Cell Biology Commons^™

Homocysteine Thiolactone From Translation Proofreading Is An Endogenous Ligand For Cell-Cell Signaling By The Receptor Sdia, Lorenzo Eugenio Leiva, Roberto A. Zúñiga, Gregory J. Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Several widespread mechanisms enable cellular communication and coordinate the behavior of bacterial populations. The modules responsible for cellular communication are often found in matching pairs: an enzyme that synthesizes a signal molecule and a specific receptor that decodes it. A notable exception is Escherichia coli SdiA, a homolog of known N-acyl-homoserine lactone (AHL) receptors, for which no corresponding AHL synthase exists. SdiA is an orphan receptor that enables cross-talk by sensing AHLs from other bacterial species. In this work, we investigated whether homocysteine thiolactone (HTL), an AHL-like molecule arising from a proofreading reaction of methionyl tRNA synthetase (MetRS) to correct …

Antioxidant Potential Of A Non-Heme Iron Complex: Mitigating H2O2-Induced Cellular Damage, Magy A. Mekhail, David M. Freire, Cameron Bowers, Grant Elam, Nora Del Bosque, Hannah K. Pyle, Sarah K. Dunn, Spencer Lanyon, Timothy J. Hubin, Giridhar Akkaraju, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Iron complexes with antioxidant activity have garnered significant interest for both general and medical applications, yet few studies have yielded functional nonheme iron-based mimics for H₂O₂ mitigation in aqueous environments. Here, we investigate water-soluble nonheme iron complexes derived from 12-membered pyridinophanes (^CF₃PyN₃, PyN₃, ^NMe₂PyN₃, and Py₂N₂) to evaluate the impact of ligand scaffolds on H₂O₂ decomposition activity both in vitro and in a cellular model. Speciation and kinetic analyses reveal that both electronic and geometric modulation of the macrocyclic …

Structural Transformation Of A Hydrogel-Forming Cell Division Protein Zapb Of Multidrug Resistant Klebsiella Pneumoniae With Small Molecules, Ayesha Khan, M. Iqbal Choudhary, Sumaira Javaid, Humaira Zafar, Innokentiy Maslennikov, Atia-Tul Wahab

Pharmacy Faculty Articles and Research

Septal ring assembly protein ZapB (EMR18431.1) is involved in Z-ring formation, and nucleoid segregation during the bacterial cell division . It promotes cell division in the initial stages of the cell cycle through direct interaction with FtsZ, thus stimulating Z-ring assembly. The ZapB inhibition can make bacterial cell susceptible to primary antibiotics, and therefore considered as an important approach for adjuvent therapy against MDR bacterial infections. Hence in the current study, ZapB protein of multidrug resistant Klebsiella pneumoniae was cloned, and expressed in E. coli system. To understand its role, and to assess the mechanism of ZapB activation, the characteristic …

Reverse Micelles Produce Hydroxyapatite Nanoparticles As More Efficient Gene Delivery Carriers Than Regular Micelles, Vuk Uskoković

Administration and Staff Articles and Research

Hydroxyapatite (HAp) is an effective inorganic gene delivery carrier due to its ability to transport genetic cargo across cell membranes, protect it from proteolysis, and enable escape from late endosomes via pH-controlled dissolution. However, its transfection efficiency remains lower than that of viral agents, prompting studies of hybrids with cationic molecules or phases to enhance the gene delivery performance. This study reports on the synthesis of HAp in regular and reverse micellar regions of a ternary microemulsion system composed of cetyltrimethylammonium bromide (CTAB), 1-hexanol and water. Spectroscopic characterization revealed that CTAB headgroups adopted more ordered supramolecular conformations in reverse micelles …

A Molecular Mechanism Of Epithelial To Mesenchymal Transition (Emt): An Evidence Based Lesson Applying Molecular Biology Through The Lens Of Cancer, Sophie Hasson, Melissa Rowland-Goldsmith

Open Educational Resources

This lesson aims to strengthen students’ critical thinking and molecular biology data analysis skills as well as their understanding of concepts related to the hallmark of cancer: tissue invasion and metastasis. Students begin by learning about the invasion of cancer cells, Epithelial-Mesenchymal Transition (EMT), and an important protein involved in EMT: E-cadherin. They then apply molecular biology knowledge to analyze data from multiple papers to infer the relationship between Snail and E-cadherin in different types of cancers. Next, they continue to interpret data from many papers to determine that a repressor transcription factor is present during EMT in cancer cells …

Editorial: Molecular Mechanisms Of Ion Channel Activation And Modulation, Meng Cui, Miao Zhang

Pharmacy Faculty Articles and Research

"Ion channels are integral membrane proteins that regulate the passage of ions across cell membranes, thereby shaping processes as diverse as neuronal signaling, muscle contraction, and hormone secretion. Channel activation is typically initiated by a stimulus such as voltage, ligand binding, or mechanical stress that induces conformational changes and opens the channel pore. Beyond activation, channels are subject to fine-tuned modulation by a wide range of endogenous and exogenous agents, from lipids and neurotransmitters to pharmacological drugs. Modulators can stabilize the open, closed, or inactivated states, shift ligand affinities, or alter gating kinetics. Dissecting the structural and dynamic basis of …

Cilia In The Brain Display Region-Dependent Oscillations Of Length And Orientation, Roudabeh Vakil Monfared, Sherif Abdelkarim, Pieter Derdeyn, Kiki Chen, Hanting Wu, Kenneth Leong, Tiffany Chang, Justine Lee, Sara Versales, Surya M. Nauli, Kevin Beier, Pierre Baldi, Amal Alachkar

Pharmacy Faculty Articles and Research

In this study, we conducted high-throughput spatiotemporal analysis of primary cilia length and orientation across 22 mouse brain regions. We developed automated image analysis algorithms, which enabled us to examine over 10 million individual cilia, generating the largest spatiotemporal atlas of cilia. We found that cilia length and orientation display substantial variations across different brain regions and exhibit fluctuations over a 24-h period, with region-specific peaks during light-dark phases. Our analysis revealed unique orientation patterns of cilia, suggesting that cilia orientation within the brain is not random but follows specific patterns. Using BioCycle, we identified rhythmic fluctuations in cilia length …

Modulation Of Redox-Sensitive Cardiac Ion Channels, Rawan S. Orfali, Al Hassan Gamal El-Din, Varnika Karthik, Elisanjer Lamis, Vanna Xiao, Alena Ramanishka, Abdullah Alwatban, Osama Alkhamees, Ali Alaseem, Young-Woo Nam, Miao Zhang

Pharmacy Faculty Articles and Research

Redox regulation is crucial for the cardiac action potential, coordinating the sodium-driven depolarization, calcium-mediated plateau formation, and potassium-dependent repolarization processes required for proper heart function. Under physiological conditions, low-level reactive oxygen species (ROS), generated by mitochondria and membrane oxidases, adjust ion channel function and support excitation–contraction coupling. However, when ROS accumulate, they modify a variety of important channel proteins in cardiomyocytes, which commonly results in reducing potassium currents, enhancing sodium and calcium influx, and enhancing intracellular calcium release. These redox-driven alterations disrupt the cardiac rhythm, promote after-depolarizations, impair contractile force, and accelerate the development of heart diseases. Experimental models demonstrate …

Abstract 2853 Prmt7 Negatively Regulates The Expression P53 In Response To Dna Damage, Molly Niswender, Lorenzo Pessi, Cecilia Lopez, Marco Bisoffi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Protein Arginine Methyltransferase 7 (PRMT7) is the only member of the protein arginine methyltransferase protein family that monomethylates its protein substrates. PRMT7 is found in both the nucleus and cytoplasm of breast cells and is believed to play a robust role in the tumorigenesis and metastasis of breast cancer. The goal of this project is to uncover possible pathways for PRMT7 to promote cancer progression. A preliminary antibody array was performed to determine the regulation of known cancer-related proteins by PRMT7. An early-stage human breast cancer cell line, MCF-7, was transfected with plasmid pCDH1-hPRMT7-GFP to over-express PRMT7. Qualitative and quantitative …

Ensemble-Based Binding Free Energy Profiling And Network Analysis Of The Kras Interactions With Darpin Proteins Targeting Distinct Binding Sites: Revealing Molecular Determinants And Universal Architecture Of Regulatory Hotspots And Allosteric Binding, Mohammed Alshahrani, Vedant Parikh, Brandon Foley, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

KRAS is a pivotal oncoprotein that regulates cell proliferation and survival through interactions with downstream effectors such as RAF1. Despite significant advances in understanding KRAS biology, the structural and dynamic mechanisms of KRAS allostery remain poorly understood. In this study, we employ microsecond molecular dynamics simulations, mutational scanning, and binding free energy calculations together with dynamic network modeling to dissect how engineered DARPin proteins K27, K55, K13, and K19 engage KRAS through diverse molecular mechanisms ranging from effector mimicry to conformational restriction and allosteric modulation. Mutational scanning across all four DARPin systems identifies a core set of evolutionarily constrained residues …

Application Of Bioactive Materials Primary Cilia As A Novel Delivery Vehicle, Ayan K. Barui, Farideh Amirrad, Vansh Goel, Sharareh Ohadi, Rajasekharreddy Pala, Ashraf M. Mohieldin, Andromeda M. Nauli, Surya M. Nauli

Pharmacy Faculty Articles and Research

Primary cilia are hair-like structured cell organelles functioning as cellular antennae with chemosensory and mechanosensory roles. Dysfunction of cilia results in ciliopathies, including renovascular diseases (polycystic kidneys, hypertension, aneurysm), mental impedances (Alzheimer's disease, Parkinson's disease, dementia), metabolic diseases (obesity, developmental skeleton defects), blindness, and so on. With a diameter of 150 nm, cilia can be cleaved, released and circulated in the body as injury biomarkers. We here assessed the potential use of isolated cilia as a novel delivery vehicle. Cilia were isolated from renal epithelial cells, and a specific-targeting chemotherapeutic was designed on the cilia. The data show a remarkable …

Diverse Roles Of Stress-Responsive Rnp Granules In Oogenesis And Infertility, M. Rebecca Glineburg, Carolee Nguyen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Effectively responding to cellular stress (e.g., nutrient deprivation, oxidative stress) is essential for cell and organismal survival. A protective mechanism is especially critical in developing oocytes, where a prolonged quiescent state and the inability to divide render oocytes highly susceptible to accumulating stress that can result in cell death if unaddressed. Despite the common view that stress granules are the primary stress-responsive ribonucleoprotein granule, accumulating evidence shows that in ovaries, other ribonucleoprotein granules also uniquely mediate gene regulation in response to stress. Here, we review recent insights into ribonucleoprotein granule dynamics and ribonucleoprotein granule protein function during stress in the …

Tdp43 Autoregulation Gives Rise To Dominant Negative Isoforms That Are Tightly Controlled By Transcriptional And Post-Translational Mechanisms, Megan M. Dykstra, Kaitlin Weskamp, Nicolás B. Gómez, Jacob Waksmacki, Elizabeth Tank, M. Rebecca Glineburg, Allison Snyder, Emile Pinarbasi, Michael Bekier, Xingli Li, Morgan R. Miller, Jen Bai, Shameena Shahzad, Neha Nedumaran, Clare Wieland, Corey Stewart, Sydney Willey, Nikolas Grotewold, Jonathon Mcbride, John J. Moran, Aditya V. Suryakumar, Michael Lucas, Peter M. Tessier, Michael Ward, Peter K. Todd, Sami J. Barmada

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation. Here, we show that sTDP43 is created as a by-product of TDP43 autoregulation and cleared by nonsense-mediated RNA decay (NMD). sTDP43-encoding transcripts that escape NMD are rapidly degraded post-translationally via the proteasome …

Exosomes And Encapsulated Exomirs In Breast Cancer: Theragnostic Applications And Clinical Implications, Muhammad Imran Sajid, Shafia Bukhari, Hamid Ilyas, Rubina Malik, Minahil Fatima, Rakesh Kumar Tiwari, Surya M. Nauli, Khawaja Husnain Haider

Pharmacy Faculty Books and Book Chapters

Exosomes, released by cells, are small vesicles that have emerged as critical theranostic tools in breast cancer due to their unique ability to transport diverse biomolecules such as proteins, lipids, and RNAs, including microRNAs (ExomiRs). These vesicles are critical in modulating the tumor microenvironment, driving processes like cancer proliferation, invasion, metastasis, and drug resistance. Exosomal microRNAs such as ExomiR-21, ExomiR-1246, and ExomiR-155, with their profound influence on the gene expressions in the recipient cells, are the unsung heroes in tumor progression and immune modulation. This chapter delves into exosome's dual diagnostic and therapeutic potential in breast cancer. It highlights their …

Enhanced Glucose Production In Norepinephrine And Palmitate Stimulated Hepatocytes Following Endurance Training, Ken D. Sumida, Vera M. Lordan, Casey M. Donovan

Health Sciences and Kinesiology Faculty Articles

Enhanced hepatic gluconeogenesis plays an important role in exercise glucose homeostasis when hepatic glycogen stores are depleted. Livers from trained animals demonstrate greater rates of gluconeogenesis in the presence of elevated substrate with and without hormonal stimulation. Training has been reported to have a particularly profound impact on norepinephrine-stimulated gluconeogenesis, but this was only demonstrated in the presence of other gluconeogenic hormones. Here we reexamine the impact of endurance training on norepinephrine-stimulated gluconeogenesis in the absence of any other hormones. Isolated hepatocytes from trained and untrained rats were incubated in 6 mM lactate with various concentrations of norepinephrine (0 nM–20 …

Early Host Defense Against Virus Infections, Søren R. Paludan, Thomas Pradeu, Andreas Pichlmair, K. Brad Wray, Jacob Giehm Mikkelsen, David Olagnier, Trine H. Mogensen

Presidential Fellows Articles and Research

Early host defense eliminates many viruses before infections are established while clearing others so they remain subclinical or cause only mild disease. The field of immunology has been shaped by broad concepts, including the pattern recognition theory that currently dominates innate immunology. Focusing on early host responses to virus infections, we analyze the literature to build a working hypothesis for the principles that govern the early line of cellular antiviral defense. Aiming to ultimately arrive at a criteria-based theory with strong explanatory power, we propose that both controlling infection and limiting inflammation are key drivers for the early cellular antiviral …

A Conjugate Of An Egfr-Binding Peptide And Doxorubicin Shows Selective Toxicity To Triple-Negative Breast Cancer Cells, Phi-Phung Than, Shih-Jing Yao, Emad Althagafi, Kamaljit Kaur

Pharmacy Faculty Articles and Research

Selective targeting of cancer cells via overexpressed cell-surface receptors is a promising strategy to enhance chemotherapy efficacy and minimize off-target side effects. In this study, we designed peptide 31 (YHWYGYTPERVI) to target the overexpressed epidermal growth factor receptor (EGFR) in triple-negative breast cancer (TNBC) cells. Peptide 31 is internalized by TNBC cells through EGFR-mediated endocytosis and shares sequence and structural similarities with human EGF (hEGF), a natural EGFR ligand. Unlike hEGF, peptide 31 does not induce cell migration in TNBC cells. A novel conjugate of peptide 31 with doxorubicin (Dox) retains selectivity for TNBC cells and exhibits significant toxicity comparable …

Identifying The Roles Of Mir-17 In Ciliogenesis And Cell Cycle, Ashwaq Alanazi, Ayan K. Barui, Ashraf M. Mohieldin, Ankan Gupta, Ramani Ramachandran, Surya M. Nauli

Pharmacy Faculty Articles and Research

Emerging evidence suggests a significant contribution of primary cilia to cell division and proliferation. MicroRNAs, especially miR-17, contribute to cell cycle regulation and proliferation. Recent investigations have highlighted the dysregulated expression of miR-17 in various malignancies, underlining its potential role in cancer. However, the correlation between primary cilia and miR-17 has yet to be fully elucidated. The present study examines the presence of miR-17 in primary cilia. The miR-17 expression is studied in selected ciliary protein knockdown cells. Using in situ hybridization (ISH), we identified the subcellular localization of miR-17 in both cilium and cell body. We confirmed the importance …

Design, Synthesis, And Evaluation Of Oleyl-Wrh Peptides For Sirna Delivery, Mrigank Shekhar Rai, Muhammad Imran Sajid, Jonathan Moreno, Keykavous Parang, Rakesh Kumar Tiwari

Pharmacy Faculty Articles and Research

Delivering nucleic acid therapeutics across cell membranes is a significant challenge. Cell-penetrating peptides (CPPs) containing arginine (R), tryptophan (W), and histidine (H) show promise for siRNA delivery. To improve siRNA delivery and silence a model STAT3 gene, we hypothesized that oleyl acylation to CPPs, specifically (WRH)n, would enhance STAT3 silencing efficiency in breast and ovarian cancer cells. Using Fmoc/tBu solid-phase peptide chemistry, we synthesized, purified, and characterized the oleyl-conjugated (WRH)n (n = 1–4) peptides. The peptide/siRNA complexes were non-cytotoxic at N/P 40 (~20 μM) against MDA-MB-231, MCF-7, SK-OV-3, and HEK-293 cells after 72 h incubation. All peptide/siRNA complexes showed serum …

Diesel Exhaust Particles Alter Mitochondrial Bioenergetics And Camp Producing Capacity In Human Bronchial Epithelial Cells, Isabella Cattani-Cavalieri, Marina Trombetta-Lima, Hong Yan, Ana L. Manzano-Covarrubias, Hoeke A. Baarsma, Asmaa Oun, Melissa Mol Van Der Veen, Emily Oosterhout, Amalia M. Dolga, Rennolds S. Ostrom, Samuel Santos Valenca, Martina Schmidt

Pharmacy Faculty Articles and Research

Introduction: Air pollution from diesel combustion is linked in part to the generation of diesel exhaust particles (DEP). DEP exposure induces various processes, including inflammation and oxidative stress, which ultimately contribute to a decline in lung function. Cyclic AMP (cAMP) signaling is critical for lung homeostasis. The impact of DEP on cAMP signaling is largely unknown.

Methods: We exposed human bronchial epithelial (BEAS-2B) cells to DEP for 24–72 h and evaluated mitochondrial bioenergetics, markers of oxidative stress and inflammation and the components of cAMP signaling. Mitochondrial bioenergetics was measured at 72 h to capture the potential and accumulative effects of …

Identifying The Roles Of Mir-17 In Ciliogenesis And Cell Cycle, Ashwaq Alanazi

Pharmaceutical Sciences (PhD) Dissertations

Emerging evidence suggests a significant contribution of primary cilia to cell division and proliferation mechanisms. MicroRNAs, especially miR-17, contribute to cell cycle regulation and proliferation. Recent investigations have highlighted the dysregulated expression of miR-17 in various malignancies, underlining its potential role in cancer. However, the correlation between primary cilia and miR-17 has yet to be fully elucidated. The present study examines the presence of miR-17 in primary cilia. The miR-17 expression is studied in selected ciliary protein knockdown cells. Using in-situ hybridization (ISH), we identified the subcellular localization of miR-17 in both cilia and cell bodies. We confirmed the importance …

Role Of Protein Kinase A And A Kinase Anchoring Proteins In Buffering And Compartmentation Of Camp Signalling In Human Airway Smooth Muscle Cells, Rinzhin T. Sherpa, Karni S. Moshal, Shailesh R. Agarwal, Rennolds S. Ostrom, Robert D. Harvey

Pharmacy Faculty Articles and Research

Background and Purpose

In human airway smooth muscle (hASM) cells, not all receptors stimulating cAMP production elicit the same effects. This can only be explained if cAMP movement throughout the cell is restricted, yet the mechanisms involved are not fully understood. Phosphodiesterases (PDEs) contribute to compartmentation of many cAMP responses, but PDE activity alone is predicted to be insufficient if cAMP is otherwise freely diffusible. We tested the hypothesis that buffering of cAMP by protein kinase A (PKA) associated with A kinase anchoring proteins (AKAPs) slows cAMP diffusion and that this contributes to receptor-mediated, compartmentalized responses.

Experimental Approach

Raster image …

Real-Time Camp Dynamics In Live Cells Using The Fluorescent Camp Difference Detector In Situ, Isabella Cattani-Cavalieri, Jordyn Margolis, Camelia Anicolaesei, Francisco J. Nuñez, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

cAMP Difference Detector In Situ (cADDis) is a novel biosensor that allows for the continuous measurement of cAMP levels in living cells. The biosensor is created from a circularly permuted fluorescent protein linked to the hinge region of Epac2. This creates a single fluorophore biosensor that displays either increased or decreased fluorescence upon binding of cAMP. The biosensor exists in red and green upward versions, as well as green downward versions, and several red and green versions targeted to subcellular locations. To illustrate the effectiveness of the biosensor, the green downward version, which decreases in fluorescence upon cAMP binding, was …

A Novel Micropeptide, Slitharin, Exerts Cardioprotective Effects In Myocardial Infarction, Ahmed G. E. Ibrahim, Alessandra Ciullo, Shukuro Yamaguchi, Chang Li, Travis Antes, Xaviar Jones, Liang Li, Ramachandran Murali, Innokentiy Maslennikov, Niveda Sundararaman, Daniel Soetkamp, Eugenio Cingolani, Jennifer Van Eyk, Eduardo Marbán

Pharmacy Faculty Articles and Research

Purpose: Micropeptides are an emerging class of proteins that play critical roles in cell signaling. Here, we describe the discovery of a novel micropeptide, dubbed slitharin (Slt), in conditioned media from Cardiosphere-derived cells (CDCs), a therapeutic cardiac stromal cell type.

Experimental design: We performed mass spectrometry of peptide-enriched fractions from the conditioned media of CDCs and a therapeutically inert cell type (human dermal fibrobasts). We then evaluated the therapeutic capacity of the candidate peptide using an in vitro model of cardiomyocyte injury and a rat model of myocardial infarction.

Results: We identified a novel 24-amino acid micropeptide …

Oxidative Stress And Ion Channels In Neurodegenerative Diseases, Razan Orfali, Adnan Z. Alwatban, Rawan S. Orfali, Liz Lau, Noble Chea, Abdullah M. Alotaibi, Young-Woo Nam, Miao Zhang

Pharmacy Faculty Articles and Research

Numerous neurodegenerative diseases result from altered ion channel function and mutations. The intracellular redox status can significantly alter the gating characteristics of ion channels. Abundant neurodegenerative diseases associated with oxidative stress have been documented, including Parkinson’s, Alzheimer’s, spinocerebellar ataxia, amyotrophic lateral sclerosis, and Huntington’s disease. Reactive oxygen and nitrogen species compounds trigger posttranslational alterations that target specific sites within the subunits responsible for channel assembly. These alterations include the adjustment of cysteine residues through redox reactions induced by reactive oxygen species (ROS), nitration, and S-nitrosylation assisted by nitric oxide of tyrosine residues through peroxynitrite. Several ion channels have been directly …

Brain Microvascular Endothelial Cells Possess A Second Cilium That Arises From The Daughter Centriole, Karthikeyan Thirugnanam, Ankan Gupta, Francisco Nunez, Shubhangi Prabhudesai, Amy Y. Pan, Surya M. Nauli, Ramani Ramchandran

Pharmacy Faculty Articles and Research

Primary cilia from the brain microvascular endothelial cells (ECs) are specialized cell-surface organelles involved in mediating sensory perception, cell signaling, and vascular stability. Immunofluorescence (IF) analysis of human primary brain microvascular ECs reveals two cilia per cell. To confirm the in vitro observation of the two-cilia phenotype in human primary brain ECs, ECs isolated from mouse brain were cultured and stained for cilium. Indeed, brain ECs from a ciliopathic mouse (polycystic kidney disease or Pkd2−/−) also possess more than one cilium. Primary cilium emerges from the mother centriole. Centriole analysis by IF suggests that in brain ECs, markers …

Prorelaxant E-Type Prostanoid Receptors Functionally Partition To Different Procontractile Receptors In Airway Smooth Muscle, Ajay P. Nayak, Elham Javed, Dominic R. Villaba, Yinna Wang, Henry P. Morelli, Sushrut D. Shah, Nicholas Kim, Rennolds S. Ostrom, Reynold A. Pannettieri Jr., Steven S. An, Dale D. Tang, Raymond B. Penn

Pharmacy Faculty Articles and Research

Prostaglandin E2 imparts diverse physiological effects on multiple airway cells through its actions on four distinct E-type prostanoid (EP) receptor subtypes (EP1–EP4). Gs-coupled EP2 and EP4 receptors are expressed on airway smooth muscle (ASM), yet their capacity to regulate the ASM contractile state remains subject to debate. We used EP2 and EP4 subtype-specific agonists (ONO-259 and ONO-329, respectively) in cell- and tissue-based models of human ASM contraction—magnetic twisting cytometry (MTC), and precision-cut lung slices (PCLSs), respectively—to study the EP2 and EP4 regulation of ASM contraction and signaling under conditions of histamine or methacholine (MCh) stimulation. ONO-329 was superior (<0.05) to ONO-259 in relaxing MCh-contracted PCLSs (log half maximal effective concentration [logEC50]: 4.9 × 10−7 vs. 2.2 × 10−6; maximal bronchodilation ± SE, 35 ± 2% vs. 15 ± 2%). However, ONO-259 and ONO-329 were similarly efficacious in relaxing histamine-contracted PCLSs. Similar differential effects were observed in MTC studies. Signaling analyses revealed only modest differences in ONO-329– and ONO-259–induced phosphorylation of the protein kinase A substrates VASP and HSP20, with concomitant stimulation with MCh or histamine. Conversely, ONO-259 failed to inhibit MCh-induced phosphorylation of the regulatory myosin light chain (pMLC20) and the F-actin/G-actin ratio (F/G-actin ratio) while effectively inhibiting their induction by histamine. ONO-329 was effective in reversing induced pMLC20 and the F/G-actin ratio with both MCh and histamine. Thus, the contractile-agonist–dependent differential effects are not explained by changes in the global levels of phosphorylated protein kinase A substrates but are reflected in the regulation of pMLC20 (cross-bridge cycling) and F/G-actin ratio (actin cytoskeleton integrity, force transmission), implicating a role for compartmentalized signaling involving muscarinic, histamine, and EP receptor subtypes.

The Pros Of Changing Trna Identity, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The notion that errors in protein synthesis are universally harmful to the cell has been questioned by findings that suggest such mistakes may sometimes be beneficial. However, how often these beneficial mistakes arise from programmed changes in gene expression as opposed to reduced accuracy of the translation machinery is still unclear. A new study published in JBC shows that some bacteria have beneficially evolved the ability to mistranslate specific parts of the genetic code, a trait that allows improved antibiotic resistance.

Novel Allosteric Effectors Targeting Human Transcription Factor Tead, Mayar Terek Ibrahim, Gennady M. Verkhivker, Jyoti Misra, Peng Tao

Mathematics, Physics, and Computer Science Faculty Articles and Research

The Hippo pathway is an evolutionary conserved signaling network involved in several cellular regulatory processes. Dephosphorylation and overexpression of Yes-associated proteins (YAPs) in the Hippo-off state are common in several types of solid tumors. YAP overexpression results in its nuclear translocation and interaction with transcriptional enhanced associate domain 1-4 (TEAD1-4) transcription factors. Covalent and non-covalent inhibitors have been developed to target several interaction sites between TEAD and YAP. The most targeted and effective site for these developed inhibitors is the palmitate-binding pocket in the TEAD1-4 proteins. Screening of a DNA-encoded library against the TEAD central pocket was performed experimentally to …

Amphiphilic Cell-Penetrating Peptides Containing Arginine And Hydrophobic Residues As Protein Delivery Agents, Jonathan Moreno, Khalid Zoghebi, David Salehi, Lois Kim, Sorour Khayyatnejad Shoushtari, Rakesh K. Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

The entry of proteins through the cell membrane is challenging, thus limiting their use as potential therapeutics. Seven cell-penetrating peptides, designed in our laboratory, were evaluated for the delivery of proteins. Fmoc solid-phase peptide synthesis was utilized for the synthesis of seven cyclic or hybrid cyclic–linear amphiphilic peptides composed of hydrophobic (tryptophan (W) or 3,3-diphenylalanine (Dip) and positively-charged arginine (R) residues, such as [WR]4, [WR]9, [WWRR]4, [WWRR]5, [(RW)5K](RW)5, [R5K]W7, and [DipR]5. Confocal microscopy was used to screen the peptides as a protein delivery system of model cargo proteins, green and red fluorescein proteins (GFP and RFP). Based on the confocal …