Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 44

Full-Text Articles in Life Sciences

Polymer-Based Microfluidic Device For On-Chip Counter-Diffusive Crystallization And In Situ X-Ray Crystallography At Room Temperature, Sarthak Saha, Can Özden, Alfred Samkutty, Silvia Russi, Aina Cohen, Margaret M. Stratton, Sarah L. Perry Jan 2023

Polymer-Based Microfluidic Device For On-Chip Counter-Diffusive Crystallization And In Situ X-Ray Crystallography At Room Temperature, Sarthak Saha, Can Özden, Alfred Samkutty, Silvia Russi, Aina Cohen, Margaret M. Stratton, Sarah L. Perry

Chemical Engineering Faculty Publication Series

Proteins are long chains of amino acid residues that perform a myriad of functions in living organisms, including enzymatic reactions, signalling, and maintaining structural integrity. Protein function is determined directly by the protein structure. X-ray crystallography is the primary technique for determining the 3D structure of proteins, and facilitates understanding the effects of protein structure on function. The first step towards structure determination is crystallizing the protein of interest. We have developed a centrifugally-actuated microfluidic device that incorporates the fluid handling and metering necessary for protein crystallization. Liquid handling takes advantage of surface forces to control fluid flow and enable …


Plants, Pipettes And Pcr, Elizabeth Vierling Jan 2022

Plants, Pipettes And Pcr, Elizabeth Vierling

Science and Engineering Saturday Seminars

Plants are amazing organisms that provide us with food, building materials, the pleasure of gardens, as well as providing the foundation of critical world ecosystems. Although they may look like they are just stuck in one place and doing not more than growing, they have many, many complex ways in which they respond to the environment. The goal of this STEM Ed session will be to discuss ways that plants can respond to the environment with hands on exercises and exploration of possible classroom activities. Participants will engage in state-of-the art methods of testing plant DNA composition using the polymerase …


Anaerobic Digestion: Awareness, Implementation, And Simulation, Kieran Tay, Nicholas Sbalbi, Michael Forozis, Flo Sabatini Jan 2022

Anaerobic Digestion: Awareness, Implementation, And Simulation, Kieran Tay, Nicholas Sbalbi, Michael Forozis, Flo Sabatini

Student Showcase

Anaerobic digestion (AD) is the process in which organic matter is fermented in an oxygen-deprived environment to produce renewable biogas. Our project is multi-faceted, with the overall goal of raising public awareness of AD as a transitional energy source. To that end, our group has named itself Undergraduates Raising Awareness for Anaerobic Digestion (URAAD). We are approaching this goal on three fronts, including (i) a website, (ii) a physical lab-scale digester, and (iii) a computer simulation of anaerobic digestion.

The first component, the website, was developed with the aim of serving as a resource for the public. It includes educational …


The Lipid Peroxidation Product Ekode Exacerbates Colonic Inflammation And Colon Tumorigenesis, Lei Lei, Jun Yang, Jianan Zhang, Guodong Zhang Jan 2021

The Lipid Peroxidation Product Ekode Exacerbates Colonic Inflammation And Colon Tumorigenesis, Lei Lei, Jun Yang, Jianan Zhang, Guodong Zhang

Food Science Department Faculty Publication Series

Oxidative stress is emerging as an important contributor to the pathogenesis of colorectal cancer (CRC), however, the molecular mechanisms by which the disturbed redox balance regulates CRC development remain undefined. Using a liquid chromatography?tandem mass spectrometry-based lipidomics, we found that epoxyketooctadecenoic acid (EKODE), which is a lipid peroxidation product, was among the most dramatically increased lipid molecules in the colon of azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC mice. This is, at least in part, due to increased oxidative stress in colon tumors, as assessed by analyzing gene expression of oxidative markers in AOM/DSS-induced CRC mice and human CRC patients in …


Evidence For The Role Of Cyp51a And Xenobiotic Detoxification In Differential Sensitivity To Azole Fungicides In Boxwood Blight Pathogens, Stefanos Stravoravdis, Robert E. Marra, Nicholas R. Leblanc, Joanne Crouch, Jonathan P. Hulvey Jan 2021

Evidence For The Role Of Cyp51a And Xenobiotic Detoxification In Differential Sensitivity To Azole Fungicides In Boxwood Blight Pathogens, Stefanos Stravoravdis, Robert E. Marra, Nicholas R. Leblanc, Joanne Crouch, Jonathan P. Hulvey

Microbiology Department Faculty Publication Series

Boxwood blight, a fungal disease of ornamental plants (Buxus spp.), is caused by two sister species, Calonectria pseudonaviculata (Cps) and C. henricotiae (Che). Compared to Cps, Che is documented to display reduced sensitivity to fungicides, including the azole class of antifungals, which block synthesis of a key fungal membrane component, ergosterol. A previous study reported an ergosterol biosynthesis gene in Cps, CYP51A, to be a pseudogene, and RNA-Seq data confirm that a functional CYP51A is expressed only in Che. The lack of additional ergosterol biosynthesis genes showing significant differential expression suggests that the functional CYP51A in Che could contribute to …


How The Protein Data Bank Changed Biology: An Introduction To The Jbc Reviews Thematic Series, Part 1, Helen M. Berman, Lila M. Gierasch Jan 2021

How The Protein Data Bank Changed Biology: An Introduction To The Jbc Reviews Thematic Series, Part 1, Helen M. Berman, Lila M. Gierasch

Biochemistry & Molecular Biology Department Faculty Publication Series

This collection of articles celebrates the 50th anniversary of the Protein Data Bank (PDB), the single global digital archive of biological macromolecular structures. The impact of the PDB is immense; we have invited a number of top researchers in structural biology to illustrate its influence on an array of scientific fields. What emerges is a compelling picture of the synergism between the PDB and the explosive progress witnessed in many scientific areas. Availability of reliable, openly accessible, well-archived structural information has arguably had more impact on cell and molecular biology than even some of the enabling technologies such as PCR. …


The Thermogenic Characteristics Of Adipocytes Are Dependent On The Regulation Of Iron Homeostasis, Jin-Seon Yook, Mikyoung You, Yongeun Kim, Mi Zhou, Zhenhua Liu, Young-Cheul Kim, Jaekwon Lee, Soonkyu Chung Jan 2021

The Thermogenic Characteristics Of Adipocytes Are Dependent On The Regulation Of Iron Homeostasis, Jin-Seon Yook, Mikyoung You, Yongeun Kim, Mi Zhou, Zhenhua Liu, Young-Cheul Kim, Jaekwon Lee, Soonkyu Chung

Nutrition Department Faculty Publication Series

The development of thermogenic adipocytes concurs with mitochondrial biogenesis, an iron-dependent pathway. Iron regulatory proteins (IRP) 1 and 2 are RNA-binding proteins that regulate intracellular iron homeostasis. IRPs bind to the iron-response element (IRE) of their target mRNAs, balancing iron uptake and deposition at the posttranscriptional levels. However, IRP/IRE-dependent iron regulation in adipocytes is largely unknown. We hypothesized that iron demands are higher in brown/beige adipocytes than white adipocytes to maintain the thermogenic mitochondrial capacity. To test this hypothesis, we investigated the IRP/IRE regulatory system in different depots of adipose tissue. Our results revealed that 1) IRP/IRE interaction was increased …


Polymeric Nanoparticles Active Against Dual-Species Bacterial Biofilms, Jessa Marie V. Makabenta, Jungmi Park, Cheng-Hsuan Li, Aritra Nath Chattopadhyay, Ahmed Nabawy, Ryan F. Landis, Akash Gupta, Suzannah Schmidt-Malan, Robin Patel, Vincent M. Rotello Jan 2021

Polymeric Nanoparticles Active Against Dual-Species Bacterial Biofilms, Jessa Marie V. Makabenta, Jungmi Park, Cheng-Hsuan Li, Aritra Nath Chattopadhyay, Ahmed Nabawy, Ryan F. Landis, Akash Gupta, Suzannah Schmidt-Malan, Robin Patel, Vincent M. Rotello

Chemistry Department Faculty Publication Series

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. …


Improving Probabilistic Infectious Disease Forecasting Through Coherence, Graham Casey Gibson, Kelly R. Moran, Nicholas G. Reich, Dave Osthus Jan 2021

Improving Probabilistic Infectious Disease Forecasting Through Coherence, Graham Casey Gibson, Kelly R. Moran, Nicholas G. Reich, Dave Osthus

Biostatistics and Epidemiology Faculty Publications Series

Author summary Seasonal influenza causes a significant public health burden nationwide. Accurate influenza forecasting may help public health officials allocate resources and plan responses to emerging outbreaks. The U.S. Centers for Disease Control and Prevention (CDC) reports influenza data at multiple geographical units, including regionally and nationally, where the national data are by construction a weighted sum of the regional data. In an effort to improve influenza forecast accuracy across all models submitted to the CDC's annual flu forecasting challenge, we examined the effect of imposing this geographical constraint on the set of independent forecasts, made publicly available by the …


Modulating Glutathione Thiol Status Alters Pancreatic Β-Cell Morphogenesis In The Developing Zebrafish (Danio Rerio) Embryo, Archit Rastogi, Emily G. Severance, Haydee M. Jacobs, Sarah M. Conlin, Sadia T. Islam, Alicia R. Timme-Laragy Jan 2021

Modulating Glutathione Thiol Status Alters Pancreatic Β-Cell Morphogenesis In The Developing Zebrafish (Danio Rerio) Embryo, Archit Rastogi, Emily G. Severance, Haydee M. Jacobs, Sarah M. Conlin, Sadia T. Islam, Alicia R. Timme-Laragy

Environmental Health Sciences Faculty Publication Series

Emerging evidence suggests that redox-active chemicals perturb pancreatic islet development. To better understand potential mechanisms for this, we used zebrafish (Danio rerio) embryos to investigate roles of glutathione (GSH; predominant cellular redox buffer) and the transcription factor Nrf2a (Nfe2l2a; zebrafish Nrf2 coortholog) in islet morphogenesis. We delineated critical windows of susceptibility to redox disruption of beta-cell morphogenesis, interrogating embryos at 24, 48 and 72 h post fertilization (hpf) and visualized Nrf2a expression in the pancreas using whole-mount immunohistochemistry at 96 hpf. Chemical GSH modulation at 48 hpf induced significant islet morphology changes at 96 hpf. Pro-oxidant exposures to tert-butylhydroperoxide (77.6 …


Computational Modeling Of The Gut Microbiota Reveals Putative Metabolic Mechanisms Of Recurrent Clostridioides Difficile Infection, Michael A. Henson Jan 2021

Computational Modeling Of The Gut Microbiota Reveals Putative Metabolic Mechanisms Of Recurrent Clostridioides Difficile Infection, Michael A. Henson

Chemical Engineering Faculty Publication Series

Author summary Clostridioides difficile is an opportunistic human pathogen responsible for acute and sometimes chronic infections of the colon. Elderly individuals who are immunocompromised, frequently hospitalized and antibiotic recipients are particular susceptible to C. difficile infection (CDI). Approximately 30% of CDI patients will suffer at least one episode of reinfection, commonly termed recurrence. The objective of the current study was to utilize computational metabolic modeling to investigate the hypothesis that recurrent infections are related to the composition of the gut bacterial community within each patient. Our modeling results suggest that patients who have high abundances of the bacterial family Enterobacteriaceae …


Unraveling The Mechanisms Of Surround Suppression In Early Visual Processing, Yao Li, Lai-Sang Young Jan 2021

Unraveling The Mechanisms Of Surround Suppression In Early Visual Processing, Yao Li, Lai-Sang Young

Mathematics and Statistics Department Faculty Publication Series

This paper uses mathematical modeling to study the mechanisms of surround suppression in the primate visual cortex. We present a large-scale neural circuit alistic modeling work are used. The remaining parameters are chosen to produce model outputs that emulate experimentally observed size-tuning curves. Our two main results are: (i) we discovered the character of the long-range connections in Layer 6 responsible for surround effects in the input layers; and (ii) we showed that a net-inhibitory feedback, i.e., feedback that excites I-cells more than E-cells, from Layer 6 to Layer 4 is conducive to producing surround properties consistent with experimental data. …


Bubble Lab Exercise, Peter Beltramo Jan 2020

Bubble Lab Exercise, Peter Beltramo

Science and Engineering Saturday Seminars

The cell membrane is a ubiquitous component in mammalian cells which control many vital biological functions. It consists of a phospholipid bilayer with embedded protein molecules which serve to transport molecules between the interior and exterior of the cell. Understanding what makes cell membranes so important and how they function requires concepts from physics, chemistry, and of course biology, but it is difficult to learn and conceptualize the structure and function of membranes due to their nanoscopic size and dynamic nature which can’t be properly appreciated in a static textbook. This activity draws analogies between the chemistry and structure of …


The Feronia Receptor Kinase Maintains Cell-Wall Integrity During Salt Stress Through Ca2+ Signaling, Wei Feng, Daniel Kita, Alexis Peaucelle, Heather N. Cartwright, Vinh Doan, Qiaohong Duan, Ming-Che Liu, Jacob Maman, Leonie Steinhorst, Ina Schmitz-Thom, Robert Yvon, Jörg Kudla, Hen-Ming Wu, Alice Y. Cheung, José R. Dinneny Jan 2018

The Feronia Receptor Kinase Maintains Cell-Wall Integrity During Salt Stress Through Ca2+ Signaling, Wei Feng, Daniel Kita, Alexis Peaucelle, Heather N. Cartwright, Vinh Doan, Qiaohong Duan, Ming-Che Liu, Jacob Maman, Leonie Steinhorst, Ina Schmitz-Thom, Robert Yvon, Jörg Kudla, Hen-Ming Wu, Alice Y. Cheung, José R. Dinneny

Biochemistry & Molecular Biology Department Faculty Publication Series

Cells maintain integrity despite changes in their mechanical properties elicited during growth and environmental stress. How cells sense their physical state and compensate for cell-wall damage is poorly understood, particularly in plants. Here we report that FERONIA (FER), a plasma-membrane-localized receptor kinase from Arabidopsis, is necessary for the recovery of root growth after exposure to high salinity, a widespread soil stress. The extracellular domain of FER displays tandem regions of homology with malectin, an animal protein known to bind di-glucose in vitro and important for protein quality control in the endoplasmic reticulum. The presence of malectin-like domains in FER …


Discovering The Secrets Of Biology As Told By A Fruit Fly, Sonia Hall Jan 2017

Discovering The Secrets Of Biology As Told By A Fruit Fly, Sonia Hall

Science and Engineering Saturday Seminars

No abstract provided.


Superhero Robotics, Frank Sup, Brian Umberger, Nick Sawyer Jan 2017

Superhero Robotics, Frank Sup, Brian Umberger, Nick Sawyer

Science and Engineering Saturday Seminars

No abstract provided.


Mechanistic Insights Into The Cholesterol-Dependent Binding Of Perfringolysin O-Based Probes And Cell Membranes, Alejandro Heuck, Juan Anguita, Benjamin B. Johnson, Mariana Brena Jan 2017

Mechanistic Insights Into The Cholesterol-Dependent Binding Of Perfringolysin O-Based Probes And Cell Membranes, Alejandro Heuck, Juan Anguita, Benjamin B. Johnson, Mariana Brena

Biochemistry & Molecular Biology Department Faculty Publication Series

Cholesterol distribution in the cell is maintained by both vesicular and non-vesicular sterol transport. Non-vesicular transport is mediated by the interaction of membrane-embedded cholesterol and water-soluble proteins. Small changes to the lipid composition of the membrane that do not change the total cholesterol content, can significantly affect how cholesterol interacts with other molecules at the surface of the membrane. The cholesterol-dependent cytolysin Perfringolysin O (PFO) constitutes a powerful tool to detect cholesterol in membranes, and the use of PFO-based probes has flourished in recent years. By using a non-lytic PFO derivative, we showed that the sensitivity of the probes for …


Molecular Mechanism Of Activation-Triggered Subunit Exchange In Human Camkii, M Bhattacharyya, Margaret M. Stratton, Catherine Going, Yongjian Huang, Ethan Mcspadden, Anna Elleman, Pawel Burkhwat, Tiago Barros, Evan Williams, John Kuriyan Jan 2016

Molecular Mechanism Of Activation-Triggered Subunit Exchange In Human Camkii, M Bhattacharyya, Margaret M. Stratton, Catherine Going, Yongjian Huang, Ethan Mcspadden, Anna Elleman, Pawel Burkhwat, Tiago Barros, Evan Williams, John Kuriyan

Biochemistry & Molecular Biology Department Faculty Publication Series

Activation triggers the exchange of subunits in Ca2+/calmodulin-dependent protein kinase II (CaMKII), an oligomeric enzyme that is critical for learning, memory, and cardiac function. The mechanism by which subunit exchange occurs remains elusive. We show that the human CaMKII holoenzyme exists in dodecameric and tetradecameric forms, and that the calmodulin (CaM)-binding element of CaMKII can bind to the hub of the holoenzyme and destabilize it to release dimers. The structures of CaMKII from two distantly diverged organisms suggest that the CaM-binding element of activated CaMKII acts as a wedge by docking at intersubunit interfaces in the hub. This converts the …


Human Acid Sphingomyelinase Structures Provide Insight To Molecular Basis Of Niemann-Pick Disease, Yan-Feng Zhou, Matthew C. Metcalf, Scott C. Garman, Tim Edmunds, Huawei Qiu, Ronnie R. Wei Jan 2016

Human Acid Sphingomyelinase Structures Provide Insight To Molecular Basis Of Niemann-Pick Disease, Yan-Feng Zhou, Matthew C. Metcalf, Scott C. Garman, Tim Edmunds, Huawei Qiu, Ronnie R. Wei

Biochemistry & Molecular Biology Department Faculty Publication Series

Acid sphingomyelinase (ASM) hydrolyzes sphingomyelin to ceramide and phosphocholine, essential components of myelin in neurons. Genetic alterations in ASM lead to ASM deficiency (ASMD) and have been linked to Niemann–Pick disease types A and B. Olipudase alfa, a recombinant form of human ASM, is being developed as enzyme replacement therapy to treat the non-neurological manifestations of ASMD. Here we present the human ASM holoenzyme and product bound structures encompassing all of the functional domains. The catalytic domain has a metallophosphatase fold, and two zinc ions and one reaction product phosphocholine are identified in a histidine-rich active site. The structures reveal …


Gelatin Diffusion Experiment, Jennifer Welborn Jan 2015

Gelatin Diffusion Experiment, Jennifer Welborn

Nanotechnology Teacher Summer Institutes

In this activity, nanotech participants will:

- See how food dyes and gelatin are used to model the delivery of nanoscale medicines to cells in the human body - Measure diffusion distances of 3 different colors of food dye by: Eye, photo image on a computer, ADI software (Analyzing Digital Images) Some useful websites:


Effect Of A 10 Day Decrease In Physical Activity On Circulating Angiogenic Cells, Gayatri Guhanarayan Jan 2014

Effect Of A 10 Day Decrease In Physical Activity On Circulating Angiogenic Cells, Gayatri Guhanarayan

Masters Theses 1911 - February 2014

Circulating angiogenic cells (CACs) are early predictors of cardiovascular health and are inversely proportional to related outcomes. Increased number and function of CACs is seen in healthy individuals compared with individuals with cardiovascular disease (CVD). Exercise increases CAC number and function in CVD populations, through a nitric oxide-mediated mechanism. Inactivity is a growing concern in industrialized nations; it is an independent risk factor for CVD and is linked to increased mortality. The purpose of this study was to understand the effect of reduced physical activity (rPA) on two CAC populations (CFU-Hill and CD34+) in highly active individuals. We …


Genetic Modification Of Plants, Alice Cheung, Hen-Ming Wu Jan 2014

Genetic Modification Of Plants, Alice Cheung, Hen-Ming Wu

Science and Engineering Saturday Seminars

No abstract provided.


Activation-Triggered Subunit Exchange Between Camkii Holoenzymes Facilitates The Spread Of Kinase Activity, Margaret M. Stratton, I H. Lee, M Bhattacharyya, S M. Christensen, L H. Chao, H Schulman, J T. Groves, J Kuriyan Jan 2014

Activation-Triggered Subunit Exchange Between Camkii Holoenzymes Facilitates The Spread Of Kinase Activity, Margaret M. Stratton, I H. Lee, M Bhattacharyya, S M. Christensen, L H. Chao, H Schulman, J T. Groves, J Kuriyan

Biochemistry & Molecular Biology Department Faculty Publication Series

The activation of the dodecameric Ca2+/calmodulin dependent kinase II (CaMKII) holoenzyme is critical for memory formation. We now report that CaMKII has a remarkable property, which is that activation of the holoenzyme triggers the exchange of subunits between holoenzymes, including unactivated ones, enabling the calcium-independent phosphorylation of new subunits. We show, using a single-molecule TIRF microscopy technique, that the exchange process is triggered by the activation of CaMKII, and that exchange is modulated by phosphorylation of two residues in the calmodulin-binding segment, Thr 305 and Thr 306. Based on these results, and on the analysis of molecular dynamics simulations, we …


Improvement Of Functional Bioactivity In Pear:Blackberry Synergies With Lactic Acid Fermentation For Type 2 Diabetes And Hypertension Management, Nicholas W. Pucel Jan 2013

Improvement Of Functional Bioactivity In Pear:Blackberry Synergies With Lactic Acid Fermentation For Type 2 Diabetes And Hypertension Management, Nicholas W. Pucel

Masters Theses 1911 - February 2014

Type II diabetes mellitus (T2DM) is a chronic disease that has a worldwide prevalence which is expected to rise dramatically over the course of the next thirty years. The disease has reached pandemic stages of development in many cultures, most notably in developing countries, followed somewhat closely by developed countries with access to an overabundance of refined carbohydrates and fat (refined oils). T2DM is a condition that can be prevented or managed, but not cured; therefore a method of stymieing the development of this disease is paramount to halting its progressively increasing morbidity. In this study, bartlett pear and kiowa …


Pollen Biology, Alice Cheung, Hen-Ming Wu Jan 2013

Pollen Biology, Alice Cheung, Hen-Ming Wu

Science and Engineering Saturday Seminars

No abstract provided.


A Test Of The Hypothesis That Environmental Chemicals Interfere With Thyroid Hormone Action In Human Placenta, Katherine Geromini Jan 2012

A Test Of The Hypothesis That Environmental Chemicals Interfere With Thyroid Hormone Action In Human Placenta, Katherine Geromini

Masters Theses 1911 - February 2014

Thyroid hormone is essential for normal brain development and recognition of this has led to universal screening of newborns for thyroid function to ensure that circulating levels of thyroid hormone are within a range known to be supportive of normal growth and mental development. Environmental chemicals that interfere with thyroid function are known to inhibit normal growth and mental development. Work from our lab and from labs internationally demonstrates in animal systems that some industrial chemicals such as PCBs, PBDEs, and others may interact with the thyroid hormone receptor(s) in ways that are not predicted by changes in serum thyroid …


Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus, Kyle S. Landry Jan 2012

Purification And Characterization Of Novel Nucleases From A Thermophilic Fungus, Kyle S. Landry

Masters Theses 1911 - February 2014

A thermophilic fungus was isolated from composted horse manure. The organism was as a Chaetomium sp. by sequencing the highly conserved ITS region of the fungus and comparing to known regions in a genomic database and was referred to as TM-417. TM-417 was found to have an optimal growth temperature of 45 oC and an optimal pH of 7.0. An extracellular DNase and RNase was found to be produced by the isolate and were purified 145.58-fold and 127.6-fold respectively using a combination of size exclusion chromatography and a novel affinity membrane purification system. The extent of purification was determined …


Proteolytic Regulation Of Ctra, The Master Regulator Of Cell Cycle In Caulobacter Crescentus, Amber M. Cantin Jan 2012

Proteolytic Regulation Of Ctra, The Master Regulator Of Cell Cycle In Caulobacter Crescentus, Amber M. Cantin

Masters Theses 1911 - February 2014

Cell cycle progression in Caulobacter crescentus depends on the master regulator, CtrA. During the transition from swarmer to stalk cell (G1 to S phase), CtrA is degraded by the AAA+ protease ClpXP and levels rise again in the predivisional stage. The focus of this work is to explore how cyclic, regulated degradation is controlled. CtrA is known to bind to the origin of replication, thereby suppressing replication, so we first asked if DNA binding had an effect on CtrA stability. CtrA is readily degraded by ClpXP on its own, but when bound to DNA containing the proper binding sites, degradation …


Investigation Of Differential Vector Competence Of Bartonella Quintana In Human Head And Body Lice, Domenic J. Previte Jan 2012

Investigation Of Differential Vector Competence Of Bartonella Quintana In Human Head And Body Lice, Domenic J. Previte

Masters Theses 1911 - February 2014

Human head and body lice are obligatory hematophagous ectoparasites that belong to a single species Pediculus humanus. Only body lice, however, are vectors of the infections gram-negative bacteria Bartonella quintana. Due to their near identical genomes, yet differential vector competency, head and body lice provide an ideal model system to study an insects ability to gain or lose vector competency. Using our in vitro louse rearing system, we have infected both head and body lice with a blood containing B. quintana in order to detect differences in B. quintana proliferation between head and body lice as well as …


Connecting Motors And Membranes: A Quantitative Investigation Of Dynein Pathway Components And In Vitro Characterization Of The Num1 Coiled Coil Domain, Bryan J. St. Germain Jan 2011

Connecting Motors And Membranes: A Quantitative Investigation Of Dynein Pathway Components And In Vitro Characterization Of The Num1 Coiled Coil Domain, Bryan J. St. Germain

Masters Theses 1911 - February 2014

In the budding yeast, Saccharomyces Cerevisiae, dynein, a minus-end directed motor, is involved in nuclear migration and proper orientation of the mitotic spindle during mitosis. Our lab has developed a model that involves the loading of cytoplasmic dynein onto the plus-end of astral microtubules through interactions with Pac1/LIS1 and Bik1/CLIP-170. Dynein is then delivered to the cell cortex and anchored through a cortical receptor protein, Num1. Num1 is a 313KDa protein that localizes to the cell cortex and is an essential component of dynein mediated nuclear migration.

Using quantitative fluorescence techniques I was able to create a molecular inventory of …