treaties (BIT), Freedom of establishment, Free movement of capital, Golden shares

Polo-like kinase-1 (Plk1) is activated before mitosis by Aurora A and its cofactor Bora. In mitosis, Bora is degraded in a manner dependent on Plk1 kinase activity and the E3 ubiquitin ligase SCF-betaTrCP. Here, we show that Plk1 is also required for the timely destruction of its activator Aurora A in late anaphase. It has been shown that Aurora A destruction is controlled by the auxiliary subunit Cdh1 of the Anaphase-Promoting Complex/Cyclosome (APC/C). Remarkably, we found that Plk1-depletion prevented the efficient dephosphorylation of Cdh1 during mitotic exit. Plk1 mediated its effect on Cdh1, at least in part, through direct phosphorylation of the human phosphatase Cdc14A, controlling the phosphorylation state of Cdh1. We conclude that Plk1 facilitates efficient Aurora A degradation through APC/C-Cdh1 activation after mitosis, with a potential role for hCdc14A.

Introduction In patients undergoing percutaneous coronary intervention (PCI), personalised medicine is key to the secondary prevention of ischaemic and bleeding events. To provide an extensive overview of the quality of secondary prevention and of personalised medicine, a consortium in the southeastern region of the Netherlands has created a PCI registry: the South-East Netherlands Heart Registry ( Zuid-Oost Nederland Hart Registratie , ZON-HR). Aim To visualise and improve personalised secondary prevention post-PCI, focussing on key elements such as antiplatelet treatment, cholesterol management and comorbidities such as diabetes mellitus. Design and population A prospective multicentre registry of all consecutive patients undergoing PCI at 4 participating PCI centres and 3 referral centres. Treatment Interventional procedures and concomitant pharmaceutical treatment are performed in accordance with the guidelines. The ZON-HR promotes risk stratification after PCI using a simplified protocol for a personalised antiplatelet strategy. Data collection and quality Demographics, laboratory values, baseline procedural characteristics and pharmaceutical treatment data are collected. Outcomes include thromboembolic and bleeding complications and medication changes. Data are pseudonymised, and a clinical event committee will review 20% of the adverse events (randomly selected). Strengths and weaknesses This registry represents the entire PCI population and visualises gaps in secondary prevention. Weaknesses are the collection of outcomes and medication changes using mostly patient-reported outcomes. Conclusion The ZON-HR is a comprehensive PCI registry that provides baseline and follow-up data of a large PCI cohort in the southeastern region of the Netherlands. The ZON-HR aims to improve secondary prevention after PCI and augment personalised treatment that focusses on key elements of secondary prevention.

An effective preventive vaccine for hepatitis C virus (HCV) remains a major unmet need. Antigenic region 3 (AR3) on the E1E2 envelope glycoprotein complex overlaps with the CD81 receptor binding site and represents an important epitope for broadly neutralizing antibodies (bNAbs) and is therefore important for HCV vaccine design. Most AR3 bNAbs utilize the V H 1-69 gene and share structural features that define the AR3C-class of HCV bNAbs. In this work, we identify recombinant HCV glycoproteins based on a permuted E2E1 trimer design that bind to the inferred V H 1-69 germline precursors of AR3C-class bNAbs. When presented on nanoparticles, these recombinant E2E1 glycoproteins efficiently activate B cells expressing inferred germline AR3C-class bNAb precursors as B cell receptors. Furthermore, we identify critical signatures in three AR3C-class bNAbs that represent two subclasses of AR3C-class bNAbs that will allow refined protein design. These results provide a framework for germline-targeting vaccine design strategies against HCV. The burden of chronic hepatitis C virus infection is exacerbated by the lack of an effective vaccine. In this work, authors use a recombinant permuted (E2E1) HCV glycoprotein design to analyze the binding of different VH1-69-derived AR3-directed broadly neutralizing antibodies to the viral envelope glycoprotein.

An effective preventive vaccine for hepatitis C virus (HCV) remains a major unmet need. Antigenic region 3 (AR3) on the E1E2 envelope glycoprotein complex overlaps with the CD81 receptor binding site and represents an important epitope for broadly neutralizing antibodies (bNAbs) and is therefore important for HCV vaccine design. Most AR3 bNAbs utilize the V 1-69 gene and share structural features that define the AR3C-class of HCV bNAbs. In this work, we identify recombinant HCV glycoproteins based on a permuted E2E1 trimer design that bind to the inferred V 1-69 germline precursors of AR3C-class bNAbs. When presented on nanoparticles, these recombinant E2E1 glycoproteins efficiently activate B cells expressing inferred germline AR3C-class bNAb precursors as B cell receptors. Furthermore, we identify critical signatures in three AR3C-class bNAbs that represent two subclasses of AR3C-class bNAbs that will allow refined protein design. These results provide a framework for germline-targeting vaccine design strategies against HCV.

Autotaxin (ATX) is secreted by diverse cell types to produce lysophosphatidic acid (LPA) that regulates multiple biological functions via G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis mainly via LPAR1; however, its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T-cell repulsion predominantly involves G(12/13)-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T-cell responses but suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from patient samples are consistent with intra-tumor ATX acting as a T-cell repellent. These studies highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T-cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities. Competing Interest Statement Z.J. is an employee and shareholder of iOnctura SA, a company developing an ATX inhibitor for use in cancer. Footnotes * Revised Title, Summary, Results and Discussion; author list updated; Figs. 1-4 updated; more extensive in vivo data shown in new Figs. 5 and 6; new Supplemental Figs. S2-S4. * https://www.ncbi.nlm.nih.gov/geo/