Pathogen-host reorganization during Chlamydia invasion revealed by cryo-electron tomography

Invasion of host cells is a key early event during bacterial infection, but the underlying pathogen-host interactions are yet to be fully visualised in three-dimensional detail. We have captured snapshots of the early stages of bacterial-mediated endocytosis in situ by exploiting the small size of chlamydial elementary bodies (EBs) for whole cell cryo-electron tomography. Chlamydiae are obligate intracellular bacteria that infect eukaryotic cells and cause sexually transmitted infections and trachoma, the leading cause of preventable blindness. We demonstrate that Chlamydia trachomatis LGV2 EBs are intrinsically polarised. One pole is characterised by a tubular inner membrane invagination, while the other exhibits asymmetric periplasmic expansion to accommodate an array of type III secretion systems (T3SSs). Strikingly, EBs orient with their T3SS-containing pole facing target cells, enabling the T3SSs to directly contact the cellular plasma membrane. This contact induces enveloping macropinosomes, actin-rich filopodia and phagocytic cups to zipper tightly around the internalising bacteria. Once encapsulated into tight early vacuoles, EB polarity and the T3SSs are lost. Our findings reveal previously undescribed structural transitions in both pathogen and host during the initial steps of chlamydial invasion

Chlamydia Hijacks ARF GTPases To Coordinate Microtubule Posttranslational Modifications and Golgi Complex Positioning.

The intracellular bacterium Chlamydia trachomatis develops in a parasitic compartment called the inclusion. Posttranslationally modified microtubules encase the inclusion, controlling the positioning of Golgi complex fragments around the inclusion. The molecular mechanisms by which Chlamydia coopts the host cytoskeleton and the Golgi complex to sustain its infectious compartment are unknown. Here, using a genetically modified Chlamydia strain, we discovered that both posttranslationally modified microtubules and Golgi complex positioning around the inclusion are controlled by the chlamydial inclusion protein CT813/CTL0184/InaC and host ARF GTPases. CT813 recruits ARF1 and ARF4 to the inclusion membrane, where they induce posttranslationally modified microtubules. Similarly, both ARF isoforms are required for the repositioning of Golgi complex fragments around the inclusion. We demonstrate that CT813 directly recruits ARF GTPases on the inclusion membrane and plays a pivotal role in their activation. Together, these results reveal that Chlamydia uses CT813 to hijack ARF GTPases to couple posttranslationally modified microtubules and Golgi complex repositioning at the inclusion.IMPORTANCEChlamydia trachomatis is an important cause of morbidity and a significant economic burden in the world. However, how Chlamydia develops its intracellular compartment, the so-called inclusion, is poorly understood. Using genetically engineered Chlamydia mutants, we discovered that the effector protein CT813 recruits and activates host ADP-ribosylation factor 1 (ARF1) and ARF4 to regulate microtubules. In this context, CT813 acts as a molecular platform that induces the posttranslational modification of microtubules around the inclusion. These cages are then used to reposition the Golgi complex during infection and promote the development of the inclusion. This study provides the first evidence that ARF1 and ARF4 play critical roles in controlling posttranslationally modified microtubules around the inclusion and that Chlamydia trachomatis hijacks this novel function of ARF to reposition the Golgi complex

Beyond the Academy: Connecting Research and Policy

In April 2021, members of New York State Covid-19 and Minority Health Disparities Engaged Researchers Working Group began contributing a series of white papers to a collection in Scholars Archive, University at Albany\u27s institutional repository. This poster reports on the reach of that collection after one year. The literature suggests that information users beyond the academy rely on a variety of sources in the course of their work, most of which can be described as grey literature. The poster will also present preliminary data collected from information users in the nonprofit and government sectors of New York State. It illustrates the potential for community-focused research published outside of traditional channels

Peacebuilding Through Food Recovery

The United States wastes approximately 133 billion pounds of food annually while 15 million American households are food insecure. Current and proposed U.S. legislation attempts to encourage food recovery efforts to address both of these problems by incentivizing donation of surplus foods by businesses to charitable organizations, yet legislation has failed to deliver. Food insecure individuals who use food banks or other safety net programs are often required to provide personal information and are subject to scrutiny in the process of acquiring food. Information can be leveraged in different ways to stigmatize or marginalize those in need. This presentation discusses the relationships between current legislation, safety net programs, and food insecure individuals to demonstrate that food recovery legislation is not a magic bullet that will address food insecurity or food waste in a system that has a long history of treating poverty as a character flaw

404 Reasons to Use Perma.cc

A 2013 study found that 70% of URLs in law journal articles and 50% of URLs cited by U.S. Supreme Court cases had suffered from reference rot and additional studies have demonstrated that reference rot increases over time. Information published online by government agencies is not immune to this phenomena. One startling example is the removal of climate change information from the Environmental Protection Agency\u27s website. Perma.cc is a service developed by the Harvard Innovation Lab to preserve web-based content cited by scholars and the courts. Unlike archiving techniques that rely on random captures of web content, Perma.cc creates a permanent link at the request of a user, ensuring future scholars can review a source as it appeared at the time of citation. Learn how you can use Perma.cc to preserve citation integrity

Content Analysis: A Research Method You Can Count On (Or Not)

Content analysis is a flexible research method used by library scholars. This poster presentation describes some content analysis basics, differences between methods, such as quantitative vs. qualitative, and some examples of questions answered using this method by LIS researchers

A Review of Grey Literature Cited by Food Loss Law and Policy Scholarship

In the United States, state and federal programs, rules, and legislation attempt to address the social, economic, and environmental impacts of food waste. Research on the efficacy of these interventions rely on a variety of grey literature resources. Grey literature is valuable to policy research but may be overlooked because it is not published commercially and is often deemed unauthoritative. This review focuses on the use of grey literature in food waste law and policy scholarship to identify the most used sources and to determine what, if any, archiving strategies authors use. Recommendations for librarians and researchers are discussed

Leadership, Development, and Expertise: A Qualitative Content Analysis of Scholarly Communication Librarian Position Announcements

In 2012, the Association of Research Libraries reported that 95% of libraries identified their libraries as leaders of scholarly communication efforts on campus. While academic librarians have long been responsible for SC issues, institutions have explicitly tasked positions with these responsibilities increasingly over time. This qualitative analysis of position announcements focuses on the ways libraries expect these librarians to engage with SC issues and responsibilities, rather than describing the prevalence of SC-related functions. Specifically, this study asks the following questions: (1) How do administrators communicate leadership expectations of SC librarian roles through job advertisements? (2) In what ways could these leadership expectations be challenging or problematic for SC librarians in non-administrator positions? The dataset consists of job advertisements posted to ALA JobList and are predominantly from North American academic libraries. Prevalent themes in position announcements include leadership, development, and expertise. These themes are discussed in terms of the SC librarian as a boundary spanning role. Issues associated with identified themes in such boundary roles may manifest in poorly defined authority of non-administrator positions. Suggestions for institutions and potential further research are discussed

Food Waste Legislation Scholarship: A Mapping Study

The purpose of this study is to examine research activity on food waste legislation published in law journals to identify top sources and experts cited by recent scholarship. Searches for food loss and food waste were conducted in three legal research databases for law journal articles published between January 2013 and January 2018. The core list of selected articles consists of 13 law journal articles. The citations from each of the core articles were collected to form a database, which was analyzed to determine what kinds of resources legal scholars rely on when conducting research in food waste legislation. Government Sources and Primary Law contribute approximately 48% of the citations in the database. News, Nonprofit, and Law Reviews and Journals contribute approximately 31% of database citations. This study provides some insight into the complexity of food law and the facets of agriculture, industry, and society that affect the success of food waste reduction legislation