Elise Rio

Listeria monocytogenes is a facultative intracellular pathogen that causes disease in immunocompromised individuals and pregnant women. Its life cycle is well characterized. The pathogen enters phagocytes of the immune system, including macrophages and dendritic cells. As seen from in vitro studies using macrophages, upon entry into phagocytes L. monocytogenes escapes the vacuole and grows in the cytosol thus avoiding phagosome-mediated killing. Mutants of L. monocytogenes in which the Listeriolysin O (LLO) gene has been deleted lack the ability to escape the phagosome into the host cell cytoplasm and are avirulent, suggesting that they die in the phagosome. Furthermore, these mutants are unable to induce adaptive immunity in the host. I hypothesize that L. monocytogenes does have to cope with initial phagosome stress before escape from the phagosome. Our current understanding of the amount of phagosome stress encountered in vivo is not complete, but it appears that L. monocytogenes may be […]

Jonathan Yang

The introduction of fluorinated moieties into pharmaceuticals can often predictably improve the lipophilicity, metabolic stability, and the conformation of drugs. A fluorinated functional group of interest is the (Z)-fluoroalkene, a non-hydrolyzable isostere for peptide bonds. Many methods used to prepare fluoroalkenes, including Wittig-type olefinations, Shapiro reactions, and bromofluorination/elimination reactions often provide olefins in low stereoselectivity. Herein we will present a copper-catalyzed SN2 substitution of fluoroalkylated alkenes to prepare a variety of (Z)-fluoroalkenes in excellent stereoselectivities.

Sylvia Targ

Largely understudied, small-scale fisheries are critical to coastal livelihoods in the global south, yet are poorly represented in conversations about development, food security, human rights, and gender equity. The creation of marine-protected areas and parks along coastal regions with marine biodiversity in mind has displaced the livelihoods of traditional fishers. I will be investigating reactions and adjustments to this displacement along the caribbean coast of Colombia.

Ethan Chung

This summer, I will be looking into the natural phenomenon of wet-induced fingertip wrinkling and the possible dynamic benefits which could come with implementing and mimicking its main properties in a mechanical system. Similar to how tire treads can improve a cars efficiency and safety on the road during heavy precipitation and how shoe treads help prevent slips, the organic wrinkling found in water-saturated human fingertips can possibly provide analogous effects for a persons grip success with wet objects or underwater scenarios. However, this possible connection has barely been addressed by engineers and doctors, as any type of effective wrinkling pattern is absent in current models of hand prostheses and less than five research papers address the influence of fingertip wrinkling on the mechanics of grasping.Through a systematic series of friction and shear force testing, I hope to gather enough data to determine a set of design guidelines for robotic […]

Cindy Chau

The presence of nutrients such as amino acids, glucose, or nitrogen and varying growth factors is hypothesized to activate the target of rapamycin (TOR) which initiates eukaryotic cell growth, development, and metabolism. Although TOR is extremely significant to plant cells growth and metabolism, little is still understood about TOR signaling within plants. As such, my project proposal investigates Asparaginyl tRNA synthetase 1 (NRS1) and its likelihood as an amino acid sensor that can stimulate TOR pathways and its importance for plant development. Comprehending how plants can sense the presence of amino acids and then activate TOR is central to breeding crops that are not as affected by nitrogen deficiencies in soil and can survive, despite lacking nutrients or poor growth factors. With the results of my research project, further research can be done to possibly confirm the importance of NRS1 in the promotion of TOR activity and establish and define […]

Faisal AlZaben

Finding the causal genetic basis of a complex trait is a challenge of biology. Current methods, such as GWAS and QTL analysis, can identify associations between variants and phenotypes, but this is limited to analysis within the species being investigated and not species-wide traits. Through a novel approach named RH-seq (reciprocal hemizygosity analysis via sequencing), causal variants that underlie interspecific differences can be identified, including those that are the basis of adaptive evolutionary changes. I will be investigating the genetic basis of the relative thermotolerance of Saccharomyces cerevisiae (budding yeast) compared to Saccharomyces paradoxus, two related yeast species that are roughly 20 million years diverged. At 39C, S. cerevisiae grows to a significantly higher density than S. paradoxus. Eight candidate genes have been previously identified through RH-seq performed at 39C. When these candidate S. cerevisiae variants are transformed into the pure S. paradoxus background, the transformants exhibit a small, but […]

Andrew Liao

Cell division is a highly regulated process through which organisms generate new cells. From a single fertilized egg, a whole organism is developed after many cell divisions have occurred. Since the majority of these divisions are mitosis, errors in mitosis can cause lethal embryos due to loss of genetic material. Therefore, it is crucial for a mitotic cell to propagate the genome faithfully. My research focuses on the machinery that distributes the genome during cell division. This machinery includes the kinetochore, the protein complex that connects chromosomes to microtubules during cell division. Specifically, I focus on the regulation of a kinetochore subunit called Ndc80. In yeast, the protein turnover of Ndc80 is highly regulated during meiosis, a specialized cell division that produces gametes. However, it is unknown whether the same type of regulation also occurs in the mitotic cell cycle. To investigate this question, I will assess when Ndc80 is […]

Connor Tou

Directed evolution takes advantage of repeated Darwinian cycles of genetic diversification and artificial selection to engineer novel biomolecular and cellular function. In the wet-lab, its success and extent is heavily dictated by the size of the genetic library that can be synthesized and transformed, in combination with labor, cost, and time. Therefore, traditional methods relying on ex-vivo diversification and in-vivo selection are highly limiting. By addressing these problems, methods for targeted, continuous in-vivo mutagenesis are extremely valuable. Recently, our lab group developed one such system termed EvolvR – an HDR-independent, multiplexable, targeted genetic diversifier that localizes error prone DNA polymerases to user-defined loci via CRISPR-guided Cas9-nickases. Prior work was carried out in E. coli; however, EvolvR holds immense promise as a species-independent technology whereby genes of interest can be evolved in a native or more suitable context. Thus, translating EvolvRs utility to yeast holds vast potential in directing the evolution […]

Kirsten Young

Tau is a microtubule-associated protein that ordinarily regulates cytoskeletal stabilization, but is abnormally hyper-phosphorylated and acetylated in neurodegenerative diseases classed as tauopathies. Although little is known about how tau becomes pathological, previous studies showed that the over-activation of the mTOR pathway could be implicated in tau pathogenesis. Multiple essential cellular functions are regulated by the two different mTOR-dependent pathwaysmTORC1 and mTORC2. These are distinguished from one another by pathway- specific proteins Raptor and Rictor, respectively. To understand which mTOR pathway is responsible for tau pathology, I will generate stable cell lines overexpressing Raptor and Rictor to analyze the effect of upregulation of each independent pathway on tau levels. Understanding tau accumulation mechanistically may help in developing treatments that decrease tau levels and ultimately slow, or even block, neurodegeneration.

Noah Epstein

Iron sulfur enzymes perform some of lifes most challenging chemical transformations, but how these enzymes function is largely unknown. I will be researching the structure, reactivity, and reduction/oxidation properties of a particular iron sulfur enzyme, the hybrid cluster protein (HCP), whose physiological function is unknown despite its presence in all domains of life. One goal of my research is to investigate how the structure of HCP dictates its reactivity towards a variety of substrates. A hallmark of HCP is the presence of an atypical iron-sulfur cluster (dubbed the hybrid cluster) whose structure is unique in biology. We hypothesize that this is the site of substrate binding and activation. I will determine the 3D structure of HCP by first crystallizing this protein and then determining precise atomic positions using X-ray Diffraction. I will then repeat this experiment in the presence of substrates (or with a mutated protein) to gain insight into […]