Cell Biology Commons^™

Receptor Number And Caveolar Co-Localization Determine Receptor Coupling Efficiency To Adenylyl Cyclase, Rennolds S. Ostrom, Caroline Gregorian, Ryan M. Drenan, Yang Xiang, John W. Regan, Paul A. Insel

Pharmacy Faculty Articles and Research

Recent evidence suggests that many signaling molecules localize in microdomains of the plasma membrane, particularly caveolae. In this study, overexpression of adenylyl cyclase was used as a functional probe of G protein-coupled receptor (GPCR) compartmentation. We found that three endogenous receptors in neonatal rat cardiomyocytes couple with different levels of efficiency to the activation of adenylyl cyclase type 6 (AC6), which localizes to caveolin-rich membrane fractions. Overexpression of AC6 enhanced the maximal cAMP response to β1-adrenergic receptor (β1AR)-selective activation 3.7-fold, to β2AR-selective activation only 1.6-fold and to prostaglandin E2 (PGE2) not at all. Therefore, the rank order of efficacy in …

Characterization Of The Biological Activities Of Recombinant Fusion Protein Green Fluorescent Protein/Human Zona Pellucida Protein 3 (Gfp/Hzp3), Zhiyong Lin

Theses and Dissertations in Biomedical Sciences

Despite numerous reports indicating the successful production of bioactive recombinant ZP3, no report has shown the rhZP3 having direct binding activity with human sperm. Recombinant ZP3 generated from our previous study displayed binding activity with human sperm through indirect evidence from hemizona assay (HZA).

This present study focused on the production of recombinant ZP3 with direct binding activity with human sperm. Through the application of a pEGFP expression vector, fusion protein GFP/ZP3 was successfully generated and expressed. The expression of GFP/ZP3 was evidenced by RT-PCR and western blot. The fusion protein was partially purified by Ni-NTA affinity column from cell …

Aquaporin 5-Deficient Mouse Lungs Are Hyperresponsive To Cholinergic Stimulation, Carissa M. Krane, Christopher N. Fortner, Arthur R. Hand, Dennis W. Mcgraw, John N. Lorenz, Susan E. Wert, Jennifer E. Towne, Richard J. Paul, Jeffrey A. Whitsett, Anil G. Menon

Biology Faculty Publications

Although aquaporin 5 (AQP5) is the major water channel expressed in alveolar type I cells in the lung, its actual role in the lung is a matter of considerable speculation. By using immunohistochemical staining, we show that AQP5 expression in mouse lung is not restricted to type I cells, but is also detected in alveolar type II cells, and in tracheal and bronchial epithelium. Aqp5 knockout (Aqp5−/−) mice were used to analyze AQP5 function in pulmonary physiology. Compared with Aqp5+/+ mice, Aqp5−/− mice show a significantly increased concentration-dependent bronchoconstriction to intravenously administered Ach, as shown by …

Hawaiian Freshwater Polychaeta: A Potentially Substantial Trophic Component Of Stream Depositional Habitats, M. Eric Benbow, Albert J. Burky, Carl M. Way

Biology Faculty Publications

In this paper we report the widespread occurrence of large annelids (Polychaeta: Nereididae) in Hawaiian stream depositional habitats, drawing attention to the lack of knowledge of Hawaiian stream energetics. Specimens of Namalycastis sp. were collected from five Hawaiian Islands from May–July 1995 and from the island of Maui from July–December 1999 and April–July 2000. Most specimens collected were N. hawaiiensis, while two specimens of N. abiuma were collected from a single site on the island of Molokai. Specimens were collected from elevations ranging from 3–240 m; several collections were from sites above at least one major (> 15 m …

Chondrocranium And Visceral Skeleton Of Atelopus Tricolor And Atelophryniscus Chrysophorus, E O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium , cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations.

Do Timing And Pattern Of Myogenesis Correlate With Life History Mode In Anurans?, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

The timing and pattern of myogenesis varies among anurans that have been studied and the different pat- terns may provide useful phylogenetic information. Specific myogenic markers have been described (Muntz, 1975; Kielbowna, 1981; Boudjelida & Muntz, 1987; Radice et al., 1989) and they can provide infor- mation on evolutionary changes for closely related lineages within a clade. For example, we previously com- pared first appearance of a muscle-specific protein, first twitch of axial muscle, onset of multinucleation within axial myotome, and first heartbeat in two pipid genera (Smetanick et al., 1999). We found that although the timing of myogenesis differed, …

Fast Transport Of Neurofilament Protein Along Microtubules In Squid Axoplasm, Veena Prahlad, Brian T. Helfand, George M. Langford, Ron D. Vale, Robert D. Goldman

Dartmouth Scholarship

Using squid axoplasm as a model system, we have visualized the fast transport of non-filamentous neurofilament protein particles along axonal microtubules. This transport occurs at speeds of 0.5-1.0 microm/second and the majority of neurofilament particles stain with kinesin antibody. These observations demonstrate, for the first time, that fast (0.5-1.0 microm/second) transport of neurofilament proteins occurs along microtubules. In addition, our studies suggest that neurofilament protein can be transported as non-membrane bound, nonfilamentous subunits along axons, and that the transport is kinesin-dependent. Microtubule-based fast transport might therefore provide a mechanism for the distribution and turnover of neurofilament, and perhaps other cytoskeletal …

Induction Of Apoptosis In Human Prostate Cancer Cells By Resveratrol, Gary Zulfikar Morris

Chemistry & Biochemistry Theses & Dissertations

Recently attention has been brought to trans-resveratrol's {TR) anticancer activity, as determined through a number of cultured cancer cell models. This activity was attributed to TR behaving as an estrogen, and the orientation of TR' s hydroxyl groups. Based on this work it was of interest to determine whether TR would also be toxic in prostate cancer cells; if toxic, did TR induce necrosis or apoptosis in the cells; was it toxic through hormone mediated pathways; and were TR's hydroxyl groups responsible for its biological activity. To this end, cellular viability was assessed in two different prostate cancer cell …

An Ultrastructural Survey Of The Nuchal Glands Of Rhabdophis Tigrinus (Serpentes: Colubridae), Kathleen A. Roberts

Biological Sciences Theses & Dissertations

Rhabdophis tigrinus, an Asian natricine snake, possesses a series of integumentary glands located in the nuchal skin. Previous studies indicated that the nuchal glands are of mesodermal origin, contain cardiac steroids analogous to bufotoxins found in the parotoid glands of toads, which are included in the snake's diet. The nuchal glands are defensive in function. Preliminary histological studies revealed differences in quality of the gland tissue compared to previous studies, and difference in fixation techniques were suspected. Seven specimens of R. tigrinus were fixed by perfusion using a conservative fixation process standard for electron microscopy. The nuchal gland series …

The Occurrence Of The Freshwater Clams, Musculium Partumeium (Say) And Pisidium Casertanum (Poli) (Bivalvia: Sphaeriidae), In The Hawaiian Islands, Albert J. Burky, Carl M. Way, Skippy Hau, M. Eric Benbow

Biology Faculty Publications

Sphaeriid clams were collected from an ancient, continuously cultivated taro pond complex at Ke‘anae Peninsula, Maui. Both species are known for adaptations for temporary pond habitats and could have been initially introduced by the earliest Hawaiian settlers transported with moist taro root stock from other areas of Oceania.

Intracellular Transport, Assembly, And Degradation Of Wild-Type And Disease-Linked Mutant Gap Junction Proteins, Judy K. Vanslyke, Suzanne M. Deschênes, Linda S. Musil

Biology Faculty Publications

More than 130 different mutations in the gap junction integral plasma membrane protein connexin32 (Cx32) have been linked to the human peripheral neuropathy X-linked Charcot–Marie–Tooth disease (CMTX). How these various mutants are processed by the cell and the mechanism(s) by which they cause CMTX are unknown. To address these issues, we have studied the intracellular transport, assembly, and degradation of three CMTX-linked Cx32 mutants stably expressed in PC12 cells. Each mutant had a distinct fate: E208K Cx32 appeared to be retained in the endoplasmic reticulum (ER), whereas both the E186K and R142W mutants were transported to perinuclear compartments from which …

The Docking Stage Of Yeast Vacuole Fusion Requires The Transfer Of Proteins From A Cis-Snare Complex To A Rab/Ypt Protein, Albert Price, Darren Seals, William Wickner, Christian Ungermann

Dartmouth Scholarship

The homotypic fusion of yeast vacuoles requires Sec18p (NSF)-driven priming to allow vacuole docking, but the mechanism that links priming and docking is unknown. We find that a large multisubunit protein called the Vam2/6p complex is bound to cis-paired SNAP receptors (SNAREs) on isolated vacuoles. This association of the Vam2/6p complex with the cis-SNARE complex is disrupted during priming. The Vam2/6p complex then binds to Ypt7p, a guanosine triphosphate binding protein of the Rab family, to initiate productive contact between vacuoles. Thus, cis-SNARE complexes can contain Rab/Ypt effectors, and these effectors can be mobilized by NSF/Sec18p-driven priming, allowing their direct …

Roles Of Hof1p, Bni1p, Bnr1p, And Myo1p In Cytokinesis In Saccharomyces Cerevisiae, Elizabeth Ann Vallen, J. Caviston, E. Bi

Biology Faculty Works

Cytokinesis in Saccharomyces cerevisiae occurs by the concerted action of the actomyosin system and septum formation. Here we report on the roles of HOF1,BNI1, and BNR1 in cytokinesis, focusing on Hof1p. Deletion of HOF1 causes a temperature-sensitive defect in septum formation. A Hof1p ring forms on the mother side of the bud neck in G2/M, followed by the formation of a daughter-side ring. Around telophase, Hof1p is phosphorylated and the double rings merge into a single ring that contracts slightly and may colocalize with the actomyosin structure. Upon septum formation, Hof1p splits into two rings, disappearing upon cell separation. Hof1p …

Whole Animal And Cellular Strategies In The Regulation Of Bone Mass In The Rat, Weidong Geng

Theses, Dissertations and Capstones

In order to determine the strategies in regulation of bone mass in the rat and better understand the pathophysiological mechanism of the postmenopausal osteoporosis, a series of studies were conducted at the whole animal and cellular level. At the whole animal level, female Sprague-Dawley rats were ovariectomized (Ovx) or sham-operated (control) at 18 weeks and the entire skeleton obtained at 24 weeks (baseline) or after an additional 31 day (28 week) interval on a normal (1.0%) or deficient (0.02%) calcium diet. Ovx rats on the normal calcium diet showed a 42% increase in whole body bone resorption and a 70% …

The Skn7 Response Regulator Of Saccharomyces Cerevisiae Interacts With Hsf1 In Vivo And Is Required For The Induction Of Heat Shock Genes By Oxidative Stress, Desmond C. Raitt, Anthony L. Johnson, Alexander M. Erkine, Kozo Makino, Brian Morgan, David S. Gross, Leland H. Johnston

Scholarship and Professional Work – COPHS

The Skn7 response regulator has previously been shown to play a role in the induction of stress-responsive genes in yeast, e.g., in the induction of the thioredoxin gene in response to hydrogen peroxide. The yeast Heat Shock Factor, Hsf1, is central to the induction of another set of stress-inducible genes, namely the heat shock genes. These two regulatory trans-activators, Hsf1 and Skn7, share certain structural homologies, particularly in their DNA-binding domains and the presence of adjacent regions of coiled-coil structure, which are known to mediate protein–protein interactions. Here, we provide evidence that Hsf1 and Skn7 interact in vitro and …

Cell Cycle-Dependent Binding Of Yeast Heat Shock Factor To Nucleosomes, Christina Bourgeois Venturi, Alexander M. Erkine, David S. Gross

Scholarship and Professional Work – COPHS

In the nucleus, transcription factors must contend with the presence of chromatin in order to gain access to their cognate regulatory sequences. As most nuclear DNA is assembled into nucleosomes, activators must either invade a stable, preassembled nucleosome or preempt the formation of nucleosomes on newly replicated DNA, which is transiently free of histones. We have investigated the mechanism by which heat shock factor (HSF) binds to target nucleosomal heat shock elements (HSEs), using as our model a dinucleosomal heat shock promoter (hsp82-ΔHSE1). We find that activated HSF cannot bind a stable, sequence-positioned nucleosome in G₁-arrested …

Cellular Release Of And Response To Atp As Key Determinants Of The Set-Point Of Signal Transduction Pathways, Rennolds S. Ostrom, Caroline Gregorian, Paul A. Insel

Pharmacy Faculty Articles and Research

The determinants of “basal” activity of signaling pathways regulating cellular responses are poorly defined. One possibility is that cells release factors to establish the set-point of such pathways. Here we show that treatment of Madin-Darby canine kidney cells with the nucleotidase apyrase decreases basal arachidonic acid release and cAMP production 30–40% and that inhibitors of P2Y receptor action also affect basal and forskolin-stimulated cAMP accumulation. Changing medium prominently increases extracellular levels of ATP in Madin-Darby canine kidney, COS-7, and HEK-293 cells. Mechanical stimulation of ATP release likely occurs in virtually every experimental protocol with cultured cells, implicating such release and …

Telomerase Activity In Human Preimplantation Embryos, Diane Lynne Wright

Theses and Dissertations in Biomedical Sciences

Telomerase, a ribonucleoprotein, has been described as an essential component of highly proliferative cells, which stabilizes the telomeres and avoids cellular senescence. Telomerase has been identified in various embryonic cell stages, hematopoietic cells, and in >85% of tumor tissue biopsies analyzed. The ability to measure the potential to proliferate successfully could provide an objective measure of an embryo's quality. The objectives of this study were to modify the telomeric repeat amplification protocol (TRAP) assay system for increased sensitivity to allow detection of telomerase activity in the single cell of an oocyte and embryo, obtain telomerase activity levels for the oocyte …

Human Gonadotropin-Releasing Hormone (Hgnrh) Gene Expression And Hormone Regulation In Human Placental Jeg-3 Cells, Heming Zheng

Theses and Dissertations in Biomedical Sciences

Using the human placental choriocarcinoma JEG-3 cell line as an in vitro human placental model, I studied the mechanisms of the tissue-specific expression and steroid hormone regulation of the hGnRH gene in the human placenta. The results showed that all of the previously identified four elements are required for the full activity of the hGnRH upstream promoter in JEG-3 cells, while the element 4 (FP4, −987/−968) is the most important. Studies performed with 5′ end deletion of this region confirmed these observations. Further, supershift assay using Oct-1 antibody demonstrated the involvement of Oct-1 in the FP4 DNA-protein interaction in JEG-3 …

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

Dartmouth 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 …

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

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 steps: adhesion, …

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …

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

Dartmouth 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 …

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

School of Medical Diagnostics & Translational Sciences 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 …

Interaction Of Laminin Beta2 With Eps8 And Desmin In Muscle Cells, Luke Xueliang Cui

Theses, Dissertations and Capstones

Laminin β2 is localized to the synaptic basal lamina (BL) in muscle and glomerular BL in kidney. To find interacting proteins, a mouse kidney cDNA library was screened with domain I of rat laminin β2 using the yeast two-hybrid system. Fifteen positive clones were found. The DNA sequence of three each of these clones corresponded to the phosphoprotein Eps8 (epidermal growth factor receptor pathway substrate clone 8, which is tyrosine phosphorylated after EGF stimulation) and the intermediate filament (IF) protein keratin. To determine if this interaction occurred in muscle cells, C2 cells transfected with the rat …

Cloning And Sequencing Of A Cellobiohydrolase Gene From Trichoderma Harzianum Fp108, Patrick Guilfoile, Ron Burns, Zu-Yi Gu, Matt Amundson, Fu-Hsian Chang

Journal of the Minnesota Academy of Science

A cbh1 cellobiohydrolase gene was cloned and sequenced from the fungus Trichoderma harzianum FP108. The cloning was performed by PCR amplification of T. harzianum genomic DNA, using PCR primers whose sequence was based on the cbh1 gene from Trichoderma reesei. The 3' end of the gene was isolated by inverse PCR; attempts to clone regions upstream of the 5' end of the gene were unsuccessful. Sequence comparisons suggest that this gene is closely related to cbb1 genes from other Trichoderma species. In particular, all catalytically important amino acids in the protein sequence deduced from the T harzianum cbb1 gene are …

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 …

Antibodies To Surface Igm Can Accelerate Apoptosis Of Mature B-Lymphocytes At Sub - Stimulatory Concentrations, Erica Anderson-Nissen, Robert F. Ashman

Journal of the Minnesota Academy of Science

Antibody to B-cell surface immunoglobulin D (IgD) or surface IgM results in crosslinking of Ig molecules and signal transduction. The function of these surface immunoglobulins has traditionally been investigated by extensive crosslinking experiments and interest has been focused on activation assays. We investigated the effects on apoptosis of culture with anti-(mathematical symbol) antibody (anti-(mathematical symbol)) concentrations ranging from 0.001 (mathematical symbol) mL-1 to 50 (mathematical symbol)g mL-1. Previous experiments have shown that weak dose anti-(mathematical symbol) antibody (anti-(mathematical symbol)) increases mature B-cell apoptosis at both 16- and 64-hour time points, while greater dose anti-(mathematical symbol) results in cell cycle entry …