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.

Cas12a (Cpf1) is an RNA-guided endonuclease in the bacterial type V-A CRISPR-Cas anti-phage immune system that can be repurposed for genome editing. Cas12a can bind and cut dsDNA targets with high specificity in vivo, making it an ideal candidate for expanding the arsenal of enzymes used in precise genome editing. However, this reported high specificity contradicts Cas12a's natural role as an immune effector against rapidly evolving phages. Here, we employed high-throughput in vitro cleavage assays to determine and compare the native cleavage specificities and activities of three different natural Cas12a orthologs (FnCas12a, LbCas12a, and AsCas12a). Surprisingly, we observed pervasive sequence-specific nicking of randomized target libraries, with strong nicking of DNA sequences containing up to four mismatches in the Cas12a-targeted DNA-RNA hybrid sequences. We also found that these nicking and cleavage activities depend on mismatch type and position and vary with Cas12a ortholog and CRISPR RNA sequence. Our analysis further revealed robust nonspecific nicking of dsDNA when Cas12a is activated by binding to a target DNA. Together, our findings reveal that Cas12a has multiple nicking activities against dsDNA substrates and that these activities vary among different Cas12a orthologs.

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.

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.

With thousands more migrants potentially traveling through the Western Balkans this year, this MPI Europe webinar explores the implications of the buttressed EU border on the bloc’s neighbors, including the issues of outsourcing migration control, EU support for addressing irregular migration in neighboring countries, and considerations for EU policymakers.

With thousands migrants potentially traveling through the Western Balkans this year, this MPI Europe webinar explores the implications of the buttressed EU border on the bloc’s neighbors, the migrants transiting these routes, and the local communities. Experts also explored how the European Union can support efforts to address irregular migration in neighboring countries, and what are the tradeoffs and considerations that policymakers must weigh. 

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.

President Trump has made reshaping the U.S. immigration system a top priority. Yet the fragmented nature of policy-making in the United States—with power split between branches and levels of government—has made it difficult to pursue some of his most ambitious proposals. This report explores the evolution of migration policy under Trump, and what these changes may mean in the long run.

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.

High school graduation is a landmark event for students. It also plays an important role in the state accountability systems designed to ensure that schools provide all students a high-quality education. Yet relying on a school's four-year graduation rate for federal accountability purposes can have unintended consequences for English Learners, who may need extra time to graduate.

The Trump administration’s decision to terminate the Deferred Action for Childhood Arrivals (DACA) deportation-relief program launched in 2012 has sparked new urgency to find a longer-term fix for "DREAMers," the unauthorized immigrants brought to the United States as children. This Policy Beat article examines movement in the courts and in Congress on the DREAM Act and similar proposals, exploring likely paths forward.

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.

Discussion at this event focused on findings from MPI's report examining the interior immigration enforcement system in the United States, including ICE data on deportations and arrests, and the responses of state and local governments, civil society, and consulates.  

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.

These fact sheets provide a sketch of key characteristics of the foreign-born and English Learner (EL) populations in select states. The fact sheets look at the demographics of these states, discuss EL student outcomes as measured by standardized tests, and conclude with an overview of state accountability mechanisms that affect ELs under relevant provisions of the Every Student Succeeds Act and predecessor No Child Left Behind Act.

As the share of U.S. children under age 8 who are Dual Language Learners (DLLs) increases, state policies have an important role to play in ensuring all young learners are able to get their education off to a good start. These fact sheets compare key characteristics of DLLs and their peers nationwide and in 30 states, and identify state policies that support equitable access to high-quality early childhood education and care programs.

States are in the midst of designing new policies to hold schools accountable for the education of English Learner (EL) students, as mandated by the federal Every Student Succeeds Act (ESSA). This series of fact sheets sketches the characteristics of immigrant and EL students in 25 states, the gaps between their educational outcomes and those of their peers, and the accountability policies each state is developing.

This meeting highlighted lessons from MPI Europe’s flagship Integration Futures initiative, which seeks to develop creative and strategic approaches to addressing today’s most difficult and pressing integration challenges—and to better plan for those around the corner.

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.

Citizenship and integration policies are often thought of as markers for whether a country is welcoming to immigrants. Yet research suggests that public opinion and political rhetoric play a bigger role in immigrants' sense of belonging. This article explores how boundaries between "us" and "them" are drawn through popular conceptions of nationhood and political rhetoric, and their impact on immigrants' belonging.

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.

Testimony of Marc R. Rosenblum, Deputy Director, U.S. Immigration Program, before the House Judiciary Committee on the efficacy of immigration enforcement at the U.S. border and in the interior.

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.

Marking the release of an MPI study, this discussion examines the operation of today’s interior enforcement system and how state and local governments, civil society, and consulates are responding.    

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.

Long a country of emigration and a springboard for migrants aiming to reach Europe, Morocco has emerged as a destination for many sub-Saharan Africans. As more migrants remain in Morocco, the kingdom has implemented policies to aid with integration. But challenges remain, with most of the estimated 700,000 sub-Saharan Africans living in precarious conditions and irregular status despite some legalization programs.

Large outflows of educated young people escaping high levels of unemployment, in tandem with inflows of unauthorized migrants, pose a fresh set of challenges for Greek policymakers. This Transatlantic Council on Migration report examines Greek emigration, and its economic implications, before exploring policy directions to minimize the costs and maximize the benefits of this mobility.

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.

Having emerged from a long era of military rule, Myanmar's leaders and many citizens are looking outward. In particular, with Burmese labor migration abroad on the rise, policymakers are examining ways in which to harness remittances as a vehicle for economic development, particularly in impoverished rural areas. This article explores Burmese labor migration flows, financial reforms, and challenges on migration and development.

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 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.

Bangladeshis in 2017 suddenly emerged as one of the top migrant groups entering Europe illegally. While Europe is a new destination, Bangladeshi labor migration has been an important part of the country's development since the 1970s, with growing numbers heading abroad, largely to the Gulf Cooperation Council countries. This article explores and contextualizes the new phenomenon of Bangladeshi migration to Europe.

Thailand has become a key destination for migrant workers, primarily from Myanmar, Cambodia, and Laos. Many lack authorization, however, and as their numbers have grown, so has the government's intent in regulating their movement—sometimes provoking unintended results. This article explores recent patterns in labor migration to Thailand and examines the likely impacts of a 2017 decree criminalizing illegal employment.

Development assistance may be a blunt tool for reshaping migration patterns—and indeed one that could increase flows over the short term. Shifting the focus away from increasing individuals’ skills and assets toward investments in the broader economic or governance structures that are a prerequisite for growth and stability may offer more alternatives to emigration in the long run.

As policymakers look for ways to address the drivers of illegal immigration, many have called for migration aims to be incorporated into development work and development tools into migration partnerships. This policy brief analyzes the benefits and risks of heightened cooperation between actors in these fields, and identifies areas where joint initiatives may prove fruitful.

As the final phase of preparations for the historic adoption of a Global Compact for Safe, Orderly, and Regular Migration approaches, this webinar explores two central objectives of the compact: enhancing the availability and flexibility of pathways for regular migration, and investing in skills development.