Jesper V. Olsen
Jun 1, 2004; 3:608-614
Technology

HIV Type 1 (HIV-1) and simian immunodeficiency virus (SIV) display differential replication kinetics in macrophages. This is because high expression levels of the active host deoxynucleotide triphosphohydrolase sterile α motif domain and histidine-aspartate domain–containing protein 1 (SAMHD1) deplete intracellular dNTPs, which restrict HIV-1 reverse transcription, and result in a restrictive infection in this myeloid cell type. Some SIVs overcome SAMHD1 restriction using viral protein X (Vpx), a viral accessory protein that induces proteasomal degradation of SAMHD1, increasing cellular dNTP concentrations and enabling efficient proviral DNA synthesis. We previously reported that SAMHD1-noncounteracting lentiviruses may have evolved to harbor RT proteins that efficiently polymerize DNA, even at low dNTP concentrations, to circumvent SAMHD1 restriction. Here we investigated whether RTs from SIVmac239 virus lacking a Vpx protein evolve during in vivo infection to more efficiently synthesize DNA at the low dNTP concentrations found in macrophages. Sequence analysis of RTs cloned from Vpx (+) and Vpx (−) SIVmac239–infected animals revealed that Vpx (−) RTs contained more extensive mutations than Vpx (+) RTs. Although the amino acid substitutions were dispersed indiscriminately across the protein, steady-state and pre-steady-state analysis demonstrated that selected SIVmac239 Vpx (−) RTs are characterized by higher catalytic efficiency and incorporation efficiency values than RTs cloned from SIVmac239 Vpx (+) infections. Overall, this study supports the possibility that the loss of Vpx may generate in vivo SIVmac239 RT variants that can counteract the limited availability of dNTP substrate in macrophages.

Helen Clark elected president of Chatham House News release jon.wallace 23 July 2021

The former New Zealand prime minister and Head of UN Development Programme has been elected president of Chatham House.

Former New Zealand prime minister and Head of the United Nations Development Programme, Helen Clark, has been elected president of Chatham House.

Ms Clark will replace former United Kingdom Prime Minister, Sir John Major, who is retiring from the role. She will join Baroness Eliza Manningham-Buller and Lord Darling as one of the institute’s three serving presidents.

Helen Clark was prime minister of New Zealand from 1999-2008. She then became the 8th and first female administrator of the UN Development Programme, completing two terms from 2009-2017.  

She is actively engaged in important international issues that are central to the institute’s priorities. She is currently chairing the Independent Panel for Pandemic Preparedness and Response with former president of Liberia, Ellen Johnson Sirleaf, which was convened by the World Health Organization last year and has just completed its main report. Her expertise extends to sustainable development, tackling climate change and developments in the Asia-Pacific.

Chatham House Director Robin Niblett welcomed the appointment:

‘We are excited to have found someone with the high-level political experience and who shares the strong reputation for integrity that Sir John enjoys. Helen Clark is highly regarded around the world for her past and current endeavours. Her election also underscores the institute’s global outlook and priorities, which she is so well qualified to help guide.’

Ms Clark was elected at the Annual General Meeting of Chatham House on 20 July which also marked the last official engagement for Lord O’Neill, who has now handed over to Sir Nigel Sheinwald as Chair of the institute.

Chatham House is delighted that Sir John Major will remain affiliated with the institute as president emeritus, and that Lord O’Neill will become a member of the institute’s panel of senior advisers.

Saturday Club introduces young people to international affairs News release jon.wallace 24 February 2022

Clubs will help 13-16 year-olds learn more about the forces that are shaping the world and discover how young people can influence the future.

National Saturday Club and Chatham House are delighted to announce the launch of the Society&Change Saturday Club. This new programme creates opportunities for UK 13–16-year-olds to develop a global mindset and build awareness of trends that will shape the world in the coming decades.

Three pilot Society&Change Clubs will be hosted by the University of Sussex, Manchester Metropolitan University, and the University of Huddersfield. Chatham House will provide speakers and generate ideas for the clubs.

National Saturday Club gives 13–16-year-olds across the country the opportunity to study subjects they love at their local university, college or cultural institution, for free.

Society&Change Club members will be introduced to a wide range of careers including policy making and diplomacy, advocacy, media and journalism, international trade and business, and the international development and humanitarian sector.

Weekly classes will be led by led by professional tutors from the host institutions. Club members will also take part in masterclasses with industry professionals, as well as an end of year summer show and graduation ceremonies.

Lucy Kennedy, Chief Executive of the Saturday Club Trust said:

‘We are delighted to be partnering with Chatham House to launch the Society&Change Saturday Club, the sixth subject within the National Saturday Club programme. Over the past 12 years, working nationally with 13–16-year-olds, we have seen that young people are eager to share their hopes and ideas for the future and address the issues the world faces.

‘We hope this new Saturday Club will empower them to shape their own futures and will bring the urgent voice of young people to international debate.’

Rose Abdollahzadeh, Managing Director for Research Partnerships at Chatham House said:

‘We are really excited about the potential for this partnership to encourage young people across the UK to explore their role in the world. The National Saturday Club network will also give Chatham House opportunities to harness the energy, ideas and passion of young people towards positive change.

‘By introducing Club members to contemporary debates on global issues and a range of professions in foreign policy and international relations, our hope is that some Club members will choose to follow a career path into this sector.’

Learn more about the Society&Change Saturday Club.

How Beijing is closing surveillance gaps in the South China Sea The World Today iallan.drupal 15 October 2024

The discovery of a new radar system on China’s Triton Island military base shows that Beijing is rapidly developing its intelligence capacities in contested waters, write John Pollock and Damien Symon.

New satellite images reveal how the Chinese military is dramatically expanding its capabilities on Triton Island, which looks set to become a one of Beijing’s key signal intelligence bases in the South China Sea.

Once completed, the radar system would significantly increase China’s signals intercept and electronic warfare capabilities across the disputed Paracel Islands archipelago and add to a wider surveillance network spanning much of the South China Sea.

The enhanced facility on Triton is likely to offer a challenge to China’s competitors in the region and internationally.

China seized control of the Paracels from Vietnam in a 1974 naval battle, and competition for access to it waters has intensified since the recent discovery of oil and gas reserves. Chinese and Vietnamese maritime militia clashed off the coast of Triton in 2014.

In addition, American, British and Australian naval forces have for the past decade patrolled the waters to collectively challenge China’s contested ‘nine-dash-line’ claim to large stretches of the South China Sea. 

Overlapping anti-stealth network

A year after work was first identified on Triton, satellite images from Maxar have helped build a clearer picture of Beijing’s efforts to defend this strategic waterway.

The most striking development is the construction of a new radar system, known as SIAR – synthetic impulse and aperture radar – which purportedly detects stealth aircraft. The counter-stealth radar on Triton is characterized by its distinctive octagonal structure, which resembles another SIAR system built by China on Subi Reef in the Spratly Islands, south of the Paracels, in 2017. A half-completed tower also sits near the SIAR radar on Triton, which is likely to be the operations centre.

Once completed, the radar on Triton will form what is believed to be a wider network of at least three overlapping counter-stealth radars built across Chinese bases in the South China Sea over the past decade, including on Hainan Island, home to several Chinese naval bases. 

The positioning of the radar on Triton, 320km south of Hainan, is telling, says J. Michael Dahm, Senior Resident Fellow for Aerospace and China Studies at the Mitchell Institute. 

‘SIAR radars cannot see over the curve of the Earth, which means there is a gap in China’s air surveillance coverage between Subi Reef and Hainan Island. The Triton Island site will help close that gap’, said Dahm.

The aim, he suggests, is to give China contiguous counter-stealth radar coverage of the South China Sea.

More construction underway

The satellite images reveal other building projects on Triton. One is a large pad at the end of the road network which will probably be used as a launching point for a mobile anti-ship missile battery. The building at the northeast end of the road is probably a storage building for missile transport vehicles. 

Diminishing Vietnam’s options

The development of a new counter-stealth radar system and other suspected signals intercept structures on Triton represents a notable increase in China’s intelligence capabilities in the Paracels. The Chinese Communist Party has not disclosed the purpose of the building work on Triton, but its effects on regional and global competitors are likely to be wide ranging.

For Vietnam, which is rapidly expanding its own bases in the South China Sea, the intelligence structures on Triton would significantly diminish its capacity to operate undetected in the area. Alongside existing radar on Triton which can detect sea-going vessels, Beijing now has the potential to track Vietnamese air movements and gain forewarning of Hanoi’s manoeuvres in the area, including efforts to access oil and gas deposits.

The desire to strengthen control over these resources may explain why China is fortifying Triton Island, says Bill Hayton, Associate Fellow in the Asia-Pacific Programme, Chatham House. ‘The developments might be a warning that China is planning to mount another drilling expedition’, he suggests.

Can the world avoid a new nuclear arms race? 18 November 2024 — 6:00PM TO 7:00PM Anonymous (not verified) 16 October 2024 Chatham House and Online

Leading experts discuss how states are expanding nuclear arsenals amid rising geopolitical challenges.

Leading experts discuss how states are expanding nuclear arsenals amid rising geopolitical challenges.

The Doomsday Clock stands at 90 seconds to midnight – the closest to global catastrophe it has ever been. As geopolitical competition intensifies, nuclear risks are resurging at an alarming rate. The collapse of key arms control agreements, such as the Intermediate-Range Nuclear Forces (INF) Treaty, has removed crucial safeguards against arms races. Efforts to extend or replace existing treaties face significant hurdles in the current geopolitical climate.

Nuclear rhetoric has become more aggressive, as evidenced by Russian and North Korean nuclear threats. Several nuclear-armed states are also engaging in extensive modernization programmes of their nuclear arsenals, potentially fuelling a new arms race.

Despite these pressures, the number of nuclear possessor states has held steady so far. The ongoing Iranian efforts to build nuclear weapons is the closest attempt by a new state to acquire nuclear weapons. As the global security environment becomes more and more tense, existing nuclear possessor states increasingly rely on their nuclear weapons. This might threaten the global consensus against nuclear proliferation.

This session examines these competing pressures and propose strategies to reduce the risks of nuclear weapons use and proliferation. Our expert panel explores diplomatic initiatives, technical measures, and policy innovations to address these critical challenges.

This expert panel discusses key questions including:

• Are we already in the middle of a global nuclear arms race?
• How can international arms control treaties be negotiated in the current geopolitical environment?
• Does a new US president change the nuclear calculus? Is the US still able to reassure allies of its ‘extended deterrence’?
• How can we reduce the risk of additional proliferation? Which states might want to acquire nuclear weapons and what can we do about it?

The institute occupies a position of respect and trust, and is committed to fostering inclusive dialogue at all events. Event attendees are expected to uphold this by adhering to our code of conduct.

As the ruling party claims victory in Georgia’s disputed election, Western condemnation is no longer enough Expert comment LToremark 29 October 2024

As tens of thousands take to the streets to protest the election results, Georgia faces a familiar crisis – with a few key differences.

As the people of Georgia went to the polls on 26 October, many were hoping not only for a democratic change of government but also for an end to one-party dominance and a return to the path of European integration. The previously weak and divided opposition had grouped itself into four major electoral centres, promising a coalition government and framing these elections as a choice between Europe and Russia. 

Ahead of the election, President Salome Zourabishvili had put forward the Georgian Charter, a blueprint for a stable and democratic transition to a new style of governance and for initiating reforms to fulfil conditions for EU accession. It was signed by all pro-European and pro-Western opposition parties. 

The official election results gave the ruling Georgian Dream party a 54 per cent majority in contrast with exit polls that gave the opposition a 10 per cent lead. President Zourabishvili and the opposition parties refuse to recognize the results, beginning a long process of contestation with allegations of fraud and street protests. As the disappointment sets in and the streets once again replace the ballot box as a conduit for democratic change, there is a sense of déja vu.

Georgia has seen this before. A party sweeps to power on the tide of popular protest, initiates reforms to meet public expectations but, by the end of its second term, it takes an authoritarian turn. As it overstays its welcome, it starts manipulating elections to cling to power. People once again take to the streets and a new party wins by a landslide only to repeat the same cycle. But with each turn, the grip the ruling elites have on power gets stronger and the methods they use become more sophisticated. State security becomes equated with regime stability, leaving no space for normal democratic contestation or expressions of dissent. 

Although what is happening in Georgia fits this familiar pattern, there are some consequential differences. 

First, these were the first fully proportional elections. Previously, a mixed system of representation meant that the incumbency always had an advantage by dominating majoritarian districts. A new electoral system had created a not unreasonable expectation that these elections, if held freely, would result in a coalition government. The hope was this could help break the vicious cycle of Georgian politics, sustained by an extreme form of majoritarianism and a winner-takes-all political culture.

The Georgian Dream party was contesting its fourth consecutive term against a backdrop of falling popularity and growing societal mobilization in opposition to its authoritarian inclinations. Despite all this, it secured – some would insist manufactured – an absolute majority in elections that international observers say were marred by serious irregularities and fell short of democratic standards. 

The second important difference is that these elections were not only about saving Georgia’s democracy but also about rescuing its European perspective. Since Georgia was granted EU candidate status in December 2023, its parliament has adopted Russian-style laws on foreign agents and combating LGBTIQ+ ‘propaganda’. 

It has also adopted a strongly Eurosceptic political discourse, pushing back on international criticism and accusing EU and US officials of interference in domestic affairs and disregard for Georgia’s sovereignty. In response, the EU has suspended accession talks with Georgia indefinitely while the US has imposed targeted sanctions on high-ranking Georgian officials and judges. 

Georgia’s democratic backsliding at home and its pivot away from the West are both simultaneous and interrelated. It was widely hoped these elections would be a course correction and return Georgia to the path of European and Euro-Atlantic integration. The election results, if they stick, will prevent this from happening. A Georgian Dream government will not work to fulfil conditions for EU accession, viewed as a challenge to its hold on power. 

The third and final difference is that these elections took place in the context of heightened geopolitical confrontation. The Georgian Dream ‘victory’ is a win for anti-liberal, conservative forces around the world championed, among others, by Hungary’s Viktor Orbán. He was the first to congratulate Georgian Dream for its declared success and even visited Tbilisi in a show of solidarity and ideological alignment. 

The election result is also a win for Russia. It strengthens Moscow’s influence in the South Caucasus, which has waned as a result of the war in Ukraine and the fall of Nagorny-Karabakh. Russian officials and propagandist were quick to congratulate Georgian Dream, wishing them success in standing up to Western pressures and offering help in case things got tough. 

From Moscow’s perspective, Georgia’s elections are part of a global hybrid war. They represent a local battle in the ongoing geopolitical contest between Russia and the West, between the rules-based global order and competitive multipolarity. 

As Georgia repeats a familiar pattern, what do the election results mean for its future? While clear predictions are difficult at this stage, it is worth bearing in mind that as the democratic resilience of the Georgian society has strengthened over time, so too has the state capacity to supress and control. 

Mohamad Navab
Jun 1, 2004; 45:993-1007
Thematic Reviews

JM Dietschy
Oct 1, 1993; 34:1637-1659
Reviews

Ronald M. Krauss
Jan 1, 1982; 23:97-104
Articles

Weerapan Khovidhunkit
Jul 1, 2004; 45:1169-1196
Thematic Reviews

RK Tangirala
Nov 1, 1995; 36:2320-2328
Articles

AE Christian
Nov 1, 1997; 38:2264-2272
Articles

G Lepage
Jan 1, 1986; 27:114-120
Articles

JE Hixson
Mar 1, 1990; 31:545-548
Articles

Insights from Climate Policy: Engaging Subnational Governments in Global Platforms 10 June 2020 — 2:45PM TO 6:00PM Anonymous (not verified) 9 February 2021 Online

How have subnational governments shaped the global agenda and created momentum on climate change where national and international governance processes could not?

Can these advances be converted into meaningful collaboration channels for policy development? What works, or does not, when it comes to engagement with multilateral negotiation processes? What ingredients are necessary for success? What are the broader implications of these trends for inclusivity and innovation in international governance?

This event is part of the Inclusive Governance Initiative, which is examining how to build more inclusive models and mechanisms of global governance fit for purpose in today’s world.

A seat at the table – why inclusivity matters in global governance 10 May 2021 — 1:30PM TO 3:00PM Anonymous (not verified) 22 April 2021 Online

Exploring the changing dynamics of global cooperation and the role inclusivity can play in building collaborative action.

Please click on the below link to confirm your participation and receive your individual joining details from Zoom for this event. You will receive a confirmation email from Zoom, which contains the option to add the event to your calendar if you so wish.

The scale of today’s global challenges demand collaborative and coordinated action. But deepening geopolitical competition is threatening multilateralism while growing inequality and social tensions continue to undermine public confidence in the ability of international institutions to deliver.

Into this challenging environment, add the complexity and sheer pace of many global challenges such as the climate crisis and the proliferation of new technologies – issues that cannot be addressed effectively by governments alone.

• How do global institutions and mechanisms need to adapt to address the demands for a fairer distribution of power between states and to engage the diverse set of actors essential today for effective solutions?
• What can be learnt from existing initiatives that bring together governments, civil society, private sector, cities, next generation leaders and other stakeholders?
• And what are the political obstacles to greater inclusivity?

This event supports the launch of a synthesis paper from Chatham House’s Inclusive Governance Initiative.

How can governance be more inclusive? Explainer Video NCapeling 28 June 2021

Short animation exploring how global governance can be reshaped to meet the challenges of today’s world.

The COVID-19 pandemic has illustrated the urgent need for change in the structures and mechanisms of international cooperation.

This animation supports the release of a major synthesis paper as part of the Inclusive Governance Initiative, which was launched in 2020 to mark Chatham House’s centenary.

Read the synthesis paper Reflections on building more inclusive global governance.

The trickle-up effect of rights-based climate litigation Expert comment NCapeling 16 November 2021

With governments failing in their pledges and companies accused of ‘green-washing’, human rights-based litigation is increasingly important for accountability.

Tuvalu’s foreign minister addressing COP26 while standing knee-deep in seawater was a stark illustration of how the climate emergency directly and imminently threatens the most basic human rights protected under international law – including to the right to life, self-determination and cultural rights.

Human rights are now a fundamental component of more than 90 per cent of the climate litigation currently taking place outside the US, highlighting the international reach of human rights law and how its emphasis on protecting the most vulnerable helps diverse communities find common arguments for shared goals.

Cases are set to continue and to evolve but three types of claim are emerging, each of which is examined in a new Chatham House briefing paper.

1. Enforcing commitments

One category of cases seeks to hold states accountable for pledges they have made on climate change, such as emission reduction targets made under the framework of the 2015 Paris Agreement. Drawing on human rights obligations, governments can be charged with not taking sufficient steps to implement these pledges.

The case of Leghari v Pakistan (2015) concerned the government’s failure to carry out the National Climate Change Policy of 2012 and the Framework for Implementation of Climate Change Policy (2014-2030). The Lahore High Court held that several of the human rights enshrined in Pakistan’s constitution cover climate change and ‘provide the necessary judicial toolkit to address the government’s response to climate change’.

The court ordered the government to carry out measures such as publishing an adaptation action plan realizable within a few months of the order and establishing a Climate Change Commission to monitor progress.

2. Positive duties to mitigate risks

Many rights-based climate cases are being brought to clarify the scope of states’ positive duties under human rights law to take meaningful steps to protect their citizens against foreseeable risks to life and other rights.

This ‘trickle-up’ effect of human rights was prominent in the case of State of the Netherlands vs the Urgenda Foundation (2019) where the Dutch Supreme Court held that reducing emissions with the highest possible level of ambition amounts to a ‘due diligence standard’ for states to comply with their positive duties to adopt adequate measures to address climate change. Human rights law was also used by the court to fill in the content of the due diligence standards.

There is also a growing trend for rights-based actions to be brought against corporations, such as a recent case which drew on the UN Guiding Principles on Business and Human Rights to define the parameters of Shell’s duty of care and due diligence obligations in relation to carbon emissions under Dutch law. The court ordered Shell to reduce emissions by a net rate of 45 per cent by the end of 2030 – relative to 2019 figures – through its group corporate policy.

3. Avoiding harm in climate action

The global human rights regime is also increasingly invoked in litigation concerning states’ negative obligations to ensure that their climate mitigation and adaptation activities do not themselves contribute to human rights violations (including discrimination) and that states prioritize adaptation measures for those most at risk in a just and equitable way.

As Chatham House’s paper makes clear, this kind of litigation ‘puts pressure on governments to expand their approach to tackling climate change beyond purely a regulatory one to a more holistic strategy’.

Closing the climate justice gap

Climate and environmental litigation grounded in human rights is set to continue given the overwhelming scientific evidence of risks associated with human-induced climate change and the limited confidence in pledges made by states and corporations alike – including those made recently at COP26.

A growing collaboration between civil society organizations and vulnerable communities in relation to both the protection of nature and the enjoyment of their land and cultural rights was evident at COP26, and this alliance will add further momentum to the trend for rights-based climate litigation based on the rights of indigenous and other vulnerable communities, especially on issues such as deforestation.

But more challenges are coming. International human rights law recognizes a duty of international cooperation but there remain significant hurdles for climate-vulnerable communities in developing countries to compel action by richer nations despite the vast debts of ‘carbon colonialism.’

One big issue is the problem of extraterritoriality, as the extent to which states owe obligations to individuals outside their territory is contested. Courts in both Germany and the Netherlands have rejected claimants from developing countries in domestic class actions on this basis. But a recent decision of the UN Committee on the Rights of the Child on a complaint brought by Greta Thunberg and other youth activists against five countries opens the door for further litigation.

One of a number of cases being brought by youth claimants across the world, the committee concluded that a state’s human rights duties can – in some instances – extend to children in other countries. This includes any activities on the territory that host states have the power to prevent from causing ‘transboundary harm’ – such as emissions from the territory – where these activities ‘significantly’ impact the enjoyment of human rights of persons outside the territory.

To date, high-profile rights-based cases have argued for policy change and stronger targets underpinned by binding legislation responsive to the science. Claims are set to become more complex and contested. Building on scientific developments in climate attribution, rights-based litigation is now tackling other difficult questions such as apportioning responsibility and remedial action.

These cases examine both historically high emitters and the public and private actors who either continue specific activities or refrains from action in the face of the overwhelming science linking human activities such as extraction and burning of fossil fuels to deforestation and climatic consequences.

Courts are also likely to explore the duties that states and corporations owe to deliver a ‘just transition’ away from carbon-intensive industries, given the benefits of growth and climate action are already unevenly distributed.

A holistic human-rights based approach

Several states together with civil society are leading the charge for global recognition of the right to a healthy, clean, and sustainable environment in the United Nations (UN) Human Rights Council, and multi-stakeholder processes are defining what effective corporate due diligence looks like.

In addition, UN-appointed special rapporteurs are delivering practical guidance on how to devise solutions which are fair, non-discriminatory, participatory, and climate-resilient without exacerbating inequality – including difficult issues of planned relocation – and UN Human Rights Treaty Bodies are unpacking the duty of international cooperation to act in good faith to address loss and damage.

Recently the Committee on the Elimination of Discrimination Against Women recommended the Marshall Islands, in order to meet its duty to its citizens, should actively seek international cooperation and assistance – including climate change financing – from other countries but in particular the US, whose ‘extraterritorial nuclear testing activities have exacerbated the adverse effects of climate change and natural disasters’ in the islands.

Mammalian circadian clocks are driven by transcription/translation feedback loops composed of positive transcriptional activators (BMAL1 and CLOCK) and negative repressors (CRYPTOCHROMEs (CRYs) and PERIODs (PERs)). CRYs, in complex with PERs, bind to the BMAL1/CLOCK complex and repress E-box–driven transcription of clock-associated genes. There are two individual CRYs, with CRY1 exhibiting higher affinity to the BMAL1/CLOCK complex than CRY2. It is known that this differential binding is regulated by a dynamic serine-rich loop adjacent to the secondary pocket of both CRYs, but the underlying features controlling loop dynamics are not known. Here we report that allosteric regulation of the serine-rich loop is mediated by Arg-293 of CRY1, identified as a rare CRY1 SNP in the Ensembl and 1000 Genomes databases. The p.Arg293His CRY1 variant caused a shortened circadian period in a Cry1−/−Cry2−/− double knockout mouse embryonic fibroblast cell line. Moreover, the variant displayed reduced repressor activity on BMAL1/CLOCK driven transcription, which is explained by reduced affinity to BMAL1/CLOCK in the absence of PER2 compared with CRY1. Molecular dynamics simulations revealed that the p.Arg293His CRY1 variant altered a communication pathway between Arg-293 and the serine loop by reducing its dynamicity. Collectively, this study provides direct evidence that allosterism in CRY1 is critical for the regulation of circadian rhythm.

Hepatocyte nuclear factor-1β (HNF-1β) is a tissue-specific transcription factor that is required for normal kidney development and renal epithelial differentiation. Mutations of HNF-1β produce congenital kidney abnormalities and inherited renal tubulopathies. Here, we show that ablation of HNF-1β in mIMCD3 renal epithelial cells results in activation of β-catenin and increased expression of lymphoid enhancer–binding factor 1 (LEF1), a downstream effector in the canonical Wnt signaling pathway. Increased expression and nuclear localization of LEF1 are also observed in cystic kidneys from Hnf1b mutant mice. Expression of dominant-negative mutant HNF-1β in mIMCD3 cells produces hyperresponsiveness to exogenous Wnt ligands, which is inhibited by siRNA-mediated knockdown of Lef1. WT HNF-1β binds to two evolutionarily conserved sites located 94 and 30 kb from the mouse Lef1 promoter. Ablation of HNF-1β decreases H3K27 trimethylation repressive marks and increases β-catenin occupancy at a site 4 kb upstream to Lef1. Mechanistically, WT HNF-1β recruits the polycomb-repressive complex 2 that catalyzes H3K27 trimethylation. Deletion of the β-catenin–binding domain of LEF1 in HNF-1β–deficient cells abolishes the increase in Lef1 transcription and decreases the expression of downstream Wnt target genes. The canonical Wnt target gene, Axin2, is also a direct transcriptional target of HNF-1β through binding to negative regulatory elements in the gene promoter. These findings demonstrate that HNF-1β regulates canonical Wnt target genes through long-range effects on histone methylation at Wnt enhancers and reveal a new mode of active transcriptional repression by HNF-1β.

Expert

Expert

RNA-protein interfaces control key replication events during the HIV-1 life cycle. The viral trans-activator of transcription (Tat) protein uses an archetypal arginine-rich motif (ARM) to recruit the host positive transcription elongation factor b (pTEFb) complex onto the viral trans-activation response (TAR) RNA, leading to activation of HIV transcription. Efforts to block this interaction have stimulated production of biologics designed to disrupt this essential RNA-protein interface. Here, we present four co-crystal structures of lab-evolved TAR-binding proteins (TBPs) in complex with HIV-1 TAR. Our results reveal that high-affinity binding requires a distinct sequence and spacing of arginines within a specific β2-β3 hairpin loop that arose during selection. Although loops with as many as five arginines were analyzed, only three arginines could bind simultaneously with major-groove guanines. Amino acids that promote backbone interactions within the β2-β3 loop were also observed to be important for high-affinity interactions. Based on structural and affinity analyses, we designed two cyclic peptide mimics of the TAR-binding β2-β3 loop sequences present in two high-affinity TBPs (KD values of 4.2 ± 0.3 and 3.0 ± 0.3 nm). Our efforts yielded low-molecular weight compounds that bind TAR with low micromolar affinity (KD values ranging from 3.6 to 22 μm). Significantly, one cyclic compound within this series blocked binding of the Tat-ARM peptide to TAR in solution assays, whereas its linear counterpart did not. Overall, this work provides insight into protein-mediated TAR recognition and lays the ground for the development of cyclic peptide inhibitors of a vital HIV-1 RNA-protein interaction.

L. Oeding
Trans. Moscow Math. Soc. 83 (), 227-250.
Abstract, references and article information

H. G. Kazaryan and V. N. Margaryan
Trans. Moscow Math. Soc. 83 (), 151-181.
Abstract, references and article information

N. R. Ikonomov and S. P. Suetin
Trans. Moscow Math. Soc. 83 (), 33-54.
Abstract, references and article information

The Electric Vehicle Revolution: Impacts on Oil Economies and Industry 24 January 2019 — 8:15AM TO 9:45AM Anonymous (not verified) 3 December 2018 Chatham House | 10 St James's Square | London | SW1Y 4LE

Electric vehicle (EV) deployment is gathering pace: the Norwegian government thinks that EV subsidies will be unnecessary by 2025 as they reach parity with diesel and petrol vehicles.

China has stipulated that EVs comprise 12 per cent of vehicle sales by 2020 while more governments are committing to banning diesel and petrol vehicles.

These developments are expected to be replicated as urban air pollution rises up the political agenda while technological developments and falling costs have given rise to ambitious forecasts on the increase in the deployment of EVs and the demise of the internal combustion engine.

Considering this, the presentations and initial discussion focus on:

• The influence of new technologies on the automotive landscape, including autonomous vehicles.
• How the automotive and oil companies are adjusting their business models to accommodate and encourage the rise in EVs.
• The risks and opportunities for the deployment of EVs for incumbents and new market actors.
• The role of government for example in public procurement and infrastructure development.
• The potential for modal shift and its impact on oil demand.

The discussion then seeks to explore the need for benchmarks of change including data and metrics to understand the changing risk landscape and the implications for different actors.

Finally, the discussion focuses on the speed of transformation and what this means for existing and new market actors.

Nuclear Energy in a Post-Brexit Europe 11 October 2019 — 8:30AM TO 10:00AM Anonymous (not verified) 18 September 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

Brexit will significantly change the balance within the EU in relation to nuclear energy. Apart from France and Finland, both of whose nuclear development programmes are behind schedule, the UK is the only member state in northern or western Europe currently investing in new nuclear capacity. Brexit will therefore leave the supporters of nuclear energy within the EU27 and the European Commission in a weaker position.

The speaker will argue that at a time when the energy industry needs to accelerate its shift away from fossil fuels, and when the electricity generation industry must cut its carbon emissions faster than it has ever managed to do in the past, this change is unhelpful.

The workshop will also address the need for additional interconnector capacity and the future of carbon-trading outside the EU emission trading system and how this relates to potential nuclear energy capacity.

Attendance at this event is by invitation only.

Impact of the US Election on Global Climate Politics 25 November 2020 — 1:00PM TO 2:00PM Anonymous (not verified) 16 November 2020 Online

Panellists discuss how Joe Biden’s victory will impact international efforts to tackle climate change. Will climate finally become a common area for global cooperation?

Joe Biden’s victory over Donald Trump is already having a positive impact on international efforts to tackle climate change. Leaders from across the world, including the UK, Canada, Australia and Fiji, have used their first messages to the President-elect to draw attention to the climate crisis.

Biden has promised to re-join the global community in its commitment to the Paris Agreement – but this could be the easy part. More difficult will be whether and how Biden is able to deliver his ambitious climate plan, and how effectively he is able to integrate climate change into foreign policy efforts and national security strategies.

Global climate action has also moved forward in the last four years. The European Union recently pledged to become climate neutral by 2050, and China, Japan and South Korea have committed to achieving carbon neutral economies.

How will the US re-enter this global landscape of distributed leadership and what difficulties does it face? Will the US be willing to work within a competitive partnership with the EU and China? How will Biden’s win change the dynamic of COP26 next year?