The actin cytoskeleton is extremely dynamic and supports diverse cellular functions in many physiological and pathological processes, including tumorigenesis. However, the mechanisms that regulate the actin-related protein 2/3 (ARP2/3) complex and thereby promote actin polymerization and organization in cancer cells are not well-understood. We previously implicated the proline-rich 11 (PRR11) protein in lung cancer development. In this study, using immunofluorescence staining, actin polymerization assays, and siRNA-mediated gene silencing, we uncovered that cytoplasmic PRR11 is involved in F-actin polymerization and organization. We found that dysregulation of PRR11 expression results in F-actin rearrangement and nuclear instability in non-small cell lung cancer cells. Results from molecular mechanistic experiments indicated that PRR11 associates with and recruits the ARP2/3 complex, facilitates F-actin polymerization, and thereby disrupts the F-actin cytoskeleton, leading to abnormal nuclear lamina assembly and chromatin reorganization. Inhibition of the ARP2/3 complex activity abolished irregular F-actin polymerization, lamina assembly, and chromatin reorganization due to PRR11 overexpression. Notably, experiments with truncated PRR11 variants revealed that PRR11 regulates F-actin through different regions. We found that deletion of either the N or C terminus of PRR11 abrogates its effects on F-actin polymerization and nuclear instability and that deletion of amino acid residues 100–184 or 100–200 strongly induces an F-actin structure called the actin comet tail, not observed with WT PRR11. Our findings indicate that cytoplasmic PRR11 plays an essential role in regulating F-actin assembly and nuclear stability by recruiting the ARP2/3 complex in human non-small cell lung carcinoma cells.

Knowledge of the molecular events in mitochondrial DNA (mtDNA) replication is crucial to understanding the origins of human disorders arising from mitochondrial dysfunction. Twinkle helicase is an essential component of mtDNA replication. Here, we employed atomic force microscopy imaging in air and liquids to visualize ring assembly, DNA binding, and unwinding activity of individual Twinkle hexamers at the single-molecule level. We observed that the Twinkle subunits self-assemble into hexamers and higher-order complexes that can switch between open and closed-ring configurations in the absence of DNA. Our analyses helped visualize Twinkle loading onto and unloading from DNA in an open-ringed configuration. They also revealed that closed-ring conformers bind and unwind several hundred base pairs of duplex DNA at an average rate of ∼240 bp/min. We found that the addition of mitochondrial single-stranded (ss) DNA–binding protein both influences the ways Twinkle loads onto defined DNA substrates and stabilizes the unwound ssDNA product, resulting in a ∼5-fold stimulation of the apparent DNA-unwinding rate. Mitochondrial ssDNA-binding protein also increased the estimated translocation processivity from 1750 to >9000 bp before helicase disassociation, suggesting that more than half of the mitochondrial genome could be unwound by Twinkle during a single DNA-binding event. The strategies used in this work provide a new platform to examine Twinkle disease variants and the core mtDNA replication machinery. They also offer an enhanced framework to investigate molecular mechanisms underlying deletion and depletion of the mitochondrial genome as observed in mitochondrial diseases.

The action mechanisms revealed by the biochemical and structural analyses of replicative and translesion synthesis (TLS) DNA polymerases (Pols) are retained in their cellular roles. In this regard, DNA polymerase θ differs from other Pols in that whereas purified Polθ misincorporates an A opposite 1,N6-ethenodeoxyadenosine (ϵdA) using an abasic-like mode, Polθ performs predominantly error-free TLS in human cells. To test the hypothesis that Polθ adopts a different mechanism for replicating through ϵdA in human cells than in the purified Pol, here we analyze the effects of mutations in the two highly conserved tyrosine residues, Tyr-2387 and Tyr-2391, in the Polθ active site. Our findings that these residues are indispensable for TLS by the purified Pol but are not required in human cells, as well as other findings, provide strong evidence that the Polθ active site is reconfigured in human cells to stabilize ϵdA in the syn conformation for Hoogsteen base pairing with the correct nucleotide. The evidence that a DNA polymerase can configure its active site entirely differently in human cells than in the purified Pol establishes a new paradigm for DNA polymerase function.

A discussion marking the 25th anniversary of the 1990 Immigration Act, where experts examinine the history of the legislation, how it was accomplished politically, and the stakeholders and issues that were critical to its passage.

As policymakers in a number of countries, the United States among them, debate limiting family-based immigration, this issue brief explores family-migration trends and policies in the United States, Australia, Canada, the United Kingdom, and several other European countries. Family admissions play a key role, even in countries that prioritize economic or other immigration streams.

This MPI Europe webinar examines innovative ways to better design and implement predeparture orientation programs for resetttling refugees. The discussion features observations from a refugee who went through an orientation program before being resettled in the Netherlands, and a resettlement agency official in Norway.

Marking the release of MPI President Andrew Selee's latest book, speakers explore emerging trends in migration, economic interdependence, technology innovation, and cultural exchange that are transforming the relationship between the United States and Mexico, and the policy implications of these changes for the future.

Though a faceoff between the U.S. executive and legislative branches is now in the courts, with President Trump's decision to declare a national emergency so he can allocate more money for construction of a border wall, a less-noted dispute has been taking place over the Department of Homeland Security's decision to add thousands more immigration detention beds than Congress provides annually, as this article explains.

A report release and presentation of first-ever U.S. estimates on the actual economic costs of skill underutilization for immigrants, their families, and the U.S. economy, in terms of forgone earnings and unrealized federal, state, and local taxes.

Over the past decade, immigrant investor programs have proliferated around the world, and Chinese applicants have dominated in a number of countries. In 2015, about 9,000 Chinese millionaires moved to other countries, many through so-called golden visa programs. This article explores the social and cultural factors driving well-off Chinese to move abroad and examines perceptions of elite emigration in China.

Award winners were honored at the second annual awards ceremony in Washington, DC, on May 18, 2010.

Winners of the 2nd annual E Pluribus Unum Prizes awarded to exceptional immigrant integration initiatives by MPI's National Center on Immigrant Integration Policy are the Illinois New Americans Integration Initiative; the Latino Community Credit Union in Durham, NC; Tacoma Community House in Tacoma, WA; and Upwardly Global in San Francisco, CA. McDonald's Corp. of Oak Brook, IL, received the sole honorable mention. The Prizes seek to reward exemplary efforts that uphold and update the ideal of "out of many, one" and inspire others to take on the important work of helping immigrants and their children join the mainstream of U.S. society as well as build stronger ties between immigrants and the native-born. Award winners were honored at the second annual awards ceremony in Washington, DC, on May 18, 2010. Watch highlights of the ceremony here.

Faced with a lack of employment opportunities and recurrent poverty, Albanian youth migrate to Italy alone in the hopes of improving their educational prospects or making money for their families. Yet upon arrival, they face many vulnerabilities. While some protections for unaccompanied minors exist in the Italy, the system is greatly fragmented and challenges, including how to return them to Albania, remain persistent.

On the campaign trail, Donald Trump made immigration the centerpiece of his campaign, offering a more detailed policy agenda than on any other issue. In the year since the election that propelled the Republican into the White House, how has the Trump administration’s record matched up with the rhetoric? This policy brief examines the executive orders and other changes to existing policy and practice made during 2017.

The Trump administration has significantly cranked up the immigration enforcement machinery in the U.S. interior. Yet even as arrests and deportations are up in the early Trump months, they remain less than half their peaks. This report demonstrates how pushback from California and other "sanctuary" locations makes it quite unlikely that ICE will be able to match record enforcement levels.

The Trump administration took sweeping action in 2018 to slow legal immigration, make life harder for some immigrants already in the United States, rebuff would-be asylum seekers, and reduce refugee resettlement. Shaping a narrative of crisis at the border, the administration significantly changed the U.S. asylum system, deployed troops and tear gas, and separated families—yet Central American migrants continued to arrive.

Approximately 11,500 unaccompanied children were apprehended at the U.S.-Mexico border in May, putting this year on track to exceed 2014's surge. As the U.S. government struggles to care for these child migrants, with public outrage mounting over reports of unsafe, filthy conditions in initial Border Patrol custody, the failure of the executive branch and Congress to plan for increased shelter and care demands are increasingly apparent, as this article explores.

As federal and state governments ramp up efforts to implement the Workforce Innovation and Opportunity Act, these fact sheets compare key characteristics of the foreign born and the U.S. born that are relevant to understanding needs for adult education and workforce training services. The fact sheets cover the United States, the 20 states and 25 counties with the largest immigrant populations, and New York City.

The third Social Innovation for Refugee Inclusion conference in Brussels, co-organized by MPI Europe with the U.S. and Canadian Missions to the European Union and the European Economic and Social Committee, explored how innovations in living situations for refugees can promote community-driven inclusion, overcome divisions, facilitate economic opportunities, and foster a sense of "home."

Even with the collapse of the Islamic State's "caliphate," thousands of Western foreign fighters are estimated to remain in the Middle East. Deciding how to handle the return of the radicalized—and their dependents—is no easy issue. Some countries seek to revoke their citizenship. Yet citizenship revocation has unclear impact and raises deep questions about the limits of a state’s responsibility to its citizens, as this article explores.

Noncitizens have long served in the U.S. military, often encouraged by the promise of a fast track to U.S. citizenship. In recent years, however, Congress and the Defense Department have made it more difficult for noncitizens to enlist. This brief give context to these policy changes and explores ways the military could better balance concerns about national security and the need for recruits with key cultural and professional skills.

This report analyzes the exploitation of migrants in three spheres: the domestic care sector, the labor market, and the sex industry. It details several obstacles governments face in their efforts to weaken the "bad actors" that profit from exploitation, and shows how one of the biggest challenges facing law enforcement is that serious criminals and lawbreakers often operate on the edge of legality and exploit legal routes wherever possible.

Marking the release of an MPI report, this briefing explores the effects of recent revisions in DHS immigration enforcement priorities on deportations within the U.S. interior.

China has been Africa’s largest trading partner since 2009, and as commerce and investment have increased, so have flows of people in both directions. With an estimated 1 million to 2 million Chinese migrants across Africa, some countries have relaxed their short-term visa requirements in hopes of facilitating cultural and business exchanges. High levels of Chinese investment do not, however, correlate with more liberal visa policies, as this article explores.

With more than 3 million Venezuelans having fled their country in crisis, this event features the release of an MPI-OAS report that examines the creative responses that host countries in Latin America are providing. These include the opening of legal pathways to residence, access to formal labor markets, and greater use of forms of ID for recognition.

Convocamos un seminario en línea (webinar) en español en la ocasión del lanzamiento del informe, Creatividad dentro de la crisis: opciones legales para inmigrantes venezolanos en América Latina, que describe donde se han radicado los migrantes venezolanos; las medidas que han utilizado los gobiernos latinoamericanos para regularizar el estatus legal de los migrantes venezolanos; y los esfuerzos por integrar a los recién llegados en sus nuevas comunidades de residencia.

This discussion on the 1986 Immigration Reform and Control Act (IRCA) showcases MPI Fellow Charles Kamasaki's book, Immigration Reform: The Corpse That Will Not Die. Kamasaki is joined by other veterans of the IRCA debate for a conversation on the lessons, the intended and unintended consequences, and how the law’s legacy has shaped contemporary politics on immigration.

The Armenian diaspora, which significantly exceeds the country's resident population, has played an instrumental role in Armenia's political and economic development since independence in 1991. Yet a picture emerges of divergent currents within the diaspora, often seen from above as a unified entity. Delve into differences in engagement among Armenia's "old" and "new" diasporas with this feature article.

With many countries in East Asia facing unfavorable demographic shifts in the form of aging populations, low fertility, and shrinking workforces, governments in 2016 continued to explore immigration as a potential policy solution. However, a tradition of cultural homogeneity and wariness among publics about increased immigration is leading policymakers to test the waters with very small steps.

For generations, migrants have emigrated from Senegal, particularly from in and around the Senegal River Valley. With France a key destination, French policy changes have had significant impact on Senegalese migrants and the hometown associations through which they support development in Senegal. This article explores how these policy shifts influence development and quality of life in the Senegal River Valley.

In the face of an uptick in unauthorized arrivals in Italy from Tunisia in 2017, the European Union dusted off earlier policy proposals such as funding to increase Tunisia’s border-control capabilities and the creation of disembarkation platforms. This article explores why contemporary developments, including a fragile Tunisian political system, suggest the need for a different approach.

This event focuses on the changing face of Mexican migration to the United States, Mexican immigrants' contributions to U.S. society and political and economic power, as well as that of those who have returned to Mexico.

While the Global Compact for Safe, Orderly, and Regular Migration was formally adopted by 164 of the UN's 193 Member States, it's worth asking how it became a point of contention and ultimately was rejected by more than a dozen countries. The answer? A long lag time between negotiation and adoption, during which overheated claims against it went largely unanswered, as this commentary explores.

In his first public address on his inaugural official visit to Washington, DC, IOM Director General António Vitorino discusses his vision for IOM; reforms in the UN system; coordination with other organizations in addressing humanitarian protection; and the operational steps IOM is taking to respond to forced migration and displacement.

The vast majority of UN Member States in December 2018 adopted the first-ever international agreement to cooperate on migration. This policy brief traces the trajectory of the Global Compact for Safe, Orderly, and Regular Migration's negotiation and endorsement. It also explores the factors that will determine whether the compact lives up to its aim of improving how states cooperate on international migration.   

This discussion marked the launch of MPI's Rethinking U.S. Immigration Policy Initiative, which aims to generate a big-picture, evidence-driven vision of the role immigration should play in America’s future, as well as to build a bipartisan center so needed reforms can be enacted. The initiative's leader, MPI Senior Fellow Doris Meissner, joins in conversation with former Bush administration Commerce Secretary Carlos Gutierrez and former Obama White House Domestic Policy Council Director Cecilia Muñoz about the prospects for action and what's needed.

Migration and development are intimately linked, but they have not always shared the international policy stage. As UN Member States kick off negotiations for the Global Compact for Safe, Orderly, and Regular Migration—and with adoption planned for 2018—this brief examines the evolving relationship between these policy areas and considers what a global compact has to offer, if well designed.