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Articles 1 - 11 of 11

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Neuronal Functions Of Ahr-1, The Caenorhabditis Elegans Homolog Of The Aryl Hydrocarbon Receptor , Hongtao Qin Jan 2006

Neuronal Functions Of Ahr-1, The Caenorhabditis Elegans Homolog Of The Aryl Hydrocarbon Receptor , Hongtao Qin

Retrospective Theses and Dissertations

The mammalian aryl hydrocarbon receptor (AHR) mediates the toxic effects of dioxins and related compounds. Toxicological and genetic studies have shown that AHR regulates important development events and physiological functions. Interestingly, AHR homologs are found in most metazoans, and studies of AHR regulation and function in invertebrate model systems may provide insight to the ancient functions of AHR. In this thesis, I analyze the endogenous functions of the ahr-1 gene in the nematode Caenorhabditis elegans. ahr-1:GFP is expressed in a subset of neurons. ahr-1 regulates the development of diverse neuronal cell types, including the AVM and PLM touch receptor ...


Molecular And Functional Analysis Of Drosophila Hillarin And Its Leech Homolog , Yun Ji Jan 2004

Molecular And Functional Analysis Of Drosophila Hillarin And Its Leech Homolog , Yun Ji

Retrospective Theses and Dissertations

This thesis describes the molecular and functional analysis of the leech Hillarin and its Drosophila homolog D-hil. Leech Hillarin was identified by screening a leech expression library with the mAb Lan3-15, which specifically labels the axon hillock region of leech neurons. Database searches revealed that leech Hillarin has a number of potential homologs in a variety of organisms such as yeast, cyanobacterium, fly, nematode, mouse and human and that these proteins share two novel protein domains, the W180 domain and the H domain. The W180 domain is enriched with tryptophans whereas the H domain shares high number of invariant residues ...


Structural And Molecular Analysis Of Leech Neuronal Proteins, Calsensin And Filamin , Deepa V. Venkitaramani Jan 2004

Structural And Molecular Analysis Of Leech Neuronal Proteins, Calsensin And Filamin , Deepa V. Venkitaramani

Retrospective Theses and Dissertations

This thesis describes the structural and molecular analysis of two leech neuronal proteins, Calsensin and Filamin. Calsensin is an EF-hand calcium-binding protein expressed by a subset of peripheral sensory neurons which fasciculate into a single tract in the leech central nervous system. Calsensin is a 9 kD protein with two EF-hand calcium-binding motifs. Calsensin can multimerize via disulfide bridge formation involving the two cysteine residues in vitro. Furthermore, Calsensin shows differential gel migration depending on the presence or absence of calcium suggesting a conformational change upon calcium binding. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone ...


Functional Analysis Of Hoxa5: Analysis Of Structural, Behavioral, And Molecular Effects Of Hoxa5 Overexpression In Transgenic Line Hoxa5sv2 , Karin Elizabeth Krieger Jan 2001

Functional Analysis Of Hoxa5: Analysis Of Structural, Behavioral, And Molecular Effects Of Hoxa5 Overexpression In Transgenic Line Hoxa5sv2 , Karin Elizabeth Krieger

Retrospective Theses and Dissertations

The purpose of this research was to provide new information on the role of a murine homeobox gene, Hoxa5, in the development of the central and peripheral nervous systems. Although Hoxa5 is expressed in the brachial spinal cord and enteric neuroblasts during development, no neural phenotype has yet been observed in the Hoxa5 knockout mutant. In the work reported here, functional HOXA5 protein was overexpressed in the developing nervous system in transgenic mice in order to gain insight into the mechanisms by which this gene exerts its effects during development. Evaluation of the phenotypes of F0 transgenics and transgenic animals ...


Characterization Of [Alpha]-Adrenoceptor-Mediated Contractile Responses In The Isolated Bovine Tail Artery And Vein And An Investigation Of Nerve-Mediated Contraction In The Bovine Tail Artery In Response To Electrical Field Stimulation , Marina Val Ioudina Jan 2000

Characterization Of [Alpha]-Adrenoceptor-Mediated Contractile Responses In The Isolated Bovine Tail Artery And Vein And An Investigation Of Nerve-Mediated Contraction In The Bovine Tail Artery In Response To Electrical Field Stimulation , Marina Val Ioudina

Retrospective Theses and Dissertations

The purpose of this study was to identify alpha-adrenoreceptor types and subtypes mediating contractile responses to adrenergic agonists in the bovine tail artery and vein and to investigate nerve-mediated contraction in the bovine tail artery in response to electrical field stimulation. Isolated tissue bath methods were used to study isometric contractile responses in vessel rings. Electrical field stimulation, under constant current conditions, was used to study vessel contraction as a result of neurotransmitter(s) release from sympathetic nerve terminals;Evidence was obtained for the presence of functional alpha1A- and alpha1D-adrenoceptors in the tail artery. Whether functional alpha 1B-adrenoceptors are present ...


The Effects Of Methylamine Osmolytes On The Cytoskeleton Microtubule Assembly , Huang-Chun Tseng Jan 1999

The Effects Of Methylamine Osmolytes On The Cytoskeleton Microtubule Assembly , Huang-Chun Tseng

Retrospective Theses and Dissertations

Methylamine osmolytes are enriched in urea-rich cells. It is unclear, however, whether methylamines can promote microtubule assembly either in vitro or in cells. The osmolyte trimethylamine N-oxide (TMAO) at 200 mM increases the extent and the rate of formation of polymerized microtubule complex caused by microtubule-associated protein tau in vitro. Furthermore, TMAO counteracts the inhibition on the assembly caused by urea. Besides TMAO, betaine, another methylamine osmolyte, was found to have the same effects on MT as TMAO;Phosphorylation can affect the function of tau. Cyclic-AMP-dependent protein kinase (PKA)-phosphorylated tau does not promote tubulin assembly as judged by spectrophotometric ...


Dynamic Changes In The Localization Of Synapse Associated Proteins During Development And Differentiation Of The Mammalian Retina , Mary Heather West Greenlee Jan 1999

Dynamic Changes In The Localization Of Synapse Associated Proteins During Development And Differentiation Of The Mammalian Retina , Mary Heather West Greenlee

Retrospective Theses and Dissertations

We have examined the developmental distribution and differential localization of presynaptic terminal associated proteins in the mammalian retina. We have used antibodies specific for synaptic vesicle associated proteins Synaptotagmin, Rab 3A, Synaptophysin and Synaptobrevin, and presynaptic terminal membrane associated proteins SNAP-25 and Syntaxin, to characterize their spatio-temporal distribution during retinal differentiation and in the mature retina;The vertebrate retina has a laminar organization consisting of three cellular layers separated by two synaptic layers, the inner piexiform layer and the outer plexiform layer. In general, immunoreactivity for presynaptic terminal associated proteins was first observed in cellular layers, and as differentiation progressed ...


Biochemical Characterization Of Tractin And Leechcam, Two Ig-Superfamily Members Involved In Regulation Of Axonal Outgrowth Of Leech Neurons , Chunfa Jie Jan 1999

Biochemical Characterization Of Tractin And Leechcam, Two Ig-Superfamily Members Involved In Regulation Of Axonal Outgrowth Of Leech Neurons , Chunfa Jie

Retrospective Theses and Dissertations

Tractin and LeechCAM are two recently identified members of the Ig-superfamily. Tractin has a highly unusual domain organization: 6 Ig-like domains, 4 FNIII-like domains, an acidic domain, 12 repeats of a novel proline- and glycine- rich motif with sequence similarity to collagen, a transmembrane domain, and an intracellular tail with an ankyrin and a PDZ-domain binding motif. Our data show that Tractin is proteolytically processed into four fragments at two cleavage sites: one located in the third FNIII domain, and the other one located just proximal to the transmembrane domain. The most NH2-terminal fragment is shown to be glycosylated with ...


Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang Jan 1997

Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang

Retrospective Theses and Dissertations

Specific carbohydrate structures on neural cell adhesion molecules are promising candidates for assisting in patterning neural connections during development. An excellent system to study the potential function of specific oligosaccharide modifications of neural proteins regulating pathway formation is in the projections of sensillar neurons in leech. At least five different monoclonal antibodies (Lan3-2, Lan2-3, Lan4-2, Laz2-369, Laz7-79) which recognize different glycoepitopes specific to the entire population as well as distinct subsets of these sensillar neurons have been identified. Their expression patterns and antibody perturbation studies are consistent with the hypothesis that a hierarchy of distinct carbohydrate structures expressed by specific ...


Molecular Analysis Of A Shaker-Related K+ Channel In Leech , Jamie Lynn Weiss Jan 1996

Molecular Analysis Of A Shaker-Related K+ Channel In Leech , Jamie Lynn Weiss

Retrospective Theses and Dissertations

Voltage-gated K+ channels play a critical role in regulating the excitability of neurons and muscle. In the nervous system of many species voltage-gated K+ channels are primarily represented by four subfamilies, Shaker, Shal, Shab, and Shaw. We have cloned a K+ channel in the leech Haemopis marmorata, called LK-1, using a PCR based screen that was designed to isolate any of the four defined subfamilies of voltage-gated K+ channels. LK-1 primary amino acid sequence reveals that it is a Shaker-related channel sharing the highest amino acid identity within the transmembrane domains (48-58%) to classified Shaker homologs in species both higher ...


Calsensin, A Novel Calcium-Binding Protein Expressed In A Subset Of Peripheral Leech Neurons Fasciculating In A Single Axon Tract , Kristen Kay Briggs Jan 1995

Calsensin, A Novel Calcium-Binding Protein Expressed In A Subset Of Peripheral Leech Neurons Fasciculating In A Single Axon Tract , Kristen Kay Briggs

Retrospective Theses and Dissertations

The lan 3-6 monoclonal antibody recognizes a subpopulation of peripheral neurons whose afferents segregate into a single fascicle within the developing leech central nervous system. The lan 3-6 monoclonal antibody was used to isolate a clone encoding a novel protein, calsensin, which contains two EF-hand calcium-binding domains. In situ hybridizations with calsensin riboprobes, Western blots of lan 3-6 monoclonal antibody immunoprecipitations, and immunohistochemistry with polyclonal antibodies generated against a partially-purified calsensin fusion protein confirmed that the sequence encoding the lan 3-6 antigen has been identified. Partially-purified calsensin fusion protein binds [superscript]45Ca[superscript]2+ in vitro, suggesting that the calsensin ...