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Full-Text Articles in Life Sciences

Biochemical And Biophysical Analysis Of The Intracellular Lipid Binding Proteins Of Adipocytes, Melanie A. Simpson, Vince J. Licata, Natalie Ribarik Coe, David A. Bernlohr Dec 1999

Biochemical And Biophysical Analysis Of The Intracellular Lipid Binding Proteins Of Adipocytes, Melanie A. Simpson, Vince J. Licata, Natalie Ribarik Coe, David A. Bernlohr

Department of Biochemistry: Faculty Publications

Adipocytes express two lipid-binding proteins; the major one termed the adipocyte lipid-binding protein or aP2 (ALBP/aP2) and a minor one referred to as the keratinocyte lipid-binding protein (KLBP). In order to evaluate the potential physiological roles for these proteins, their biochemical and biophysical properties have been analyzed and compared. ALBP/aP2 and KLBP exhibit similar binding affinities for most long-chain fatty acids; however, ALBP/aP2 exhibits a two to three-fold increased affi nity for myristic, palmitic, oleic and linoleic acids, the predominant fatty acids of adipocytes. As measured by guanidinium hydrochloride denaturation, the stability of ALBP/aP2 is nearly 3 kcal/mol greater than …


Melanoma Chondroitin Sulphate Proteoglycan Regulates Cell Spreading Through Cdc42, Ack-1 And P130Cas, Kathryn M. Eisenmann, James B. Mccarthy, Melanie A. Simpson, Patricia J. Keely, Jun-Lin Guan, Kouichi Tachibana, Louis Lim, Ed Manser, Leo T. Furcht, Joji Iida Dec 1999

Melanoma Chondroitin Sulphate Proteoglycan Regulates Cell Spreading Through Cdc42, Ack-1 And P130Cas, Kathryn M. Eisenmann, James B. Mccarthy, Melanie A. Simpson, Patricia J. Keely, Jun-Lin Guan, Kouichi Tachibana, Louis Lim, Ed Manser, Leo T. Furcht, Joji Iida

Department of Biochemistry: Faculty Publications

Melanoma chondroitin sulphate proteoglycan (MCSP) is a cell-surface antigen that has been implicated in the growth and invasion of melanoma tumors. Although this antigen is expressed early in melanoma progression, its biological function is unknown. MCSP can stimulate the integrin-α4β1-mediated adhesion and spreading of melanoma cells. Here we show that stimulated MCSP recruits tyrosine- phosphorylated p130cas, an adaptor protein important in tumor cell motility and invasion. MCSP stimulation also results in a pronounced activation and recruitment of the Rho-family GTPase Cdc42. MCSP-induced spreading of melanoma cells is dependent upon active Cdc42, a Cdc42-associated tyrosine kinase (Ack-1) and tyrosine phosphorylation of …


New Mammalian Selenocysteine-Containing Proteins Identified With An Algorithm That Searches For Selenocysteine Insertion Sequence Elements, Gregory V. Kryukov, Valentin M. Kryukov, Vadim N. Gladyshev Nov 1999

New Mammalian Selenocysteine-Containing Proteins Identified With An Algorithm That Searches For Selenocysteine Insertion Sequence Elements, Gregory V. Kryukov, Valentin M. Kryukov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Mammalian selenium-containing proteins identified thus far contain selenium in the form of a selenocysteine residue encoded by UGA. These proteins lack common amino acid sequence motifs, but 3’-untranslated regions of selenoprotein genes contain a common stem-loop structure, selenocysteine insertion sequence (SECIS) element, that is necessary for decoding UGA as selenocysteine rather than a stop signal. We describe here a computer program, SECISearch, that identifies mammalian selenoprotein genes by recognizing SECIS elements on the basis of their primary and secondary structures and free energy requirements. When SECISearch was applied to search human dbEST, two new mammalian selenoproteins, designated SelT and SelR, …


Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford Nov 1999

Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasonic imaging system includes a receive beam former that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path includes both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality.


An Insulator Element And Condensed Chromatin Region Separate The Chicken Β-Globin Locus From An Independently Regulated Erythroid-Specific Folate Receptor Gene, Marie-Noelle Prioleau, Pascale Nony, Melanie A. Simpson, Gary Felsenfeld Oct 1999

An Insulator Element And Condensed Chromatin Region Separate The Chicken Β-Globin Locus From An Independently Regulated Erythroid-Specific Folate Receptor Gene, Marie-Noelle Prioleau, Pascale Nony, Melanie A. Simpson, Gary Felsenfeld

Department of Biochemistry: Faculty Publications

We have identified a folate receptor gene upstream of the chicken β-globin locus and separated from it by a 16 kbp region of silent chromatin. We find that this receptor is expressed only at a stage of erythroid differentiation (CFU-E) preceding the activation of β-globin genes, consistent with the role of folate receptors in proliferation. This discovery raises the question of how these two loci are regulated during erythropoiesis. Our data suggest that the folate receptor gene and the β-globin locus are regulated independently. We show that a 3.3 kbp DNA region upstream of the folate receptor gene is sufficient …


Redox Regulation Of Cell Signaling By Selenocysteine In Mammalian Thioredoxin Reductases, Qi-An Sun, Yalin Wu, Francesca Zappacosta, Kuan-Teh Jeang, Byeong Jae Lee, Dolph L. Hatfield, Vadim N. Gladyshev Aug 1999

Redox Regulation Of Cell Signaling By Selenocysteine In Mammalian Thioredoxin Reductases, Qi-An Sun, Yalin Wu, Francesca Zappacosta, Kuan-Teh Jeang, Byeong Jae Lee, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

The intracellular generation of reactive oxygen species, together with the thioredoxin and glutathione systems, is thought to participate in redox signaling in mammalian cells. The activity of thioredoxin is dependent on the redox status of thioredoxin reductase (TR), the activity of which in turn is dependent on a selenocysteine residue. Two mammalian TR isozymes (TR2 and TR3), in addition to that previously characterized (TR1), have now been identified in humans and mice. All three TR isozymes contain a selenocysteine residue that is located in the penultimate position at the carboxyl terminus and which is encoded by a UGA codon. The …


Posttranscriptional Regulation Of Mammalian Methionine Synthase By B12, Sumedha Gulati, Lawrence C. Brody, Ruma V. Banerjee Jul 1999

Posttranscriptional Regulation Of Mammalian Methionine Synthase By B12, Sumedha Gulati, Lawrence C. Brody, Ruma V. Banerjee

Department of Biochemistry: Faculty Publications

Methionine synthase is one of two key enzymes involved in the removal of the metabolite, homocysteine. Elevated homocysteine levels constitute a risk factor for cardiovascular diseases and for neural tube defects. In cell culture, the activity of methionine synthase is enhanced several-fold by supplementation with its cofactor, B12. The mechanism of this regulation is unknown, although it has been ascribed to a shift from apoenzyme to holoenzyme. Using sensitive assay techniques as well as a combination of Northern and Western analyses, we demonstrate that the effect of B,, on induction of methionine synthase activity is paralleled by an …


Optimal Replication Activity Of Vesicular Stomatitis Virus Rna Polymerase Requires Phosphorylation Of A Residue(S) At Carboxy-Terminal Domain Ii Of Its Accessory Subunit, Phosphoprotein P, Leroy N. Hwang, Nathan Englund, Tapas Das, Amiya K. Florida, Asit K. Pattnaik Jul 1999

Optimal Replication Activity Of Vesicular Stomatitis Virus Rna Polymerase Requires Phosphorylation Of A Residue(S) At Carboxy-Terminal Domain Ii Of Its Accessory Subunit, Phosphoprotein P, Leroy N. Hwang, Nathan Englund, Tapas Das, Amiya K. Florida, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

The phosphoprotein, P, of vesicular stomatitis virus (VSV) is a key subunit of the viral RNA-dependent RNA polymerase complex. The protein is phosphorylated at multiple sites in two different domains. We recently showed that specific serine and threonine residues within the amino-terminal acidic domain I of P protein must be phosphorylated for in vivo transcription activity, but not for replication activity, of the polymerase complex. To examine the role of phosphorylation of the carboxy-terminal domain II residues of the P protein in transcription and replication, we have used a panel of mutant P proteins in which the phosphate acceptor sites …


Nucleotide Sequences For Detection Of Serpulina Hyodysenteriae, Gerald E. Duhamel, Robert Elder Feb 1999

Nucleotide Sequences For Detection Of Serpulina Hyodysenteriae, Gerald E. Duhamel, Robert Elder

School of Veterinary and Biomedical Sciences: Faculty Publications

The invention provides a method for detecting the presence of Serpulina hyOdysenteriae in a biological Sample, an oligonucleotide primer and an S. hyodysenteriae-specific oligonucleotide probe useful in that method, and an article of manufacture that contains the primers and/or probe. Also provided are an about 2.3-kb DNA fragment derived from genomic DNA of S. hyodysenteriae and encoding for an about 56 kDa polypeptide, a recombinant expression vector containing the DNA fragment, the 56 kDa polypeptide and a monoclonal antibody reactive with the peptide, and a method of assaying for antibodies reactive with the 56 kDa peptide.


Levels Of Major Selenoproteins In T Cells Decrease During Hiv Infection And Low Molecular Mass Selenium Compounds Increase, Vadim Gladyshev, Thressa C. Stadtman, Dolph L. Hatfield, Kuan-Teh Jeang Feb 1999

Levels Of Major Selenoproteins In T Cells Decrease During Hiv Infection And Low Molecular Mass Selenium Compounds Increase, Vadim Gladyshev, Thressa C. Stadtman, Dolph L. Hatfield, Kuan-Teh Jeang

Vadim Gladyshev Publications

It has been observed previously that plasma selenium and glutathione levels are subnormal in HIV-infected individuals, and plasma glutathione peroxidase activity is decreased. Under these conditions the survival rate of AIDS patients is reduced significantly. In the present study, using 75Se-labeled human Jurkat T cells, we show that the levels of four 75Se-containing proteins are lower in HIV-infected cell populations than in uninfected cells. These major selenoproteins migrated as 57-, 26-, 21-, and 15-kDa species on SDS/PAGE gels. In our earlier studies, the 57-kDa protein was purified from T cells and identified as a subunit of thioredoxin reductase. …


In Situ Hybridization For The Detection And Localization Of Swine Chlamydia Trachomatis, C. Chae, D.-S. Cheon, D. Kwon, O. Kim, B. Kim, J. Suh, D. G. Rogers, K. D. E. Everett, A. A. Anderson Jan 1999

In Situ Hybridization For The Detection And Localization Of Swine Chlamydia Trachomatis, C. Chae, D.-S. Cheon, D. Kwon, O. Kim, B. Kim, J. Suh, D. G. Rogers, K. D. E. Everett, A. A. Anderson

School of Veterinary and Biomedical Sciences: Faculty Publications

Gnotobiotic piglets were inoculated intralaryngeally with swine Chlamydia trachomatis strain R33 or orally with swine C. trachmatis strain R27. Archived formalin-fixed, paraffin-embedded tissues from piglets euthanatized 4–7 days postinoculation were examined by in situ hybridization for C. trachomatis nucleic acid using a nonradioactive digoxigenin-labeled DNA probes that targeted specific ribosomal RNA or omp1 mRNA molecules of the swine C. trachomatis strains. Positive hybridization signals were detected in bronchial epithelial cells, bronchiolar epithelial cells, pneumocytes, alveolar and interstitial macrophages, and jejunal and ileal enterocytes. Chlamydia-infected cells had a strong signal that was confined to the intracytoplasmic inclusions. Positive hybridization signals were …


Yeast And Human Frataxin Are Processed To Mature Form In Two Sequential Steps By The Mitochondrial Processing Peptidase, Steven S. Branda, Patrizia Cavadini, Jiri Adamec, Frantisek Kalousek, Franco Taroni, Grazia Isaya Jan 1999

Yeast And Human Frataxin Are Processed To Mature Form In Two Sequential Steps By The Mitochondrial Processing Peptidase, Steven S. Branda, Patrizia Cavadini, Jiri Adamec, Frantisek Kalousek, Franco Taroni, Grazia Isaya

Department of Biochemistry: Faculty Publications

Frataxin is a nuclear-encoded mitochondrial protein which is deficient in Friedreich’s ataxia, a hereditary neurodegenerative disease. Yeast mutants lacking the yeast frataxin homologue (Yfh1p) show iron accumulation in mitochondria and increased sensitivity to oxidative stress, suggesting that frataxin plays a critical role in mitochondrial iron homeostasis and free radical toxicity. Both Yfh1p and frataxin are synthesized as larger precursor molecules that, upon import into mitochondria, are subject to two proteolytic cleavages, yielding an intermediate and a mature size form. A recent study found that recombinant rat mitochondrial processing peptidase (MPP) cleaves the mouse frataxin precursor to the intermediate but not …


Affinity Chromatography: A Review Of Clinical Applications, David S. Hage Jan 1999

Affinity Chromatography: A Review Of Clinical Applications, David S. Hage

David Hage Publications

Affinity chromatography is a type of liquid chromatography that makes use of biological-like interactions for the separation and specific analysis of sample components. This review describes the basic principles of affinity chromatography and examines its use in the testing of clinical samples, with an emphasis on HPLCbased methods. Some traditional applications of this approach include the use of boronate, lectin, protein A or protein G, and immunoaffinity supports for the direct quantification of solutes. Newer techniques that use antibody-based columns for on- or off-line sample extraction are examined in detail, as are methods that use affinity chromatography in combination with …


Early And Late Endosomal Compartments Of Entamoeba Histolytica Are Enriched In Cysteine Proteases, Acid Phosphatase And Several Ras-Related Rab Gtpases, Lesly A. Temesvari, Ed Harris, Samuel L. Stanley Jr., James Cardelli Jan 1999

Early And Late Endosomal Compartments Of Entamoeba Histolytica Are Enriched In Cysteine Proteases, Acid Phosphatase And Several Ras-Related Rab Gtpases, Lesly A. Temesvari, Ed Harris, Samuel L. Stanley Jr., James Cardelli

Department of Biochemistry: Faculty Publications

Pure populations of early and late endosomes of Entamoeba histolytica were isolated by magnetic fractionation and characterized. It was shown that these vesicles were enriched in acid phosphatase and cysteine protease activities. An important virulence factor, a 27-kDa cysteine protease, was also enriched in early and late endosomes of E. histolytica. These data suggest that E. histolytica hydrolases reside in compartments that are part of or communicate with the endosomal pathway. To begin to identify the role of Rab GTPases in E. histolytica, an oligonucleotide approach was employed to screen an E. histolytica cDNA library for genes encoding …


Plasmd Bearing A Cdna Copy Of The Genome Of Bovine Viral Diarrhea Virus, Chimeric Derivatives Thereof, And Method Of Producing An Infectious Bovine Wral Darrheavirus Using Sad Plasmid, Ruben O. Donis, Ventzislav B. Vassilev Jan 1999

Plasmd Bearing A Cdna Copy Of The Genome Of Bovine Viral Diarrhea Virus, Chimeric Derivatives Thereof, And Method Of Producing An Infectious Bovine Wral Darrheavirus Using Sad Plasmid, Ruben O. Donis, Ventzislav B. Vassilev

School of Veterinary and Biomedical Sciences: Faculty Publications

A plasmid bearing a cDNA copy of the genome of bovine viral diarrhea virus (BVDV), chimeric derivatives of the plasmid and a method of producing an infectious bovine viral diarrhea virus using the plasmid are disclosed. The invention relates to a plasmid DNA molecule that replicates easily in E. coli and contains a sufficient portion of the genome of BVDV, cloned as cDNA, to be a suitable template to produce RNA in vitro which, upon transfection into bovine cells, gives rise to infectious BVDV. The BVDV created by the process of the invention can be engineered for use as a …


Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris Jan 1999

Carmoviruses (Tombusviridae), Feng Qu, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Carmovirus is one of two officially recognized genera of Tombusviridae. Members of Tombusviridae all have icosahedral virions of about 30 nm in diameter with T = 3 symmetry that consists of 180 coat protein (CP) subunits of about 38- 43 kDa and a single-stranded (ss) RNA genome ranging in size from 4.0 to 4.7 kb. Carmoviruses share recognizable sequence similarity in both the polymerase and structural genes with members of the other genus, Tombusvirus. Sequence comparisons and phylogenetic analysis of these genes support the view that the genera are distinct but closely related. In addition, the genome organization of the …