Molecular Biology Commons^™

Validating Functional Mechanisms For Non-Coding Genetic Variants Associated With Complex Traits, Cynthia Ann Kalita

Wayne State University Dissertations

Genome-wide association studies (GWAS) have identified a large number of genetic variants associated with disease as well as normal phenotypic variation for complex traits. However challenges remain in determining the functional relevance of human DNA sequence variants. Even after fine mapping, most variants are located in non-coding regions making it difficult to infer mechanisms linking individual genetic variants with the disease trait. In addition, we do not know under which environmental conditions the sequence variants have a functional impact, and whether they become one of many factors involved in complex phenotypes at the organismal level.

Chapter 1 describes computational methods …

Asymmetric Patterns Of Small Molecule Transport After Nanosecond And Microsecond Electropermeabilization, Esin B. Sözer, C. Florencia Pocetti, P. Thomas Vernier

Bioelectrics Publications

Imaging of fluorescent small molecule transport into electropermeabilized cells reveals polarized patterns of entry, which must reflect in some way the mechanisms of the migration of these molecules across the compromised membrane barrier. In some reports, transport occurs primarily across the areas of the membrane nearest the positive electrode (anode), but in others cathode-facing entry dominates. Here we compare YO-PRO-1, propidium, and calcein uptake into U-937 cells after nanosecond (6 ns) and microsecond (220 µs) electric pulse exposures. Each of the three dyes exhibits a different pattern. Calcein shows no preference for anode- or cathode-facing entry that is detectable with …

Expression And Function Of Nuclear Receptor Coactivator 4 Isoforms In Transformed Endometriotic And Malignant Ovarian Cells, Stephanie Rockfield, Idhaliz Flores, Meera Nanjundan

Molecular Biosciences Faculty Publications

Iron is proposed to contribute to the transition from endometriosis to specific subtypes of ovarian cancers (OVCAs). Regulation of intracellular iron occurs via a ferritinophagic process involving NCOA4 (Nuclear Receptor Coactivator 4), represented by two major isoforms (NCOA4α and NCOA4β), whose contribution to ovarian cancer biology remains uninvestigated. We thus generated transformed endometriotic cells (via HRAS^V12A, c-MYC^T58A, and p53 inactivation) whose migratory potential was increased in response to conditioned media from senescent endometriotic cells. We identified elevated NCOA4 mRNA in transformed endometriotic cells (relative to non-transformed). Knockdown of NCOA4 increased ferritin heavy chain (FTH1) and p21 …

Mbd2-Cp2c Loop Drives Adult-Type Globin Gene Expression And Definitive Erythropoiesis, Min Young Kim, Ji Sook Kim, Seung Han Son, Chang Su Lim, Hea Young Eum, Dae Hyun Ha, Mi Ae Park, Eun Jung Baek, Buom-Yong Ryu, Ho Chul Kang, Vladimir N. Uversky, Chul Geun Kim

Molecular Biosciences Faculty Publications

During hematopoiesis, red blood cells originate from the hematopoietic stem cell reservoir. Although the regulation of erythropoiesis and globin expression has been intensively investigated, the underlining mechanisms are not fully understood, including the interplay between transcription factors and epigenetic factors. Here, we uncover that the Mbd2-free NuRD chromatin remodeling complex potentiates erythroid differentiation of proerythroblasts via managing functions of the CP2c complexes. We found that both Mbd2 and Mbd3 expression is downregulated during differentiation of MEL cells in vitro and in normal erythropoiesis in mouse bone marrow, and Mbd2 downregulation is crucial for erythropoiesis. In uninduced MEL cells, the Mbd2-NuRD …

Yeast Lifespan Variation Correlates With Cell Growth And Sir2 Expression, Jessica T. Smith, Jill W. White, Huzefa Dungrawala, Hui Hua, Brandt L. Schneider

Molecular Biosciences Faculty Publications

Isogenic wild type yeast cells raised in controlled environments display a significant range of lifespan variation. Recent microfluidic studies suggest that differential growth or gene expression patterns may explain some of the heterogeneity of aging assays. Herein, we sought to complement this work by similarly examining a large set of replicative lifespan data from traditional plate assays. In so doing, we reproduced the finding that short-lived cells tend to arrest at senescence with a budded morphology. Further, we found that wild type cells born unusually small did not have an extended lifespan. However, large birth size and/or high inter-generational growth …

Radx Modulates Rad51 Activity To Control Replication Fork Protection, Kamakoti P. Bhat, Archana Krishnamoorthy, Huzefa Dungrawala, Edwige B. Garcin, Mauro Modesti, David Cortez

Molecular Biosciences Faculty Publications

RAD51 promotes homologous recombination repair (HR) of double-strand breaks and acts during DNA replication to facilitate fork reversal and protect nascent DNA strands from nuclease digestion. Several additional HR proteins regulate fork protection by promoting RAD51 filament formation. Here, we show that RADX modulates stalled fork protection by antagonizing RAD51. Consequently, silencing RADX restores fork protection in cells deficient for BRCA1, BRCA2, FANCA, FANCD2, or BOD1L. Inactivating RADX prevents both MRE11- and DNA2-dependent fork degradation. Furthermore, RADX overexpression causes fork degradation that is dependent on these nucleases and fork reversal. The amount of RAD51 determines the fate of stalled replication …

Septal Secretion Of Protein A In Staphylococcus Aureus Requires Seca And Lipoteichoic Acid Synthesis, Wenqi Yu, Dominique Missiakas, Olaf Schneewind

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus are secreted across septal membranes for assembly into the bacterial cross-wall. This localized secretion requires the YSIRK/GXXS motif signal peptide, however the mechanisms supporting precursor trafficking are not known. We show here that the signal peptide of staphylococcal protein A (SpA) is cleaved at the YSIRK/GXXS motif. A SpA signal peptide mutant defective for YSIRK/GXXS cleavage is also impaired for septal secretion and co-purifies with SecA, SecDF and LtaS. SecA depletion blocks precursor targeting to septal membranes, whereas deletion of secDF diminishes SpA secretion into the cross-wall. Depletion of LtaS blocks lipoteichoic acid synthesis and …

Functional Characterization Of Scaffold Protein Shoc2, Hyein Jang

Theses and Dissertations--Molecular and Cellular Biochemistry

Signaling scaffolds are critical for the correct spatial organization of enzymes within the ERK1/2 signaling pathway and proper transmission of intracellular information. However, mechanisms that control molecular dynamics within scaffolding complexes, as well as biological activities regulated by the specific assemblies, remain unclear.

The scaffold protein Shoc2 is critical for transmission of the ERK1/2 pathway signals. Shoc2 accelerates ERK1/2 signaling by integrating Ras and RAF-1 enzymes into a multi-protein complex. Germ-line mutations in shoc2 cause Noonan-like RASopathy, a disorder with a wide spectrum of developmental deficiencies. However, the physiological role of Shoc2, the nature of ERK1/2 signals transduced through this …

Detection Of Local Steroidogenic Enzyme Gene Expression In Brown Anoles, Ada Spahija

Honors Program Theses

The endocrine system in vertebrates responds to stress by releasing steroid hormones, mainly glucocorticoids (GC), which increase blood glucose levels to supply key organs and muscles with energy needed for survival. Steroid hormones are synthesized via an enzymatic pathway that converts cholesterol into either GCs, androgens, or estrogens in a step-wise manner. The adrenal cortex is known to produce GCs, but evidence suggests that individual organs can also produce steroid hormones de novo in response to stress. This study aims to quantify gene expression of four steroidogenic enzymes, encoded by CYP19A1, CYP17A1, StAR, and HSD17ß3 genes, via qRT-PCR to determine …

Proteogenomic Study Of Nitrogen-Fixing Cyanobacterium Anabaena Cylindrica, Yeyan Qiu

Electronic Theses and Dissertations

Cyanobacteria are gram-negative photosynthetic bacteria. In some filamentous cyanobacteria such as Anabaena cylindrica, every 10^th to 20^th vegetative cells can differentiate into nitrogen fixing heterocysts. Heterocyst can induce the neighboring cells developing into spore-like akinetes. The specialized cell functions and resourceful networks have contributed to the prosperity of cyanobacteria for over 2 billion years, but the genetic mechanisms for multi-cellular differentiation are barely known, especially for akinete formation. The heterocysts, akinetes and vegetative cells of Anabaena cylindrica were isolated for proteomic study. This study identified a total of 1395 proteins, including 664 proteins from akinetes, 751 proteins from …

Cold Atmospheric Plasma As A Potential Tool For Multiple Myeloma Treatment, Dehui Xu, Yujing Xu, Qingjie Cui, Dingxin Liu, Zhijie Liu, Xiaohua Wang, Yanjie Yang, Niaojuan Feng, Rong Liang, Hailan Chen, Kai Ye, Michael G. Kong

Bioelectrics Publications

Multiple myeloma (MM) is a fatal and incurable hematological malignancy thus new therapy need to be developed. Cold atmospheric plasma, a new technology that could generate various active species, could efficiently induce various tumor cells apoptosis. More details about the interaction of plasma and tumor cells need to be addressed before the application of gas plasma in clinical cancer treatment. In this study, we demonstrate that He+O₂ plasma could efficiently induce myeloma cell apoptosis through the activation of CD95 and downstream caspase cascades. Extracellular and intracellular reactive oxygen species (ROS) accumulation is essential for CD95-mediated cell apoptosis in response …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Zebrafish Model Of Mll-Rearranged Acute Myeloid Leukemia, Alex J. Belt

Theses and Dissertations

Acute myeloid leukemia (AML) is the second most common type of leukemia and accounts for 80% of adult acute leukemia cases and is characterized by the accumulation of poorly or undifferentiated myeloid blast cells. Standard treatment includes chemotherapy, which if unsuccessful, is followed by more rigorous chemotherapy as well as stem cell transplantation. Considering most patients are over the age of 45, these more rigorous therapies are not always possible, and as such, new therapies must be developed. Furthermore, AML patients harboring a chromosomal rearrangement involving Multiple Lineage Leukemia (MLL) that results in the expression of an MLL fusion protein …

Coordination Of Different Ligands To Copper(Ii) And Cobalt(Iii) Metal Centers Enhances Zika Virus And Dengue Virus Loads In Both Arthropod Cells And Human Keratinocytes, Shovan Dutta, Michael J. Celestine, Supreet Khanal, Alexis Huddleston, Colin Simms, Jessa Faye Arca, Amlam Mitra, Loree Heller, Piotr Kraj, Michael Ledizet, John F. Anderson, Girish Neelakanta, Alvin A. Holder, Hameeda Sultana

Biological Sciences Faculty Publications

Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex …

Rack1 Is A Critical Component In Ires-Mediated Translation, Ethan Asher Lafontaine

Legacy Theses & Dissertations (2009 - 2024)

Due to its sheer number of interacting partners, core ribosomal protein RACK1 is a key player in many cellular processes and has been shown to play a vital role of translation initiation of the Hepatitis C virus RNA. The HCV 5′ untranslated region contains an internal ribosome entry site. IRES-mediated translation is a process employed in eukaryotes by select viruses and some cellular mRNAs by which translation initiation bypasses the canonical mRNA cap-dependent pathway by means of an RNA secondary structure (the IRES). While cap-dependent translation requires the recruitment of a suite of initiation factors, IRES-mediated translation requires few to …

Cyclic Adenosine Monophosphate Signaling In Mycobacterium Tuberculosis : New Insights Into A Universal Second Messenger, Richard Mcpherson Johnson

Legacy Theses & Dissertations (2009 - 2024)

Despite being the focus of intense research for many years Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), remains the deadliest bacterial pathogen plaguing mankind today. Humans are the sole host and reservoir for Mtb, and Mtb has coevolved closely with its human host for thousands of years. Mtb currently infects over two billion people worldwide and over 1.5 million people die from TB each year, arguably making Mtb the most successful bacterial pathogen on the planet.

Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora

Legacy Theses & Dissertations (2009 - 2024)

Germ cells are the only cell in an organism that have the capacity to give rise to a new organism and are passed from one generation to the next. Therefore, to maintain this unique ability of totipotency and immortality, germ cells execute specific functions, such as, repression of a somatic program and contour a germ line-specific pre- and post-transcriptional gene regulatory landscape. In many sexually reproducing organisms, germ cells are formed during the earliest stages of embryogenesis and undergoes several stages of development to eventually get encapsulated by the somatic cells of the gonad. Once, in the gonad, the germ …

Chromatin-Signaling Axis Orchestrates The Formation Of Germline Stem Cell Differentiation Niche In Drosophila, Maitreyi Upadhyay

Legacy Theses & Dissertations (2009 - 2024)

Stem cells have the unique capability of self-renewing into stem cells and differentiating into several terminal cell types. Loss of either of these processes can lead to aging, progression towards degenerative diseases and cancers. Insight into how self-renewal and differentiation are regulated will have tremendous therapeutic impact. Drosophila is an excellent model system for stem cell study due to the availability of various mutants, markers and RNAi technology. In order to study stem cell biology, we use female Drosophila gonads, whose stem cell population – the germline stem cells (GSCs) gives rise to gametes.

Evaluating The Effects Of Vitamin D And Hyaluronic Acid On The Radiation Response Of Normal Mammary Epithelial Cells And Breast Cancer Cells, Lauren Rose-Boehnlein

Legacy Theses & Dissertations (2009 - 2024)

Each year over 200,000 American women are diagnosed with breast cancer. Nearly 25% of them are told they have triple negative breast cancer (TNBC), the most aggressive and lethal form, with few targeted treatment options beyond the standard regimen of surgery, chemotherapy, and radiotherapy. Over 40% of TNBC cases overexpress hyaluronan synthase 2 (HAS2), a cell membrane enzyme that synthesizes the extracellular matrix (ECM) polysaccharide hyaluronic acid (HA). HA binds to and activates the cell surface receptor CD44, which is highly enriched on the cell surface of cancer stem cells (CSCs) and has been associated with epithelial to mesenchymal transition …

Retinoic Acid Receptor Isoform-Specific Control Of Mouse Salivary Gland Development And Regeneration, Kara Desantis

Legacy Theses & Dissertations (2009 - 2024)

Controlled expansion and differentiation of progenitor cell populations is essential for organogenesis followed by continued maintenance of the population into and through adulthood. As the K5+ basal cell population is regulated by retinoic acid signaling, we interrogated the contribution of specific RAR isoforms to the regulation of these cells during submandibular salivary gland (SMG) organogenesis and regeneration. Retinoic acid has previously been shown to be involved in the development of the salivary gland, and recently, lack of retinoid signaling has been shown to impact the K5+ population of basal progenitor cells. Since retinoic acid is known to exert stimulatory effects …