Current Search: Cellular signal transduction. (x)
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- Title
- Evaluation of marine sponge metabolites for cytotoxicity and signal transduction activity.
- Creator
- Longley, Ross E., McConnell, O. J., Essich, E., Harmody, Dedra K., Harbor Branch Oceanographic Institute
- Date Issued
- 1993
- PURL
- http://purl.flvc.org/FCLA/DT/3318961
- Subject Headings
- Marine metabolites, Sponges --Research, Cell-mediated cytotoxicity, Cellular signal transduction
- Format
- Document (PDF)
- Title
- Characterization of the motor protein, KIF9, in mammalian cell mitotic progression.
- Creator
- Hoke, Jordan, Harriet L. Wilkes Honors College
- Abstract/Description
-
The kinesin family of microtubule motors is divided into subfamilies based on structure and function. KIF9, founder of the Kinesin-9 family, has been found to interact with the GTPase Gem. Subsequent studies have shown that KIF9 is vital for flagellar movement and podosome regulation. Previous work has proposed KIF9 is required for microtubule organization as well as proper mitotic entry, progression and completion. In this study, I examined the function of KIF0 in mitotic progression using...
Show moreThe kinesin family of microtubule motors is divided into subfamilies based on structure and function. KIF9, founder of the Kinesin-9 family, has been found to interact with the GTPase Gem. Subsequent studies have shown that KIF9 is vital for flagellar movement and podosome regulation. Previous work has proposed KIF9 is required for microtubule organization as well as proper mitotic entry, progression and completion. In this study, I examined the function of KIF0 in mitotic progression using shRNA-mediated knockdown, and overexpression. In knockdown cells, I saw a significant delay in mitotic progression as well as an increase in multipolarity and multinuclearity, suggesting a failure of cytokinesis. Overexpression of KIF9 produced similar effects on mitotic progression, as well as a marked increase in chromosome distance during anaphase. Taken with previous results, my research indicated that KIF9 is required for normal mitotic progression and completion, possible via regulation of the contractile ring.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359298
- Subject Headings
- Cells, Motility, Protoplasmic streaming, Cell organelles, Cellular signal transduction, Cytoskeletal proteins
- Format
- Document (PDF)
- Title
- Manipulation of normal cells to produce a cancer-like mitotic phenotype.
- Creator
- Luffman, Christina., Harriet L. Wilkes Honors College
- Abstract/Description
-
Most tumors contain multiple karyotypes due to genomic instability gained through chromosomal segregational defects. The variability of genomic changes within a population makes it difficult to study specific processes without the existence of confounding mutations. My project is to create a model system for observation of mitotic defects, specifically multipolar spindles, in a normal cell line, where the genome is intact. Induction of centrosome amplification is required for formation of...
Show moreMost tumors contain multiple karyotypes due to genomic instability gained through chromosomal segregational defects. The variability of genomic changes within a population makes it difficult to study specific processes without the existence of confounding mutations. My project is to create a model system for observation of mitotic defects, specifically multipolar spindles, in a normal cell line, where the genome is intact. Induction of centrosome amplification is required for formation of multipolar spindles. Treatments with colcemid showed a 10% increase in abnormal centrosome numbers over control. However, treatment with hydroxyurea and transfection of hMPSl showed little increase. Extra centrosomes are insufficient to drive multipolarity, therefore, I am using siRNA-mediated knockdown of Nek2 or HSET to decluster the extra centrosomes. Successful declustering will preferably show an increase in multipolar frequency, allowing us to study the formation and resolution of these structres to better understand how they contribute to aneuploidy and tumor progression.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/3325079
- Subject Headings
- Cell division, Karyokinesis, Cancer, Genetic aspects, Genomics, Cellular signal transduction, Centrosomes
- Format
- Document (PDF)
- Title
- Correlation between specific carcinogenic chemicals and specific mitotic defects and the restorative role of antioxidants.
- Creator
- Yates, Travis., Harriet L. Wilkes Honors College
- Abstract/Description
-
The progression of cancerous cells towards a more aggressive tumor can be linked to external elements called carcinogens. The goal of this project is to examine the correlation between exposure to specific carcinogens and an increase of mitotic defects. These defects can manifest as lagging chromosomes, multipolar spindles, and anaphase bridges. Some of these instabilities are associated with the formation of reactive oxygen species (ROS), which are known to damage DNA. The potential for...
Show moreThe progression of cancerous cells towards a more aggressive tumor can be linked to external elements called carcinogens. The goal of this project is to examine the correlation between exposure to specific carcinogens and an increase of mitotic defects. These defects can manifest as lagging chromosomes, multipolar spindles, and anaphase bridges. Some of these instabilities are associated with the formation of reactive oxygen species (ROS), which are known to damage DNA. The potential for damage to the genome can be averted via antioxidants. Using the oral cancer cell line UPCI:SCC103, we established a baseline for the mitotic defects in the absence and presence of various ROS-inducing carcinogens using DAPI-stained fixed cells examined by immunofluorescent microscopy, The cells were treated with varying concentrations of the antioxidants, Vitamin C, (Sb(B-Carotene, and Vitamin E. The reactive oxygen scavengers significantly reduced the number of mitotic defects. A possible link between the carcinogens and lagging chromosomes was established.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/210007
- Subject Headings
- Cellular signal transduction, Genetic regulation, Antioxidants, Therapeutic use, Apoptosis, Molecular aspects, Cancer, Chemoprevention
- Format
- Document (PDF)
- Title
- Adopting the orphan: determining the role of the motor protein KIF9 during the cell cycle.
- Creator
- Rivera Rios, Miguel E., Harriet L. Wilkes Honors College
- Abstract/Description
-
The kinesin superfamily of microtubule motor proteins is subdivided into families based upon structure and function. KIF9 is the founding member of the Kinesin-9 family, which is a largely uncharacterized group of kinesins. It was originally identified by sequence homology to other kinesins. Subsequent studies have shown that KIF9 interacts with proteins involved in cell shape remodeling, cell migration and proper centrosomal positioning. We have examined KIF9 function in mammalian cells...
Show moreThe kinesin superfamily of microtubule motor proteins is subdivided into families based upon structure and function. KIF9 is the founding member of the Kinesin-9 family, which is a largely uncharacterized group of kinesins. It was originally identified by sequence homology to other kinesins. Subsequent studies have shown that KIF9 interacts with proteins involved in cell shape remodeling, cell migration and proper centrosomal positioning. We have examined KIF9 function in mammalian cells using shRNA-mediated knockdown and GFP-plasmid overexpression. By knocking dow KIF9 expression in these cells, we have seen several effects on normal cell cycle progression. Using various cell cycle markers, we have observed a decrease in the number of cells in late S phase. In addition, there is a marked increase in the number of cells in early mitosis in unexpected time intervals. We propose that KIF9 is required for proper cell progression, via a potentially novel checkpoint mechanism.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3359321, http://purl.flvc.org/fau/fd/FADT3359321
- Subject Headings
- Cell organelles, Formation, Cellular signal transduction, Protoplasmic streaming, Cells, Motility, Cell division, Research
- Format
- Document (PDF)
- Title
- An investigation of membrane transporter proteins in the distal vertebrate retina: excitatory amino acid transporters and sodium potassium chloride cotransporters.
- Creator
- Purpura, Lauren Angeline, Shen, Wen, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Neurons are able to maintain membrane potential and synaptic integrity by an intricate equilibrium of membrane transporter proteins and ion channels. Two membrane proteins of particular importance in the vertebrate retina are the excitatory amino acid transporters (EAATs) which are responsible for the reuptake of glutamate into both glial and neuronal cells and the sodium potassium chloride cotransporters (NKCCs) that are responsible for the uptake of chloride ions into the cell. NKCCs are...
Show moreNeurons are able to maintain membrane potential and synaptic integrity by an intricate equilibrium of membrane transporter proteins and ion channels. Two membrane proteins of particular importance in the vertebrate retina are the excitatory amino acid transporters (EAATs) which are responsible for the reuptake of glutamate into both glial and neuronal cells and the sodium potassium chloride cotransporters (NKCCs) that are responsible for the uptake of chloride ions into the cell. NKCCs are electro-neutral with the uptake of 2 Cl- coupled to an exchange of a potassium and Na+ ion into the cells. Therefore, there is little change of cell membrane potential in the action of NKCCs. In this study the localization and function of EAATs in the distal retina is investigated. Whole cell patch clamp recordings in lower vertebrate retina have demonstrated that EAAT2 is the main synaptic EAATs in rod photoreceptors and it is localized to the axon terminals. Furthermore, the action of the transporter seems to be modified by intracellular calcium concentration. There is also evidence that EAAT2 might be regulated by feedback from the neuron network by glycinergic and GABAergic mechanisms. The second half of this study investigates expression of NKCCs in the retina by western blot analysis and quantitative polymerase chain reaction. There are two forms of NKCCs, NKCC1 and NKCC2. NKCC1 is mostly expressed in the central nervous system and NKCC2 was thought to only be expressed in the kidneys. NKCC1 is responsible for the majority of chloride uptake into neuronal and epithelial cells and NKCC1 is expressed in the distal retina where photoreceptors synapse on second order horizontal and bipolar cells. This study found the expression of NKCC1 in the distal retina to be regulated by temporal light and dark adaptation. Light adaptation increased phosphorylated NKCC1 expression (the active form of the cotransporter). The increase in NKCC1 expression during light adaptation was modulated by dopamine. Specifically, a D1 receptor agonist increased phosphorylated NKCC1 expression. Dopamine is an essential chemical and receptor known for initiating light adaptation in retina. Finally, an NKCC1 knockout mouse model was examined and it revealed that both forms of NKCC are expressed in the vertebrate retina.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004224, http://purl.flvc.org/fau/fd/FA00004224
- Subject Headings
- Biological transport, Carrier proteins, Cellular signal transduction, Neural receptors, Retina -- Cytology
- Format
- Document (PDF)
- Title
- Characterization of SNAG-zinc finger protein (ZFP) transcription factors.
- Creator
- Chiang, Cindy Chung-Yue., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Transcriptional regulation is an important area of research due to the fact that it leads to gene expression. Transcription factors associated with the regulation can either be activators or repressors of target genes, acting directly or with the aid of other factors. A majority of transcriptional repressors are zinc finger proteins (ZFPs) which bind to specific DNA sequences. The Snail/Gfi (SNAG) domain family, with members such as Slug, Smuc, Snail, and Scratch, are transcriptional...
Show moreTranscriptional regulation is an important area of research due to the fact that it leads to gene expression. Transcription factors associated with the regulation can either be activators or repressors of target genes, acting directly or with the aid of other factors. A majority of transcriptional repressors are zinc finger proteins (ZFPs) which bind to specific DNA sequences. The Snail/Gfi (SNAG) domain family, with members such as Slug, Smuc, Snail, and Scratch, are transcriptional repressors shown to play a role in various diseases such as cancer. The SNAG transcription factors contain a conserved SNAG repression domain and DNA binding domain zinc fingers. The specific DNA sequences to which each SNAG-ZFP binds, as well as a general consensus -TGCACCTGTCCGA, have been determined. Also, putative protein-protein interactions in which the Slug domain participates has been identified via binding assays. All these results contribute to better understanding of SNAG-ZFP functions.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/186676
- Subject Headings
- Zinc-finger proteins, Synthesis, Metalloproteins, Synthesis, Genetic transcription, Regulation, Cellular signal transduction, Gene expression
- Format
- Document (PDF)
- Title
- Cleavage of brain glutamic acid decarboxylase 65 by calpain under pathological conditions.
- Creator
- Buddhala, Chandana, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Brain glutamic acid decarboxylase 65 (GAD65) catalyzes the rate-limiting step in the biosynthesis of the major inhibitory neurotransmitter-amino butyric acid (GABA) from the substrate L-glutamic acid. Severe lapse in GABA neurotransmission is one of the etiologies documented in the manifestation of certain neurodegenerative diseases such as epilepsy, Parkinson's disease, Huntington's disease etc. Because GAD65 synthesizes GABA, any modulation of GAD65, therefore, has direct implications on...
Show moreBrain glutamic acid decarboxylase 65 (GAD65) catalyzes the rate-limiting step in the biosynthesis of the major inhibitory neurotransmitter-amino butyric acid (GABA) from the substrate L-glutamic acid. Severe lapse in GABA neurotransmission is one of the etiologies documented in the manifestation of certain neurodegenerative diseases such as epilepsy, Parkinson's disease, Huntington's disease etc. Because GAD65 synthesizes GABA, any modulation of GAD65, therefore, has direct implications on the quanta of GABA released at the synapse. Hence, the major objective of this study was to focus on the regulation of GAD65, with special emphasis on investigating the proteolytic cleavage of fGAD65. Previously, we have shown in vitro that GAD65 was cleaved to form its truncated form (tGAD65), which was more active than the full length form (fGAD65). The enzyme responsible for cleavage was later identified as calpain. Calpain is known to cleave its substrates either under a transient physiologica l stimulus or upon a sustained pathological insult. However, the precise role of calpain cleavage of fGAD65 is poorly understood. In this study, we examined the cleavage of fGAD65 under a range of conditions encompassing both physiological and pathological aspects, including rats under ischemia/reperfusion insult, rat brain synaptosomes or primary neuronal cultures subjected to excitotoxic stimulation with KCl. It was observed that the formation of tGAD65 progressively increased with increasing stimulus concentration. More importantly, cleavage of synaptic vesicle (SV) - associated fGAD65 by calpain was demonstrated, and the resulting tGAD65 harboring the active site of the enzyme was detached from the SVs. Vesicular uptake of the newly synthesized GABA into the SVs was found to be reduced in calpain treated SVs. Furthermore, we also observed that the levels of tGAD65 in the focal cerebral ischemic rat brain tissue increased corresponding to the elevation of local glutamate indica, d by in vivo micro dialysis. Based on these observations, we conclude that calpain cleavage of fGAD65 occurs under pathological conditions.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342053
- Subject Headings
- Glutamic acids, Antagonists, Proteolytic enzymes, Research, Cellular signal transduction, Calpain, Glutamic acid, Metabolism
- Format
- Document (PDF)
- Title
- DNAJC25 Pro90Leu J-domain mutation demonstrates decreased chaperone activity in vitro.
- Creator
- Chauss, Daniel C., Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
-
Molecular chaperones guide peptide fold conformation throughout the lifetime of the peptide. One network of chaperone proteins involved in this activity, Heat shock protein 70s (Hsp70s), are well characterized at restoring peptide fold, utilizing J-domain containing protein chaperone cofactors to activate Hsp70 activity. DnaJ (Hsp40) homolog, subfamily C, member 25 (DNAJC25) is a class III transmembrane J-domain containing protein that to date is underrepresented in the literature. Recently,...
Show moreMolecular chaperones guide peptide fold conformation throughout the lifetime of the peptide. One network of chaperone proteins involved in this activity, Heat shock protein 70s (Hsp70s), are well characterized at restoring peptide fold, utilizing J-domain containing protein chaperone cofactors to activate Hsp70 activity. DnaJ (Hsp40) homolog, subfamily C, member 25 (DNAJC25) is a class III transmembrane J-domain containing protein that to date is underrepresented in the literature. Recently, Hejtmancik et al. 2012. (unpublished data) have revealed that missense mutation to DNACJ25 at Pro90Leu (P90L) is strongly correlated with inherited Closed-Angle Glaucoma. Inherited mutations are well characterized for Open-Angle Glaucoma, however, prior to this finding, were unknown for Closed-Angle Glaucoma. In this report, analysis of the in vitro chaperone activity of DNAJC25 w+ and P90L is assessed utilizing an Hsp70 mediated Glucose-6-Phosphate Dehydrogenase refolding system, SWISS-MODEL predictions are performed for the J-domain structure of DNAJC25 w+ and P90L with consequent analysis of DNAJC25 Pro90 conservation relative to other type I, II, and III J-domain containing proteins. DNAJC25 P90L demonstrated decreased chaperone activity in vitro compared to w+ DNAJC25.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342040
- Subject Headings
- Cell physiology, Methodology, Molecular chaperones, Physiological effect, Cellular signal transduction, Proteolytic enzymes
- Format
- Document (PDF)
- Title
- DNA fingerprints of human oral microbiome: a first step towards early diagnosis of oral diseases.
- Creator
- Chakraborty, Shreyasee, Esiobu, Nwadiuto, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
This study evaluated the stability of oral bacteria in healthy subjects and documented community shifts in smokers and oral/periodontal disease by employing PCR-RFLP, DGGE and sequence analysis of the 16S rDNA gene from metagenomes and plate-wash (cultured) bacteria of oral wash from 15 participants,. A stable core of bacterial DNA fingerprint was detected within and between subjects and did not change over time when analyzed in smokers and healthy non-smokers. Signature bands in smokers, non...
Show moreThis study evaluated the stability of oral bacteria in healthy subjects and documented community shifts in smokers and oral/periodontal disease by employing PCR-RFLP, DGGE and sequence analysis of the 16S rDNA gene from metagenomes and plate-wash (cultured) bacteria of oral wash from 15 participants,. A stable core of bacterial DNA fingerprint was detected within and between subjects and did not change over time when analyzed in smokers and healthy non-smokers. Signature bands in smokers, non-smokers and periodontal disease subjects were evident suggesting the presence of potential indicators of health and poor oral health. Taxon diversity was higher in smokers including members of the genera Rothia, Synechococcus, Neisseria, Thiomargarita and Pyrobaculum but highest in periodontal disease. The two techniques successfully aligned the subjects within appropriate categories (based on their oral microbial genetic patterns)confirming their diagnostic suitability.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004184, http://purl.flvc.org/fau/fd/FA00004184
- Subject Headings
- Molecular microbiology., Mouth--Microbiology., Bacterial genetics., Cellular signal transduction., Microbial genomics.
- Format
- Document (PDF)
- Title
- Chronic variable stress affects hippocampal neurotrophic factor gene expression in the novelty-seeking phenotype: epigenetic regulation.
- Creator
- Oztan, Ozge., Charles E. Schmidt College of Medicine
- Abstract/Description
-
Experimentally naive rats exhibit varying degrees of novelty exploration. Some rats display high rates of locomotor reactivity to novelty (high responders; HR), and others display low rates (low responders; LR). The novelty-seeking phenotype (LRHR) is introduced as a model of stress responsiveness. In this thesis I examined effects of chronic variable physical and social stress or control handling on the levels of various neurotrophins in the hippocampus, and changes in mossy fibre terminal...
Show moreExperimentally naive rats exhibit varying degrees of novelty exploration. Some rats display high rates of locomotor reactivity to novelty (high responders; HR), and others display low rates (low responders; LR). The novelty-seeking phenotype (LRHR) is introduced as a model of stress responsiveness. In this thesis I examined effects of chronic variable physical and social stress or control handling on the levels of various neurotrophins in the hippocampus, and changes in mossy fibre terminal fields in LRHR rats. A positive correlation is seen between histone deacetylase 2 and brain-derived neurotrophic factor (BDNF) levels both of which are oppositely regulated in LRHR CA3 fields in response to chronic social stress. Increase in BDNF levels in CA3 field accompanied increase in supra-pyramidal mossy fibre terminal field size (SP-MF) in HRs, and decrease in BDNF levels accompanied decrease in SP-MF volume in LRs. Epigenetic regulation of neurotrophic support underlying these structural changes is discussed.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/215290
- Subject Headings
- Rats as laboratory animals, Cellular signal transduction, Gene expression, Hippocampus (Brain), Physiology, Neural transmission, Genetic regulation
- Format
- Document (PDF)
- Title
- Developmental delays in methionine sulfoxide reductase mutants in Drosophila Melanogaster.
- Creator
- Hausman, William, Binninger, David, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Aging is a biological process that has many detrimental effects due to the accumulation of oxidative damage to key biomolecules due to the action of free radicals. Methionine sulfoxide reductase (Msr) functions to repair oxidative damage to methionine residues. Msr comes in two forms, MsrA and MsrB, each form has been shown to reduce a specific enantiomer of bound and free oxidized methionine. Effects of Msr have yet to be studied in the major developmental stages of Drosophila melanogaster...
Show moreAging is a biological process that has many detrimental effects due to the accumulation of oxidative damage to key biomolecules due to the action of free radicals. Methionine sulfoxide reductase (Msr) functions to repair oxidative damage to methionine residues. Msr comes in two forms, MsrA and MsrB, each form has been shown to reduce a specific enantiomer of bound and free oxidized methionine. Effects of Msr have yet to be studied in the major developmental stages of Drosophila melanogaster despite the enzymes elevated expression during these stages. A developmental timeline was determined for MsrA mutant, MsrB mutant, and double null mutants against a wild type control. Results show that the Msr double mutant is delayed approximately 20 hours in the early/mid third instar stage while each of the single mutants showed no significant difference to the wild type. Data suggests that the reasoning of this phenomenon is due to an issue gaining mass.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004200, http://purl.flvc.org/fau/fd/FA00004200
- Subject Headings
- Aging -- Molecular aspects, Cellular signal transduction, Drosophila melanogaster -- Genetics, Mitochondrial pathology, Mutation (Biology), Oxidative stress
- Format
- Document (PDF)
- Title
- Functional roles of L1-Cam/Neuroglian in the nervous system of Drosophila Melanogaster.
- Creator
- Kudumala, Sirisha, Godenschwege, Tanja A., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Neuronal cell adhesion molecules of L1 family play a critical role in proper nervous system development. Various mutations on human L1-CAM that lead to severe neurodevelopmental disorders like retardation, spasticity etc. termed under L1 syndrome. The vertebrr their roles in axon pathfinding, neurite extension and cell migration, howeverate L1CAM and its homolog in Drosophila, neuroglian (nrg) have been well studied fo, much less is known about the mechanisms by which they fine tune synaptic...
Show moreNeuronal cell adhesion molecules of L1 family play a critical role in proper nervous system development. Various mutations on human L1-CAM that lead to severe neurodevelopmental disorders like retardation, spasticity etc. termed under L1 syndrome. The vertebrr their roles in axon pathfinding, neurite extension and cell migration, howeverate L1CAM and its homolog in Drosophila, neuroglian (nrg) have been well studied fo, much less is known about the mechanisms by which they fine tune synaptic connectivity to control the development and maintenance of synaptic connections within neuronal circuits. Here we characterized the essential role of nrg in regulating synaptic structure and function in vivo in a well characterized Drosophila central synapse model neuron, the Giant Fiber (GF) system. Previous studies from our lab revealed that the phosphorylation status of the tyrosine in the Ankyrin binding FIGQY motif in the intracellular domain of Nrg iscrucial for synapse formation of the GF to Tergo-Trochanteral Motor neuron (TTMn) synapse in the GF circuit. The present work provided us with novel insights into the role of Nrg-Ank interaction in regulating Nrg function during synapse formation and maintenance. By utilizing a sophisticated Pacman based genomic rescue strategy we have shown that dynamic regulation of the Neuroglian–Ankyrin interaction is required to coordinate transsynaptic development in the GF–TTMn synapse. In contrast, the strength of Ankyrin binding directly controls the balance between synapse formation and maintenance at the NMJ. Human L1 pathological mutations affect different biological processes distinctively and thus their proper characterization in vivo is essential to understand L1CAM function. By utilizing nrg14;P[nrg180ΔFIGQY] mutants that have exclusive synaptic defects and the previously characterized nrg849 allele that affected both GF guidance and synaptic function, we were able to analyze pathological L1CAM missense mutations with respect to their effects on guidance and synapse formation in vivo. We found that the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation and not for axon guidance while L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004131, http://purl.flvc.org/fau/fd/FA00004131
- Subject Headings
- Cell adhesion molecules, Cellular signal transduction, Cognitive neuroscience, Cognitive neuroscience, Drosophila melanogaster, Molecular neurobiology
- Format
- Document (PDF)
- Title
- Determining the subcellular localization of a group II p21-activated kinase - PAK6.
- Creator
- John, Ciny, Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
-
p-21-activated kinase 6 (PAK6) is a serine-threonine protein kinase originally identified as an Androgen Receptor (AR) interacting protein. In current study, we determined the subcellular localization of PAK6 through mutational analysis. We have found that the N-terminal CRIB domain is partly responsible for plasma membrane targeting, the region between amino acid residues #292 to #368 is functionally relevant to plasma membrane localization and that amino acid residues #119 through #190 are...
Show morep-21-activated kinase 6 (PAK6) is a serine-threonine protein kinase originally identified as an Androgen Receptor (AR) interacting protein. In current study, we determined the subcellular localization of PAK6 through mutational analysis. We have found that the N-terminal CRIB domain is partly responsible for plasma membrane targeting, the region between amino acid residues #292 to #368 is functionally relevant to plasma membrane localization and that amino acid residues #119 through #190 are responsible for nuclear targeting of PAK6, in addition to a stretch of positively charged N-terminal residues (#2-#11) since mutants lacking this sequence mis-localizes to cytoplasm. In junction forming epithelial cells, PAK6 is demonstrated to co-localize with B-catenin at adherens junctions, suggesting that PAK6 is an activation-dependent event and that PAK6 translocates from plasma membrane to the cytoplasm in response activation via the PKA signal pathway.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3355569
- Subject Headings
- Cellular signal transduction, Serine proteinases, Phosphorylation, Protein kinases, Pathophysiology, Phosphoroproteins, Metabolism
- Format
- Document (PDF)
- Title
- Elucidating the role of Semaphorin 7A in breast cancer.
- Creator
- Garcia-Areas, Ramon A., lragavarapu-Charyulu, Vijaya, Florida Atlantic University, Charles E Schmidt College of Science, Department of Biomedical Science
- Abstract/Description
-
Solid tumors can hijack many of the same programs used in neurogenesis to enhance tumor growth and metastasis, thereby generating a plethora of neurogenesis-related molecules including semaphorins Among them, we have identified Semaphorin7A (SEMA7A) in breast cancer We first used to the DA-3 mammary tumor model to determine the effect of tumor-derived SEMA7A on immune cells We found that tumor-derived SEMA7A can modulate the production of proangiogenic chemokines CXCL2/MIP-2 and CXCL 1, and...
Show moreSolid tumors can hijack many of the same programs used in neurogenesis to enhance tumor growth and metastasis, thereby generating a plethora of neurogenesis-related molecules including semaphorins Among them, we have identified Semaphorin7A (SEMA7A) in breast cancer We first used to the DA-3 mammary tumor model to determine the effect of tumor-derived SEMA7A on immune cells We found that tumor-derived SEMA7A can modulate the production of proangiogenic chemokines CXCL2/MIP-2 and CXCL 1, and prometastatic MMP-9 in macrophages We next aimed to determine the expression and function of SEMA7A in mammary tumor cells We found that SEMA7A is highly expressed in both metastatic human and murine breast cancer cells We show that both TGF-β and hypoxia elicits the production of SEMA 7 A in mammary cells SEMA7 A shRNA silencing in 4T1 cells resulted in decreased mesenchymal markers MMP-3, MMP-13, Vimentin and TGF-β) SEMA7A silenced cells show increased stiffness with reduced migratory and proliferative potential In vivo, SEMA7A silenced 4T1 tumor bearing mice showed decreased tumor growth and metastasis Genetic ablation of host-derived SEMA7A synergized to further decrease the growth and metastasis of 4T1 cells Our findings suggest novel functional roles for SEMA7A in breast cancer and that SEMA7A could be a novel therapeutic target to limit tumor growth and metastasis
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004802
- Subject Headings
- Breast--Cancer--Diagnosis, Semaphorins, Protein precursors, Cellular signal transduction, Cell receptors
- Format
- Document (PDF)
- Title
- Activators and repressors of transcription: using bioinformatics approaches to analyze and group human transcription factors.
- Creator
- Savitskaya, Ala., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Transcription factors are macromolecules that are involved in transcriptional regulation by interacting with specific DNA regions, and they can cause activation or silencing of their target genes. Gene regulation by transcriptional control explains different biological processes such as development, function, and disease. Even though transcriptional control has been of great interest for molecular biology, much still remains unknown. This study was designed to generate the most current list...
Show moreTranscription factors are macromolecules that are involved in transcriptional regulation by interacting with specific DNA regions, and they can cause activation or silencing of their target genes. Gene regulation by transcriptional control explains different biological processes such as development, function, and disease. Even though transcriptional control has been of great interest for molecular biology, much still remains unknown. This study was designed to generate the most current list of human transcription factor genes. Unique entries of transcription factor genes were collected and entered into Microsoft Office 2007 Access Database along with information about each gene. Microsoft Office 2007 Access tools were used to analyze and group collected entries according to different properties such as activator or repressor record, or presence of certain protein domains. Furthermore, protein sequence alignments of members of different groups were performed, and phylogenetic trees were used to analyze relationship between different members of each group. This work contributes to the existing knowledge of transcriptional regulation in humans.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/1930495
- Subject Headings
- Transcription factors, Genetic transcription, Regulation, Cellular signal transduction, DNA microarrays, Bioinformatics
- Format
- Document (PDF)
- Title
- Influence of small conductance calcium-activated potassium channels (SK,Kca2) on long-term memory: global and local analysis across time- and task- dependent measures.
- Creator
- Vick, Kyle A., Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
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Small conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and modulate the encoding of learning and memory. Systemic injection of 1-ethyl-2-benzimidalzolinoe (EBIO), a SK channel activator, impairs the encoding of novel object memory and locomotion but spares fear memory encoding in C57BL/6NHsd mice. The memory impairments discovered were not due to non-cognitive performance confounds such as ataxia, anxiety, attention or analgesia. Further...
Show moreSmall conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and modulate the encoding of learning and memory. Systemic injection of 1-ethyl-2-benzimidalzolinoe (EBIO), a SK channel activator, impairs the encoding of novel object memory and locomotion but spares fear memory encoding in C57BL/6NHsd mice. The memory impairments discovered were not due to non-cognitive performance confounds such as ataxia, anxiety, attention or analgesia. Further investigation with intra-hippocampal application of EBIO revealed SK channels in dorsal CA1 contribute to the encoding deficits seen systemically, but do not account for the full extent of the impairment. Concentrated activation of dorsal CA1 SK channels do not influence fear memory encoding or locomotor impairments. Taken together, these data indicate SK channels, especially in the dorsal hippocampus, have a modulatory role on novel object memory encoding, but not retrieval; however, pharmacological activation of hippocampal SK channels does not appear to influence fear memory encoding.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/192991
- Subject Headings
- Mice as laboratory animals, Cellular signal transduction, Memory, Research, Biological transport, Research, Potassium channels, Physiological effect
- Format
- Document (PDF)
- Title
- Inflammatory response in stress and the role of autophagy in breast cancer.
- Creator
- Onwuha-Ekpete, Lillian C., Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
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We attempted to understand the molecular regulators that impact inflammation using a rat model of human sensation-seeking/risk-taking trait for drug and stress vulnerability, based on their exploratory behavior displaying high rates (HRs) or low rates of locomotor reactivity (LRs) to environmental stress. We found that HRs have a pro-inflammatory phenotype as indicated by increased protein expression of the inflammatory cytokine TNF-(Sa(B. Furthermore, we found that HRs have a lower gene...
Show moreWe attempted to understand the molecular regulators that impact inflammation using a rat model of human sensation-seeking/risk-taking trait for drug and stress vulnerability, based on their exploratory behavior displaying high rates (HRs) or low rates of locomotor reactivity (LRs) to environmental stress. We found that HRs have a pro-inflammatory phenotype as indicated by increased protein expression of the inflammatory cytokine TNF-(Sa(B. Furthermore, we found that HRs have a lower gene expression of the glucocorticoid receptor and histone deacetylase 2 which are known to play an immunosuppressive role. Autophagy (macroautophagy) is a homeostatic process needed for cell maintenance, growth and proliferation and known to assist in tumor survival. FYVE and coiled-coil domain containing 1 (FYCO1) is a novel protein implicated to assist in the plus-end directed trafficking and fusion of autophagosomes. In these studies, we show that FYCO1 gene expression among human breast cell lines of varying degrees of malignancy.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/fcla/dt/3362042
- Subject Headings
- Breast, Cancer, Genetic aspects, Cancer, Molecular aspects, Carcinogenesis, Cellular signal transduction, Stress (Physiology)
- Format
- Document (PDF)
- Title
- Mutant huntingtin reduces palmitoylation of GAD65 and impairs its vesicular trafficking.
- Creator
- Rush, Daniel., Charles E. Schmidt College of Medicine, Department of Biomedical Science
- Abstract/Description
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Huntington's disease (HD) is caused by an expanded plyglutamine repeat in the huntingtin protein. In this study, I focused on the effect of the mutant huntingtin protein (mhtt) on the subcellular localization of glutamic acid decarboxylase (GAD), the enzyme responsible for synthesizing gama-aminobutyric acid (GABA). Subcellular distribution of GAD65 is significantly altered in two neuronal cell lines that express either the N-terminus or full length mhtt. GAD65 is predominantly associated...
Show moreHuntington's disease (HD) is caused by an expanded plyglutamine repeat in the huntingtin protein. In this study, I focused on the effect of the mutant huntingtin protein (mhtt) on the subcellular localization of glutamic acid decarboxylase (GAD), the enzyme responsible for synthesizing gama-aminobutyric acid (GABA). Subcellular distribution of GAD65 is significantly altered in two neuronal cell lines that express either the N-terminus or full length mhtt. GAD65 is predominantly associated with the Golgi membrane in cells expressing normal huntingtin (Htt). However, it diffuses in the cytosol of cells expressing mhtt. Palmitoylation of GAD65 is required for GAD65 trafficking, and I demonstrated the palmitoylation of GAD65 is reduced in the HD model. Overexpression of huntingtin-interacting protein 14 (HIP14), the enzyme that palmitoylates GAD65, rescues GAD65 palmitoylation and vesicle-associated trafficking. This data suggests that impairment of GAD65 palmitoylation by mhtt may alter its localization and lead to altered inhibitory neurotransmission in HD.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352831
- Subject Headings
- Glutamic acids, Antagonists, Cellular signal transduction, Proteolytic enzymes, Research, Proteins, Physiological transport, Huntington's chorea, Research
- Format
- Document (PDF)
- Title
- The effect of small conductance calcium-activated potassium channels on emotional learning and memory.
- Creator
- Sanguinetti, Shannon, Stackman, Robert W., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Psychology
- Abstract/Description
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Small conductance Ca2+-activated K+ (SK) channels have been shown to alter the encoding of spatial and non-spatial memory in the hippocampus by shaping glutamatergic postsynaptic potentials and modulating NMDA receptor-dependent synaptic plasticity. When activated, dendritic SK channels reduce hippocampal neuronal excitability and LTP. Similar SK channel properties have been demonstrated in lateral amygdala (LA) pyramidal neurons. Additionally, induction of synaptic plasticity and beta...
Show moreSmall conductance Ca2+-activated K+ (SK) channels have been shown to alter the encoding of spatial and non-spatial memory in the hippocampus by shaping glutamatergic postsynaptic potentials and modulating NMDA receptor-dependent synaptic plasticity. When activated, dendritic SK channels reduce hippocampal neuronal excitability and LTP. Similar SK channel properties have been demonstrated in lateral amygdala (LA) pyramidal neurons. Additionally, induction of synaptic plasticity and beta-adrenoreceptor activation in LA pyramidal neurons causes PKA-mediated internalization of SK channels from the postsynaptic density. Chronic activation of the amygdala through repetitive stressful stimuli can lead to excitatory synaptic strengthening that may create permanent hyper-excitability in its circuitry. This mechanism may contribute to a number of mood and anxiety disorders. The selective influence of SK channels in the LA on anxiety and fear conditioning are not known. The thesis project outlined herein examined whether SK channel blockade by bee venom peptide, apamin, during a repetitive acute fear conditioning paradigm was sufficient to alter fear memory encoding and the resulting behavioral outcome. Following the final fear memory test session, mice were tested in the open field immediately after the second fear conditioning test session. The findings indicate that intracranial LA microinfusions of apamin did not affect memory encoding or subsequent anxiety.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004543, http://purl.flvc.org/fau/fd/FA00004543
- Subject Headings
- Biological transport -- Research, Cellular signal transduction, Memory -- Research, Mice as laboratory animals, Potassium channels -- Physiological effect
- Format
- Document (PDF)