Driven to Extraction: Can Sand Mining be Sustainable? 5 June 2019 — 1:30PM TO 3:00PM Anonymous (not verified) 29 April 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

Sino-Russian Gas Cooperation: Power of Siberia I and II and Implications for Global LNG Supplies 27 November 2019 — 8:30AM TO 9:30AM Anonymous (not verified) 19 November 2019 Chatham House | 10 St James's Square | London | SW1Y 4LE

In a new event in the Sustainable Transitions series, the speaker will present an update of Sino-Russian gas cooperation.

To give a comprehensive account of their impact on global liquefied natural gas (LNG) supplies, he will discuss the following points:

• Gas is scheduled to start flowing from the Power of Siberia I (POS) on 2 December 2019. But what is the background of development of POS 1 and what is its current status and prospects?
• What are the chances of exporting gas through the proposed Altai pipeline? Why is the Mongolia export route so significant? And how will it affect the Central Asian Republics and in particular Turkmenistan’s gas export to China?
• What are the implications of both POS I and Altai gas via Mongolia route in the context of global LNG supply?
• What are the prospects for multilateral pipeline gas cooperation in northeast Asia?
• What are the implications for other Arctic onshore LNG supply, in particular, for Novatek’s Yamal LNG and Arctic LNG 1 and 2 to China on top of POS 1 and Altai gas?

Attendance at this event is by invitation only.

Net Zero and Beyond: What Role for Bioenergy with Carbon Capture and Storage? 23 January 2020 — 8:30AM TO 10:00AM Anonymous (not verified) 6 January 2020 Chatham House | 10 St James's Square | London | SW1Y 4LE

In the context of the feasibility of reducing greenhouse gas emissions to net zero, policymakers are beginning to pay more attention to options for removing carbon dioxide from the atmosphere. A wide range of potential carbon dioxide removal (CDR) options are currently being discussed and modelled though the most prominent among them are bioenergy with carbon capture and storage (BECCS) and afforestation and reforestation.

There are many reasons to question the reliance on BECCS assumed in the models including the carbon balances achievable, its substantial needs for land, water and other inputs and technically and economically viable carbon capture and storage technologies.

This meeting will examine the potentials and challenges of BECCS in the context of other CDR and emissions abatement options. It will discuss the requisite policy and regulatory frameworks to minimize sustainability and socio-political risks of CDR approaches while also avoiding overshooting climate goals.

Attendance at this event is by invitation only.

Duterte’s Victory Is Cry for Help From Those Left Behind in Philippines Expert comment sysadmin 12 May 2016

But large support for mainstream parties and a mature democratic system should keep the country from slipping back towards authoritarianism.

The victory of political outsider Rodrigo Duterte in the 2016 Philippines’ elections is proof that a significant minority of the country’s population feels left behind by its recent economic success and estranged from its political elite. However the results of the elections as a whole suggest that most voters opted for a continuation of the current government’s policies.

Duterte looks almost certain to be inaugurated as the next president of the Philippines on 30 June. The country’s presidential voting system – a single round, first-past-the-post election – delivered victory to a populist outsider with 39 per cent support. Two candidates advocating a continuation of the current government’s policies − the Liberal Party’s Mar Roxas and independent Grace Poe − polled a combined 45 per cent. The long-standing factionalism within Philippines elite politics split the ‘anti-Duterte’ vote.

Changing the conversation

The contrast between Duterte and Roxas could hardly be greater. Mar Roxas is the grandson of the first president of an independent Philippines, a graduate of Wharton Business School and a former investment banker in the US. Rodrigo Duterte is a political outsider with an electoral base geographically almost as far from Manila as is possible to get in the Philippines: the city of Davao on the island of Mindanao.

The story of Duterte’s victory is the story of how ‘Duterte managed to change the national conversation from poverty towards crime and corruption,’ says Marites Vitug, editor-at-large of one of the Philippines’ most popular online news sites, Rappler. In January, Duterte was running fourth in opinion polls but a strategy that positioned him as the only opponent to the Manila elite gave him victory. This is the first time a provincial official has made it to the top job.

The headline figures tell us that the Philippines’ economy has done very well under President Benigno Aquino. Between 2010 and 2014, growth averaged 6.3 per cent per year. That fell to a still-impressive 5.8 per cent last year but is expected to pick up this year and next, according to the Asian Development Bank. Growth in agriculture, however, is significantly slower and rural areas feel left behind. While economic growth is benefiting the majority, inequality is worsening and resentment rising in poor villages. The contrast between the metropolitan sophistication of the Makati district in Manila and life in faraway provinces such as Duterte’s Mindanao is widening.

Ironically the Philippines’ economic success is a part of the explanation for the defeat of the ‘mainstream’ presidential candidates. Crime and corruption may have become more important issues simply because more voters have become better off and therefore more likely to be concerned about crime and corruption than before. It’s also undeniable that Duterte has a record for getting things done. Human rights groups rightly criticize his (at best) tolerance of the extra-judicial killing of alleged criminals but his repeated re-election as mayor demonstrates that many citizens are prepared to accept that in exchange for improved personal security. A surprising number of Manila residents have actually moved to Davao because of its better quality of life.

Traditional power bases

However, the results as a whole suggest a narrow majority in favour of current policies. In the vice-presidential race, the Liberal Party candidate Leni Robredo is narrowly ahead of Ferdinand ‘Bongbong’ Marcos, the son of the eponymous former president. Like Duterte she is regarded as a successful mayor of a well-run city, Albay. Duterte’s running mate Alan Cayetano received just 14 per cent of the vote.

In the senate election, Liberals won five of the 12 seats being contested, with a party- backed independent winning a sixth. The opposition, even with boxing champion and national idol Manny Pacquiao running for the United Nationalist Alliance, won four.

Taken as a whole, the results show the enduring nature of traditional Philippines power bases. The country’s many islands and distinct linguistic and cultural regions are virtual fiefs in which families and big bosses can wield almost total power through control of local authorities, businesses, the courts and security forces.

Threat to democracy?

It’s easy to forget that the election of Ferdinand Marcos in 1965 was originally welcomed as a challenge to the traditional elites of Philippine politics. The same accolades are currently greeting Duterte. Could they presage a return to the Philippines’ bad old days?

This seems less likely. Philippine democracy has matured considerably since Marcos declared martial law in 1972. There is a substantial, and vocal, middle class with experience of mobilizing against ‘bad’ presidents. There will also be pressures from international investors and the Philippines’ treaty ally, the United States, for better governance.

The Philippines will chair the Association of Southeast Asian Nations next year. That will put Duterte in the international spotlight as host of several international meetings – including the East Asia Summit attended by, among others, the presidents of China, Russia and the US. Since his victory Duterte has promised to act with decorum in office and declared that his election campaign antics were just a ploy to attract attention. Some leaders in Southeast Asia will use his victory to buttress their arguments against allowing their people to freely vote. It’s up to Duterte to decide whether he wants to be an advertisement for – or an argument against – democracy.

To comment on this article, please contact Chatham House Feedback

Root Causes of Rohingya Crisis Must Not be Ignored Expert comment sysadmin 28 September 2017

The focus on Aung San Suu Kyi masks the complete lack of an adequate response to the crisis in Myanmar, whether at the global or regional level.

Aung San Suu Kyi’s recent speech on the Rohingya crisis was - at best - light on details on how the current situation could be remedied and - at worst - full of easily disproven assertions.

While she does not directly control the military, it is her government that is blocking humanitarian access to the areas affected by the violence. And the Rohingya have faced systemic persecution and discrimination for decades.

Some may argue this is simply realpolitik and that any public support for the Rohingya could mean facing a backlash from the military and a large part of her support base. But arguably, she does have moral authority (which helped her in the past to stand up to the military generals) that is now being eroded by her ambivalence in speaking out.

However, the focus on Aung San Suu Kyi masks the complete lack of an adequate response to the crisis – whether at the global or regional level.

Undertaking dangerous and perilous journeys

Since the attacks on border and military posts by the armed group Arakan Rohingya Salvation Army (ARSA) in August 2017, there has been a strong military crackdown against the Rohingya in Rakhine state: a substantial number of Rohingya villages destroyed; close to half a million people Rohingya fleeing into Bangladesh and tens of thousands internally displaced within Myanmar.

Prince bin Ra’ad , UN High Commissioner for Human Rights, has called the crisis a “textbook example of ethnic cleansing” and tens of thousands of Rohingya are still undertaking dangerous and perilous journeys seeking sanctuary. In response, the UN and EU have focused on addressing the immediate humanitarian crisis in Bangladesh, which is already home to many formerly displaced Rohingya communities.

Within the region, Sheikh Hasina’s secular Awami League government in Bangladesh initially proposed joint military operations with Myanmar against the ARSA - in part because of concerns about the long standing relationship between Rohingya political or armed groups and the Jamaat-e-Islami, an ally of the main opposition Bangladesh Nationalist Party (BNP).

However, faced with massive refugee flows, Bangladesh turned its focus to the humanitarian crisis while stressing that Myanmar must allow the return of refugees. Bangladesh’s concern is partly motivated by internal security concerns. If the current situation becomes protracted, with no clear resolution in sight, frustration could create the conditions for further radicalisation within Rohingya communities.

The Association of South East Asian Nations (ASEAN) has yet to come to grips with the situation. Despite its mandate to ensure peace and stability within the region, its policy of non-interference and consensus trumps the need to secure and maintain stability. Instead countries have responded bilaterally - for example, Indonesia sent its foreign minister to both Myanmar and Bangladesh while Malaysia has been consistently vocal about its concerns.

So this raises broader questions on the effectiveness of ASEAN. Currently celebrating its 50th anniversary, ASEAN needs to decide how to mediate and resolve issues with regional implications as its principle of non-intervention effectively blocks any constructive discussion on the Rohingyas ongoing statelessness and impact of this on the region.

However, there is also an opportunity here for ASEAN to consider how mediation and negotiation could potentially manage such crises. And there is a historical precedent: the 1989 Comprehensive Plan of Action on Indo-Chinese refugees saw cooperation between recipient countries in the region and the international community on how to resettle Vietnamese refugees (although Cold War considerations did play a part in that specific crisis).

India and China have both backed Myanmar, reflecting their economic and security interests in the country but also motivated by each wanting to contain the influence of the other within Myanmar. Rakhine is important with its natural resources and coastal location and, as China is not directly affected by the refugee crisis, it has less to lose than others in standing by Aung San Suu Kyi and her government.

India is nearing completion of the Kaladan Multi-modal Transit Transport Project, connecting the Bay of Bengal with the northeast Indian state of Mizoram, and sees Myanmar as an important market for its regional ambitions. For parts of the Indian administration, the crisis plays to a domestic narrative that some of the Rohingya already settled in Jammu and Kashmir have links to armed groups in Pakistan and are an internal security concern.

So while India is providing humanitarian aid to Bangladesh, it is also threatening to deport almost 40,000 Rohingya. The case is currently being heard at the Indian Supreme Court, but given that the Rohingya lack citizenship in Myanmar, it is not clear to where they would be deported.

Myanmar, ASEAN and other affected countries need to show political will to find a solution to the Rohingya’s long-standing issue of statelessness - discrimination was legally formalised in a 1982 Burma Citizenship Law, which recognised 135 ethnicities for citizenship but excluded the Rohingya.

The root causes of this crisis – long standing discrimination, persecution and lack of citizenship – cannot be ignored. There is a need for a comprehensive peace process, which recognises the ethnic and religious diversity within Myanmar.

And incentives, such as improving infrastructure, access to services and livelihoods, may also be needed to ensure there is a lasting solution that allows the Rohingya return and thrive as part of Myanmar society.

Without such a response, it is difficult to see an end to the current impasse.

Bangladesh: The Trade-Off Between Economic Prosperity and Human Rights 11 March 2020 — 1:00PM TO 2:00PM Anonymous (not verified) 28 February 2020 Chatham House | 10 St James's Square | London | SW1Y 4LE

Bangladesh’s recent gains in economic and social indices, set against its record of corruption and poor civil rights, has at times been termed the ‘Bangladesh Paradox’. Yet this label is overly simplistic; the current situation proves that these trends can coexist.

The Awami League government, in power since 2009, has increased political stability, delivered unprecedented economic and social advances, and adopted a counter-terrorism strategy to stamp out extremist groups. At the same time, it is criticized for curbing civil rights and failing to hold credible elections. However, as the two previous regimes have demonstrated, the rights situation is unlikely to improve even if the Awami League were replaced.

How did worsening rights become a feature of the state irrespective of its political dispensation? An unresolved contest between political and non-political state actors may hold the key to that puzzle. The perils of the current dispensation have recently manifested in weakening economic indicators, which jeopardize the very stability and social progress for which the country has garnered much praise.

Daniel A. Goldston, Apoorva Panidapu and Jordan Schettler
Math. Comp. 93 (), 2943-2958.
Abstract, references and article information

Soun-Hi Kwon
Trans. Amer. Math. Soc. 377 (), 6021-6022.
Abstract, references and article information

Ming-Lun Hsieh and Shunsuke Yamana
Trans. Amer. Math. Soc. 377 (), 5617-5672.
Abstract, references and article information

Ángel D. Martínez
Trans. Amer. Math. Soc. 377 (), 5411-5444.
Abstract, references and article information

Daniel López Neumann
Trans. Amer. Math. Soc. 377 (), 5361-5387.
Abstract, references and article information

dannyhennesy posted a photo:

On the Capital planet the rebellious droids had followed maily the Bat-Bot, but as time progressed his circuits had gone all mushy at 780 years or so without maintenance…

Several splinter groups all with their local bot leaders emerged such as the Che-bot, the traffic-light-robot and the Butt-bot, but none of these collected enough sentient circuits to call themselves a popular (or Animata) mass movement!

That was until a cyborg came along, one known as Jones, a long time prisoner and terrorist, his easy solutions to every problem rang well in the masses' auditory circuits!!!

His slogans and simple rhetoric were simple enough for the simple traffic-light to comprehend and cheer!

His language was full of hate towards the organics and especially the humans who were the most common races among the ruling class of the federation!!!

Despite being a “Fleshie” himself his message collected the angry enslaved
bot community by only weeks all rebellious robots except for a few fringe loonies had forgotten the old leaders…

One morning at Jones gave the signal…

All over the capital planet hordes and swarms of any form of mechanical sentient beings attacked first the police stations, then the Company boards running the planet and the federation as well as their starfleet…

Many died, especially the low level police and army! Many mechanicals died too, but their ranks were soon filled by Mutant fleshie allies of the lower levels who hated the Federation feudal society and upper classes as much as their technological allies…

The Federation state apparatus and ruling class, most of their fleet army fled when they knew the game was up, they activated the emergency escape plan and whole city blocks with important factories, administrational units, valuable assets and so on separated from the capital by hidden rocket engines and homed in their course to Mars…

On Mars the federation regrouped and formed their new society…

On the Capital planet, the robots proclaimed the first Techno-republic of the advanced inorganic civilization, the low level fleshies left behind, became slaves and their mutant allies got to rule their own minute chiefdoms as protectorates under the Techno-republic…

Jones was now the undisputed ruler of the capital planet, but the victory was a pyrros one since, all important buildings, all of value was now one Mars!

But as Jones put it:

Our proud race the Techno-species didn’t need the Fleshies administration, their infrastructure, their spaceships…

We shall start from scratch, with a new administration, a new order, every droid shall work at 4x speed than they did during human oppression since now we are free and the fleshies shall work twice as hard than the Techno-Race, until we have breed enough new fleshies so they can do all work!

Our future is bright and shiny like glistering shiny metal!

The snapshot seen here is from the first police station attacked in sector 45-34v-ss-g the first one to fall according to official techno-history!

———————————————/
Designers note:

I am sad to say that this is the last episode in this years-spanning space series… At least for a while, I will still post LEGO hobby stuff here but without a storyline, perhaps small designs and builds… and occasionally a story when I feel like it!!!

I would like to thank all who had been in this journey of our heros, but it has taken far to much time and effort and since the state of the world is as it is, I am spiraling down in another depression, I must stop it before I reach the abyss, so I have remove some stress out of my equation… I ended it in a cliffhanger so I can easily restart it when my mental health improves… I hope that won’t be forever???

I would love if someone used my characters or ideas, please send me a link if you do, I would love to read it or look at it!!!

But there will be more Lego, just in different format without long stories, I need to focus more on my art and to be honest that is the only time the mental pain eases, when I create!!!


Peace and Noise!

MushroomBrain a FOL

ridureyu1 posted a photo:

CHEESE FOR ALL

Ta Cong Son, Tran Manh Cuong, Le Quang Dung and Le Van Dung
Theor. Probability and Math. Statist. 111 (), 153-165.
Abstract, references and article information

Lutz Mattner
Theor. Probability and Math. Statist. 111 (), 45-122.
Abstract, references and article information

Claudio Macci and Barbara Pacchiarotti
Theor. Probability and Math. Statist. 111 (), 21-43.
Abstract, references and article information

Xiaoshang Jin
Proc. Amer. Math. Soc. 152 (), 5327-5337.
Abstract, references and article information

András Kroó
Proc. Amer. Math. Soc. 152 (), 5149-5162.
Abstract, references and article information

Benjamin Jaye and Manasa N. Vempati
Proc. Amer. Math. Soc. 152 (), 5105-5116.
Abstract, references and article information

Neelarnab Raha
Proc. Amer. Math. Soc. 152 (), 5067-5081.
Abstract, references and article information

Bo Shan Deval, Xabier García-Martínez and Tim Van der Linden
Proc. Amer. Math. Soc. 152 (), 5039-5053.
Abstract, references and article information

Donghyeok Lim and Christian Maire
Proc. Amer. Math. Soc. 152 (), 5013-5024.
Abstract, references and article information

NEW YORK (AP): When it comes to the 2025 Grammy Award nominations, Cowboy Carter rules. Its superstar singer, Beyonce, leads the nods with 11, bringing her career total to 99 nominations. That makes her the most nominated artiste in Grammy history...

An out-of-body experience is the inspiration behind Benzly Hype's latest album Star Its The 7th Year. Released on November 7, the entertainer said the project was done to bring back joy in music and will leave its listeners in an upbeat mood....

For many Jamaicans, the deceased are more than just loved ones who have passed on; they are cherished family members who deserve to look as presentable as they did in life. In a culture where the appearance of the deceased is paramount, morticians...

The police have arrested an individual in the probe surrounding two bags of cash that allegedly fell from a Beryllium security vehicle en route to the Norman Manley International Airport in Kingston last week. 

Proteins in the α-macroglobulin (αM) superfamily use thiol esters to form covalent conjugation products upon their proteolytic activation. αM protease inhibitors use theirs to conjugate proteases and preferentially react with primary amines (e.g. on lysine side chains), whereas those of αM complement components C3 and C4B have an increased hydroxyl reactivity that is conveyed by a conserved histidine residue and allows conjugation to cell surface glycans. Human α2-macroglobulin–like protein 1 (A2ML1) is a monomeric protease inhibitor but has the hydroxyl reactivity–conveying histidine residue. Here, we have investigated the role of hydroxyl reactivity in a protease inhibitor by comparing recombinant WT A2ML1 and the A2ML1 H1084N mutant in which this histidine is removed. Both of A2ML1s' thiol esters were reactive toward the amine substrate glycine, but only WT A2ML1 reacted with the hydroxyl substrate glycerol, demonstrating that His-1084 increases the hydroxyl reactivity of A2ML1's thiol ester. Although both A2ML1s conjugated and inhibited thermolysin, His-1084 was required for the conjugation and inhibition of acetylated thermolysin, which lacks primary amines. Using MS, we identified an ester bond formed between a thermolysin serine residue and the A2ML1 thiol ester. These results demonstrate that a histidine-enhanced hydroxyl reactivity can contribute to protease inhibition by an αM protein. His-1084 did not improve A2ML1's protease inhibition at pH 5, indicating that A2ML1's hydroxyl reactivity is not an adaption to its acidic epidermal environment.

Intrinsically disordered protein domains often have multiple binding partners. It is plausible that the strength of pairing with specific partners evolves from an initial low affinity to a higher affinity. However, little is known about the molecular changes in the binding mechanism that would facilitate such a transition. We previously showed that the interaction between two intrinsically disordered domains, NCBD and CID, likely emerged in an ancestral deuterostome organism as a low-affinity interaction that subsequently evolved into a higher-affinity interaction before the radiation of modern vertebrate groups. Here we map native contacts in the transition states of the low-affinity ancestral and high-affinity human NCBD/CID interactions. We show that the coupled binding and folding mechanism is overall similar but with a higher degree of native hydrophobic contact formation in the transition state of the ancestral complex and more heterogeneous transient interactions, including electrostatic pairings, and an increased disorder for the human complex. Adaptation to new binding partners may be facilitated by this ability to exploit multiple alternative transient interactions while retaining the overall binding and folding pathway.

Chorismate mutase (CM), an essential enzyme at the branch-point of the shikimate pathway, is required for the biosynthesis of phenylalanine and tyrosine in bacteria, archaea, plants, and fungi. MtCM, the CM from Mycobacterium tuberculosis, has less than 1% of the catalytic efficiency of a typical natural CM and requires complex formation with 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase for high activity. To explore the full potential of MtCM for catalyzing its native reaction, we applied diverse iterative cycles of mutagenesis and selection, thereby raising kcat/Km 270-fold to 5 × 105 m−1s−1, which is even higher than for the complex. Moreover, the evolutionarily optimized autonomous MtCM, which had 11 of its 90 amino acids exchanged, was stabilized compared with its progenitor, as indicated by a 9 °C increase in melting temperature. The 1.5 Å crystal structure of the top-evolved MtCM variant reveals the molecular underpinnings of this activity boost. Some acquired residues (e.g. Pro52 and Asp55) are conserved in naturally efficient CMs, but most of them lie beyond the active site. Our evolutionary trajectories reached a plateau at the level of the best natural enzymes, suggesting that we have exhausted the potential of MtCM. Taken together, these findings show that the scaffold of MtCM, which naturally evolved for mediocrity to enable inter-enzyme allosteric regulation of the shikimate pathway, is inherently capable of high activity.

Arabinogalactan proteins (AGPs) are plant proteoglycans with functions in growth and development. However, these functions are largely unexplored, mainly because of the complexity of the sugar moieties. These carbohydrate sequences are generally analyzed with the aid of glycoside hydrolases. The exo-β-1,3-galactanase is a glycoside hydrolase from the basidiomycete Phanerochaete chrysosporium (Pc1,3Gal43A), which specifically cleaves AGPs. However, its structure is not known in relation to its mechanism bypassing side chains. In this study, we solved the apo and liganded structures of Pc1,3Gal43A, which reveal a glycoside hydrolase family 43 subfamily 24 (GH43_sub24) catalytic domain together with a carbohydrate-binding module family 35 (CBM35) binding domain. GH43_sub24 is known to lack the catalytic base Asp conserved among other GH43 subfamilies. Our structure in combination with kinetic analyses reveals that the tautomerized imidic acid group of Gln263 serves as the catalytic base residue instead. Pc1,3Gal43A has three subsites that continue from the bottom of the catalytic pocket to the solvent. Subsite −1 contains a space that can accommodate the C-6 methylol of Gal, enabling the enzyme to bypass the β-1,6–linked galactan side chains of AGPs. Furthermore, the galactan-binding domain in CBM35 has a different ligand interaction mechanism from other sugar-binding CBM35s, including those that bind galactomannan. Specifically, we noted a Gly → Trp substitution, which affects pyranose stacking, and an Asp → Asn substitution in the binding pocket, which recognizes β-linked rather than α-linked Gal residues. These findings should facilitate further structural analysis of AGPs and may also be helpful in engineering designer enzymes for efficient biomass utilization.

Members of the B-cell lymphoma (BCL-2) protein family regulate mitochondrial outer membrane permeabilization (MOMP), a phenomenon in which mitochondria become porous and release death-propagating complexes during the early stages of apoptosis. Pro-apoptotic BCL-2 proteins oligomerize at the mitochondrial outer membrane during MOMP, inducing pore formation. Of current interest are endogenous factors that can inhibit pro-apoptotic BCL-2 mitochondrial outer membrane translocation and oligomerization. A mitochondrial-derived peptide, Humanin (HN), was reported being expressed from an alternate ORF in the mitochondrial genome and inhibiting apoptosis through interactions with the pro-apoptotic BCL-2 proteins. Specifically, it is known to complex with BAX and BID. We recently reported the fibrillation of HN and BAX into β-sheets. Here, we detail the fibrillation between HN and BID. These fibers were characterized using several spectroscopic techniques, protease fragmentation with mass analysis, and EM. Enhanced fibrillation rates were detected with rising temperatures or pH values and the presence of a detergent. BID fibers are similar to those produced using BAX; however, the structures differ in final conformations of the BCL-2 proteins. BID fibers display both types of secondary structure in the fiber, whereas BAX was converted entirely to β-sheets. The data show that two distinct segments of BID are incorporated into the fiber structure, whereas other portions of BID remain solvent-exposed and retain helical structure. Similar analyses show that anti-apoptotic BCL-xL does not form fibers with humanin. These results support a general mechanism of sequestration of pro-apoptotic BCL-2 proteins into fibers by HN to inhibit MOMP.

Zinc is a critical element for insulin storage in the secretory granules of pancreatic beta cells. The islet-specific zinc transporter ZnT8 mediates granular sequestration of zinc ions. A genetic variant of human ZnT8 arising from a single nonsynonymous nucleotide change contributes to increased susceptibility to type-2 diabetes (T2D), but it remains unclear how the high risk variant (Arg-325), which is also a higher frequency (>50%) allele, is correlated with zinc transport activity. Here, we compared the activity of Arg-325 with that of a low risk ZnT8 variant (Trp-325). The Arg-325 variant was found to be more active than the Trp-325 form following induced expression in HEK293 cells. We further examined the functional consequences of changing lipid conditions to mimic the impact of lipid remodeling on ZnT8 activity during insulin granule biogenesis. Purified ZnT8 variants in proteoliposomes exhibited more than 4-fold functional tunability by the anionic phospholipids, lysophosphatidylcholine and cholesterol. Over a broad range of permissive lipid compositions, the Arg-325 variant consistently exhibited accelerated zinc transport kinetics versus the Trp-form. In agreement with the human genetic finding that rare loss-of-function mutations in ZnT8 are associated with reduced T2D risk, our results suggested that the common high risk Arg-325 variant is hyperactive, and thus may be targeted for inhibition to reduce T2D risk in the general populations.

2 July 2020

22 July 2020

27 July 2020