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2004

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Articles 1 - 30 of 35

Full-Text Articles in Cell Biology

Regulation Of Cell Cycle By The Anaphase Spindle Midzone, Maki Murata-Hori, Greenfield Sluder, Yu-Li Wang Dec 2004

Regulation Of Cell Cycle By The Anaphase Spindle Midzone, Maki Murata-Hori, Greenfield Sluder, Yu-Li Wang

Open Access Articles

BACKGROUND: A number of proteins accumulate in the spindle midzone and midbody of dividing animal cells. Besides proteins essential for cytokinesis, there are also components essential for interphase functions, suggesting that the spindle midzone and/or midbody may play a role in regulating the following cell cycle.

RESULTS: We microsurgically severed NRK epithelial cells during anaphase or telophase, such that the spindle midzone/midbody was associated with only one of the daughter cells. Time-lapse recording of cells severed during early anaphase indicated that the cell with midzone underwent cytokinesis-like cortical contractions and progressed normally through the interphase, whereas the cell ...


Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd Dec 2004

Kinetics And Relative Importance Of Phosphorolytic And Hydrolytic Cleavage Of Cellodextrins And Cellobiose In Cell Extracts Of Clostridium Thermocellum, Yie.-Heng P. Zhang, Lee R. Lynd

Open Dartmouth: Faculty Open Access Scholarship

Rates of phosphorolytic cleavage of 􏰁-glucan substrates were determined for cell extracts from Clostridium thermocellum ATCC 27405 and were compared to rates of hydrolytic cleavage. Reactions with cellopentaose and cellobiose were evaluated for both cellulose (Avicel)- and cellobiose-grown cultures, with more limited data also obtained for cellotetraose. To measure the reaction rate in the chain-shortening direction at elevated temper- atures, an assay protocol was developed featuring discrete sampling at 60°C followed by subsequent analysis of reaction products (glucose and glucose-1-phosphate) at 35°C. Calculated rates of phosphorolytic cleavage for cell extract from Avicel-grown cells exceeded rates of hydrolytic cleavage ...


Biomimetic Actuators: Where Technology And Cell Biology Merge [Review Article], Michael Knoblauch, Winfried Peters Nov 2004

Biomimetic Actuators: Where Technology And Cell Biology Merge [Review Article], Michael Knoblauch, Winfried Peters

Winfried S. Peters

The structural and functional analysis of biological macromolecules has reached a level of resolution that allows mechanistic interpretations of molecular action, giving rise to the view of enzymes as molecular machines. This machine analogy is not merely metaphorical, as bio-analogous molecular machines actually are being used as motors in the fields of nanotechnology and robotics. As the borderline between molecular cell biology and technology blurs, developments in the engineering and material sciences become increasingly instructive sources of models and concepts for biologists. In this review, we provide a – necessarily selective – summary of recent progress in the usage of biological and ...


Inducible Changes In Cell Size And Attachment Area Due To Expression Of A Mutant Swi/Snf Chromatin Remodeling Enzyme, David A. Hill, Simion I. Chiosea, Saha Jamaluddin, Kanaklata Roy, Andrew H. Fischer, Douglas D. Boyd, Jeffrey A. Nickerson, Anthony N. Imbalzano Nov 2004

Inducible Changes In Cell Size And Attachment Area Due To Expression Of A Mutant Swi/Snf Chromatin Remodeling Enzyme, David A. Hill, Simion I. Chiosea, Saha Jamaluddin, Kanaklata Roy, Andrew H. Fischer, Douglas D. Boyd, Jeffrey A. Nickerson, Anthony N. Imbalzano

Open Access Articles

The SWI/SNF enzymes belong to a family of ATP-dependent chromatin remodeling enzymes that have been functionally implicated in gene regulation, development, differentiation and oncogenesis. BRG1, the catalytic core subunit of some of the SWI/SNF enzymes, can interact with known tumor suppressor proteins and can act as a tumor suppressor itself. We report that cells that inducibly express ATPase-deficient versions of BRG1 increase in cell volume, area of attachment and nuclear size upon expression of the mutant BRG1 protein. Examination of focal adhesions reveals qualitative changes in paxillin distribution but no difference in the actin cytoskeletal structure. Increases in ...


Mitochondrial Remodeling In Adipose Tissue Associated With Obesity And Treatment With Rosiglitazone, Leanne Wilson-Fritch, Sarah M. Nicoloro, My T. Chouinard, Mitchell A. Lazar, Patricia C. Chui, John D. Leszyk, Juerg R. Straubhaar, Michael P. Czech, Silvia Corvera Nov 2004

Mitochondrial Remodeling In Adipose Tissue Associated With Obesity And Treatment With Rosiglitazone, Leanne Wilson-Fritch, Sarah M. Nicoloro, My T. Chouinard, Mitchell A. Lazar, Patricia C. Chui, John D. Leszyk, Juerg R. Straubhaar, Michael P. Czech, Silvia Corvera

Open Access Articles

Adipose tissue plays a central role in the control of energy homeostasis through the storage and turnover of triglycerides and through the secretion of factors that affect satiety and fuel utilization. Agents that enhance insulin sensitivity, such as rosiglitazone, appear to exert their therapeutic effect through adipose tissue, but the precise mechanisms of their actions are unclear. Rosiglitazone changes the morphological features and protein profiles of mitochondria in 3T3-L1 adipocytes. To examine the relevance of these effects in vivo, we studied white adipocytes from ob/ob mice during the development of obesity and after treatment with rosiglitazone. The levels of ...


The 4q Subtelomere Harboring The Fshd Locus Is Specifically Anchored With Peripheral Heterochromatin Unlike Most Human Telomeres, Rose Tam, Kelly P. Smith, Jeanne B. Lawrence Oct 2004

The 4q Subtelomere Harboring The Fshd Locus Is Specifically Anchored With Peripheral Heterochromatin Unlike Most Human Telomeres, Rose Tam, Kelly P. Smith, Jeanne B. Lawrence

Open Access Articles

This paper investigates the nuclear localization of human telomeres and, specifically, the 4q35 subtelomere mutated in facioscapulohumeral dystrophy (FSHD). FSHD is a common muscular dystrophy that has been linked to contraction of D4Z4 tandem repeats, widely postulated to affect distant gene expression. Most human telomeres, such as 17q and 17p, avoid the nuclear periphery to reside within the internal, euchromatic compartment. In contrast, 4q35 localizes at the peripheral heterochromatin with 4p more internal, generating a reproducible chromosome orientation that we relate to gene expression profiles. Studies of hybrid and translocation cell lines indicate this localization is inherent to the distal ...


Smooth Muscle Archvillin: A Novel Regulator Of Signaling And Contractility In Vascular Smooth Muscle, Samudra S. Gangopadhyay, Norio Takizawa, Cynthia Gallant, Amy L. Barber, Hyun-Dong Je, Tara C. Smith, Elizabeth J. Luna, Kathleen G. Morgan Sep 2004

Smooth Muscle Archvillin: A Novel Regulator Of Signaling And Contractility In Vascular Smooth Muscle, Samudra S. Gangopadhyay, Norio Takizawa, Cynthia Gallant, Amy L. Barber, Hyun-Dong Je, Tara C. Smith, Elizabeth J. Luna, Kathleen G. Morgan

Women’s Health Research Faculty Publications

The mechanisms by which protein kinase C (PKC) and extracellular-signal-regulated kinases (ERK1/2) govern smooth-muscle contractility remain unclear. Calponin (CaP), an actin-binding protein and PKC substrate, mediates signaling through ERK1/2. We report here that CaP sequences containing the CaP homology (CH) domain bind to the C-terminal 251 amino acids of smooth-muscle archvillin (SmAV), a new splice variant of supervillin, which is a known actin- and myosin-II-binding protein. The CaP-SmAV interaction is demonstrated by reciprocal yeast two-hybrid and blot-overlay assays and by colocalization in COS-7 cells. In differentiated smooth muscle, endogenous SmAV and CaP co-fractionate and co-translocate to the cell ...


The Bvg Virulence Control System Regulates Biofilm Formation In Bordetella Bronchiseptica, Yasuhiko Irie, Seema Mattoo, Ming H. Yuk Sep 2004

The Bvg Virulence Control System Regulates Biofilm Formation In Bordetella Bronchiseptica, Yasuhiko Irie, Seema Mattoo, Ming H. Yuk

Biology Faculty Publications

Bordetella species utilize the BvgAS (Bordetella virulence gene) two-component signal transduction system to sense the environment and regulate gene expression among at least three phases: a virulent Bvg+ phase, a nonvirulent Bvg phase, and an intermediate Bvgi phase. Genes expressed in the Bvg+ phase encode known virulence factors, including adhesins such as filamentous hemagglutinin (FHA) and fimbriae, as well as toxins such as the bifunctional adenylate cyclase/hemolysin (ACY). Previous studies showed that in the Bvgi phase, FHA and fimbriae continue to be expressed, but ACY expression is significantly downregulated. In this report, we determine that Bordetella bronchiseptica ...


A Novel Phosphatidylinositol(3,4,5)P3 Pathway In Fission Yeast, Prasenjit Mitra, Yingjie Zhang, Lucia E. Rameh, Mariya P. Ivshina, Dannel Mccollum, John J. Nunnari, Gregory M. Hendricks, Monica L. Kerr, Seth J. Field, Lewis C. Cantley, Alonzo H. Ross Jul 2004

A Novel Phosphatidylinositol(3,4,5)P3 Pathway In Fission Yeast, Prasenjit Mitra, Yingjie Zhang, Lucia E. Rameh, Mariya P. Ivshina, Dannel Mccollum, John J. Nunnari, Gregory M. Hendricks, Monica L. Kerr, Seth J. Field, Lewis C. Cantley, Alonzo H. Ross

Open Access Articles

The mammalian tumor suppressor, phosphatase and tensin homologue deleted on chromosome 10 (PTEN), inhibits cell growth and survival by dephosphorylating phosphatidylinositol-(3,4,5)-trisphosphate (PI[3,4,5]P3). We have found a homologue of PTEN in the fission yeast, Schizosaccharomyces pombe (ptn1). This was an unexpected finding because yeast (S. pombe and Saccharomyces cerevisiae) lack the class I phosphoinositide 3-kinases that generate PI(3,4,5)P3 in higher eukaryotes. Indeed, PI(3,4,5)P3 has not been detected in yeast. Surprisingly, upon deletion of ptn1 in S. pombe, PI(3,4,5)P3 became detectable at ...


The Ultrastructure Of The Olfactory System In Two Species Of Short-Tailed Shrews, Blarina Brevicauda And Blarina Carolinensis, Lisa Johnson Byrum Jul 2004

The Ultrastructure Of The Olfactory System In Two Species Of Short-Tailed Shrews, Blarina Brevicauda And Blarina Carolinensis, Lisa Johnson Byrum

Theses and Dissertations in Biomedical Sciences

Several studies of the fine structure of the olfactory system of rodents have been conducted, but very little research has been done on members of the Insectivora. The olfactory systems of the northern short-tailed shrew, Blarina brevicauda, and the southern short-tailed shrew, Blarina carolinensis, were examined by light and electron microscopy. These shrews were live trapped in the vicinity of Norfolk, Virginia throughout all months of the year. Olfactory tissues were processed following standard transmission and scanning electron microscopy protocols. The olfactory system structures investigated included the olfactory epitheliumlmucosa (OEM), main olfactory bulb (MOB), accessory olfactory bulb (AOB), anterior olfactory ...


Identification And Functional Analysis Of The Essential And Regulatory Light Chains Of The Only Type Ii Myosin Myo1p In Saccharomyces Cerevisiae, J. Luo, Elizabeth Ann Vallen, C. Dravis, S. E. Tcheperegine, B. Drees, E. Bi Jun 2004

Identification And Functional Analysis Of The Essential And Regulatory Light Chains Of The Only Type Ii Myosin Myo1p In Saccharomyces Cerevisiae, J. Luo, Elizabeth Ann Vallen, C. Dravis, S. E. Tcheperegine, B. Drees, E. Bi

Biology Faculty Works

Cytokinesis in Saccharomyces cerevisiae involves coordination between actomyosin ring contraction and septum formation and/or targeted membrane deposition. We show that Mlc1p, a light chain for Myo2p (type V myosin) and lqg1p (IQGAP), is the essential light chain for Myo1p, the only type 11 myosin in S. cerevisiae. However, disruption or reduction of Mlc1p-Myo1p interaction by deleting the Mlc1p binding site on Myo1p or by a point mutation in MLC1, mlc1-93, did not cause any obvious defect in cytokinesis. In contrast, a different point mutation, mlc1-11, displayed defects in cytokinesis and in interactions with Myo2p and lqg1p. These data suggest ...


Cell Cycle Progression After Cleavage Failure: Mammalian Somatic Cells Do Not Possess A "Tetraploidy Checkpoint", Yumi Uetake, Greenfield Sluder Jun 2004

Cell Cycle Progression After Cleavage Failure: Mammalian Somatic Cells Do Not Possess A "Tetraploidy Checkpoint", Yumi Uetake, Greenfield Sluder

Open Access Articles

Failure of cells to cleave at the end of mitosis is dangerous to the organism because it immediately produces tetraploidy and centrosome amplification, which is thought to produce genetic imbalances. Using normal human and rat cells, we reexamined the basis for the attractive and increasingly accepted proposal that normal mammalian cells have a "tetraploidy checkpoint" that arrests binucleate cells in G1, thereby preventing their propagation. Using 10 microM cytochalasin to block cleavage, we confirm that most binucleate cells arrest in G1. However, when we use lower concentrations of cytochalasin, we find that binucleate cells undergo DNA synthesis and later proceed ...


Growth Rate Gradients And Extracellular Ph In Roots: How To Control An Explosion, Winfried S. Peters May 2004

Growth Rate Gradients And Extracellular Ph In Roots: How To Control An Explosion, Winfried S. Peters

Winfried S. Peters

This paper has no abstract; this is the first paragraph. As plant growth is restricted to defined zones of growing organs, the methodologically consistent analysis of spatial growth rate patterns in organ growth zones is prerequisite for studies into the regulation of cell growth in situ (Silk, 1984). The elongation zones at the tips of growing roots are classical objects of kinematic growth analysis, which aims at the quantitative description of growth rate gradients (Erickson & Sax, 1956). Root growth zones were generally believed to be characterized by growth rates that change gradually along bell-shaped growth gradients (Erickson & Sax, 1956; Sharp ...


Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko May 2004

Food Based Approaches For A Healthy Nutrition In Africa, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The latest estimates of the FAO demonstrate the problems of the fight against hunger. These problems are manifested by the ever-increasing number of chronically undernourished people worldwide. Their numbers during the 1999-2001 period were estimated at about 840 million of which 798 million live in developing countries. Sub-Saharan Africa alone represented 198 million of those. In this part of Africa the prevalence of undernourishment ranges from 5-34%, causing growth retardation and insufficient weight gain among one third of the children under five years of age and resulting in a mortality of 5-15% among these children. Malnutrition resulting from undernourishment is ...


Characterization Of The Role Of Pkn In Tgf-Beta 1-Mediated Differentiation Of Vascular Smooth Muscle Cells, Rebecca Ann Deaton B.S. May 2004

Characterization Of The Role Of Pkn In Tgf-Beta 1-Mediated Differentiation Of Vascular Smooth Muscle Cells, Rebecca Ann Deaton B.S.

Theses and Dissertations

Rebecca Ann Deaton, Characterization of the role of PKN in TGF-beta 1-mediated differentiation of vascular smooth muscle cells. Doctor of Philosophy (Biomedical Sciences), May 2004, 178 pp, 5 tables, 34 illustrations, references, 197 titles. Differentiated vascular smooth cells (SMCs) exhibit a work phenotype characterized by expression of several well-documented contractile apparatus-associated proteins. However, when exposed to mitogens such as serum or growth factors. SMCs retain the ability to de-differentiate into an “immature” proliferative phenotype, in which they lack contractile myofilaments. Proliferation of SMCs is involved in the formation of atherosclerotic plaques as well as arterial restenosis following balloon angioplasty. Thus ...


Hypertrophic Versus Apoptotic Response Of Vascular Smooth Muscle To Β1 Adrenergic Receptor Stimulation, Sherry Beth Hannon B.S. May 2004

Hypertrophic Versus Apoptotic Response Of Vascular Smooth Muscle To Β1 Adrenergic Receptor Stimulation, Sherry Beth Hannon B.S.

Theses and Dissertations

Hannon, Sherry Beth., Hypertrophic vs. Apoptotic Response of Vascular Smooth Muscle to β1 Adrenergic Receptor Stimulation. Master of Science (Biotechnology), May, 2004, 64 pp., 3 tables, 16 illustrations, references, 41 titles. This project explores how β1 adrenoceptor (β1-AR) stimulation affects cellular hypertrophy and apoptosis in PAC-1, a cultured rat pulmonary artery cell line. Insights into these responses may further the current understanding of vascular remodeling. Promoter-reporter activity for the hypertrophy-specific gene smooth muscle myosin heavy chain decreased as measured by a luciferase assay when PAC-1 cells were treated with the selective β1-AR agonist dobutamine (DOB) in 0.4% fetal bovine ...


Development And Characterization Of Eukaryotic Biomimetic Liposomes, Bradley Jay Taylor May 2004

Development And Characterization Of Eukaryotic Biomimetic Liposomes, Bradley Jay Taylor

All Graduate Theses and Dissertations

This study developed and characterized phospholipid vesicles, or liposomes, that mimic cell surfaces. Microemulsified liposomes contained biotinylated phosphatidylethanolamine, allowing them to be immobilized to avidin-coated glass. Laminin (LN), glycosphingolipids (GMl and GM3), and Escherichia coli's mechanosensitive channel of large conductance (EcoMscL) were embedded into liposome membranes. It was determined whether these embedded molecules exhibited their physiological roles of adhesion, cell recognition, and mechanosensation, respectively. Confocal laser scanning microscopy (CLSM) was employed to examine the interaction of fluorescently probed proteins, toxins, and bacteria with the immobilized microemulsified liposomes. Capture of individual and simultaneous multiple species of bacteria by GMl, GM3 ...


Forisomes, A Novel Type Of Ca2+-Dependent Contractile Protein Motor [Review Article], Michael Knoblauch, Winfried Peters Apr 2004

Forisomes, A Novel Type Of Ca2+-Dependent Contractile Protein Motor [Review Article], Michael Knoblauch, Winfried Peters

Winfried S. Peters

This paper has no abstract; this is the first paragraph. Motility of cell components in both animal and plant cells is mostly based on the movement of motor proteins along actin filaments or microtubules [Boal, 2002]. The dominance of ATP hydrolysis as the energy source for such movements is so complete, that modern textbooks define “motor proteins” as nucleoside triphosphate-dependent actuators [e.g., Alberts et al., 2002]. In only one known case, a reversible mechanism of cell motility is driven by the interaction of Ca2+ and the responsive protein(s). Some sessile ciliates control the effective length of their stalk ...


The Role Of E2f1 In Endocycle Regulation, Lindsay Black Apr 2004

The Role Of E2f1 In Endocycle Regulation, Lindsay Black

Life and Environmental Sciences Undergraduate Theses

In D. melanogaster, CycE and E2F1 are critical proteins in endocycle control. It is known that both of these proteins are required for endocycling and that cycE mRNA and protein oscillate in endoreduplicating tissues (ERT’s). The mechanism of endocycle regulation by E2F1 through CycE, however, has not been elucidated. Here, I implicate E2F1 protein oscillation in the fluctuation of two of its specific target genes, cycE and rnr2, which is then responsible for the G-S transition ofDrosophila ERT’s. The results also suggest that E2F1 control of S phase initiation within the endocycling cell is dependent on nutritional inputs.


Differential Expression Of Mitochondrial Proteins In Alzheimer’S Disease Patients Compared To Age-Matched Controls, Erin Flaherty Apr 2004

Differential Expression Of Mitochondrial Proteins In Alzheimer’S Disease Patients Compared To Age-Matched Controls, Erin Flaherty

Life and Environmental Sciences Undergraduate Theses

To date, the pathology of Alzheimer’s remains unknown, and many researchers have focused on the mitochondria as playing a significant role in its progression. In earlier studies, it was found that mRNA levels of mitochondrial proteins of Alzheimer’s Disease patients were altered in mouse and human models. Additional research is warranted to determine if the mRNA differences are translated to the protein level. It has been shown that mitochondrial genes are differentially expressed in Alzheimer’s patients when compared to age-matched controls. I propose the levels of the translated gene product will also be altered. To test this ...


Drosophila As An Emerging Model To Study Metastasis, Madhuri Kango-Singh, Georg Halder Mar 2004

Drosophila As An Emerging Model To Study Metastasis, Madhuri Kango-Singh, Georg Halder

Biology Faculty Publications

Metastasis is the primary cause of human cancer-related deaths. Two recent studies describe a system for testing how multiple genetic events synergize to promote neoplastic growth and metastasis in Drosophila, paving the way for systematic approaches to understanding metastasis using the powerful tools of Drosophila genetics.


In Vitro Frap Reveals The Atp-Dependent Nuclear Mobilization Of The Exon Junction Complex Protein Srm160, Stefan Wagner, Simion I. Chiosea, Mariya P. Ivshina, Jeffrey A. Nickerson Mar 2004

In Vitro Frap Reveals The Atp-Dependent Nuclear Mobilization Of The Exon Junction Complex Protein Srm160, Stefan Wagner, Simion I. Chiosea, Mariya P. Ivshina, Jeffrey A. Nickerson

Open Access Articles

We present a new in vitro system for characterizing the binding and mobility of enhanced green fluorescent protein (EGFP)-labeled nuclear proteins by fluorescence recovery after photobleaching in digitonin-permeabilized cells. This assay reveals that SRm160, a splicing coactivator and component of the exon junction complex (EJC) involved in RNA export, has an adenosine triphosphate (ATP)-dependent mobility. Endogenous SRm160, lacking the EGFP moiety, could also be released from sites at splicing speckled domains by an ATP-dependent mechanism. A second EJC protein, RNPS1, also has an ATP-dependent mobility, but SRm300, a protein that binds to SRm160 and participates with it in ...


Disruption Of Gradient Expression Of Zic3 Resulted In Abnormal Intra-Retinal Axon Projection, Jinhua Zhang, Zhe Jin, Zheng-Zheng Bao Feb 2004

Disruption Of Gradient Expression Of Zic3 Resulted In Abnormal Intra-Retinal Axon Projection, Jinhua Zhang, Zhe Jin, Zheng-Zheng Bao

Open Access Articles

The targeting of retinal ganglion axons toward the optic disc is the first step in axon pathfinding in the visual system. The molecular mechanisms involved in guiding the retinal axons to project towards the optic disc are not well understood. We report that a gene encoding a zinc-finger transcription factor, Zic3, is expressed in a periphery-high and center-low gradient in the retina at the stages of active axon extension inside the retina. The gradient expression of Zic3 recedes towards the periphery over the course of development, correlating with the progression of retinal cell differentiation and axonogenesis. Disruption of gradient expression ...


Expression Of Rag2 And V(D)J Recombinase Activity Are Reduced In Aged Mice As A Result Of Changes In The Bone Marrow Microenvironment: A Dissertation, Joseph E. Labrie Iii Feb 2004

Expression Of Rag2 And V(D)J Recombinase Activity Are Reduced In Aged Mice As A Result Of Changes In The Bone Marrow Microenvironment: A Dissertation, Joseph E. Labrie Iii

GSBS Dissertations and Theses

Both humans and mice display an age-related decline in immunity. Reduced generation of mature B cells may be a contributing factor due to reduced entry of mature B cells with novel B cell receptors and specificity for pathogens into the mature B cell pool. In aged mice the numbers of B cell precursors within the bone marrow are diminished; there is a severe reduction in numbers of pre-B cells and an increase in numbers of re-circulated mature B cells. Other defects in developing B cells include reduced expression of rag1 and rag2 when measured in total bone marrow precursor populations ...


Cyclin-Dependent Kinase 5 Phosphorylates The N-Terminal Domain Of The Postsynaptic Density Protein Psd-95 In Neurons, Maria A. Morabito, Morgan Sheng, Li-Huei Tsai Jan 2004

Cyclin-Dependent Kinase 5 Phosphorylates The N-Terminal Domain Of The Postsynaptic Density Protein Psd-95 In Neurons, Maria A. Morabito, Morgan Sheng, Li-Huei Tsai

Morabito Lab Publications

PSD-95 (postsynaptic density 95) is a postsynaptic scaffolding protein that links NMDA receptors to the cytoskeleton and signaling molecules. The N-terminal domain of PSD-95 is involved in the synaptic targeting and clustering of PSD-95 and in the clustering of NMDA receptors at synapses. The N-terminal domain of PSD-95 contains three consensus phosphorylation sites for cyclin-dependent kinase 5 (cdk5), a proline-directed serine-threonine kinase essential for brain development and implicated in synaptic plasticity, dopamine signaling, cocaine addiction, and neurodegenerative disorders. We report that PSD-95 is phosphorylated in the N-terminal domain by cdk5 in vitro and in vivo, and that this phosphorylation is ...


Analysis Of Microtubule Sliding Patterns In Chlamydomonas Flagellar Axonemes Reveals Dynein Activity On Specific Doublet Microtubules, M. J. Wargo, Mark A. Mcpeek, Elizabeth F. Smith Jan 2004

Analysis Of Microtubule Sliding Patterns In Chlamydomonas Flagellar Axonemes Reveals Dynein Activity On Specific Doublet Microtubules, M. J. Wargo, Mark A. Mcpeek, Elizabeth F. Smith

Open Dartmouth: Faculty Open Access Scholarship

Generating the complex waveforms characteristic of beating eukaryotic cilia and flagella requires spatial regulation of dynein-driven microtubule sliding. To generate bending, one prediction is that dynein arms alternate between active and inactive forms on specific subsets of doublet microtubules. Using an in vitro microtubule sliding assay combined with a structural approach, we determined that ATP induces sliding between specific subsets of doublet microtubules, apparently capturing one phase of the beat cycle. These studies were also conducted using high Ca2+ conditions. InChlamydomonas, high Ca2+ induces changes in waveform which are predicted to result from regulating dynein

activity on specific microtubules. Our ...


Bcma Is Essential For The Survival Of Long-Lived Bone Marrow Plasma Cells, Brian P. O'Connor, Vanitha S. Raman, Loren D. Erickson, W. James Cook, Lehn K. Weaver, Cory Ahonen, Ling-Li Lin, George Mantchev, Richard J. Bram, Randolph J. Noelle Jan 2004

Bcma Is Essential For The Survival Of Long-Lived Bone Marrow Plasma Cells, Brian P. O'Connor, Vanitha S. Raman, Loren D. Erickson, W. James Cook, Lehn K. Weaver, Cory Ahonen, Ling-Li Lin, George Mantchev, Richard J. Bram, Randolph J. Noelle

Open Dartmouth: Faculty Open Access Scholarship

Long-lived humoral immunity is manifested by the ability of bone marrow plasma cells (PCs) to survive for extended periods of time. Recent studies have underscored the importance of BLyS and APRIL as factors that can support the survival of B lineage lymphocytes. We show that BLyS can sustain PC survival in vitro, and this survival can be further enhanced by inter- leukin 6. Selective up-regulation of Mcl-1 in PCs by BLyS suggests that this 􏰀-apoptotic gene product may play an important role in PC survival. Blockade of BLyS, via transmembrane activator and cyclophilin ligand interactor–immunoglobulin treatment, inhibited PC survival ...


Effects Of Perceived Treatment On Quality Of Life And Medical Outcomesin A Double-Blind Placebo Surgery Trial, Cynthia Mcrae, Eva Cherin, T. Gayle Yamazaki, Gretchen Diem, Alexander H. Vo, Daniel W. Rusell, J. Heiner Ellgring, Stanley Fahn, Paul Greene, Sandra Dillon, Hal Winfield, Kimberly B. Bjugstad, Curt R. Freed Jan 2004

Effects Of Perceived Treatment On Quality Of Life And Medical Outcomesin A Double-Blind Placebo Surgery Trial, Cynthia Mcrae, Eva Cherin, T. Gayle Yamazaki, Gretchen Diem, Alexander H. Vo, Daniel W. Rusell, J. Heiner Ellgring, Stanley Fahn, Paul Greene, Sandra Dillon, Hal Winfield, Kimberly B. Bjugstad, Curt R. Freed

Human Development and Family Studies Publications

Context This study was part of a large double-blind sham surgery–controlled trial designed to determine the effectiveness of transplantation of human embryonic dopamine neurons into the brains of persons with advanced Parkinson's disease. This portion of the study investigated the quality of life (QOL) of participants during the 1 year of double-blind follow-up.

Objectives To determine whether QOL improved more in the transplant group than in the sham surgery group and to investigate outcomes at 1 year based on perceived treatment (the type of surgery patients thought they received).

Design Participants were randomly assigned to receive either the ...


Nitric Oxide Inhibition Of Adenylyl Cyclase Type 6 Activity Is Dependent Upon Lipid Rafts And Caveolin Signaling Complexes, Rennolds S. Ostrom, Richard A. Bundey, Paul A. Insel Jan 2004

Nitric Oxide Inhibition Of Adenylyl Cyclase Type 6 Activity Is Dependent Upon Lipid Rafts And Caveolin Signaling Complexes, Rennolds S. Ostrom, Richard A. Bundey, Paul A. Insel

Pharmacy Faculty Articles and Research

Several cell types, including cardiac myocytes and vascular endothelial cells, produce nitric oxide (NO) via both constitutive and inducible isoforms of NO synthase. NO attenuates cardiac contractility and contributes to contractile dysfunction in heart failure, although the precise molecular mechanisms for these effects are poorly defined. Adenylyl cyclase (AC) isoforms type 5 and 6, which are preferentially expressed in cardiac myocytes, may be inhibited via a direct nitrosylation by NO. Because endothelial NO synthase (eNOS and NOS3), β-adrenergic ( AR) receptors, and AC6 all can localize in lipid raft/caveolin-rich microdomains, we sought to understand the role of lipid rafts in ...


Singularity Formation In Chemotaxis--A Conjecture Of Nagai, Howard A. Levine, Joanna Renclawowicz Jan 2004

Singularity Formation In Chemotaxis--A Conjecture Of Nagai, Howard A. Levine, Joanna Renclawowicz

Mathematics Publications

Consider the initial-boundary value problem for the system (S)ut = uxx - (uvx)x, vt= u- av on an interval [0,1] for t > 0, where a > 0 with ux(0,t) = ux(1,t)= 0. Suppose \mu, v0 are positive constants. The corresponding spatially homogeneous global solution U(t) = \mu, V(t) = \mu a + (v0 - \mu a)\exp(-at) is stable in the sense that if (\mu',v0' ) are positive constants, the corresponding spatially homogeneous solution will be uniformly close to (U(\cdot),V(\cdot)).

We consider, in sequence space, an ...