View All Items

Title: AN RNAI SCREEN TO IDENTIFY COMPONENTS OF A POLYAMINE TRANSPORT SYSTEM.
Creator: Foley, Adam J, Von Kalm, Laurence, University of Central Florida
Abstract / Description: Polyamines, specifically putrescine, spermidine, and spermine, are small cationic molecules found in all organisms. Cells can biosynthetically make these molecules, or alternatively, they can be transported from the extracellular environment. Malignant cells have been shown to require relatively high amounts of polyamines. There is a chemotherapeutic agent, DFMO, used to block the biosynthesis of polyamines. Many malignant cells can circumvent DFMO therapy by activating their transport system...
Show morePolyamines, specifically putrescine, spermidine, and spermine, are small cationic molecules found in all organisms. Cells can biosynthetically make these molecules, or alternatively, they can be transported from the extracellular environment. Malignant cells have been shown to require relatively high amounts of polyamines. There is a chemotherapeutic agent, DFMO, used to block the biosynthesis of polyamines. Many malignant cells can circumvent DFMO therapy by activating their transport system. A potential solution is to simultaneously block biosynthesis and transport of polyamines. However, little is known about the polyamine transport system in higher eukaryotes. This thesis aims to add to the basic biological understanding of the polyamine transport system, as well as contribute to our understanding of the way in which malignant cells are able to sustain rapid growth. This was done by screening six candidate genes believed to be involved in the polyamine transport system. These six genes were identified using various bioinformatics databases. They were screened using RNAi to knock down each gene of interest and by using an assay developed in our lab. One of the genes, RabX6, may play a possible role in the transport of putrescine.
Show less
Date Issued: 2017
Identifier: CFH2000187, ucf:46043
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000187

Title: GENETIC ANALYSIS OF RHOA SIGNALING DURING EPITHELIAL MORPHOGENESIS IN DROSOPHILA.
Creator: Leppert, Amanda Fitch, von Kalm, Laurence, University of Central Florida
Abstract / Description: Epithelial morphogenesis is contingent upon cell shape changes. Cell shape changes are the driving force for the metamorphosis of the adult Drosophila leg from the leg imaginal disc precursor. Genetic analysis has identified several Drosophila genes involved in regulating cell shape changes during leg disc morphogenesis. These include members of the RhoA signaling pathway and the product of the Stubble-stubbloid (Sb-sbd) locus, a transmembrane serine protease. Mutations in the Sb-sbd gene...
Show moreEpithelial morphogenesis is contingent upon cell shape changes. Cell shape changes are the driving force for the metamorphosis of the adult Drosophila leg from the leg imaginal disc precursor. Genetic analysis has identified several Drosophila genes involved in regulating cell shape changes during leg disc morphogenesis. These include members of the RhoA signaling pathway and the product of the Stubble-stubbloid (Sb-sbd) locus, a transmembrane serine protease. Mutations in the Sb-sbd gene interact genetically with the members of the RhoA signaling pathway, however the nature of the relationship between Sb-sbd serine protease activity and RhoA signaling is not understood.To identify additional components of the RhoA signaling pathway that may help us to understand the role of the Sb-sbd protease in RhoA signaling the Drosophila genome was systematically scanned for genes that interact with Sb-sbd and RhoA mutations using deletions/deficiencies of specified regions of each chromosome. A total of 201 deficiencies uncovering approximately 84.9-91% of the euchromatic genome and spanning the X, second, and third chromosoms were tested. Of the 201 deficiencies tested, five putative interacting genetic regions and one gene within these deficiencies were identified. The candidate gene Eip78C encodes a nuclear steroid hormone receptor previously identified as having an important role in metamorphosis.
Show less
Date Issued: 2004
Identifier: CFE0000046, ucf:46104
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000046

Title: NOTOPLEURAL MUTATIONS ENHANCE DEFECTS IN IMAGINAL DISC EPITHELIAL MORPHOGENESIS AND MACROCHETE ELONGATION ASSOCIATED WITH MUTATIONS IN THE STUBBLE-STUBBLOID LOCUS.
Creator: Ruggiero, Robert, von Kalm, Laurence, University of Central Florida
Abstract / Description: The Stubble-stubbloid locus encodes a transmembrane serine protease (Stubble) necessary for the proper formation of sensory bristles, and the morphogenesis of leg and wing epithelia. Genetic and cell biological analysis indicate a role for Stubble in actin cytoskeletal dynamics and cell shape changes in developing epithelia and bristles. Previously reported genetic interactions between Stubble and the Rho1 signaling pathway suggest Stubble influences actin cytoskeleton dynamics in developing...
Show moreThe Stubble-stubbloid locus encodes a transmembrane serine protease (Stubble) necessary for the proper formation of sensory bristles, and the morphogenesis of leg and wing epithelia. Genetic and cell biological analysis indicate a role for Stubble in actin cytoskeletal dynamics and cell shape changes in developing epithelia and bristles. Previously reported genetic interactions between Stubble and the Rho1 signaling pathway suggest Stubble influences actin cytoskeleton dynamics in developing imaginal discs through interactions with the Rho1 pathway. This work will discuss a genetic screen conducted to further investigate the role of Stubble in bristle and imaginal disc morphogenesis. From 50,000 EMS-mutagenized chromosomes 12 enhancers of the recessive sbd201 allele were identified, including 6 new sbd alleles. Consistent with the current understanding of genetic interactions regulating imaginal disc morphogenesis, mutations in two Rho1 pathway genes, zipper (2 alleles) and Rho1, were isolated. Additionally, three new mutant enhancers of sbd201 were isolated, one of which has been identified as an allele of the cadherin gene Dacshous, another as an allele of the muscle myosin heavy chain gene, and the last as an allele of Notopleural (Np). Dominant and recessive mutations in the Stubble locus interact with the Np allele identified in this screen, in regards to both limb and bristle development, respectively. Mutations in the Np locus were first identified in 1936, but this locus remains poorly characterized and has never been cloned The genetic and phenotypic characterization of Np will be discussed along with experiments that have mapped the position of the Np locus to a 50kb region at the border of the 44F12, 45A1 cytological regions.
Show less
Date Issued: 2006
Identifier: CFE0001347, ucf:46986
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001347

Title: MAPPING AND CHARACTERIZATION OF 18-5 AND 12-5, GENES WHICH POTENTIALLY LINK THE RHOA SIGNALING PATHWAY TO THE ECDYSONE RESPONSE IN DROSOPHILA EPITHELIAL MORPHOGENESIS.
Creator: Fox, Samuel, von Kalm, Laurence, University of Central Florida
Abstract / Description: Systemic steroid hormone and intracellular signaling pathways are known to act cooperatively during the development of vertebrate and invertebrate epithelia. However, the mechanism of this interaction is poorly understood. Morphogenesis of Drosophila leg imaginal disc epithelia is regulated both by the steroid hormone 20-hydroxyecdysone (ecdysone) and the RhoA GTPase signaling pathway. Recent evidence suggests that these pathways act cooperatively to control imaginal disc morphogenesis. Thus,...
Show moreSystemic steroid hormone and intracellular signaling pathways are known to act cooperatively during the development of vertebrate and invertebrate epithelia. However, the mechanism of this interaction is poorly understood. Morphogenesis of Drosophila leg imaginal disc epithelia is regulated both by the steroid hormone 20-hydroxyecdysone (ecdysone) and the RhoA GTPase signaling pathway. Recent evidence suggests that these pathways act cooperatively to control imaginal disc morphogenesis. Thus, leg imaginal disc morphogenesis is an excellent system in which to study the interaction of steroid hormone and intracellular signaling pathways. We have identified mutations in three genes, 12-5, 18-5, and 31-6, with roles in the morphogenesis of leg epithelia. Of particular interest, these mutations interact genetically with each other, mutations in the RhoA signaling pathway, and the ecdysone regulated Sb-sbd (Stubble) transmembrane serine protease. This suggests that the 12-5, 18-5, and 31-6 gene products may link hormone and RhoA signaling responses. The goal of this research was to identify and characterize the 18-5 and 12-5 genes in order to discern the mechanistic relationship between the RhoA pathway and ecdysone hierarchy.18-5 and 12-5 were precisely mapped to molecular locations within the Drosophila genome utilizing a P-element recombination mapping technique. This work narrowed the location of the 18-5 locus to within an interval of 112 kb within the Drosophila genome sequence. This interval contains 17 known and predicted genes. I also mapped the location of the 12-5 locus to a 2.6 Mb interval of the 2nd chromosome. Based on phenotypic analyses and the site of the molecularly mapped interval, a candidate gene for the 18-5 mutation was identified. Sequence analysis of the candidate gene was inconclusive and requires further analysis. Genetic interaction assays indicate that the 18-5 gene product acts upstream or at the level of Rho kinase in the RhoA signaling pathway.
Show less
Date Issued: 2006
Identifier: CFE0001290, ucf:46882
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001290

Title: STRUCTURE-FUNCTION ANALYSIS OF THE DROSOPHILA STUBBLE TYPE II TRANSMEMBRANE SERINE PROTEASE.
Creator: Morgan, Rachel, von Kalm, Laurence, University of Central Florida
Abstract / Description: Hormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important...
Show moreHormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important roles in the development and homeostasis of a number of mammalian tissues. Aberrant expression of TTSPs is linked to several human disorders, including deafness, heart and respiratory disease and cancer. However, the mechanism by which these proteases function remains unknown. The ecdysone-responsive Stubble TTSP of Drosophila serves as a good model in which to study the functional mechanism of the TTSP family. The Stubble protease interacts with the intracellular Rho1 (RhoA) pathway to control epithelial development in imaginal discs. The Rho1 signaling pathway regulates cellular behavior via control of gene expression and actin cytoskeletal dynamics. However, the mechanism by which the Stubble protease interacts with the Rho1 pathway to control epithelial development, in particular leg imaginal disc morphogenesis, has yet to be elucidated. The Stubble protein consists of several conserved domains. One approach to a better understanding of the mechanism of action of Stubble in regulating Rho1 signaling is to define which of the conserved domains within the protease are required for proper function. Sequence analysis of twelve recessive Stubble mutant alleles has revealed that the proteolytic domain is essential for proper function. Alleles containing mutations which disrupt regions of the protease domain necessary for protease activation or substrate binding, as well as those with deletions or truncations that remove some portion of the proteolytic domain, result in defective epithelial development in vivo. In contrast, mutations in other regions of the Stubble protein, including the disulfide-knotted and cytoplasmic domains, were not observed. Another important step for defining the connection between Stubble and Rho1 signaling is to identify a Stubble target that acts as an upstream regulator of the Rho1 pathway. We performed a genetic screen in which 97 of the 147 Drosophila non-olfactory and non-gustatory G-protein-coupled receptors (GPCRs), a family of proteins that has been shown to be protease-activated and to activate Rho1 signaling, were tested for interactions with a mutant allele of Stubble. We found 4 genomic regions uncovering a total of 7 GPCRs that interact genetically when in heterozygous combination with a Stubble mutant. Further analysis of these genes is necessary to determine if any of these GPCRs is targeted by Stubble during activation of the Rho1 pathway.
Show less
Date Issued: 2008
Identifier: CFE0002285, ucf:47875
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002285

Title: IDENTIFICATION OF FABRICS LIKELY TO COLLECT AND DISPERSE FEL D 1.
Creator: Jones, Mary, von Kalm, Laurence, University of Central Florida
Abstract / Description: Individuals sensitive to domestic cat allergen Fel d 1 experience a variety of symptoms including eye irritation, respiratory irritation, asthma, and severe respiratory distress. Fel d 1 is a protein produced in the saliva and on the skin of domestic cats. Previous studies have demonstrated that Fel d 1 adheres to clothing, upholstery, and human hair and has been found in non-cat environments in levels high enough to cause allergic reactions in sensitive individuals. In a general sense, two...
Show moreIndividuals sensitive to domestic cat allergen Fel d 1 experience a variety of symptoms including eye irritation, respiratory irritation, asthma, and severe respiratory distress. Fel d 1 is a protein produced in the saliva and on the skin of domestic cats. Previous studies have demonstrated that Fel d 1 adheres to clothing, upholstery, and human hair and has been found in non-cat environments in levels high enough to cause allergic reactions in sensitive individuals. In a general sense, two very different approaches have been adopted to study Fel d 1. One area of the literature focuses on the molecular biology of Fel d 1 and its functions at the cellular level. These studies hold long-term promise for an effective clinical response to this persistent allergen. An entirely separate literature focuses on immediate practical solutions that remove Fel d 1 from the domestic environment. Within this literature there has been minimal emphasis on the possibility that different fabrics may have different affinities for Fel d 1. Therefore, the affinity of Fel d 1 for different fabrics is the focus of this study. The findings from this study will be of use in reducing allergic reactions in sensitive individuals through the choice of appropriate fabrics in clothing and upholstery. Forty domestic household cats were chosen for this study. Each cat was rubbed, in a manner similar to petting, with an assembled fabric square based on a Latin-square design. Each Latin-square design consisted of a 6x6 fabric grid and included the fabrics silk dupioni, wool suiting, cotton denim, cotton damask, polyester suede and polyester knit. The random organization of the fabrics into the grid removed bias for the location of fabrics within the square during Fel d 1 collection. After rubbing, the Latin-square fabric block was disassembled and Fel d 1 was extracted from each fabric type and analyzed via quantitative ELISA. The results were statistically analyzed with a univariate ANOVA. Fabrics significantly differ (p<0.001) in Fel d 1 retention and fall into three groups. Silk dupioni collected the least amount of Fel d 1. Wool suiting, cotton denim and cotton damask were intermediate in Fel d 1 collection, while polyester suede and polyester knit collected the highest amounts of Fel d 1. Samples were also collected for a time study to determine if Fel d 1 bound on fabric degrades, or otherwise diminishes, over time. 14 weeks (approximately 3 months) after collection, Fel d 1 was extracted from fabrics and quantified by ELISA. A paired T-test was used to evaluate changes in Fel d 1 levels on specific fabrics over the 14 week period. When compared to extractions performed immediately after exposure, the amount of Fel d 1 released from specific fabrics after 14 weeks was significantly reduced. From these studies I conclude that an individual allergic to Fel d 1 may be able to limit their allergen exposure by selecting fabrics less likely to collect the allergen for their environment. Natural fibers (silk, wool, and cotton) collected less Fel d 1 than polyester fabrics, suggesting that natural fibers are recommended over fabrics containing polyester for persons allergic to cats.
Show less
Date Issued: 2011
Identifier: CFE0003963, ucf:48710
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0003963

Title: STUDIES OF NORSPERMIDINE UPTAKE IN DROSOPHILA SUGGEST THE EXISTENCE OF MULTIPLE POLYAMINE TRANSPORT PATHWAYS.
Creator: Dieffenbach, Michael, Von Kalm, Laurence, Teter, Kenneth, University of Central Florida
Abstract / Description: Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-?-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport....
Show morePolyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-?-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding the transport system would allow us to identify compounds that inhibit polyamine transport, which could then be used in tandem with DFMO to treat cancer. Our laboratory has identified one gene in Drosophila, called CG32000, as a component of this transport system, and numerous other candidate genes remain to be tested. To better characterize this system, this project investigated the ability of the Drosophila transport system to take up a toxic polyamine analogue called norspermidine, with the initial goal of developing a new screening method to find polyamine transport genes. My experiments have demonstrated significant differences in norspermidine uptake and toxicity between C. elegans and Drosophila which may imply a secondary polyamine transport system in higher eukaryotes. In the long term, it is hoped that this thesis will facilitate the development of more effective cancer medications by providing new information about the polyamine transport system.
Show less
Date Issued: 2018
Identifier: CFH2000294, ucf:45869
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000294

Title: INVESTIGATING THE ROLE OF NEURONAL AGING IN FRAGILE X-ASSOCIATED TREMOR/ATAXIA SYNDROME.
Creator: Hencak, Katlin Marie, von Kalm, Laurence, Southwell, Amber, University of Central Florida
Abstract / Description: Fragile X-associated tremor/ataxia syndrome (FXTAS) is an X-linked late-onset neurodegenerative disorder caused by a noncoding trinucleotide repeat expansion in the FMR1 gene. This gene produces fragile x mental retardation protein (FMRP), an RNA binding protein whose targets are involved in brain development and synaptic plasticity. One of the proposed mechanisms of FXTAS pathogenesis is an RNA gain-of-function in which the repeat expansion causes toxic mRNA that sequesters important...
Show moreFragile X-associated tremor/ataxia syndrome (FXTAS) is an X-linked late-onset neurodegenerative disorder caused by a noncoding trinucleotide repeat expansion in the FMR1 gene. This gene produces fragile x mental retardation protein (FMRP), an RNA binding protein whose targets are involved in brain development and synaptic plasticity. One of the proposed mechanisms of FXTAS pathogenesis is an RNA gain-of-function in which the repeat expansion causes toxic mRNA that sequesters important proteins in the cell, interfering with their functions. Another suggested method of pathogenesis is through a mutant protein called FMRpolyG. This protein results from repeat-associated non-AUG (RAN) translation, in which the expanded repeats are translated where they otherwise would not be. This protein co-localizes with intranuclear inclusions and nuclear membrane proteins, causing disorganization of the nuclear lamina in FXTAS patient brain samples and neurons differentiated from FXTAS patient-derived induced pluripotent stem cells (iPSCs). iPSC technology involves reprogramming an adult somatic cell back to an embryonic-like state, allowing it to be differentiated into all cell types. A limit with iPSCs, though, is modeling late-onset disorders because the cells lose all age-related features during reprogramming. Progerin, a truncated form of the lamin A protein, has been used to age neurons differentiated from Parkinson Disease (PD) patient-derived iPSCs. Progerin-mediated aging was found to unmask PD-like phenotypes in those neurons, making it a promising technology for modeling late-onset disorders such as FXTAS. In this study, we investigated the link between the aging process and FXTAS pathogenesis in neurons differentiated from FXTAS patient-derived iPSCs with the use of progerin. Progerin transduction was successful in aging the FXTAS neurons. The presence of FMRpolyG was confirmed and an interaction with Lap2b was observed. In some neurons, there was also an observed interaction between FMRpolyG and progerin. Overall, this data suggests that there is an interaction between the mutant FMRpolyG protein and the nuclear membrane during aging, which may contribute to the cell death that causes neurodegeneration in FXTAS patients.
Show less
Date Issued: 2019
Identifier: CFH2000554, ucf:45678
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000554

Drosophila (3)	+ -
Rho1 (2)	+ -
RhoA (2)	+ -
Stubble (2)	+ -
epithelial morphogenesis (2)	+ -

12-5 (1)	+ -
18-5 (1)	+ -
Allergy (1)	+ -
Asthma (1)	+ -
Cancer (1)	+ -
Cat Allergen (1)	+ -
ELISA (1)	+ -
Epithelial morphogenesis (1)	+ -
Fabric (1)	+ -
Fel d 1 (1)	+ -
G protein-coupled receptor (1)	+ -
GPCR (1)	+ -
Notopleural (1)	+ -
Polyamine Transport (1)	+ -
Polyamines (1)	+ -
Protein (1)	+ -
Rho (1)	+ -
Stubble-stubbloid (1)	+ -
TTSP (1)	+ -
actin cytoskeleton (1)	+ -
aging (1)	+ -
contractile belt (1)	+ -
ecdysone (1)	+ -
epithelia (1)	+ -
imaginal disc (1)	+ -

ETD Collection (5)	+ -
Honors Collection (3)	+ -

University of Central Florida (8)	+ -
von Kalm, Laurence (6)	+ -
Von Kalm, Laurence (2)	+ -
Dieffenbach, Michael (1)	+ -
Foley, Adam J (1)	+ -

Fox, Samuel (1)	+ -
Hencak, Katlin Marie (1)	+ -
Jones, Mary (1)	+ -
Leppert, Amanda Fitch (1)	+ -
Morgan, Rachel (1)	+ -
Ruggiero, Robert (1)	+ -
Southwell, Amber (1)	+ -
Teter, Kenneth (1)	+ -

Search In

Sort Results By:

Narrow results by:

Topical Subject

Collection

Type of Resource

Language

Creator

Format

Owner