Probing the Secondary Structure of the Monomeric Conformation in the HIV-1 5`-Leader RNA by NMR Spectroscopy

Human Immunodeficiency Virus (HIV), the AIDS pathogen, proliferates within infected human helper T cells, compromising an otherwise healthy and responsive immune system. Viral replication is mediated by the 5`Leader (5`L) element in viral genomic RNA. This 5`-L RNA exists in an equilibrium of two structural conformers – monomer and dimer, by which it directs and mediates viral assembly and replication. Here, we demonstrate an approach to probe for and characterize secondary structure in the 5`-L monomeric conformer by high-field nuclear magnetic resonance (NMR) spectroscopy, a technique used for high-resolution biomolecular structural studies. Signal assignment and validation of characteristic peaks in NMR experiments designed to explore the through-space interactions of base-paired residues provide evidence to support the formation of distinct secondary structures in our proposed model. Our study of the HIV-1 5`-L monomeric conformer structure and the processes that this highly conserved RNA sequence mediates in retroviral replication not only provide further insight into our current understanding of the functional and dynamic nature of three-dimensional RNA structure, but also highlight potential therapeutic value in the monomer as a drug target in clinical medicine.

Using DNA Sequences to Determine the Geographic Origins of Agriculturally Important Invasive Leafmining Flies

The increased global movement of people and goods has resulted in introduction of agricultural pests into new areas. Understanding the patterns and processes of colonization by introduced species is crucial in planning interventions and management strategies. However, determining the origin and colonization patterns of invasive species can be difficult. Molecular markers such as DNA sequence data can help determine the history of movement by an invasive species. Liriomyza huidobrensis is a leafmining fly that feeds within leaf tissue of crops, including potatoes and beans. Although native to South America, it has spread throughout the world and is of great concern. Understanding the origin and pathways of dispersion can determine the means of spread, possibly leading to the development of interception and control programs. We analyzed 2125 base pairs of mitochondrial cytochrome oxidase genes (COI & COII) in a phylogeographic approach to uncover distribution of genetic variation of L. huidobrensis. Our phylogeographic analysis of mitochondrial COI and COII found substantial geographic structure within L. huidobrensis in its native range, but almost none within and between invasive populations around the world.The data suggest that the invasive populations trace to the Peru/Ecuador region. We are collecting additional data to test this hypothesis.

Come check out Kayla Barrett's poster at URCAD!

In 2015, a TEDtalk-style documentary produced in China entitled “Under the Dome” went viral on the internet, alerting the entire world to the problem of air pollution and the lack of environmental safeguards in place in China. In a modern society, the protection of the environment is vital to the health of the people, not to mention the legitimacy of the government. This research addresses the question of how the government has managed environmental policy, the nature and scope of the health crisis facing Chinese society, and the strategies the Chinese people have taken to cope. To assess the impact of pollution on society, I analyzed government policies, popular media and scholarly reports, focused on air pollution in major cities, especially Beijing. The paper concludes that the Chinese state is continuing to put economic expansion above environmental health and leaving the people to defend themselves from the ever-growing problem.

Kayla Barrett
The Social Impact of Air Pollution in China
Mentor: Constantine Vaporis
UC Ballroom | 10:00 a.m. – Noon

• Tuesday March 22nd, 10AM - 6PM
• Wednesday March 23rd, 12PM - 4PM

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