Biochemistry, Biophysics, and Structural Biology Commons^™

Serial Recombineering Cloning To Build Selectable And Tagged Genomic P[Acman] Bac Clones For Selection Transgenesis And Functional Gene Analysis Using Drosophila Melanogaste, Koen J T Venken, Nick Matinyan, Yezabel Gonzalez, Herman A Dierick

Faculty, Staff and Students Publications

Transgenes with genomic DNA fragments that encompass genes of interest are the gold standard for complementing null alleles in rescue experiments in the fruit fly Drosophila melanogaster. Of particular interest are genomic DNA clones available as bacterial artificial chromosomes (BACs) or fosmids from publicly available genomic DNA libraries. Genes contained within BAC and fosmid clones can be easily modified by recombineering cloning to insert peptide or protein tags to localize, visualize, or manipulate gene products, and to create point mutations or deletions for structure-function analysis of the inserted genes. However, since transgenesis efficiency is inversely correlated with transgene size, obtaining …

The Roles Of Cyp1a2 And Cyp2d In Pharmacokinetic Profiles Of Serotonin And Norepinephrine Reuptake Inhibitor Duloxetine And Its Metabolites In Mice, Xuan Qin, Cen Xie, John M Hakenjos, Kevin R Mackenzie, Shelton R Boyd, Mercedes Barzi, Karl-Dimiter Bissig, Damian W Young, Feng Li

Faculty, Staff and Students Publications

Duloxetine (DLX) is widely used to treat major depressive disorder. Little is known about the mechanistic basis for DLX-related adverse effects (e.g., liver injury). Human CYP1A2 and CYP2D6 mainly contributes to DLX metabolism, which was proposed to be involved in its adverse effects. Here, we investigated the roles of Cyp1a2 and Cyp2d on DLX pharmacokinetic profile and tissue distribution using a Cyp1a2 knockout (Cyp1a2-KO) mouse model together with a Cyp2d inhibitor (propranolol). Cyp1a2-KO has the few effects on the systematic exposure (area under the plasma concentration-time curve, AUC) and tissue disposition of DLX and its primary metabolites. Propranolol dramatically increased …

Dynamics Of Gametes And Embryos In The Oviduct: What Can In Vivo Imaging Reveal?, Shang Wang, Irina V Larina

Faculty, Staff and Students Publications

IN BRIEF: In vivo imaging of gametes and embryos in the oviduct enables new studies of the native processes that lead to fertilization and pregnancy. This review article discusses recent advancements in the in vivo imaging methods and insights which contribute to understanding the oviductal function.

ABSTRACT: Understanding the physiological dynamics of gametes and embryos in the fallopian tube (oviduct) has significant implications for managing reproductive disorders and improving assisted reproductive technologies. Recent advancements in imaging of the mouse oviduct in vivo uncovered fascinating dynamics of gametes and embryos in their native states. These new imaging approaches and observations are …

Identifying Biomarkers Of Differential Chemotherapy Response In Tnbc Patient-Derived Xenografts With A Ctd/Wgcna Approach, Varduhi Petrosyan, Lacey E Dobrolecki, Lillian Thistlethwaite, Alaina N Lewis, Christina Sallas, Ramakrishnan R Srinivasan, Jonathan T Lei, Vladimir Kovacevic, Predrag Obradovic, Matthew J Ellis, C Kent Osborne, Mothaffar F Rimawi, Anne Pavlick, Maryam Nemati Shafaee, Heidi Dowst, Antrix Jain, Alexander B Saltzman, Anna Malovannaya, Elisabetta Marangoni, Alana L Welm, Bryan E Welm, Shunqiang Li, Gerburg M Wulf, Olmo Sonzogni, Chen Huang, Suhas Vasaikar, Susan G Hilsenbeck, Bing Zhang, Aleksandar Milosavljevic, Michael T Lewis

Faculty, Staff and Students Publications

Although systemic chemotherapy remains the standard of care for TNBC, even combination chemotherapy is often ineffective. The identification of biomarkers for differential chemotherapy response would allow for the selection of responsive patients, thus maximizing efficacy and minimizing toxicities. Here, we leverage TNBC PDXs to identify biomarkers of response. To demonstrate their ability to function as a preclinical cohort, PDXs were characterized using DNA sequencing, transcriptomics, and proteomics to show consistency with clinical samples. We then developed a network-based approach (CTD/WGCNA) to identify biomarkers of response to carboplatin (MSI1, TMSB15A, ARHGDIB, GGT1, SV2A, SEC14L2, SERPINI1, ADAMTS20, DGKQ) and docetaxel (c, MAGED4, …

Automating The High-Throughput Screening Of Protein-Based Optical Indicators And Actuators, Jihwan Lee, Beatriz Campillo, Shaminta Hamidian, Zhuohe Liu, Matthew Shorey, François St-Pierre

Faculty, Staff and Students Publications

Over the last 25 years, protein engineers have developed an impressive collection of optical tools to interface with biological systems: indicators to eavesdrop on cellular activity and actuators to poke and prod native processes. To reach the performance level required for their downstream applications, protein-based tools are usually sculpted by iterative rounds of mutagenesis. In each round, libraries of variants are made and evaluated, and the most promising hits are then retrieved, sequenced, and further characterized. Early efforts to engineer protein-based optical tools were largely manual, suffering from low throughput, human error, and tedium. Here, we describe approaches to automating …

Mechanism Of Ca2+ Transport By Ferroportin, Jiemin Shen, Azaan Saalim Wilbon, Ming Zhou, Yaping Pan

Faculty, Staff and Students Publications

Ferroportin (Fpn) is a transporter that releases ferrous ion (Fe2+) from cells and is important for homeostasis of iron in circulation. Export of one Fe2+ by Fpn is coupled to import of two H+ to maintain charge balance. Here, we show that human Fpn (HsFpn) binds to and mediates Ca2+ transport. We determine the structure of Ca2+-bound HsFpn and identify a single Ca2+ binding site distinct from the Fe2+ binding sites. Further studies validate the Ca2+ binding site and show that Ca2+ transport is not coupled to transport of another ion. In addition, Ca2+ transport is significantly inhibited in the …

A Bioengineered Probiotic For The Oral Delivery Of A Peptide Kv13 Channel Blocker To Treat Rheumatoid Arthritis, Yuqing Wang, Duolong Zhu, Laura C Ortiz-Velez, Jacob L Perry, Michael W Pennington, Joseph M Hyser, Robert A Britton, Christine Beeton

Faculty, Staff and Students Publications

New therapeutics that combine efficacy with limited side effects and can be delivered noninvasively are needed to adequately treat patients with rheumatoid arthritis (RA) and other autoimmune diseases. Kv1.3 channel-expressing CCR7− effector memory T (TEM) lymphocytes are significant players in the pathogenesis of multiple autoimmune diseases, and blocking Kv1.3 reduces disease severity in rat models of RA and patients with plaque psoriasis. However, peptide therapeutics require repeated injections, reducing patient compliance. We used a bioengineered Lactobacillus reuteri as an oral delivery method of a Kv1.3 blocker for immunomodulation in rat models of atopic dermatitis and RA. This study demonstrates a …

Rbp Image Database: A Resource For The Systematic Characterization Of The Subcellular Distribution Properties Of Human Rna Binding Proteins, Louis Philip Benoit Bouvrette, Xiaofeng Wang, Jonathan Boulais, Jian Kong, Easin Uddin Syed, Steven M Blue, Lijun Zhan, Sara Olson, Rebecca Stanton, Xintao Wei, Brian Yee, Eric L Van Nostrand, Xiang-Dong Fu, Christopher B Burge, Brenton R Graveley, Gene W Yeo, Eric Lécuyer

Faculty, Staff and Students Publications

RNA binding proteins (RBPs) are central regulators of gene expression implicated in all facets of RNA metabolism. As such, they play key roles in cellular physiology and disease etiology. Since different steps of post-transcriptional gene expression tend to occur in specific regions of the cell, including nuclear or cytoplasmic locations, defining the subcellular distribution properties of RBPs is an important step in assessing their potential functions. Here, we present the RBP Image Database, a resource that details the subcellular localization features of 301 RBPs in the human HepG2 and HeLa cell lines, based on the results of systematic immuno-fluorescence studies …

A Low-Fat/Sucrose Diet Rich In Complex Carbohydrates Reverses High-Fat/Sucrose Diet-Induced Corneal Dysregulation, Prince K Akowuah, Carolina Lema, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

High-fat/sucrose diet feeding in mice causes loss of corneal nerve function and impairs corneal wound healing. While changing to a diet with a low fat/sugar composition and enrichments in complex carbohydrates mitigates the reduction in nerve function, it remains to be determined if it has an effect on corneal wound healing. In this study, 6-week-old C57BL/6 male mice were fed either a normal diet or a high-fat/sucrose diet for 20 weeks. A third group (diet reversal) was placed on a high-fat/sucrose diet for 10 weeks followed by a normal diet for an additional 10 weeks. A central corneal epithelial abrasion …

S-Acylation Is A Key Regulator Of Orai1/Stim1-Mediated Store-Operated Calcium Entry In T Cells, Savannah J. West Diaz

Dissertations and Theses (Open Access)

Orai1 and STIM1 proteins are the essential components of the Ca²⁺ release activated Ca²⁺ (CRAC) channel which is required for store-operated Ca²⁺ entry (SOCE) in T cells and subsequent signaling events leading to T cell activation, proliferation, and differentiation. Plasma membrane (PM)-localized Orai1 is the pore-forming subunit of the CRAC channel, and STIM1 is the Ca²⁺ sensor localized to the endoplasmic reticulum (ER) membrane in quiescent T cells. T cell receptor (TCR) stimulation leads to depletion of ER Ca²⁺ stores resulting in Ca²⁺ no longer being bound to STIM1. This activates STIM1 by triggering …

Development Of A Peripheral Blood Transcriptomic Gene Signature To Predict Bronchopulmonary Dysplasia, Alvaro Moreira, Miriam Tovar, Alisha M Smith, Grace C Lee, Justin A Meunier, Zoya Cheema, Axel Moreira, Caitlyn Winter, Shamimunisa B Mustafa, Steven Seidner, Tina Findley, Joe G N Garcia, Bernard Thébaud, Przemko Kwinta, Sunil K Ahuja

Faculty, Staff and Students Publications

Bronchopulmonary dysplasia (BPD) is the most common lung disease of extreme prematurity, yet mechanisms that associate with or identify neonates with increased susceptibility for BPD are largely unknown. Combining artificial intelligence with gene expression data is a novel approach that may assist in better understanding mechanisms underpinning chronic lung disease and in stratifying patients at greater risk for BPD. The objective of this study is to develop an early peripheral blood transcriptomic signature that can predict preterm neonates at risk for developing BPD. Secondary analysis of whole blood microarray data from 97 very low birth weight neonates on day of …

A Novel Interaction Between Extracellular Vimentin And Fibrinogen In Fibrin Formation, Marina Martinez-Vargas, Adrian Cebula, Lisa S Brubaker, Nitin Seshadri, Fong W Lam, Michele Loor, Todd K Rosengart, Andrew Yee, Rolando E Rumbaut, Miguel A Cruz

Faculty, Staff and Students Publications

INTRODUCTION: Thrombosis is frequently manifested in critically ill patients with systemic inflammation, including sepsis and COVID-19. The coagulopathy in systemic inflammation is often associated with increased levels of fibrinogen and D-dimer. Because elevated levels of vimentin have been detected in sepsis, we sought to investigate the relationship between vimentin and the increased fibrin formation potential observed in these patients.

MATERIALS AND METHODS: This hypothesis was examined by using recombinant human vimentin, anti-vimentin antibodies, plasma derived from healthy and critically ill patients, confocal microscopy, co-immunoprecipitation assays, and size exclusion chromatography.

RESULTS: The level of vimentin in plasma derived from critically ill …

A Novel Use Of Bar Code Medication Administration Data To Assess Nurse Staffing And Workload, Melissa K Knox, Paras D Mehta, Lynette E Dorsey, Christine Yang, Laura A Petersen

Faculty, Staff and Students Publications

OBJECTIVE: The aim of the study is to introduce an innovative use of bar code medication administration (BCMA) data, medication pass analysis, that allows for the examination of nurse staffing and workload using data generated during regular nursing workflow.

METHODS: Using 1 year (October 1, 2014-September 30, 2015) of BCMA data for 11 acute care units in one Veterans Affairs Medical Center, we determined the peak time for scheduled medications and included medications scheduled for and administered within 2 hours of that time in analyses. We established for each staff member their daily peak-time medication pass characteristics (number of patients, …

A Rare Case Of Pancreatic Actinomyces, Marguerite Poche, Kyle Liu, Codey Pham, Shilpa Jain, Robert Sealock

Faculty, Staff and Students Publications

Actinomyces israelii is a filamentous, gram-positive anaerobic bacterium commonly found in the upper gastrointestinal tract, colon, and female genital tract. Rarely, actinomycosis can infect the pancreas most commonly after pancreatic instrumentation, often mimicking malignancy. We describe a case of a 26-year-old woman who presented with epigastric abdominal pain and nausea without prior pancreatic instrumentation. Abdominal imaging demonstrated a mass in the pancreatic head with fine-needle biopsy revealing Actinomyces. The patient was successfully treated with long-term antibiotic therapy resulting in resolution of the mass. Our case emphasizes the importance of considering nonmalignant etiologies in the differential diagnosis of pancreatic masses.

Neprilysin Inhibitors In Heart Failure: The Science, Mechanism Of Action, Clinical Studies, And Unanswered Questions, Biykem Bozkurt, Ajith P Nair, Arunima Misra, Claire Z Scott, Jamal H Mahar, Savitri Fedson

Faculty, Staff and Students Publications

This article provides a contemporary review and a new perspective on the role of neprilysin inhibition in heart failure (HF) in the context of recent clinical trials and addresses potential mechanisms and unanswered questions in certain HF patient populations. Neprilysin is an endopeptidase that cleaves a variety of peptides such as natriuretic peptides, bradykinin, adrenomedullin, substance P, angiotensin I and II, and endothelin. It has a broad role in cardiovascular, renal, pulmonary, gastrointestinal, endocrine, and neurologic functions. The combined angiotensin receptor and neprilysin inhibitor (ARNi) has been developed with an intent to increase vasodilatory natriuretic peptides and prevent counterregulatory activation …

Native Bk Polyomavirus Nephropathy In An Orthotopic Heart Transplant Patient, Zachary M Thompson, George Ajene, Prathit A Kulkarni, Nidhi Aggarwal, Savitri Fedson, Maulin K Shah

Faculty, Staff and Students Publications

BK polyomavirus nephropathy (BKVN) is a common cause of nephropathy in kidney transplant patients and is typically seen within the first year after transplantation. BK polyomavirus nephropathy can occur in the native kidneys of patients with nonrenal solid-organ transplants (NRSOT). However, this is rare, especially outside the early post-transplant period, and BKVN is not usually considered in the differential diagnosis for acute kidney injury in NRSOT patients. We present a case of a 75-year-old man who had undergone orthotopic heart transplant 13 years prior with stable allograft function who developed progressive renal dysfunction in the setting of recent unilateral obstructive …

Impact Of Gastrointestinal Polymerase Chain Reaction Panels On Antibiotic Utilization In Hospitalized Adult Patients, Gillean A Kelly, Roumen Iordanov, Alex Franklin, Amna Ahmed, Krithika Srinivasan, Jesica Hayon, Todd Lasco, Rosie Amini, Sabra Shay, Prathit A Kulkarni, Mayar Al Mohajer

Faculty, Staff and Students Publications

Multiplex stool polymerase chain reaction (PCR) panels offer rapid comprehensive testing for patients with infectious diarrhea. We compared antibiotic utilization among hospitalized patients with suspected infectious diarrhea who underwent diagnostic testing with either a stool culture or stool PCR panel. No significant differences in antibiotic utilization were identified.

Treatment Of Severe Covid-19 Infection With Remdesivir In Peritoneal Dialysis, Ryan Geffin, Shazia Raheem, Lavannya M Pandit, Andrew S Hunter, Michael W Holliday, Aditya V Rao, Maulin K Shah

Faculty, Staff and Students Publications

End-stage kidney disease (ESKD) has been shown to be correlated with an increased risk of COVID-19 infection and mortality. Remdesivir is an effective non-EUA U.S. Food and Drug Administration (FDA)-approved antiviral agent for the treatment of COVID-19 in hospitalized adult and pediatric patients, though a lack of data has prevented its use in patients with severe kidney disease including dialysis patients. Some observational studies report the use of remdesivir in hemodialysis patients, but there are no reports of patients treated with remdesivir on peritoneal dialysis. Dialysis modalities may affect drug pharmacokinetics, and safety and efficiency of remdesivir in peritoneal dialysis …

Second Virtual International Symposium On Cellular And Organismal Stress Responses, September 8-9, 2022, Patricija Van Oosten-Hawle, Sarah J Backe, Anat Ben-Zvi, Dimitra Bourboulia, Mara Brancaccio, Jeff Brodsky, Melody Clark, Giorgio Colombo, Marc B Cox, Paolo De Los Rios, Frank Echtenkamp, Adrienne Edkins, Brian Freeman, Pierre Goloubinoff, Walid Houry, Jill Johnson, Paul Lapointe, Wei Li, Valerie Mezger, Len Neckers, Nadinath B Nillegoda, Veena Prahlad, Adam Reitzel, Ruth Scherz-Shouval, Lea Sistonen, Francis T F Tsai, Mark R Woodford, Mehdi Mollapour, Andrew W Truman

Faculty, Staff and Students Publications

The Second International Symposium on Cellular and Organismal Stress Responses took place virtually on September 8-9, 2022. This meeting was supported by the Cell Stress Society International (CSSI) and organized by Patricija Van Oosten-Hawle and Andrew Truman (University of North Carolina at Charlotte, USA) and Mehdi Mollapour (SUNY Upstate Medical University, USA). The goal of this symposium was to continue the theme from the initial meeting in 2020 by providing a platform for established researchers, new investigators, postdoctoral fellows, and students to present and exchange ideas on various topics on cellular stress and chaperones. We will summarize the highlights of …

Targeting Hiv-1 Reservoirs In T Cell Subsets, Min Li, Marietta M Budai, Min Chen, Jin Wang

Faculty, Staff and Students Publications

The HIV-1 reservoirs harbor the latent proviruses that are integrated into the host genome. It is a challenging task to eradicate the proviruses in order to achieve an HIV cure. We have described a strategy for the clearance of HIV-1 infection through selective elimination of host cells harboring replication-competent HIV (SECH), by inhibition of autophagy and promotion of apoptosis during viral re-activation. HIV-1 can infect various CD4+ T cell subsets, but it is not known whether the SECH approach is equally effective in targeting HIV-1 reservoirs in these different subsets in vivo. In a humanized mouse model, we found …

Mortality Difference From Klebsiella Aerogenes Vs Enterobacter Cloacae Bloodstream Infections, Andrew Chou, Richard Sucgang, Richard J Hamill, Lynn Zechiedrich, Barbara W Trautner

Faculty, Staff and Students Publications

Members of the order Enterobacterales, including Escherichia coli , Klebsiella species and Enterobacter species, are important pathogens in healthcare-associated infections. Higher mortality has been reported from infections due to Klebsiella pneumoniae than from E. coli , but prior studies comparing Enterobacter aerogenes (recently renamed Klebsiella aerogenes ) bacteraemia and Enterobacter cloacae complex bacteraemia have yielded conflicting results regarding whether clinical outcomes differ. We found bacteraemia with K. aerogenes was independently associated with greater risk of 30-day mortality than bacteraemia with Enterobacter cloacae complex.

Oral Gauze For Bleeding Control In Perioral And Perinasal Dermatologic Surgery, Riyad N H Seervai, Jose A Cervantes, Ikue Shimizu, Ida F Orengo

Faculty, Staff and Students Publications

The use of oral gauze is a quick, cheap, and effective method of preventing bleeding into the patient's mouth during dermatologic surgery. We recommend this technique combined with appropriate positioning for lesions in the perioral and perinasal regions. Similar approaches may be applied for the prevention of bleeding into the ear canal during facial/periauricular surgery.

Adeno-Associated Virus 8 Delivers An Immunomodulatory Peptide To Mouse Liver More Efficiently Than To Rat Liver, Yuqing Wang, Ayrea Hurley, Marco De Giorgi, Mark R Tanner, Rong-Chi Hu, Michael W Pennington, William R Lagor, Christine Beeton

Faculty, Staff and Students Publications

Targeting the Kv1.3 potassium channel has proven effective in reducing obesity and the severity of animal models of autoimmune disease. Stichodactyla toxin (ShK), isolated from the sea anemone Stichodactyla helianthus, is a potent blocker of Kv1.3. Several of its analogs are some of the most potent and selective blockers of this channel. However, like most biologics, ShK and its analogs require injections for their delivery, and repeated injections reduce patient compliance during the treatment of chronic diseases. We hypothesized that inducing the expression of an ShK analog by hepatocytes would remove the requirement for frequent injections and lead to a …

Combating Hypertension Beyond Genome-Wide Association Studies: Microbiome And Artificial Intelligence As Opportunities For Precision Medicine, Sachin Aryal, Ishan Manandhar, Xue Mei, Beng S Yeoh, Ramakumar Tummala, Piu Saha, Islam Osman, Jasenka Zubcevic, David J Durgan, Matam Vijay-Kumar, Bina Joe

Faculty, Staff and Students Publications

The single largest contributor to human mortality is cardiovascular disease, the top risk factor for which is hypertension (HTN). The last two decades have placed much emphasis on the identification of genetic factors contributing to HTN. As a result, over 1,500 genetic alleles have been associated with human HTN. Mapping studies using genetic models of HTN have yielded hundreds of blood pressure (BP) loci but their individual effects on BP are minor, which limits opportunities to target them in the clinic. The value of collecting genome-wide association data is evident in ongoing research, which is beginning to utilize these data …

Optical Coherence Tomography For Dynamic Investigation Of Mammalian Reproductive Processes, Kohei Umezu, Irina V Larina

Faculty, Staff and Students Publications

The biological events associated with mammalian reproductive processes are highly dynamic and tightly regulated by molecular, genetic, and biomechanical factors. Implementation of live imaging in reproductive research is vital for the advancement of our understanding of normal reproductive physiology and for improving the management of reproductive disorders. Optical coherence tomography (OCT) is emerging as a promising tool for dynamic volumetric imaging of various reproductive processes in mice and other animal models. In this review, we summarize recent studies employing OCT-based approaches toward the investigation of reproductive processes in both, males and females. We describe how OCT can be applied to …

Open-Source, Highly Efficient, Post-Acquisition Synchronization For 4d Dual-Contrast Imaging Of The Mouse Embryonic Heart Over Development With Optical Coherence Tomography, Andre C Faubert, Irina V Larina, Shang Wang

Faculty, Staff and Students Publications

Dynamic imaging of the beating embryonic heart in 3D is critical for understanding cardiac development and defects. Optical coherence tomography (OCT) plays an important role in embryonic heart imaging with its unique imaging scale and label-free contrasts. In particular, 4D (3D + time) OCT imaging enabled biomechanical analysis of the developing heart in various animal models. While ultrafast OCT systems allow for direct volumetric imaging of the beating heart, the imaging speed remains limited, leading to an image quality inferior to that produced by post-acquisition synchronization. As OCT systems become increasingly available to a wide range of biomedical researchers, a …

Engineered Cd4 T Cells Expressing A Membrane Anchored Viral Inhibitor Restrict Hiv-1 Through Cis And Trans Mechanisms, Weiming Wang, Khanghy Truong, Chaobaihui Ye, Suman Sharma, Huan He, Lihong Liu, Michael Wen, Anisha Misra, Paul Zhou, Jason T Kimata

Faculty, Staff and Students Publications

HIV-1 infection of target cells can occur through either cell-free virions or cell-cell transmission in a virological synapse, with the latter mechanism of infection reported to be 100- to 1,000-fold more efficient. Neutralizing antibodies and entry inhibitors effectively block cell-free HIV-1, but with few exceptions, they display much less inhibitory activity against cell-mediated HIV-1 transmission. Previously, we showed that engineering HIV-1 target cells by genetically linking single-chain variable fragments (scFvs) of antibodies to glycosyl phosphatidylinositol (GPI) potently blocks infection by cell-free virions and cell-mediated infection by immature dendritic cell (iDC)-captured HIV-1. Expression of scFvs on CD4

Structural Basis Of Ferroportin Inhibition By Minihepcidin Pr73, Azaan Saalim Wilbon, Jiemin Shen, Piotr Ruchala, Ming Zhou, Yaping Pan

Faculty, Staff and Students Publications

Ferroportin (Fpn) is the only known iron exporter in humans and is essential for maintaining iron homeostasis. Fpn activity is suppressed by hepcidin, an endogenous peptide hormone, which inhibits iron export and promotes endocytosis of Fpn. Hepcidin deficiency leads to hemochromatosis and iron-loading anemia. Previous studies have shown that small peptides that mimic the first few residues of hepcidin, i.e., minihepcidins, are more potent than hepcidin. However, the mechanism of enhanced inhibition by minihepcidins remains unclear. Here, we report the structure of human ferroportin in complex with a minihepcidin, PR73 that mimics the first 9 residues of hepcidin, at 2.7 …

How Do Necrotic Cells Expose Phosphatidylserine To Attract Their Predators-What’S Unique And What’S In Common With Apoptotic Cells, Yoshitaka Furuta, Zheng Zhou

Faculty, Staff and Students Publications

Phosphatidylserine (PS) is a lipid component of the plasma membrane. It is asymmetrically distributed to the inner leaflet in live cells. In cells undergoing apoptosis, phosphatidylserine is exposed to the outer surfaces. The exposed phosphatidylserine acts as an evolutionarily conserved “eat-me” signal that attracts neighboring engulfing cells in metazoan organisms, including the nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and mammals. During apoptosis, the exposure of phosphatidylserine to the outer surface of a cell is driven by the membrane scramblases and flippases, the activities of which are regulated by caspases. Cells undergoing necrosis, a kind of cell …

Quantitative Measurement Of Protac Intracellular Accumulation, Xin Yu, Jin Wang

Faculty, Staff and Students Publications

In recent years, Proteolysis Targeting Chimera (PROTAC) technology has emerged as one of the most promising approaches to remove disease-associated proteins by utilizing cells' own destruction machinery. To achieve successful degradation of a protein of interest (POI), the heterobifunctional PROTAC molecules must penetrate into the cells first, followed by target engagement and formation of the POI-PROTAC-E3 ligase complex. Based on this understanding, the assessment of cell permeability and in cell target engagement are of great importance to evaluate the efficacy of PROTAC candidates. PROTAC molecules can be classified as non-covalent and covalent, and covalent PROTACs can be further divided into …