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A Functional Analysis of microRNAs in Nicotiana tabacum
(East Carolina University, 2012)
MicroRNAs (miRNAs) are a newly discovered class of endogenous post-transcriptional gene regulators that are typically 20-22 nucleotides in length that do not code for proteins. MiRNAs regulate gene expression by either ...
The role of peroxisome proliferator-activated receptor-gamma in surfactant catabolism in the alveolar macrophage
(East Carolina University, 2009)
Pulmonary alveolar proteinosis (PAP) is a lung disease characterized by surfactant accumulation in the alveolar spaces and alveolar macrophages. Although PAP is rare, surfactant abnormalities occur in many lung diseases ...
CaMKII Protein Expression and Phosphorylation in Mouse Skeletal Muscle Following Atrophy and Hypertrophy
(East Carolina University, 2012)
The maintenance of skeletal muscle mass is vital for life, and elucidation of the molecular mechanisms that control this process is a critical first step towards the development of pharmaceutical treatments for muscle ...
Investigations into the roles of bacteroides fragilis thioredoxins during the oxidative stress response
(East Carolina University, 2011)
The Gram-negative Bacteroides fragilis is the most frequently isolated bacterium from anaerobic infections. Native to the human intestinal tract, it serves a symbiotic role breaking down complex polysaccharides and ...
COMPARATIVE ANALYSIS OF TWO HUMAN CANCER CELL LINES FOLLOWING EXPOSURE TO LOW DOSE RADIATION
(East Carolina University, 2011)
Over the past two decades, studies on the cellular response to very low dose radiation have been revolutionizing historically-held paradigms of cellular radioresponse. Indeed, a host of seemingly contradictory events have ...
The Role of GSK-3[beta] in MCF-7 Breast Cancer Cell Signaling and Drug Resistance
(East Carolina University, 2011)
Glycogen synthase kinase- 3beta (GSK-3beta) is well documented to participate in a complex array of critical cellular processes. This versatile protein is involved in numerous signaling pathways that influence metabolism, ...
Characterizing the Expression Pattern of miR167-Regulated ZmArf3 and ZmArf30 in Maize Inflorescences
(East Carolina University, 2014)
Plant growth and development depends on the activity of meristems, pools of stem cells that generate leaves and other organs. Maize (corn) produces two inflorescences, the tassel and ear, which are patterned by a series ...
PROLACTIN FUNCTION IN ZEBRAFISH DEVELOPMENT
(East Carolina University, 2010)
Extensive studies have implicated a myriad of functional roles for prolactin (PRL) and prolactin receptor (PRLR) across a variety of adult vertebrate species. However, much less is known about the physiological role(s) of ...
Molecular mechanisms of TMEFF2 action in Prostate Cancer
(East Carolina University, 2013)
The transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) is an evolutionarily conserved type I transmembrane protein expressed in the embryo and limited adult tissues, mainly the brain ...
The unique roles of IFE-1, a germline-specific isoform of eukaryotic translation factor 4E, during gametogenesis
(East Carolina University, 2009)
Fertility and embryonic viability are measures of efficient germ cell growth and differentiation. During oogenesis, spermatogenesis and embryogenesis cells initially proliferate then differentiate into specific tissues. New proteins are required for both cell growth and differentiation, requiring qualitative and quantitative changes in protein synthesis. During late gametogenesis and early embryogenesis the expression of the appropriate proteins is a primarily due to translational control. Translational control of mRNAs is mediated in part by eukaryotic initiation factor 4E (eIF4E). eIF4E binds the methylated 5' cap of mRNA and recruits it to the ribosome. The nematode worm C.elegans expresses five isoforms of eIF4E (termed IFE-1 through 5). IFE-1 is expressed primarily in the germline and is the only isoform that associates with P granules by binding directly to PGL-1. P granules are ribonucleoprotein particles (RNPs) that contain stored mRNAs and proteins needed for oogenesis and early embryogenesis. Using a strain that lacks IFE-1, I assessed the translational efficiency of maternal mRNAs bound and not bound to P granules by polysome fractionation. Translation of pos-1, pal-1, mex-1, oma-1, ced-4 and glp-1 mRNAs was inefficient in the ife-1 strain relative to wild type worms. GAPDH (gpd-3) mRNA translation was not affected. We also observed differences in the pattern of expression of the MEX-1 protein during oogenesis. In males, secondary spermatocytes failed to complete cytokinesis at 25°C in absence of IFE-1. Males deficient of IFE-1 therefore lacked mature sperm. In addition, ife-1 spermatocytes prematurely accumulated pro-apoptotic CED-4, homolog to mammalian Apaf-1, during spermatogenesis. In ife-1 worms fertility was decreased by 80% due to decreased viability of both oocytes and spermatocytes. Our data indicate two unique roles for eIF4E (IFE-1 isoform) in late oogenesis and spermatogenesis. We suggest that IFE-1 preferentially recruits regulated mRNAs at critical times during germ cell development. ...