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University of Tennessee, Knoxville

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

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Iteratively Improving Hi-C Experiments One Step At A Time, Rosela Golloshi, Jacob T. Sanders, Rachel Patton Mccord Apr 2018

Iteratively Improving Hi-C Experiments One Step At A Time, Rosela Golloshi, Jacob T. Sanders, Rachel Patton Mccord

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The 3D organization of eukaryotic chromosomes affects key processes such as gene expression, DNA replication, cell division, and response to DNA damage. The genome-wide chromosome conformation capture (Hi-C) approach can characterize the landscape of 3D genome organization by measuring interaction frequencies between all genomic regions. Hi-C protocol improvements and rapid advances in DNA sequencing power have made Hi-C useful to study diverse biological systems, not only to elucidate the role of 3D genome structure in proper cellular function, but also to characterize genomic rearrangements, assemble new genomes, and consider chromatin interactions as potential biomarkers for diseases. Yet, the Hi-C protocol …


Characterizing Tmx And Chemotactic Receptor Arrays Through Bacterial Two-Hybrid And Beta-Galactosidase Assays, Adam Keith Hubler May 2017

Characterizing Tmx And Chemotactic Receptor Arrays Through Bacterial Two-Hybrid And Beta-Galactosidase Assays, Adam Keith Hubler

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

No abstract provided.


Mechanism Of Lignin Inhibition Of Enzymatic Biomass Deconstruction, Josh V. Vermaas, Loukas Petridis, Xianghong Qi, Roland Schulz, Benjamin Lindner, Jeremy C. Smith Dec 2015

Mechanism Of Lignin Inhibition Of Enzymatic Biomass Deconstruction, Josh V. Vermaas, Loukas Petridis, Xianghong Qi, Roland Schulz, Benjamin Lindner, Jeremy C. Smith

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

The conversion of plant biomass to ethanol via enzymatic cellulose hydrolysis offers a potentially sustainable route to biofuel production. However, the inhibition of enzymatic activity in pretreated biomass by lignin severely limits the efficiency of this process.

Results

By performing atomic-detail molecular dynamics simulation of a biomass model containing cellulose, lignin, and cellulases (TrCel7A), we elucidate detailed lignin inhibition mechanisms. We find that lignin binds preferentially both to the elements of cellulose to which the cellulases also preferentially bind (the hydrophobic faces) and also to the specific residues on the cellulose-binding module of the cellulase that are …


Highly Dynamic Animal Contact Network And Implications On Disease Transmission, Shi Chen, Brad J. White, Michael W. Sanderson, David E. Amrine, Amiyaal Ilany, Cristina Lanzas Mar 2014

Highly Dynamic Animal Contact Network And Implications On Disease Transmission, Shi Chen, Brad J. White, Michael W. Sanderson, David E. Amrine, Amiyaal Ilany, Cristina Lanzas

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Contact patterns among hosts are considered as one of the most critical factors contributing to unequal pathogen transmission. Consequently, networks have been widely applied in infectious disease modeling. However most studies assume static network structure due to lack of accurate observation and appropriate analytic tools. In this study we used high temporal and spatial resolution animal position data to construct a high-resolution contact network relevant to infectious disease transmission. The animal contact network aggregated at hourly level was highly variable and dynamic within and between days, for both network structure (network degree distribution) and individual rank of degree distribution in …


Regulation Of Ethanol-Related Behavior And Ethanol Metabolism By The Corazonin Neurons And Corazonin Receptor In Drosophila Melanogaster, Kai Sha, Seung-Hoon Choi, Jeongdae Im, Gyunghee G. Lee, Frank Loeffler, Jae H. Park Jan 2014

Regulation Of Ethanol-Related Behavior And Ethanol Metabolism By The Corazonin Neurons And Corazonin Receptor In Drosophila Melanogaster, Kai Sha, Seung-Hoon Choi, Jeongdae Im, Gyunghee G. Lee, Frank Loeffler, Jae H. Park

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Impaired ethanol metabolism can lead to various alcohol-related health problems. Key enzymes in ethanol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH); however, neuroendocrine pathways that regulate the activities of these enzymes are largely unexplored. Here we identified a neuroendocrine system involving Corazonin (Crz) neuropeptide and its receptor (CrzR) as important physiological regulators of ethanol metabolism in Drosophila. Crz-cell deficient (Crz-CD) flies displayed significantly delayed recovery from ethanol-induced sedation that we refer to as hangover-like phenotype. Newly generated mutant lacking Crz Receptor (CrzR01) and CrzR-knockdown flies showed even more severe hangover-like phenotype, which is causally …


The Global Translation Profile In A Ribosomal Protein Mutant Resembles That Of An Eif3 Mutant, Bayu Sisay Tiruneh, Byung-Hoon Kim, Daniel R. Gallie, Bijoyita Roy, Albrecht G. Von Arnim Dec 2013

The Global Translation Profile In A Ribosomal Protein Mutant Resembles That Of An Eif3 Mutant, Bayu Sisay Tiruneh, Byung-Hoon Kim, Daniel R. Gallie, Bijoyita Roy, Albrecht G. Von Arnim

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Genome-wide assays performed in Arabidopsis and other organisms have revealed that the translation status of mRNAs responds dramatically to different environmental stresses and genetic lesions in the translation apparatus. To identify additional features of the global landscape of translational control, we used microarray analysis of polysomal as well as non-polysomal mRNAs to examine the defects in translation in a poly(A) binding protein mutant, pab2 pab8, as well as in a mutant of a large ribosomal subunit protein, rpl24b/shortvalve1.

Results

The mutation of RPL24B stimulated the ribosome occupancy of mRNAs for nuclear encoded ribosomal proteins. Detailed analysis …


The Drosophila Gypsy Insulator Supports Transvection In The Presence Of The Vestigial Enhancer, Todd Schoborg, Srilalitha Kuruganti, Ryan Rickels, Mariano Labrador Nov 2013

The Drosophila Gypsy Insulator Supports Transvection In The Presence Of The Vestigial Enhancer, Todd Schoborg, Srilalitha Kuruganti, Ryan Rickels, Mariano Labrador

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Though operationally defined as cis-regulatory elements, enhancers can also communicate with promoters on a separate homolog in trans, a mechanism that has been suggested to account for the ability of certain alleles of the same gene to complement one another in a process otherwise known as transvection. This homolog-pairing dependent process is facilitated in Drosophila by chromatin-associated pairing proteins, many of which remain unknown and their mechanism of action uncharacterized. Here we have tested the role of the gypsy chromatin insulator in facilitating pairing and communication between enhancers and promoters in trans using a transgenic eGFP reporter system …


Myosin Xik Of Arabidopsis Thaliana Accumulates At The Root Hair Tip And Is Required For Fast Root Hair Growth, Eunsook Park, Andreas Nebenführ Oct 2013

Myosin Xik Of Arabidopsis Thaliana Accumulates At The Root Hair Tip And Is Required For Fast Root Hair Growth, Eunsook Park, Andreas Nebenführ

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Myosin motor proteins are thought to carry out important functions in the establishment and maintenance of cell polarity by moving cellular components such as organelles, vesicles, or protein complexes along the actin cytoskeleton. In Arabidopsis thaliana, disruption of the myosin XIK gene leads to reduced elongation of the highly polar root hairs, suggesting that the encoded motor protein is involved in this cell growth. Detailed live-cell observations in this study revealed that xik root hairs elongated more slowly and stopped growth sooner than those in wild type. Overall cellular organization including the actin cytoskeleton appeared normal, but actin filament …


Evolution Of The Toxins Muscarine And Psilocybin In A Family Of Mushroom-Forming Fungi, Pawel Kosentka, Sarah L. Sprague, Martin Ryberg, Jochen Gartz, Amanda L. May, Shawn R. Campagna, P Brandon Matheny May 2013

Evolution Of The Toxins Muscarine And Psilocybin In A Family Of Mushroom-Forming Fungi, Pawel Kosentka, Sarah L. Sprague, Martin Ryberg, Jochen Gartz, Amanda L. May, Shawn R. Campagna, P Brandon Matheny

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine whether muscarine was present in 30 new samples …


Essential Role Of Grim-Led Programmed Cell Death For The Establishment Of Corazonin-Producing Peptidergic Nervous System During Embryogenesis And Metamorphosis In Drosophila Melanogaster, G Lee, R Sehgal, Z Wang, S Nair, K Kikuno, C H. Chen, B Hay, Jae H. Park Mar 2013

Essential Role Of Grim-Led Programmed Cell Death For The Establishment Of Corazonin-Producing Peptidergic Nervous System During Embryogenesis And Metamorphosis In Drosophila Melanogaster, G Lee, R Sehgal, Z Wang, S Nair, K Kikuno, C H. Chen, B Hay, Jae H. Park

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

In Drosophila melanogaster, combinatorial activities of four death genes, head involution defective (hid), reaper (rpr), grim, and sickle (skl), have been known to play crucial roles in the developmentally regulated programmed cell death (PCD) of various tissues. However, different expression patterns of the death genes also suggest distinct functions played by each. During early metamorphosis, a great number of larval neurons unfit for adult life style are removed by PCD. Among them are eight pairs of corazonin-expressing larval peptidergic neurons in the ventral nerve cord (vCrz). To reveal death genes responsible for the PCD of vCrz neurons, we examined extant …


Down-Regulation Of The Caffeic Acid O-Methyltransferase Gene In Switchgrass Reveals A Novel Monolignol Analog, Timothy J. Tschaplinski, Robert F. Standaert, Nancy L. Engle, Madhavi Z. Martin, Amandeep K. Sangha, Jerry M. Parks, Jeremy C. Smith, Reichel Samuel, Nan Jiang, Yunqiao Pu, Arthur J. Ragauskas, Choo Y. Hamilton, Chunxiang Fu, Zeng-Yu Wang, Brian H. Davidson, Richard A. Dixon, Jonathan R. Mielenz Sep 2012

Down-Regulation Of The Caffeic Acid O-Methyltransferase Gene In Switchgrass Reveals A Novel Monolignol Analog, Timothy J. Tschaplinski, Robert F. Standaert, Nancy L. Engle, Madhavi Z. Martin, Amandeep K. Sangha, Jerry M. Parks, Jeremy C. Smith, Reichel Samuel, Nan Jiang, Yunqiao Pu, Arthur J. Ragauskas, Choo Y. Hamilton, Chunxiang Fu, Zeng-Yu Wang, Brian H. Davidson, Richard A. Dixon, Jonathan R. Mielenz

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography–mass spectrometry (GCMS)-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial …


A Coarse-Grained Model For Synergistic Action Of Multiple Enzymes On Cellulose, Andrea Asztalos, Marcus Daniels, Anurag Sethi, Tongye Shen, Paul Langan, Antonio Redondo, Sandrasegaram Gnanakaran Aug 2012

A Coarse-Grained Model For Synergistic Action Of Multiple Enzymes On Cellulose, Andrea Asztalos, Marcus Daniels, Anurag Sethi, Tongye Shen, Paul Langan, Antonio Redondo, Sandrasegaram Gnanakaran

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Degradation of cellulose to glucose requires the cooperative action of three classes of enzymes, collectively known as cellulases. Endoglucanases randomly bind to cellulose surfaces and generate new chain ends by hydrolyzing β-1,4-D-glycosidic bonds. Exoglucanases bind to free chain ends and hydrolyze glycosidic bonds in a processive manner releasing cellobiose units. Then, β-glucosidases hydrolyze soluble cellobiose to glucose. Optimal synergistic action of these enzymes is essential for efficient digestion of cellulose. Experiments show that as hydrolysis proceeds and the cellulose substrate becomes more heterogeneous, the overall degradation slows down. As catalysis occurs on the surface of crystalline cellulose, several factors …


Bovine Serum Albumin Further Enhances The Effects Of Organic Solvents On Increased Yield Of Polymerase Chain Reaction Of Gc-Rich Templates, Eric M. Farell, University Of Tennessee - Knoxville May 2012

Bovine Serum Albumin Further Enhances The Effects Of Organic Solvents On Increased Yield Of Polymerase Chain Reaction Of Gc-Rich Templates, Eric M. Farell, University Of Tennessee - Knoxville

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

While being a standard powerful molecular biology technique, applications of the PCR to the amplification of high GC-rich DNA samples still present challenges which include limited yield and poor specificity of the reaction. Organic solvents, including DMSO and formamide, have been often employed as additives to increase the efficiency of amplification of high GC content (GC > 60%) DNA sequences. Bovine serum albumin (BSA) has been used as an additive in several applications, including restriction enzyme digestions as well as in PCR amplification of templates from environmental samples that contain potential inhibitors such as phenolic compounds.

Findings

Significant increase in …


Translation Reinitiation And Development Are Compromised In Similar Ways By Mutations In Translation Initiation Factor Eif3h And The Ribosomal Protein Rpl24, Fujun Zhou, Bijoyita Roy, Albrecht G. Von Arnim Aug 2010

Translation Reinitiation And Development Are Compromised In Similar Ways By Mutations In Translation Initiation Factor Eif3h And The Ribosomal Protein Rpl24, Fujun Zhou, Bijoyita Roy, Albrecht G. Von Arnim

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Within the scanning model of translation initiation, reinitiation is a non-canonical mechanism that operates on mRNAs harboring upstream open reading frames. The h subunit of eukaryotic initiation factor 3 (eIF3) boosts translation reinitiation on the uORF-containing mRNA coding for the Arabidopsis bZip transcription factor, AtbZip11, among others. The RPL24B protein of the large ribosomal subunit, which is encoded by SHORT VALVE1, likewise fosters translation of uORF-containing mRNAs, for example mRNAs for auxin response transcription factors (ARFs).

Results

Here we tested the hypothesis that RPL24B and eIF3h affect translation reinitiation in a similar fashion. First, like eif3h mutants, rpl24b …


Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Yi-Feng Chen, Zhiyong Gao, Robert J. Kerriss Iii, Wuyi Wang, Brad M. Binder, G. Eric Schaller Jan 2010

Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Yi-Feng Chen, Zhiyong Gao, Robert J. Kerriss Iii, Wuyi Wang, Brad M. Binder, G. Eric Schaller

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The gaseous plant hormone ethylene is perceived in Arabidopsis thaliana by a five-member receptor family composed of ETR1, ERS1, ETR2, ERS2, and EIN4. Methodology/Principal Findings

Gel-filtration analysis of ethylene receptors solubilized from Arabidopsis membranes demonstrates that the receptors exist as components of high-molecular-mass protein complexes. The ERS1 protein complex exhibits an ethylene-induced change in size consistent with ligand-mediated nucleation of protein-protein interactions. Deletion analysis supports the participation of multiple domains from ETR1 in formation of the protein complex, and also demonstrates that targeting to and retention of ETR1 at the endoplasmic reticulum only requires the first 147 amino acids of …


Ppar Agonists Down-Regulate The Expression Of Atp10c Mrna During Adipogenesis, A Peretich, Maria Cekanova Ms, Rndr, Phd, S Hurst, Sj Baek, Madhu Dahr Nov 2009

Ppar Agonists Down-Regulate The Expression Of Atp10c Mrna During Adipogenesis, A Peretich, Maria Cekanova Ms, Rndr, Phd, S Hurst, Sj Baek, Madhu Dahr

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

No abstract provided.


Morphogenesis Signaling Components Influence Cell Cycle Regulation By Cyclin Dependent Kinase, Brian Td Tobe, Ana A. Kitazono, Jacqueline S. Garcia, Renee A. Garber, Brooke J. Bevis, John S. Choy, Daniel Chasman, Stephen J. Kron Jul 2009

Morphogenesis Signaling Components Influence Cell Cycle Regulation By Cyclin Dependent Kinase, Brian Td Tobe, Ana A. Kitazono, Jacqueline S. Garcia, Renee A. Garber, Brooke J. Bevis, John S. Choy, Daniel Chasman, Stephen J. Kron

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

The yeast cell cycle is largely controlled by the cyclin-dependent kinase (CDK) Cdc28. Recent evidence suggests that both CDK complex stability as well as function during mitosis is determined by precise regulation of Swe1, a CDK inhibitory kinase and cyclin binding partner. A model of mitotic progression has been provided by study of filamentous yeast. When facing nutrient-limited conditions, Ras2-mediated PKA and MAPK signaling cascades induce a switch from round to filamentous morphology resulting in delayed mitotic progression.

Results

To delineate how the dimorphic switch contributes to cell cycle regulation, temperature sensitive cdc28 mutants exhibiting constitutive filamentation were subjected …


The Fast Technique: A Simplified Agrobacterium-Based Transformation Method For Transient Gene Expression Analysis In Seedlings Of Arabidopsis And Other Plant Species, Jian-Feng Li, Eunsook Park, Albrecht G. Von Arnim, Andreas Nebenführ May 2009

The Fast Technique: A Simplified Agrobacterium-Based Transformation Method For Transient Gene Expression Analysis In Seedlings Of Arabidopsis And Other Plant Species, Jian-Feng Li, Eunsook Park, Albrecht G. Von Arnim, Andreas Nebenführ

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Plant genome sequencing has resulted in the identification of a large number of uncharacterized genes. To investigate these unknown gene functions, several transient transformation systems have been developed as quick and convenient alternatives to the lengthy transgenic assay. These transient assays include biolistic bombardment, protoplast transfection and Agrobacterium-mediated transient transformation, each having advantages and disadvantages depending on the research purposes.

Results

We present a novel transient assay based on cocultivation of young Arabidopsis (Arabidopsis thaliana) seedlings with Agrobacterium tumefaciens in the presence of a surfactant which does not require any dedicated equipment and can be carried …


The Fast Technique: A Simplified Agrobacterium-Based Transformation Method For Transient Gene Expression Analysis In Seedlings Of Arabidopsis And Other Plant Species, Jian-Feng Li, Eunsook Park, Albrecht G. Von Arnim, Andreas Nebenführ Jan 2009

The Fast Technique: A Simplified Agrobacterium-Based Transformation Method For Transient Gene Expression Analysis In Seedlings Of Arabidopsis And Other Plant Species, Jian-Feng Li, Eunsook Park, Albrecht G. Von Arnim, Andreas Nebenführ

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

Plant genome sequencing has resulted in the identification of a large number of uncharacterized genes. To investigate these unknown gene functions, several transient transformation systems have been developed as quick and convenient alternatives to the lengthy transgenic assay. These transient assays include biolistic bombardment, protoplast transfection and Agrobacterium-mediated transient transformation, each having advantages and disadvantages depending on the research purposes.

Results

We present a novel transient assay based on cocultivation of young Arabidopsis (Arabidopsis thaliana) seedlings with Agrobacterium tumefaciens in the presence of a surfactant which does not require any dedicated equipment and can be carried …


Mutational Optimization Of The Coelenterazine-Dependent Luciferase From Renilla, Jongchan Woo, Albrecht G. Von Arnim Sep 2008

Mutational Optimization Of The Coelenterazine-Dependent Luciferase From Renilla, Jongchan Woo, Albrecht G. Von Arnim

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Renilla luciferase (RLUC) is a popular reporter enzyme for gene expression and biosensor applications, but it is an unstable enzyme whose catalytic mechanism remains to be elucidated. We titrated that one RLUC molecule can turn over about one hundred molecules of coelenterazine substrate. Mutagenesis of active site residue Pro220 extended the half-life of photon emission, yielding brighter luminescence in E. coli. Random mutagenesis uncovered two new mutations that stabilized and increased photon emission in vivo and in vitro, while ameliorating substrate inhibition. Further amended with a previously identified mutation, a new triple mutant showed a threefold improved k …


Gene Alterations By Peroxisome Proliferator-Activated Receptor Gamma Agonists In Human Colorectal Cancer Cells, Maria Cekanova, X Li, J Yuan, K B. Kim, Seung J. Baek Apr 2008

Gene Alterations By Peroxisome Proliferator-Activated Receptor Gamma Agonists In Human Colorectal Cancer Cells, Maria Cekanova, X Li, J Yuan, K B. Kim, Seung J. Baek

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear transcription factor that controls the genes involved in metabolism and carcinogenesis. In the present study, we examined the alteration of gene expression in HCT-116 human colorectal cancer cells by PPARgamma agonists: MCC-555 (5 microM), rosiglitazone (5 microM), and 15-deoxy-Delta12,14-prostaglandin J2 (1 microM). The long-oligo microarray data revealed a list of target genes commonly induced (307 genes) and repressed (32 genes) by tested PPARgamma agonists. These genes were analyzed by Onto-Express software and KEGG pathway analysis and revealed that PPARgamma agonists are involved in cell proliferation, focal adhesion, and several signaling pathways. …


Mutational Optimization Of The Coelenterazine-Dependent Luciferase From Renilla, Jongchan Woo, Albrecht G. Von Arnim Jan 2008

Mutational Optimization Of The Coelenterazine-Dependent Luciferase From Renilla, Jongchan Woo, Albrecht G. Von Arnim

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Renilla luciferase (RLUC) is a popular reporter enzyme for gene expression and biosensor applications, but it is an unstable enzyme whose catalytic mechanism remains to be elucidated. We titrated that one RLUC molecule can turn over about one hundred molecules of coelenterazine substrate. Mutagenesis of active site residue Pro220 extended the half-life of photon emission, yielding brighter luminescence in E. coli. Random mutagenesis uncovered two new mutations that stabilized and increased photon emission in vivo and in vitro, while ameliorating substrate inhibition. Further amended with a previously identified mutation, a new triple mutant showed a threefold improved k …


Ethylene Stimulates Nutations That Are Dependent On The Etr1 Receptor, Brad M. Binder, Ronan C. O'Malley, Wuyi Wang, Tobias C. Zutz, Anthony B. Bleeker Jan 2006

Ethylene Stimulates Nutations That Are Dependent On The Etr1 Receptor, Brad M. Binder, Ronan C. O'Malley, Wuyi Wang, Tobias C. Zutz, Anthony B. Bleeker

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Ethylene influences a number of processes in Arabidopsis (Arabidopsis thaliana) through the action of five receptors. In this study, we used high-resolution, time-lapse imaging to examine the long-term effects of ethylene on growing, etiolated Arabidopsis seedlings. These measurements revealed that ethylene stimulates nutations of the hypocotyls with an average delay in onset of over 6 h. The nutation response was constitutive in ctr1-2 mutants maintained in air, whereas ein2-1 mutants failed to nutate when treated with ethylene. Ethylene-stimulated nutations were also eliminated in etr1-7 loss-of-function mutants. Transformation of the etr1-7 mutant with a wild-type genomic ETR1 transgene rescued the nutation …


Soluble Fibrin Inhibits Monocyte Adherence And Cytotoxicity Against Tumor Cells: Implications For Cancer Metastasis, John Biggerstaff, Brandy Weidow, Jacqueline Vidosh, Judith Dexheimer, Shonak Patel, Pretesh Patel Jan 2006

Soluble Fibrin Inhibits Monocyte Adherence And Cytotoxicity Against Tumor Cells: Implications For Cancer Metastasis, John Biggerstaff, Brandy Weidow, Jacqueline Vidosh, Judith Dexheimer, Shonak Patel, Pretesh Patel

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background Soluble fibrin (sFn) is a marker for disseminated intravascular coagulation and may have prognostic significance, especially in metastasis. However, a role for sFn in the etiology of metastatic cancer growth has not been extensively studied. We have reported that sFn cross-linked platelet binding to tumor cells via the major platelet fibrin receptor αIIbβ3, and tumor cell CD54 (ICAM-1), which is the receptor for two of the leukocyte β2 integrins (αLβ2 and aMβ2). We hypothesized that sFn may also affect leukocyte adherence, recognition, and killing of tumor cells. Furthermore, in a rat experimental metastasis model sFn pre-treatment of tumor cells …


Expression Of G-Protein Inwardly Rectifying Potassium Channels (Girks) In Lung Cancer Cell Lines, Howard Plummer 3rd, Madhu Dhar, Maria Cekanova Ms, Rndr, Phd, Hildegard Schuller Aug 2005

Expression Of G-Protein Inwardly Rectifying Potassium Channels (Girks) In Lung Cancer Cell Lines, Howard Plummer 3rd, Madhu Dhar, Maria Cekanova Ms, Rndr, Phd, Hildegard Schuller

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

BACKGROUND: Previous data from our laboratory has indicated that there is a functional link between the beta-adrenergic receptor signaling pathway and the G-protein inwardly rectifying potassium channel (GIRK1) in human breast cancer cell lines. We wanted to determine if GIRK channels were expressed in lung cancers and if a similar link exists in lung cancer. METHODS: GIRK1-4 expression and levels were determined by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. GIRK protein levels were determined by western blots and cell proliferation was determined by a 5-bromo-2'-deoxyuridine (BrdU) assay. RESULTS: GIRK1 mRNA was expressed in three of six small …


Molecular Characterization Of A Isoenzyme Of The Targeting Peptide Degrading Protease, Prep2- Catalysis, Subcellular Localization, Expression And Evolution, S. Bhushan, A. Stahl, S. Nilsson, B. Lefebvre, D. Mcwilliams, S.J. Wright, M. Seki, D.A. Liberles, K. Shinozaki, Barry D. Bruce, M. Boutry, E. Glaser Jan 2005

Molecular Characterization Of A Isoenzyme Of The Targeting Peptide Degrading Protease, Prep2- Catalysis, Subcellular Localization, Expression And Evolution, S. Bhushan, A. Stahl, S. Nilsson, B. Lefebvre, D. Mcwilliams, S.J. Wright, M. Seki, D.A. Liberles, K. Shinozaki, Barry D. Bruce, M. Boutry, E. Glaser

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

We have previously identified a zinc metalloprotease involved in the degradation of mitochondrial and chloroplast targeting peptides, the presequence protease (PreP). In the Arabidopsis thaliana genomic database, there are two genes that correspond to the protease, the zinc metalloprotease (AAL90904) and the putative zinc metalloprotease (AAG13049). We have named the corresponding proteins AtPreP1 and AtPreP2, respectively. AtPreP1 and AtPreP2 show significant differences in their targeting peptides and the proteins are predicted to be localized in different compartments. AtPreP1 was shown to degrade both mitochondrial and chloroplast targeting peptides and to be dual targeted to both organelles using an ambiguous targeting …


Liver-Specific Expression Of The Agouti Gene In Transgenic Mice Promotes Liver Carcinogenesis In The Absence Of Obesity And Diabetes, Alexander I. Kuklin, Randall L. Mynatt, Mitchell L. Klebig, Laura L. Kiefer, William O. Wilkison, Richard P. Woychik, Edward J. Michaud Jun 2004

Liver-Specific Expression Of The Agouti Gene In Transgenic Mice Promotes Liver Carcinogenesis In The Absence Of Obesity And Diabetes, Alexander I. Kuklin, Randall L. Mynatt, Mitchell L. Klebig, Laura L. Kiefer, William O. Wilkison, Richard P. Woychik, Edward J. Michaud

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Background

The agouti protein is a paracrine factor that is normally present in the skin of many species of mammals. Agouti regulates the switch between black and yellow hair pigmentation by signalling through the melanocortin 1 receptor (Mc1r) on melanocytes. Lethal yellow (Ay) and viable yellow (Avy) are dominant regulatory mutations in the mouse agouti gene that cause the wild-type protein to be produced at abnormally high levels throughout the body. Mice harboring these mutations exhibit a pleiotropic syndrome characterized by yellow coat color, obesity, hyperglycemia, hyperinsulinemia, and increased susceptibility to hyperplasia and carcinogenesis …


Expression And Localization Of Estrogen Receptor-Alpha Protein In Normal And Abnormal Term Placentae And Stimulation Of Trophoblast Differentiation By Estradiol, A Bukovsky, Maria Cekanova Ms, Rndr, Phd, Mr Caudle, J Wimalasena, Js Foster, Dc Henley, Rf Elder Feb 2003

Expression And Localization Of Estrogen Receptor-Alpha Protein In Normal And Abnormal Term Placentae And Stimulation Of Trophoblast Differentiation By Estradiol, A Bukovsky, Maria Cekanova Ms, Rndr, Phd, Mr Caudle, J Wimalasena, Js Foster, Dc Henley, Rf Elder

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Estrogens play an important role in the regulation of placental function, and 17-beta-estradiol (E2) production rises eighty fold during human pregnancy. Although term placenta has been found to specifically bind estrogens, cellular localization of estrogen receptor alpha (ER-alpha) in trophoblast remains unclear. We used western blot analysis and immunohistochemistry with h-151 and ID5 monoclonal antibodies to determine the expression and cellular localization of ER-alpha protein in human placentae and cultured trophoblast cells. Western blot analysis revealed a ~65 kDa ER-alpha band in MCF-7 breast carcinoma cells (positive control). A similar band was detected in five normal term placentae exhibiting strong …


Intrinsic Role Of Polysialylated Neural Cell Adhesion Molecule In Photic Phase Resetting Of The Mammalian Circadian Clock, Rebecca Prosser Jan 2003

Intrinsic Role Of Polysialylated Neural Cell Adhesion Molecule In Photic Phase Resetting Of The Mammalian Circadian Clock, Rebecca Prosser

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The suprachiasmatic nuclei (SCN), the location of the mammalian circadian clock, are one of the few adult brain regions that express the highly polysialylated form of neural cell adhesion molecule (PSA-NCAM). A role for the polysialic acid (PSA) component of PSA-NCAM, which is known to promote tissue plasticity, has been reported for photic entrainment of circadian rhythmicity in vivo. The in vivo results, however, do not discriminate between PSA acting upstream or downstream of the glutamatergic synapses that convey photic information to the SCN. To address this key issue, we exploited an in vitro rat brain slice preparation that retains …


Placental Expression Of Estrogen Receptor Beta And Its Hormone Binding Variant – Comparison With Estrogen Receptor Alpha And A Role For Estrogen Receptors In Asymmetric Division And Differentiation Of Estrogen-Dependent Cells, Antonin Bukovsky, Michael R. Caudle, Maria Cekanova Ms, Rndr, Phd, Romaine I. Fernando, Jay Wimalasena, James S. Foster, Donald C. Henley, Robert F. Elder Jan 2003

Placental Expression Of Estrogen Receptor Beta And Its Hormone Binding Variant – Comparison With Estrogen Receptor Alpha And A Role For Estrogen Receptors In Asymmetric Division And Differentiation Of Estrogen-Dependent Cells, Antonin Bukovsky, Michael R. Caudle, Maria Cekanova Ms, Rndr, Phd, Romaine I. Fernando, Jay Wimalasena, James S. Foster, Donald C. Henley, Robert F. Elder

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

During human pregnancy, the production of 17-beta-estradiol (E2) rises steadily to eighty fold at term, and placenta has been found to specifically bind estrogens. We have recently demonstrated the expression of estrogen receptor alpha (ER-alpha) protein in human placenta and its localization in villous cytotrophoblast (CT), vascular pericytes, and amniotic fibroblasts. In vitro, E2 stimulated development of large syncytiotrophoblast (ST) aggregates. In the present study we utilized ER-beta affinity purified polyclonal (N19:sc6820) and ER-alpha monoclonal (clone h-151) antibodies. Western blot analysis revealed a single ~52 kDa ER-beta band in chorionic villi (CV) protein extracts. In CV, strong cytoplasmic ER-beta immunoreactivity …