Cell Biology Commons^™

Minimal Structural Elements Required For Midline Repulsive Signaling And Regulation Of Drosophila Robo1, Haley E. Brown, Timonthy A. Evans

Biological Sciences Faculty Publications and Presentations

The Roundabout (Robo) family of axon guidance receptors has a conserved ectodomain arrangement of five immunoglobulin-like (Ig) domains plus three fibronectin type III (Fn) repeats. Based on the strong evolutionary conservation of this domain structure among Robo receptors, as well as in vitro structural and domain-domain interaction studies of Robo family members, this ectodomain arrangement is predicted to be important for Robo receptor signaling in response to Slit ligands. Here, we define the minimal ectodomain structure required for Slit binding and midline repulsive signaling in vivo by Drosophila Robo1. We find that the majority of the Robo1 ectodomain is dispensable …

Cryo‑Electron Microscopy Structure Of The 70s Ribosome From Enterococcus Faecalis, Eileen L. Murphy, Kavindra V. Singh, Bryant Avila, Torsten Kleffmann, Steven T. Gregory, Barbara E. Murray, Kurt L. Krause, Reza Khayat, Gerwald Jogl

Publications and Research

Enterococcus faecalis is a gram-positive organism responsible for serious infections in humans, but as with many bacterial pathogens, resistance has rendered a number of commonly used antibiotics ineffective. Here, we report the cryo-EM structure of the E. faecalis 70S ribosome to a global resolution of 2.8 Å. Structural differences are clustered in peripheral and solvent exposed regions when compared with Escherichia coli, whereas functional centres, including antibiotic binding sites, are similar to other bacterial ribosomes. Comparison of intersubunit conformations among five classes obtained after three-dimensional classification identifies several rotated states. Large ribosomal subunit protein bL31, which forms intersubunit bridges to …

Tdp-43 Mediated Blood-Brain Barrier Permeability And Leukocyte Infiltration Promote Neurodegeneration In A Low-Grade Systemic Inflammation Mouse Model, Frank Zamudio, Anjanet R. Loon, Shayna Smeltzer, Khawla Benyamine, Nanda K. Navalpur Shanmugam, Nicholas J. F. Stewart, Daniel C. Lee, Kevin Nash, Maj-Linda B. Selenica

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: Neuronal cytoplasmic inclusions containing TAR DNA-binding protein 43 (TDP-43) are a neuropathological feature of several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Alzheimer's Disease (AD). Emerging evidence also indicates that systemic inflammation may be a contributor to the pathology progression of these neurodegenerative diseases.

METHODS: To investigate the role of systemic inflammation in the progression of neuronal TDP-43 pathology, AAV9 particles driven by the UCHL1 promoter were delivered to the frontal cortex of wild-type aged mice via intracranial injections to overexpress TDP-43 or green fluorescent protein (GFP) in corticospinal motor neurons. Animals were then subjected …

Dysregulation Of Ryr Calcium Channel Causes The Onset Of Mitochondrial Retrograde Signaling, Anindya Roy Chowdhury, Satish Srinivasan, György Csordás, György Hajnóczky, Narayan G Avadhani

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

This study shows that multiple modes of mitochondrial stress generated by partial mtDNA depletion or cytochrome c oxidase disruption cause ryanodine receptor channel (RyR) dysregulation, which instigates the release of Ca2+ in the cytoplasm of C2C12 myoblasts and HCT116 carcinoma cells. We also observed a reciprocal downregulation of IP3R channel activity and reduced mitochondrial uptake of Ca2+. Ryanodine, an RyR antagonist, abrogated the mitochondrial stress-mediated increase in [Ca2+]c and the entire downstream signaling cascades of mitochondrial retrograde signaling. Interestingly, ryanodine also inhibited mitochondrial stress-induced invasive behavior in mtDNA-depleted C2C12 cells and HCT116 carcinoma cells. In addition, co-immunoprecipitation shows reduced FKBP12 …

Phosphorylation Of Cyclophilin D At Serine 191 Regulates Mitochondrial Permeability Transition Pore Opening And Cell Death After Ischemia-Reperfusion, Stephen Hurst, Fabrice Gonnot, Maya Dia, Claire Crola Da Silva, Ludovic Gomez, Shey-Shing Sheu

Department of Medicine Faculty Papers

The mitochondrial permeability transition pore (mPTP) plays a critical role in the pathogenesis of cardiovascular diseases, including ischemia/reperfusion injury. Although the pore structure is still unresolved, the mechanism through which cyclophilin D (CypD) regulates mPTP opening is the subject of intensive studies. While post-translational modifications of CypD have been shown to modulate pore opening, specific phosphorylation sites of CypD have not yet been identified. We hypothesized here that phosphorylation of CypD on a serine residue controls mPTP opening and subsequent cell death at reperfusion. We combined in silico analysis with in vitro and genetic manipulations to determine potential CypD phosphorylation …

Effect Of S100b Deletion On Membrane Properties And Localization Of Ncald And Hpca, Natasha Hesketh

Graduate School of Biomedical Sciences Theses and Dissertations

Calcium signaling is particularly important for neuronal function. Neurons utilize a wide range of calcium-binding proteins. Dysregulation of such proteins is linked to neurodegeneration. Neurocalcin delta (NCALD), hippocalcin (HPCA), and S100B are calcium sensors that are expressed in the hippocampus, a brain region essential to memory and severely damaged in Alzheimer’s disease (AD). Despite the potential importance of these proteins, we do not fully understand the physiological significance of their relationship. Because NCALD and HPCA are known to interact with S100B, we hypothesized that the loss of S100B affects NCALD and HPCA localization, and therefore electrical properties, of hippocampal neurons. …

Epigenetic Targeting Of Mcl-1 Is Synthetically Lethal With Bcl-Xl/Bcl-2 Inhibition In Model Systems Of Glioblastoma, Enyuan Shang, Trang T. T. Nguyen, Chang Shu, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

Apoptotic resistance remains a hallmark of glioblastoma (GBM), the most common primary brain tumor in adults, and a better understanding of this process may result in more efficient treatments. By utilizing chromatin immunoprecipitation with next-generation sequencing (CHIP-seq), we discovered that GBMs harbor a super enhancer around the Mcl-1 locus, a gene that has been known to confer cell death resistance in GBM.We utilized THZ1, a known super-enhancer blocker, and BH3-mimetics, including ABT263, WEHI-539, and ABT199. Combined treatment with BH3-mimetics and THZ1 led to synergistic growth reduction in GBM models. Reduction in cellular viability was accompanied by significant cell death induction …

Tissue-Resident Myeloid-Derived Suppressor Cells Modulate Immune Homeostasis In Healthy Adipose., Katlin Brooke Stivers

Electronic Theses and Dissertations

Our goal with this study was to gain insight into the homeostatic immune cell network in healthy adipose tissue. Specifically, we sought to determine if the immature myeloid cells found in healthy and inflamed adipose were, in fact, tissue-resident myeloid-derived suppressor cells (MDSCs). Using various in vitro and in vivo methods, we have uncovered a population of CD11b^Hi Ly6C^Hi Ly6G^- MDSCs resident in healthy adipose tissue. To the best of our knowledge this is the first time that these cells have been investigated and described in healthy adipose tissue. Systemic MDSC depletion lead to the accumulation of …

Comparative Molecular Transporter Properties Of Cyclic Peptides Containing Tryptophan And Arginine Residues Formed Through Disulfide Cyclization, Eman H. M. Mohammed, Dindyal Mandal, Saghar Mozaffari, Magdy Abdel-Hamied Zahran, Amany Mostafa Osman, Rakesh Kumar Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

We have previously reported cyclic cell-penetrating peptides [WR]₅ and [WR]₄ as molecular transporters. To optimize further the utility of our developed peptides for targeted therapy in cancer cells using the redox condition, we designed a new generation of peptides and evaluated their cytotoxicity as well as uptake behavior against different cancer cell lines. Thus, cyclic [C(WR)_xC] and linear counterparts (C(WR)_xC), where x = 4–5, were synthesized using Fmoc/tBu solid-phase peptide synthesis, purified, and characterized. The compounds did not show any significant cytotoxicity (at 25 µM) against ovarian (SK-OV-3), leukemia (CCRF-CEM), gastric adenocarcinoma (CRL-1739), breast …

The Anti-Proliferative Effects Of Methotrexate And Novel Ucp1162 On Acute Myeloid Leukemia Cell Lines, Jacqueline Klepinger, Charles Giardina, Didem Ozcan

Honors Scholar Theses

Cancer cells proliferate at rapid rates due to the aberrant activity of proteins involved in regulating the cell cycle. This characteristic allows mutated cancer cells to spread and metastasize, causing lesions to form throughout the body. Two treatment conditions, one classical antifolate methotrexate (MTX) and non-classical, novel antifolate UCP1162, were tested on a panel of acute myeloid leukemia (AML) cell lines to determine if UCP1162 has higher anti-proliferative activity. High dose MTX is used as a first line chemotherapy in common childhood malignancies such as acute lymphoid leukemia (ALL). Methotrexate is excluded from acute myeloid leukemia (AML) treatments based on …

The Autoimmune System: The Effect Of Physiological Stressors On Autoantibody Glycosylation And Fidelity Of Autoantibody Profiles, Rahil Kheirkhah

Graduate School of Biomedical Sciences Theses and Dissertations

The presence of thousands of autoantibodies (aABs) in the human sera is typical, and therefore it is possible to identify an aAB profile for each individual. In the first part of this thesis, we will show the cerebrospinal fluid also exhibits an extraordinarily complex immunoglobulin G aAB profile that is composed of thousands of aABs. We show that the pattern of expression of individual aABs in CSF closely mimics that in the blood, indicative of a blood-based origin for CSF aABs. In addition, using longitudinal serum samples obtained over a span of nine years, we show remarkable stability in aAB …

Cloning, Protein Expression, And Characterization Of Interleukin 1 Alpha, Musaab Habeeb Ali Al Ameer

Graduate Theses and Dissertations

Recombinant DNA technology and the ability to produce recombinant proteins have significantly changed the world of pharmaceutical market. Recombinant DNA technology using E. coli cells has successfully produced many therapeutic proteins. In this study, the designed tag Ark-RUBY-tag facilitates rapid, and reproducible purification of recombinant proteins expressed as inclusion bodies in E. coli cells. Purification of Ark-RUBY-fused recombinant protein(s) can be obtained by using imidazole fractions. Target protein can be easily removed from the Ark-RUBY-tag by enzymatic cleavage. Ark-RUBY-fused recombinant proteins can be quantitatively detected using polyclonal antibodies. Ark-RUBY-tag can be used to purify small peptides. By using Ark-RUBY-tag, purified …

Photoactivatable Cre Recombinase 3.0 For In Vivo Mouse Applications, Kumi Morikawa, Kazuhiro Furuhashi, Carmen De Sena-Tomas, Alvaro L. Garcia-Garcia, Ramsey Bekdash, Alison D. Klein, Nicholas Gallerani, Hannah E. Yamamoto, Seon Hye E. Park, Grant S. Collins, Fuun Kawano, Moritoshi Sato, Chyuan Sheng Lin, Kimara L. Targoff, Edmund Au, Michael C. Salling, Masayuki Yazawa

School of Medicine Faculty Publications

Optogenetic genome engineering tools enable spatiotemporal control of gene expression and provide new insight into biological function. Here, we report the new version of genetically encoded photoactivatable (PA) Cre recombinase, PA-Cre 3.0. To improve PA-Cre technology, we compare light-dimerization tools and optimize for mammalian expression using a CAG promoter, Magnets, and 2A self-cleaving peptide. To prevent background recombination caused by the high sequence similarity in the dimerization domains, we modify the codons for mouse gene targeting and viral production. Overall, these modifications significantly reduce dark leak activity and improve blue-light induction developing our new version, PA-Cre 3.0. As a resource, …

Regenerative Medicine Therapy: Adipose Derived Extracellular Vesicles In Viral Myocarditis, David Gorelov, Damian N. Di Florio, Gary R. Salomon, Angita Jain, Nick E. Saikaili, Danielle J. Beetler, Swikriti Shrestha, Ming Tian, Joy Wolfram Phd, Delisa Fairweather Phd, Katelyn Bruno Phd, Judith D. Ochrietor Phd

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Objective: Myocarditis, inflammation of the heart muscle, is an autoimmune heart disease that can be caused by viruses, bacteria and toxins. Myocarditis can lead to dilated cardiomyopathy (DCM) and heart failure. Currently there are no disease-specific therapies for treating myocarditis or preventing progression to DCM. Adipose Extracellular Vesicles (AEVs) are lipid bilayer nanoparticles that are released into the outside environment of adipocytes and provide promising regenerative potential for inflammatory diseases like myocarditis.

Methods: Lipoaspirate was obtained from women and men and AEVs isolated from the lipoaspirate using tangential flow filtration. We injected wild type male BALB/c mice with 250uL AEVs …

Elucidation Of The Mechanisms By Which Anesthetics Induce Blood-Brain Barrier Breakdown And Delirium In The Elderly, George A. Godsey Ii

Graduate School of Biomedical Sciences Theses and Dissertations

Delirium is a highly prevalent neuropsychiatric or neurocognitive disorder that presents a major problem to modern healthcare. Patients suffering from delirium normally have a worse prognosis, prolonged hospital stay, increased hospital cost, long-term cognitive impairment, and higher mortality rates. Many factors can predispose one to develop delirium, which makes treating this disorder a daunting task. Unfortunately, delirium is the most common psychiatric syndrome found in the hospital setting. In fact, a form of delirium known as postoperative delirium (POD) is one of the most common postoperative complications faced by elderly patients undergoing surgery.

POD is a major problem in modern …

A Native Function For Ran Translation And Cgg Repeats In Regulating Fragile X Protein Synthesis, Caitlin M. Rodriguez, Shannon E. Wright, Michael G. Kearse, Jill M. Haenfler, Brittany N. Flores, Yu Liu, Marius F. Ifrim, M. Rebecca Glineburg, Amy Krans, Paymaan Jafar-Nejad, Michael A. Sutton, Gary J. Bassell, Jack M. Parent, Frank Rigo, Sami J. Barmada, Peter K. Todd

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Repeat-associated non-AUG-initiated translation of expanded CGG repeats (CGG RAN) from the FMR1 5′-leader produces toxic proteins that contribute to neurodegeneration in fragile X-associated tremor/ataxia syndrome. Here we describe how unexpanded CGG repeats and their translation play conserved roles in regulating fragile X protein (FMRP) synthesis. In neurons, CGG RAN acts as an inhibitory upstream open reading frame to suppress basal FMRP production. Activation of mGluR5 receptors enhances FMRP synthesis. This enhancement requires both the CGG repeat and CGG RAN initiation sites. Using non-cleaving antisense oligonucleotides (ASOs), we selectively blocked CGG RAN. This ASO blockade enhanced endogenous FMRP expression in human …

Kinetics Of Notch Signaling During Osteoclastogenesis, Amber Larissa Framstad

EWU Masters Thesis Collection

Bone remodeling, the process of removing and replacing damaged bone matrix, is a dynamic physiological process essential to maintaining bone composition and integrity. Improper coordination of resorption and formation can lead to pathologic changes in bone composition and quality, as is seen in osteoporosis, a bone disorder most seen in post-metapausal women attributed to decreased estrogen levels. The Notch signal pathway is a highly conserved direct cell communication pathway known to regulate cell proliferation, differentiation and survival in many cell types including the differentiation of osteoclasts from bone marrow macrophages (BMMs). Osteoclastogenesis is initiated in BMMs by receptor activator of …

Combination Of Investigational Cell-Based Therapy And Deep Brain Stimulation To Alter The Progression Of Parkinson’S Disease, Nader El Seblani

Theses and Dissertations--Pharmacy

Parkinson’s disease (PD) is the second most common neurodegenerative disorder and the motor symptoms are caused by progressive loss of midbrain dopamine neurons. There is no current treatment that can slow or reverse PD. Our current “DBS-Plus” clinical trial (NCT02369003) features the implantation in vivo of autologous Schwann cells (SCs) derived from a patient’s sural nerve into the substantia nigra pars compacta (SNpc) in combination with Deep Brain Stimulation (DBS) therapy for treating patients with advanced PD.

The central hypothesis of our research is that transdifferentiated SCs within conditioned nerve tissue will deliver pro-regenerative factors to enhance the survival of …

A "Choose-Your-Own" Classroom-Based Activity That Promotes Scientific Inquiry About Rna Interference, Jeremy L. Hsu

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

RNA interference (RNAi), the process that results in the degradation of a target gene’s mRNA, is a fundamental part of eukaryotic gene regulation and is also an important molecular technique that allows for experimental manipulation of gene expression without altering DNA sequences. Despite the importance of RNAi, there have been relatively few lecture-based activities designed to teach about the consequences of this process and counter common misconceptions. I present here an inquiry-based activity that is centered around a “choose your own experiment” design where students generate hypotheses and critically evaluate their ideas by choosing several simulated experiments. The activity presents …

Restructuring Of The Axon Initial Segment In Mouse Models Of Neurodevelopmental Disorders, Rachel Ali Rodriguez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Neurodevelopmental disorders (NDDs) affect more than 36% of children in countries with low- and middle- incomes (Boivin, 2015; McCoy, 2016). Interestingly, these heterogeneous disorders share a high incidence of epileptic seizures, suggesting a shared pathology. Seizures result when neuronal firing activity becomes disturbed and neurons fire excessively or in unregulated patterns. A key site in the control of neuronal firing patterns is the axon initial segment (AIS), where the local density of proteins and the morphology of the AIS in part determine the firing of neurons. We hypothesized that a disruption in the morphology and/or composition of the AIS can …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

Quantitative Study Of The Antimicrobial Effects Of Silver On The Motility Of Escherichia Coli, Benjamin Russell

Graduate Theses and Dissertations

In recent decades, the number of antibiotic-resistant bacterial infections has grown to become a serious global threat. This rise can be attributed to the widespread misuse of antibiotics and the lack of newly developed drugs to fight resistant organisms. Novel bactericidal substances have, therefore, garnered significant research interest. Silver, due to its powerful antimicrobial effects, is one such substance. Silver is typically most effective in cationic form; however, advancements in nanotechnology have paved the way for the controlled fabrication of nano-silver. Silver nanoparticles have been shown to have increased antibacterial potency for a variety of reasons, including the release of …

Dormant Pathogenic Cd4(+) T Cells Are Prevalent In The Peripheral Repertoire Of Healthy Mice, Anna Cebula, Michal Kuczma, Edyta Szurek, Maciej Pietrzak, Natasha Savage, Wessam R. Elhefnawy, Grzegorz Rempala, Piotr Kraj, Leszek Ignatowicz

Computer Science Faculty Publications

Thymic central tolerance eliminates most immature T cells with autoreactive T cell receptors (TCR) that recognize self MHC/peptide complexes. Regardless, an unknown number of autoreactive CD4+Foxp3⁻ T cells escape negative selection and in the periphery require continuous suppression by CD4+Foxp3⁺ regulatory cells (Tregs). Here, we compare immune repertoires of Treg-deficient and Treg-sufficient mice to find Tregs continuously constraining one-third of mature CD4⁺Foxp3⁻ cells from converting to pathogenic effectors in healthy mice. These dormant pathogenic clones frequently express TCRs activatable by ubiquitous autoantigens presented by class II MHCs on conventional dendritic cells, including selfpeptides that select …

Natural Autoantibodies: Origin, Function And Utility For Diagnosis Of Disease, Abhirup Sarkar

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies (aAbs) by the simplest definitions have been described as antibodies against self-antigens and were exclusively associated with autoimmune diseases. Eventually, studies demonstrated that they are abundant in the blood of all human sera, regardless of age, gender, or the presence or absence of disease, and were thus named as ‘natural autoantibodies’. The underlying reason for their ubiquity has remained elusive, but we have hypothesized that they are responsible for clearing blood-borne cell and tissue debris generated under conditions of health and disease. To test this, we chose to use two widely different disease model systems, namely neurodegenerative diseases and …

The Gsk-3Β-Fbxl21 Axis Regulates Tcap Via Ubiquitin-Mediated Proteasomal Pathway In The Cytoplasm, Jiah Yang

Dissertations and Theses (Open Access)

Protein turnover is one of the most essential mechanisms controlling circadian rhythms. F-Box and Leucine Rich Repeat Protein21 (FBXL21) is a circadian E3 ligase which shows oscillatory mRNA transcripts and protein levels. It was previously found to perform subcellular compartment-specific E3 ligase activities targeting the core clock proteins CRYPTOCHROME(CRY)1/2. Here we identified a new sarcomeric target substrate, Telethonin(TCAP), which also shows circadian oscillation in its mRNA transcript and protein expression and, importantly, interaction with FBXL21 in an anti-phasic manner. Via computational and pharmacological tests, we identified Glycogen Synthase Kinase-3β(GSK-3β) as a regulator of FBXL21. Biochemical and molecular characterizations demonstrated that …

The Expression Of Connexin-43 By Cd11c+ Dendritic Cells Is Required To Maintain Cd4+ Foxp3+ Regulatory T Cell Population In Peripheral Lymphoid Organs, Caroline Titus Miller

Biological Sciences Theses & Dissertations

Foxp3⁺ regulatory T cells (T_R) are an immunosuppressive subset of CD4⁺ T cells that maintain homeostasis of the immune system. They are sustained by the interaction between the Major Histocompatibility Complex (MHC) molecules present on antigen presenting dendritic cells and the T Cell Receptor (TCR) expressed on T_R cells that is specific for the MHC loaded with an antigenic peptide. Here, we show that in addition to MHC/TCR interaction, Connexin-43 (Cx43) expression by dendritic cells is required to maintain the TR cell population. CD11c⁺ dendritic cells represent a major subset of antigen presenting cells. …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Evaluating The Potential Of Repurposing Commercially Available Drugs For The Treatment Of Viral Infections, Brennan Connor Mcewan

Undergraduate Honors Capstone Projects

Viral infections that are often overlooked as common seasonal illnesses such as influenza can rapidly become a public threat. They threaten society as new, more dangerous strains of these common viruses emerge and as strains develop resistance to current vaccines and antiviral treatments (Kochanek, Murphy, Xu, & Tejada-Vera, 2014). To combat this, the development of antiviral treatments with novel mechanisms of action is essential. Repurposing drugs instead of developing new drugs can save years of development time and hundreds of millions of dollars (DiMasi, Hansen, & Grabowski, 2003). To support the effort to discover drugs with unique mechanisms of action, …

Cyclin C: The Story Of A Non-Cycling Cyclin, Jan Jezek, Daniel G J Smethurst, David C Stieg, Z A C Kiss, Sara E Hanley, Vidyaramanan Ganesan, Kai-Ti Chang, Katrina F Cooper, Randy Strich

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The class I cyclin family is a well-studied group of structurally conserved proteins that interact with their associated cyclin-dependent kinases (Cdks) to regulate different stages of cell cycle progression depending on their oscillating expression levels. However, the role of class II cyclins, which primarily act as transcription factors and whose expression remains constant throughout the cell cycle, is less well understood. As a classic example of a transcriptional cyclin, cyclin C forms a regulatory sub-complex with its partner kinase Cdk8 and two accessory subunits Med12 and Med13 called the Cdk8-dependent kinase module (CKM). The CKM reversibly associates with the multi-subunit …

Mechanisms Of Trinucleotide Repeat Instability During Dna Synthesis, Kara Y. Chan

Theses and Dissertations--Toxicology and Cancer Biology

Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a …