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1999

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Articles 1 - 28 of 28

Full-Text Articles in Cell Biology

The Ccaat Displacement Protein/Cut Homeodomain Protein Represses Osteocalcin Gene Transcription And Forms Complexes With The Retinoblastoma Protein-Related Protein P107 And Cyclin A, Maria F. Van Gurp, Jitesh Pratap, Mai X. Luong, Amjad Javed, Heidi M. Hoffmann, Antonio Giordano, Janet L. Stein, Ellis J. Neufeld, Jane B. Lian, Gary S. Stein, Andre J. Van Wijnen Dec 1999

The Ccaat Displacement Protein/Cut Homeodomain Protein Represses Osteocalcin Gene Transcription And Forms Complexes With The Retinoblastoma Protein-Related Protein P107 And Cyclin A, Maria F. Van Gurp, Jitesh Pratap, Mai X. Luong, Amjad Javed, Heidi M. Hoffmann, Antonio Giordano, Janet L. Stein, Ellis J. Neufeld, Jane B. Lian, Gary S. Stein, Andre J. Van Wijnen

Open Access Articles

Developmental control of bone tissue-specific genes requires positive and negative regulatory factors to accommodate physiological requirements for the expression or suppression of the encoded proteins. Osteocalcin (OC) gene transcription is restricted to the late stages of osteoblast differentiation. OC gene expression is suppressed in nonosseous cells and osteoprogenitor cells and during the early proliferative stages of bone cell differentiation. The rat OC promoter contains a homeodomain recognition motif within a highly conserved multipartite promoter element (OC box I) that contributes to tissue-specific transcription. In this study, we demonstrate that the CCAAT displacement protein (CDP), a transcription factor related to the ...


Direct Interaction Of Pericentrin With Cytoplasmic Dynein Light Intermediate Chain Contributes To Mitotic Spindle Organization, Aruna Purohit, Sharon H. Tynan, Richard B. Vallee, Stephen J. Doxsey Nov 1999

Direct Interaction Of Pericentrin With Cytoplasmic Dynein Light Intermediate Chain Contributes To Mitotic Spindle Organization, Aruna Purohit, Sharon H. Tynan, Richard B. Vallee, Stephen J. Doxsey

Open Access Articles

Pericentrin is a conserved protein of the centrosome involved in microtubule organization. To better understand pericentrin function, we overexpressed the protein in somatic cells and assayed for changes in the composition and function of mitotic spindles and spindle poles. Spindles in pericentrin-overexpressing cells were disorganized and mispositioned, and chromosomes were misaligned and missegregated during cell division, giving rise to aneuploid cells. We unexpectedly found that levels of the molecular motor cytoplasmic dynein were dramatically reduced at spindle poles. Cytoplasmic dynein was diminished at kinetochores also, and the dynein-mediated organization of the Golgi complex was disrupted. Dynein coimmunoprecipitated with overexpressed pericentrin ...


The Correlation Of Profiles Of Surface Ph And Elongation Growth In Maize Roots, Winfried Peters, Hubert Felle Oct 1999

The Correlation Of Profiles Of Surface Ph And Elongation Growth In Maize Roots, Winfried Peters, Hubert Felle

Winfried S. Peters

High-resolution profiles of surface pH and growth along vertically growing maize (Zea mays) primary root tips were determined simultaneously by pH-sensitive microelectrodes and marking experiments. Methodological tests were carried out that proved the reliability of our kinematic growth analysis, while questioning the validity of an alternative technique employed previously. A distal acidic zone around the meristematic region and a proximal one around the elongation zone proper were detected. This pattern as such persisted irrespective of the bulk pH value. The proximal acidic region coincided with maximum relative elemental growth rates (REGR), and both characters reacted in a correlated manner to ...


The Kinesin-Related Protein, Hset, Opposes The Activity Of Eg5 And Cross-Links Microtubules In The Mammalian Mitotic Spindle, Vicki Mountain, Calvin Simerly, Louisa Howard, Asako Ando, Gerald Schatten, Duane A. Compton Oct 1999

The Kinesin-Related Protein, Hset, Opposes The Activity Of Eg5 And Cross-Links Microtubules In The Mammalian Mitotic Spindle, Vicki Mountain, Calvin Simerly, Louisa Howard, Asako Ando, Gerald Schatten, Duane A. Compton

Open Dartmouth: Faculty Open Access Scholarship

We have prepared antibodies specific for HSET, the human homologue of the KAR3 family of minus end-directed motors. Immuno-EM with these antibodies indicates that HSET frequently localizes between microtubules within the mammalian metaphase spindle consistent with a microtubule cross-linking function. Microinjection experiments show that HSET activity is essential for meiotic spindle organization in murine oocytes and taxol-induced aster assembly in cultured cells. However, inhibition of HSET did not affect mitotic spindle architecture or function in cultured cells, indicating that centrosomes mask the role of HSET during mitosis. We also show that (acentrosomal) microtubule asters fail to assemble in vitro without ...


The Cell Cycle Regulator P27kip1 Contributes To Growth And Differentiation Of Osteoblasts, Hicham Drissi, Dennet Hushka, Fauzia Aslam, Que Nguyen, Elizabeth Buffone, Andrew Koff, Andre J. Van Wijnen, Jane B. Lian, Janet L. Stein, Gary S. Stein Aug 1999

The Cell Cycle Regulator P27kip1 Contributes To Growth And Differentiation Of Osteoblasts, Hicham Drissi, Dennet Hushka, Fauzia Aslam, Que Nguyen, Elizabeth Buffone, Andrew Koff, Andre J. Van Wijnen, Jane B. Lian, Janet L. Stein, Gary S. Stein

Open Access Articles

The cyclin-dependent kinase (cdk) inhibitors are key regulators of cell cycle progression. p27 and p21 are members of the Cip/Kip family of cdk inhibitors and regulate cell growth by inactivating cell cycle stage-specific CDK-cyclin complexes. Because down-regulation of osteoprogenitor proliferation is a critical step for osteoblast differentiation, we investigated expression of p27 and p21 during development of the osteoblast phenotype in rat calvarial osteoblasts and in proliferating and growth-inhibited osteosarcoma ROS 17/2.8 cells. Expression of these proteins indicates that p21, which predominates in the growth period, is related to proliferation control. p27 levels are maximal postproliferatively, suggesting ...


Decontamination Device And Method Thereof, Eric Henderson, James Vesenka Aug 1999

Decontamination Device And Method Thereof, Eric Henderson, James Vesenka

Iowa State University Patents

One embodiment of a decontamination device for a surface, such as a probe, and method thereof in accordance with the present invention includes a first electrode, a second electrode, and a transformer. The first electrode comprises a housing with an opening and one end of the second electrode is positioned in the opening. The second electrode has an elongated-shape which tapers to a point at the one end adjacent to the opening. The transformer is mounted in the housing and has first and second pairs of leads. One of the second pair of leads is coupled to the first electrode ...


Goosecoid Acts Cell Autonomously In Mesenchyme-Derived Tissues During Craniofacial Development, Jaime A. Rivera-Pérez, Maki Wakamiya, Richard R. Behringer Aug 1999

Goosecoid Acts Cell Autonomously In Mesenchyme-Derived Tissues During Craniofacial Development, Jaime A. Rivera-Pérez, Maki Wakamiya, Richard R. Behringer

Rivera Lab Publications

Mice homozygous for a targeted deletion of the homeobox gene Goosecoid (Gsc) have multiple craniofacial defects. To understand the mechanisms responsible for these defects, the behavior of Gsc-null cells was examined in morula aggregation chimeras. In these chimeras, Gsc-null cells were marked with beta-galactosidase (beta-gal) activity using the ROSA26 lacZ allele. In addition, mice with a lacZ gene that had been introduced into the Gsc locus were used as a guide to visualize the location of Gsc-expressing cells. In Gsc-null<->wild-type chimeras, tissues that would normally not express Gsc were composed of both Gsc-null and wild-type cells that were well ...


Regulation Of F-Actin Binding To Platelet Moesin In Vitro By Both Phosphorylation Of Threonine 558 And Polyphosphatidylinositides, F. Nakamura, L. Huang, Kersi N. Pestonjamasp, Elizabeth J. Luna, H. Furthmayr Aug 1999

Regulation Of F-Actin Binding To Platelet Moesin In Vitro By Both Phosphorylation Of Threonine 558 And Polyphosphatidylinositides, F. Nakamura, L. Huang, Kersi N. Pestonjamasp, Elizabeth J. Luna, H. Furthmayr

Women’s Health Research Faculty Publications

Activation of human platelets with thrombin transiently increases phosphorylation at (558)threonine of moesin as determined with phosphorylation state-specific antibodies. This specific modification is completely inhibited by the kinase inhibitor staurosporine and maximally promoted by the phosphatase inhibitor calyculin A, making it possible to purify the two forms of moesin to homogeneity. Blot overlay assays with F-actin probes labeled with either [32P]ATP or 125I show that only phosphorylated moesin interacts with F-actin in total platelet lysates, in moesin antibody immunoprecipitates, and when purified. In the absence of detergents, both forms of the isolated protein are aggregated. Phosphorylated, purified moesin ...


Tissue-Specific Expression And Steroid Hormone Regulation Of Human Gonadotropin -Releasing Hormone (Hgnrh) Gene In Placental Cells (Jeg -3 Cells), Zhengguang Chen Jul 1999

Tissue-Specific Expression And Steroid Hormone Regulation Of Human Gonadotropin -Releasing Hormone (Hgnrh) Gene In Placental Cells (Jeg -3 Cells), Zhengguang Chen

Theses and Dissertations in Biomedical Sciences

Using JEG-3 cells as an in vitro model, I investigated the mechanisms behind the tissue-specific expression and steroid hormone regulation of the hGnRH gene in the human placenta. The hGnRH upstream promoter was found to be functionally active in JEG-3 cells. The DNA sequence responsible for functioning of the upstream promoter in JEG-3 cells is narrowed to a region between –1048 bp and –730 bp. This DNA fragment contains four elements, which can bind with nuclear extract from JEG-3 cells (but not from GT1-7 cells).

Estradiol (E2) represses the hGnRH upstream promoter activity in JEG-3 cells. This inhibition is receptor-mediated ...


Identification And Characterization Of Determinants Of Head And Neck Tumor Cell Invasion, Yangguan Wu Jul 1999

Identification And Characterization Of Determinants Of Head And Neck Tumor Cell Invasion, Yangguan Wu

Theses and Dissertations in Biomedical Sciences

Head and neck squamous cell carcinoma (HNSCC) is a common malignant disease with poor prognosis. The majority of patients die from local invasion or lymphatic metastasis. The mechanism(s) underlining the invasiveness of HNSCC are poorly understood. Utilizing a panel of HNSCC cell lines previously established in our laboratory, we tested the application and relevance of the three-step hypothesis of tumor invasion to HNSCC and investigated the mechanism(s) pertaining to the regulation of each step in the invasive process. Data presented in this thesis demonstrated that tumor cell invasion in HNSCC is a complex process involving three repeated sequential ...


Domain Analysis Of Supervillin, An F-Actin Bundling Plasma Membrane Protein With Functional Nuclear Localization Signals, J. D. Wulfkuhle, I. E. Donina, N. H. Stark, Robert K. Pope, Kersi N. Pestonjamasp, M. L. Niswonger, Elizabeth J. Luna Jun 1999

Domain Analysis Of Supervillin, An F-Actin Bundling Plasma Membrane Protein With Functional Nuclear Localization Signals, J. D. Wulfkuhle, I. E. Donina, N. H. Stark, Robert K. Pope, Kersi N. Pestonjamasp, M. L. Niswonger, Elizabeth J. Luna

Women’s Health Research Faculty Publications

A growing number of actin-associated membrane proteins have been implicated in motile processes, adhesive interactions, and signal transduction to the cell nucleus. We report here that supervillin, an F-actin binding protein originally isolated from bovine neutrophil plasma membranes, contains functional nuclear targeting signals and localizes at or near vinculin-containing focal adhesion plaques in COS7-2 and CV1 cells. Overexpression of full-length supervillin in these cells disrupts the integrity of focal adhesion plaques and results in increased levels of F-actin and vinculin. Localization studies of chimeric proteins containing supervillin sequences fused with the enhanced green fluorescent protein indicate that: (1) the amino ...


Cell Cycle-Dependent Sequencing Of Cell Fate Decisions In Caenorhabditis Elegans Vulva Precursor Cells, Victor Ambros Apr 1999

Cell Cycle-Dependent Sequencing Of Cell Fate Decisions In Caenorhabditis Elegans Vulva Precursor Cells, Victor Ambros

Open Dartmouth: Faculty Open Access Scholarship

In Caenorhabditis elegans, the fates of the six multipotent vulva precursor cells (VPCs) are specified by extracellular signals. One VPC expresses the primary (1°) fate in response to a Ras-mediated inductive signal from the gonad. The two VPCs flanking the 1° cell each express secondary (2°) fates in response to lin-12-mediated lateral signaling. The remaining three VPCs each adopt the non- vulval tertiary (3°) fate. Here I describe experiments examining how the selection of these vulval fates is affected by cell cycle arrest and cell cycle-restricted lin-12 activity. The results suggest that lin-12 participates in two

INTRODUCTION

Cell-cell signaling is ...


Xet-Related Genes And Growth Kinematics In Barley Leaves, Winfried Peters, Wieland Fricke, Peter Chandler Apr 1999

Xet-Related Genes And Growth Kinematics In Barley Leaves, Winfried Peters, Wieland Fricke, Peter Chandler

Winfried S. Peters

Recently Schünmann et al. (1997; Plant, Cell and Environment 20, 1439–1450) investigated the correlation of spatial patterns of xyloglucan-endotransglycosylase (XET) activity, XET-related mRNAs, and growth in elongating barley (Hordeum vulgare L.) leaves. Here, methodological difficulties in the kinematic growth analysis are discussed, and it is concluded that the role that XET-related gene activity plays in the control of spatial growth patterns remains undetermined.


Insulinlike Growth Factor 1- And 2-Augmented Collagen Gel Repair Of Facial Osseous Defects, James S. Toung, Roy C. Ogle, Raymond F. Morgan, William H. Lindsey Apr 1999

Insulinlike Growth Factor 1- And 2-Augmented Collagen Gel Repair Of Facial Osseous Defects, James S. Toung, Roy C. Ogle, Raymond F. Morgan, William H. Lindsey

Medical Diagnostics & Translational Sciences Faculty Publications

BACKGROUND: Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models.

OBJECTIVE: To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model.

METHODS: Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with ...


Nucleo-Cytoplasmic Interactions That Control Nuclear Envelope Breakdown And Entry Into Mitosis In The Sea Urchin Zygote, Edward H. Hinchcliffe, Elizabeth A. Thompson, Frederick J. Miller, Jing Yang, Greenfield Sluder Mar 1999

Nucleo-Cytoplasmic Interactions That Control Nuclear Envelope Breakdown And Entry Into Mitosis In The Sea Urchin Zygote, Edward H. Hinchcliffe, Elizabeth A. Thompson, Frederick J. Miller, Jing Yang, Greenfield Sluder

Open Access Articles

In sea urchin zygotes and mammalian cells nuclear envelope breakdown (NEB) is not driven simply by a rise in cytoplasmic cyclin dependent kinase 1-cyclin B (Cdk1-B) activity; the checkpoint monitoring DNA synthesis can prevent NEB in the face of mitotic levels of Cdk1-B. Using sea urchin zygotes we investigated whether this checkpoint prevents NEB by restricting import of regulatory proteins into the nucleus. We find that cyclin B1-GFP accumulates in nuclei that cannot complete DNA synthesis and do not break down. Thus, this checkpoint limits NEB downstream of both the cytoplasmic activation and nuclear accumulation of Cdk1-B1. In separate experiments ...


Processing Of Endogenous Pre-Mrnas In Association With Sc-35 Domains Is Gene Specific, Kelly P. Smith, Phillip T. Moen Jr., Karen L. Wydner, John R. Coleman, Jeanne B. Lawrence Feb 1999

Processing Of Endogenous Pre-Mrnas In Association With Sc-35 Domains Is Gene Specific, Kelly P. Smith, Phillip T. Moen Jr., Karen L. Wydner, John R. Coleman, Jeanne B. Lawrence

Open Access Articles

Analysis of six endogenous pre-mRNAs demonstrates that localization at the periphery or within splicing factor-rich (SC-35) domains is not restricted to a few unusually abundant pre-mRNAs, but is apparently a more common paradigm of many protein-coding genes. Different genes are preferentially transcribed and their RNAs processed in different compartments relative to SC-35 domains. These differences do not simply correlate with the complexity, nuclear abundance, or position within overall nuclear space. The distribution of spliceosome assembly factor SC-35 did not simply mirror the distribution of individual pre-mRNAs, but rather suggested that individual domains contain both specific pre-mRNA(s) as well as ...


The Dhc1b (Dhc2) Isoform Of Cytoplasmic Dynein Is Required For Flagellar Assembly, Gregory J. Pazour, Bethany L. Dickert, George B. Witman Feb 1999

The Dhc1b (Dhc2) Isoform Of Cytoplasmic Dynein Is Required For Flagellar Assembly, Gregory J. Pazour, Bethany L. Dickert, George B. Witman

Open Access Articles

Dyneins are microtubule-based molecular motors involved in many different types of cell movement. Most dynein heavy chains (DHCs) clearly group into cytoplasmic or axonemal isoforms. However, DHC1b has been enigmatic. To learn more about this isoform, we isolated Chlamydomonas cDNA clones encoding a portion of DHC1b, and used these clones to identify a Chlamydomonas cell line with a deletion mutation in DHC1b. The mutant grows normally and appears to have a normal Golgi apparatus, but has very short flagella. The deletion also results in a massive redistribution of raft subunits from a peri-basal body pool (Cole, D.G., D.R ...


Interaction Between The Mec1-Dependent Dna Synthesis Checkpoint And G1 Cyclin Function In Saccharomyces Cerevisiae, Elizabeth Ann Vallen, F. R. Cross Feb 1999

Interaction Between The Mec1-Dependent Dna Synthesis Checkpoint And G1 Cyclin Function In Saccharomyces Cerevisiae, Elizabeth Ann Vallen, F. R. Cross

Biology Faculty Works

The completion of DNA synthesis in yeast is monitored by a checkpoint that requires MEC1 and RAD53. Here we show that deletion of the Saccharomyces cerevisiae G1 cyclins CLN1 and CLN2 suppressed the essential requirement for MEC1 function. Wild-type levels of CLN1 and CLN2, or overexpression of CLN1, CLN2, or CLB5, but not CLN3, killed mec1 strains. We identified RNR1, which encodes a subunit of ribonucleotide reductase, as a high-copy suppressor of the lethality of mec1 GAL1-CLN1. Northern analysis demonstrated that RNR1 expression is reduced by CLN1 or CLN2 overexpression. Because limiting RNR1 expression would be expected to decrease dNTP ...


The Small Gtp-Binding Protein Rho Regulates Cortical Activities In Cultured Cells During Division, Christopher B. O'Connell, Sally P. Wheatley, Sohail Ahmed, Yu-Li Wang Jan 1999

The Small Gtp-Binding Protein Rho Regulates Cortical Activities In Cultured Cells During Division, Christopher B. O'Connell, Sally P. Wheatley, Sohail Ahmed, Yu-Li Wang

Open Access Articles

We have investigated the role of the small GTP-binding protein Rho in cytokinesis by microinjecting an inhibitor, C3 ribosyltransferase, into cultured cells. Microinjection of C3 into prometaphase or metaphase normal rat kidney epithelial cells induced immediate and global cortical movement of actin toward the metaphase plate, without an apparent effect on the mitotic spindle. During anaphase, concentrated cortical actin filaments migrated with separating chromosomes, leaving no apparent concentration of actin filaments along the equator. Myosin II in injected epithelial cells showed a diffuse distribution throughout cell division. All treated, well-adherent cells underwent cleavage-like activities and most of them divided successfully ...


Cooperative Binding Of Heat Shock Factor To The Yeast Hsp82 Promoter In Vivo And In Vitro, Alexander M. Erkine, Serena F. Magrogan, Edward A. Sekinger, David S. Gross Jan 1999

Cooperative Binding Of Heat Shock Factor To The Yeast Hsp82 Promoter In Vivo And In Vitro, Alexander M. Erkine, Serena F. Magrogan, Edward A. Sekinger, David S. Gross

Scholarship and Professional Work – COPHS

revious work has shown that heat shock factor (HSF) plays a central role in remodeling the chromatin structure of the yeastHSP82 promoter via constitutive interactions with its high-affinity binding site, heat shock element 1 (HSE1). The HSF-HSE1 interaction is also critical for stimulating both basal (noninduced) and induced transcription. By contrast, the function of the adjacent, inducibly occupied HSE2 and -3 is unknown. In this study, we examined the consequences of mutations in HSE1, HSE2, and HSE3 on HSF binding and transactivation. We provide evidence that in vivo, HSF binds to these three sites cooperatively. This cooperativity is seen ...


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 ...


Molecular And Genetic Analysis Of Jil-1, A Chromatin Associated Protein Kinase Implicated In Transcriptional Regulation In Drosophila , Ye Jin Jan 1999

Molecular And Genetic Analysis Of Jil-1, A Chromatin Associated Protein Kinase Implicated In Transcriptional Regulation In Drosophila , Ye Jin

Retrospective Theses and Dissertations

Chromatin remodeling is an essential step for many chromatin-related fundamental cellular processes, such as gene replication, transcription, recombination and gene silencing. Two classes of protein complexes contribute to chromatin remodeling: protein complexes with ATPase activity and protein complexes capable of enzymatic modifications of chromosomal proteins, especially histones. Compared to well-studied histone acetylation which has been directly linked to gene transcription, the role of histone phosphorylation in chromatin remodeling for gene transcription is still poorly understood although there is some correlation between histone phosphorylation and gene transcription;A novel nuclear tandem protein kinase JIL-1 was cloned and identified in Kristen Johansen ...


Application Of Spectral Hole Burning To The Study Of In Vitro Cellular Systems , Nebojsa Milanovich Jan 1999

Application Of Spectral Hole Burning To The Study Of In Vitro Cellular Systems , Nebojsa Milanovich

Retrospective Theses and Dissertations

The high resolution spectroscopic technique of nonphotochemical hole burning (NPHB) was applied to the study of in vitro cellular systems. Suspensions of two well-characterized cell lines were used for these studies: (1) MCF-10F cells, a normal human breast epithelial cell line, and (2) MCF-7 cells, a human breast adenocarcinoma cell line. Both cell lines were stained with the dye aluminum phthalocyanine tetrasulfonate (APT) and prepared for spectroscopic study at liquid helium temperatures. Routinely measured hole burning parameters were obtained for the two cell types and compared in order to differentiate between physical properties of normal and cancer cells;A comparison ...


Novel G-Dna Binding Proteins From The Ciliate Tetrahymena Thermophila: Purification, Characterization, Cloning And Functional Analyses , Quan Lu Jan 1999

Novel G-Dna Binding Proteins From The Ciliate Tetrahymena Thermophila: Purification, Characterization, Cloning And Functional Analyses , Quan Lu

Retrospective Theses and Dissertations

G-DNA is a family of novel four-stranded DNA structures characterized by motifs called G-quartets. Evidence is growing to suggest that G-DNA exists and plays biological roles in vivo. In order to further elucidate the functions of G-DNA, we have studied proteins that specifically bind to the DNA structure;Two G-DNA binding activities, TGPI and TGP3, were purified from the ciliate Tetrahymena thermophila. Based on the peptide sequences obtained from direct internal peptide sequencing, the cDNAs coding for the genes were cloned. Deduced protein sequences showed that TGP1 and TGP3 are novel proteins but share significant homology with each other. Furthermore ...


Effect Of The Presence Of The Mammary Gland On Periparturient Immunosuppression In Dairy Cows , Kayoko Kimura Jan 1999

Effect Of The Presence Of The Mammary Gland On Periparturient Immunosuppression In Dairy Cows , Kayoko Kimura

Retrospective Theses and Dissertations

Impaired neutrophil and lymphocyte function during the periparturient period is a contributing factor to the high incidence of infectious disease observed in the periparturient cow. Using 8 multiparous Jersey cows, we demonstrated that populations of T cells, especially T helper cells and gd T cells declined during the periparturient period coincident with reported losses of immune cell function;We hypothesized that milk production may be an important immunosuppressive factor. To test this hypothesis, we used 10 mastectomized and 8 intact multiparous Jersey cows and examined phenotype of peripheral blood mononuclear cells (PBMC), adhesion molecule expression and myeloperoxidase activity in neutrophils ...


Fatty Acid Modification Of Cells In Culture By Overexpression Of Exogenous Desaturases , Travis Jay Knight Jan 1999

Fatty Acid Modification Of Cells In Culture By Overexpression Of Exogenous Desaturases , Travis Jay Knight

Retrospective Theses and Dissertations

COS-1 cells were transfected transiently with expression vectors encoding stearoyl-acyl-carrier-protein desaturase (SACPD) from castor bean, stearoyl-CoA desaturase (SCD) from mice, and a control vector containing SACPD cDNA in reverse orientation. The hypothesis was that both exogenous desaturases would be active in COS-1 cells, thereby increasing the proportion of monounsaturated fatty acids produced by the cells. Messenger RNA and anti-myc immunoreactive proteins were detected at 12 and 24 hours post-transfection respectively and increased through 48 hours post-transfection. When acetate was used as the fatty acid precursor in cultures for a 24-hour period starting 24 hours post-transfection, the ratio of monounsaturated to ...


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 ...


Inhibition Of Cpla2-Mediated Arachidonic Acid Release By Cyclic Amp Defines A Negative Feedback Loop For P2y-Receptor Activation In Mdck-D1 Cells, Mingzhao Xing, Steven Post, Rennolds S. Ostrom, Michael Samardzija, Paul A. Insel Jan 1999

Inhibition Of Cpla2-Mediated Arachidonic Acid Release By Cyclic Amp Defines A Negative Feedback Loop For P2y-Receptor Activation In Mdck-D1 Cells, Mingzhao Xing, Steven Post, Rennolds S. Ostrom, Michael Samardzija, Paul A. Insel

Pharmacy Faculty Articles and Research

In Madin-Darby canine kidney D1cells extracellular nucleotides activate P2Y receptors that couple to several signal transduction pathways, including stimulation of multiple phospholipases and adenylyl cyclase. For one class of P2Y receptors, P2Y2 receptors, this stimulation of adenylyl cyclase and increase in cAMP occurs via the conversion of phospholipase A2 (PLA2)-generated arachidonic acid (AA) to prostaglandins (e.g. PGE2). These prostaglandins then stimulate adenylyl cyclase activity, presumably via activation of prostanoid receptors. In the current study we show that agents that increase cellular cAMP levels (including PGE2, forskolin, and the β-adrenergic agonist isoproterenol) can inhibit P2Y receptor-promoted AA release. The ...