Medical Molecular Biology Commons^™

Developing A Bacterial Panel For The Evaluation Of Novel Anti-Infective Compounds, Clare Euteneuer

UNO Student Research and Creative Activity Fair

Antibiotic resistance is one of the leading causes of concern for the world health community. Drugs used to stop various infections for years are now becoming easier for bacteria to resist due to mutations and plasmids conferring resistance. To combat this problem, new drug can help alleviate this concern. We developed an assay that allows us to screen novel drug-like compounds against bacteria in an effort to identify promising new anti-infective compounds. Our assay was designed using known drugs against a panel of gram positive and negative bacilli and cocci including S. epidermidis, P. mirabilis, N. mucosa, and E. …

Role Of Ribosome Recycling Factor In Natural Termination And Translational Coupling As A Ribosome Releasing Factor, Yoshio Inokuchi, Fabio Quaglia, Akikazu Hirashima, Yoshihiro Yamamoto, Hideko Kaji, Akira Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

The role of ribosome recycling factor (RRF) of E. coli was studied in vivo and in vitro. We used the translational coupling without the Shine-Dalgarno sequence of downstream ORF (d-ORF) as a model system of the RRF action in natural termination of protein synthesis. For the in vivo studies we used the translational coupling by the adjacent coat and lysis genes of RNA phage GA sharing the termination and initiation (UAAUG) and temperature sensitive RRF. The d-ORF translation was measured by the expression of the reporter lacZ gene connected to the 5'-terminal part of the lysis gene. The results showed …

Harnessing Transcriptionally Driven Chromosomal Instability Adaptation To Target Therapy-Refractory Lethal Prostate Cancer., Brittiny Dhital, Sandra Santasusagna, Perumalraja Kirthika, Michael Xu, Peiyao Li, Marc Carceles-Cordon, Rajesh K. Soni, Zhuoning Li, Ronald C. Hendrickson, Matthew J. Schiewer, William K. Kelly, Cora N. Sternberg, Jun Luo, Amaia Lujambio, Carlos Cordon-Cardo, Monica Alvarez-Fernandez, Marcos Malumbres, Haojie Huang, Adam Ertel, Josep Domingo-Domenech, Veronica Rodriguez-Bravo

Kimmel Cancer Center Papers, Presentations, and Grand Rounds

Metastatic prostate cancer (PCa) inevitably acquires resistance to standard therapy preceding lethality. Here, we unveil a chromosomal instability (CIN) tolerance mechanism as a therapeutic vulnerability of therapy-refractory lethal PCa. Through genomic and transcriptomic analysis of patient datasets, we find that castration and chemotherapy-resistant tumors display the highest CIN and mitotic kinase levels. Functional genomics screening coupled with quantitative phosphoproteomics identify MASTL kinase as a survival vulnerability specific of chemotherapy-resistant PCa cells. Mechanistically, MASTL upregulation is driven by transcriptional rewiring mechanisms involving the non-canonical transcription factors androgen receptor splice variant 7 and E2F7 in a circuitry that restrains deleterious CIN and …

Semi-Quantitative Detection Of Pseudouridine Modifications And Type I/Ii I/Ii Hypermodifications In Human Mrnas Using Direct Long-Read Sequencing, Sepideh Tavakoli, Mohammad Nabizadeh, Amr Makhamreh, Howard Gamper, Caroline A Mccormick, Neda K Rezapour, Ya-Ming Hou, Meni Wanunu, Sara H Rouhanifard

Department of Biochemistry and Molecular Biology Faculty Papers

Here, we develop and apply a semi-quantitative method for the high-confidence identification of pseudouridylated sites on mammalian mRNAs via direct long-read nanopore sequencing. A comparative analysis of a modification-free transcriptome reveals that the depth of coverage and specific k-mer sequences are critical parameters for accurate basecalling. By adjusting these parameters for high-confidence U-to-C basecalling errors, we identify many known sites of pseudouridylation and uncover previously unreported uridine-modified sites, many of which fall in k-mers that are known targets of pseudouridine synthases. Identified sites are validated using 1000-mer synthetic RNA controls bearing a single pseudouridine in the center position, demonstrating systematic …

Disruption Of The Interaction Between Mutationally Activated Gαq And Gβγ Attenuates Aberrant Signaling, Jenna L Aumiller, Philip B Wedegaertner

Department of Biochemistry and Molecular Biology Faculty Papers

Heterotrimeric G protein stimulation via G protein-coupled receptors promotes downstream proliferative signaling. Mutations can occur in Gα proteins which prevent GTP hydrolysis; this allows the G proteins to signal independently of G protein-coupled receptors and can result in various cancers, such as uveal melanoma (UM). Most UM cases harbor Q209L, Q209P, or R183C mutations in Gαq/11 proteins, rendering the proteins constitutively active (CA). Although it is generally thought that active, GTP-bound Gα subunits are dissociated from and signal independently of Gβγ, accumulating evidence indicates that some CA Gα mutants, such as Gαq/11, retain binding to Gβγ, and this interaction is …

Differentiating Pc12 Cells To Evaluate Neurite Densities Through Live-Cell Imaging, Jordyn Karliner, Diane E Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Although PC12 cells are a valuable tool in neuroscience research, previously published PC12 cell differentiation techniques fail to consider the variability in differentiation rates between different PC12 cell strains and clonal variants. Here, we present a comprehensive protocol to differentiate PC12 cells into equivalent neurite densities through live-cell imaging for morphological, immunocytochemical, and biochemical analyses. We detail steps on optimized substrate coating, plating techniques, culture media, validation steps, and quantification techniques.

The Mucin Family Of Proteins: Candidates As Potential Biomarkers For Colon Cancer, Kristin E. Cox, Shanglei Liu, Thinzar M. Lwin, Robert M. Hoffman, Surinder K. Batra, Michael Bouvet

Journal Articles: Biochemistry & Molecular Biology

Mucins (MUC1-MUC24) are a family of glycoproteins involved in cell signaling and barrier protection. They have been implicated in the progression of numerous malignancies including gastric, pancreatic, ovarian, breast, and lung cancer. Mucins have also been extensively studied with respect to colorectal cancer. They have been found to have diverse expression profiles amongst the normal colon, benign hyperplastic polyps, pre-malignant polyps, and colon cancers. Those expressed in the normal colon include MUC2, MUC3, MUC4, MUC11, MUC12, MUC13, MUC15 (at low levels), and MUC21. Whereas MUC5, MUC6, MUC16, and MUC20 are absent from the normal colon and are expressed in colorectal …

Microrna-1 Attenuates The Growth And Metastasis Of Small Cell Lung Cancer Through Cxcr4/Foxm1/Rrm2 Axis, Parvez Khan, Jawed A. Siddiqui, Prakash Kshirsagar Dr., Ramakanth Chirravuri Venkata, Shailendra K. Maurya, Tamara Mirzapoiazova, Naveenkumar Perumal, Sanjib Chaudhary, Ranjana K. Kanchan, Mahek Fatima, Md Arafat Khan, Asad Ur Rehman, Imayavaramban Lakshmanan, Sidharth Mahapatra, Geoffrey A. Talmon, Prakash Kulkarni, Apar Kishor Ganti, Maneesh Jain, Ravi Salgia, Surinder K. Batra, Mohd W. Nasser

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Small cell lung cancer (SCLC) is an aggressive lung cancer subtype that is associated with high recurrence and poor prognosis. Due to lack of potential drug targets, SCLC patients have few therapeutic options. MicroRNAs (miRNAs) provide an interesting repertoire of therapeutic molecules; however, the identification of miRNAs regulating SCLC growth and metastasis and their precise regulatory mechanisms are not well understood.

METHODS: To identify novel miRNAs regulating SCLC, we performed miRNA-sequencing from donor/patient serum samples and analyzed the bulk RNA-sequencing data from the tumors of SCLC patients. Further, we developed a nanotechnology-based, highly sensitive method to detect microRNA-1 (miR-1, …

Elevated Paf1-Rad52 Axis Confers Chemoresistance To Human Cancers, Sanchita Rauth, Koelina Ganguly, Pranita Atri, Seema Parte, Rama Krishna Nimmakayala, Venkatesh Varadharaj, Palanisamy Nallasamy, Raghupathy Vengoji, Ayoola O. Ogunleye, Imayavaramban Lakshmanan, Ramakanth Chirravuri, Mika Bessho, Jesse L. Cox, Jason M. Foster, Geoffrey A. Talmon, Tadayoshi Bessho, Apar Kishor Ganti, Surinder K. Batra, Moorthy P. Ponnusamy

Journal Articles: Biochemistry & Molecular Biology

Cisplatin- and gemcitabine-based chemotherapeutics represent a mainstay of cancer therapy for most solid tumors; however, resistance limits their curative potential. Here, we identify RNA polymerase II-associated factor 1 (PAF1) as a common driver of cisplatin and gemcitabine resistance in human cancers (ovarian, lung, and pancreas). Mechanistically, cisplatin- and gemcitabine-resistant cells show enhanced DNA repair, which is inhibited by PAF1 silencing. We demonstrate an increased interaction of PAF1 with RAD52 in resistant cells. Targeting the PAF1 and RAD52 axis combined with cisplatin or gemcitabine strongly diminishes the survival potential of resistant cells. Overall, this study shows clinical evidence that the expression …

Molecular Signaling Network And Therapeutic Developments In Breast Cancer Brain Metastasis, Mercilena Benjamin, Pushkar Malakar, Rohit Anthony Sinha, Mohd Wasim Nasser, Surinder K. Batra, Jawed A. Siddiqui, Bandana Chakravarti

Journal Articles: Biochemistry & Molecular Biology

Breast cancer (BC) is one of the most frequently diagnosed cancers in women worldwide. It has surpassed lung cancer as the leading cause of cancer-related death. Breast cancer brain metastasis (BCBM) is becoming a major clinical concern that is commonly associated with ER-ve and HER2+ve subtypes of BC patients. Metastatic lesions in the brain originate when the cancer cells detach from a primary breast tumor and establish metastatic lesions and infiltrate near and distant organs via systemic blood circulation by traversing the BBB. The colonization of BC cells in the brain involves a complex interplay in the tumor microenvironment (TME), …

Stabilized Core Gene And Pathway Election Uncovers Pan-Cancer Shared Pathways And A Cancer-Specific Driver, Pathum Kossinna, Weijia Cai, Xuewen Lu, Carrie S Shemanko, Qingrun Zhang

Department of Cancer Biology Faculty Papers

Approaches systematically characterizing interactions via transcriptomic data usually follow two systems: (i) coexpression network analyses focusing on correlations between genes and (ii) linear regressions (usually regularized) to select multiple genes jointly. Both suffer from the problem of stability: A slight change of parameterization or dataset could lead to marked alterations of outcomes. Here, we propose Stabilized COre gene and Pathway Election (SCOPE), a tool integrating bootstrapped least absolute shrinkage and selection operator and coexpression analysis, leading to robust outcomes insensitive to variations in data. By applying SCOPE to six cancer expression datasets (BRCA, COAD, KIRC, LUAD, PRAD, and THCA) in …

High-Resolution Cryo-Em Structure Of The Shigella Virus Sf6 Genome Delivery Tail Machine, Fenglin Li, Chun-Feng David Hou, Ruoyu Yang, Richard Whitehead, Carolyn M. Teschke, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

Sf6 is a bacterial virus that infects the human pathogen Shigella flexneri. Here, we describe the cryo–electron microscopy structure of the Sf6 tail machine before DNA ejection, which we determined at a 2.7-angstrom resolution. We built de novo structures of all tail components and resolved four symmetry-mismatched interfaces. Unexpectedly, we found that the tail exists in two conformations, rotated by ~6° with respect to the capsid. The two tail conformers are identical in structure but differ solely in how the portal and head-to-tail adaptor carboxyl termini bond with the capsid at the fivefold vertex, similar to a diamond held over …

In Silico Identification Of A Β2-Adrenoceptor Allosteric Site That Selectively Augments Canonical Β2ar-Gs Signaling And Function, Sushrut D Shah, Christoffer Lind, Francesco De Pascali, Raymond B Penn, Alexander D Mackerell, Deepak A Deshpande

Department of Biochemistry and Molecular Biology Faculty Papers

Activation of β2-adrenoceptors (β2ARs) causes airway smooth muscle (ASM) relaxation and bronchodilation, and β2AR agonists (β-agonists) are front-line treatments for asthma and other obstructive lung diseases. However, the therapeutic efficacy of β-agonists is limited by agonist-induced β2AR desensitization and noncanonical β2AR signaling involving β-arrestin that is shown to promote asthma pathophysiology. Accordingly, we undertook the identification of an allosteric site on β2AR that could modulate the activity of β-agonists to overcome these limitations. We employed the site identification by ligand competitive saturation (SILCS) computational method to comprehensively map the entire 3D structure of in silico-generated β2AR intermediate conformations and identified …

Investigating The Pi3k/Akt/Atm Pathway, Telomeric Dna Damage, T Cell Death, And Crispr/Cas9-Mediated Gene Editing During Acute And Chronic Hiv Infection, Sushant Khanal

Electronic Theses and Dissertations

Human Immunodeficiency Virus (HIV) infection initiates major metabolic and cell- survival complications. Anti-retroviral therapy (ART) is the current approach to suppress active HIV replication to a level of undetected viral load, but it is not a curative approach. Newer and sophisticated gene editing technologies could indeed be a potent antiviral therapy to achieve a clinical sterilization/cure of HIV infection. Chronic HIV patients, even under a successful ART regimen, exhibit a low-grade inflammation, immune senescence, premature aging, telomeric DNA attrition, T cell apoptosis, and cellular homeostasis. In this dissertation, we investigated CD4 T cell homeostasis, degree of T cell apoptosis, an …

Terminase Subunits From The Pseudomonas-Phage E217, Ravi K Lokareddy, Chun-Feng David Hou, Steven G Doll, Fenglin Li, Richard E Gillilan, Francesca Forti, David S Horner, Federica Briani, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

Pseudomonas phages are increasingly important biomedicines for phage therapy, but little is known about how these viruses package DNA. This paper explores the terminase subunits from the Myoviridae E217, a Pseudomonas-phage used in an experimental cocktail to eradicate P. aeruginosa in vitro and in animal models. We identified the large (TerL) and small (TerS) terminase subunits in two genes ∼58 kbs away from each other in the E217 genome. TerL presents a classical two-domain architecture, consisting of an N-terminal ATPase and C-terminal nuclease domain arranged into a bean-shaped tertiary structure. A 2.05 Å crystal structure of the C-terminal domain revealed …

Structure Of The Pre-Mrna Leakage 39-Kda Protein Reveals A Single Domain Of Integrated Zf-C3hc And Rsm1 Modules, Hideharu Hashimoto, Daniel H. Ramirez, Ophélie Lautier, Natalie Pawlak, Günter Blobel, Benoît Palancade, Erik W. Debler

Department of Biochemistry and Molecular Biology Faculty Papers

In Saccharomyces cerevisiae, the pre-mRNA leakage 39-kDa protein (ScPml39) was reported to retain unspliced pre-mRNA prior to export through nuclear pore complexes (NPCs). Pml39 homologs outside the Saccharomycetaceae family are currently unknown, and mechanistic insight into Pml39 function is lacking. Here we determined the crystal structure of ScPml39 at 2.5 Å resolution to facilitate the discovery of orthologs beyond Saccharomycetaceae, e.g. in Schizosaccharomyces pombe or human. The crystal structure revealed integrated zf-C3HC and Rsm1 modules, which are tightly associated through a hydrophobic interface to form a single domain. Both zf-C3HC and Rsm1 modules belong to the Zn-containing BIR (Baculovirus IAP …

Attenuation Of Relapsing Fever Neuroborreliosis In Mice By Il-17a Blockade, Meihui Cheng, Jingwen Xu, Kaiyun Ding, Jing Zhang, Wei Lu, Jiansheng Liu, Jiahong Gao, Kishore R Alugupalli, Hongqi Liu

Department of Microbiology and Immunology Faculty Papers

Relapsing fever due to Borrelia hermsiiis characterized by recurrent bacteremia episodes. However, infection of B. hermsii, if not treated early, can spread to various organs including the central nervous system (CNS). CNS disease manifestations are commonly referred to as relapsing fever neuroborreliosis (RFNB). In the mouse model of B. hermsiiinfection, we have previously shown that the development of RFNB requires innate immune cells as well as T cells. Here, we found that prior to the onset of RFNB, an increase in the systemic proinflammatory cytokine response followed by sustained levels of IP-10 concurrent with the CNS disease phase. RNA sequencing …

Viral Small Terminase: A Divergent Structural Framework For A Conserved Biological Function., Ravi K. Lokareddy, Chun-Feng David Hou, Fenglin Li, Ruoyu Yang, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

The genome packaging motor of bacteriophages and herpesviruses is built by two terminase subunits, known as large (TerL) and small (TerS), both essential for viral genome packaging. TerL structure, composition, and assembly to an empty capsid, as well as the mechanisms of ATP-dependent DNA packaging, have been studied in depth, shedding light on the chemo-mechanical coupling between ATP hydrolysis and DNA translocation. Instead, significantly less is known about the small terminase subunit, TerS, which is dispensable or even inhibitory in vitro, but essential in vivo. By taking advantage of the recent revolution in cryo-electron microscopy (cryo-EM) and building upon a …

The Role Of Ubiquitination In Spinal And Bulbar Muscular Atrophy, Medha Sengupta, Anna Pluciennik, Diane E. Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is a neurodegenerative and neuromuscular genetic disease caused by the expansion of a polyglutamine-encoding CAG tract in the androgen receptor (AR) gene. The AR is an important transcriptional regulator of the nuclear hormone receptor superfamily; its levels are regulated in many ways including by ubiquitin-dependent degradation. Ubiquitination is a post-translational modification (PTM) which plays a key role in both AR transcriptional activity and its degradation. Moreover, the ubiquitin-proteasome system (UPS) is a fundamental component of cellular functioning and has been implicated in diseases of protein misfolding and aggregation, including polyglutamine (polyQ) repeat expansion diseases …

Young Transposable Elements Rewired Gene Regulatory Networks In Human And Chimpanzee Hippocampal Intermediate Progenitors, Sruti Patoori, Samantha M Barnada, Christopher Large, John I Murray, Marco Trizzino

Department of Biochemistry and Molecular Biology Faculty Papers

The hippocampus is associated with essential brain functions, such as learning and memory. Human hippocampal volume is significantly greater than expected compared with that of non-human apes, suggesting a recent expansion. Intermediate progenitors, which are able to undergo multiple rounds of proliferative division before a final neurogenic division, may have played a role in evolutionary hippocampal expansion. To investigate the evolution of gene regulatory networks underpinning hippocampal neurogenesis in apes, we leveraged the differentiation of human and chimpanzee induced pluripotent stem cells into TBR2 (or EOMES)-positive hippocampal intermediate progenitor cells (hpIPCs). We found that the gene networks active in hpIPCs …