Life Sciences Commons^™

Infection Of Peripancreatic Lymph Nodes But Not Islets Precedes Kilham Rat Virus-Induced Diabetes In Bb/Wor Rats, David Brown, Raymond Welsh, Arthur Like

David C. Brown

A parvovirus serologically identified as Kilham rat virus (KRV) reproducibly induces acute type I diabetes in diabetes-resistant BB/Wor rats. The tissue tropism of KRV was investigated by in situ hybridization with a digoxigenin-labelled plasmid DNA probe containing approximately 1.6 kb of the genome of the UMass isolate of KRV. Partial sequencing of the KRV probe revealed high levels of homology to the sequence of minute virus of mice (89%) and to the sequence of H1 (99%), a parvovirus capable of infecting rats and humans. Of the 444 bases sequenced, 440 were shared by H1. KRV mRNA and DNA were readily …

The Fly Camta Transcription Factor Potentiates Deactivation Of Rhodopsin, A G Protein-Coupled Light Receptor, Junhai Han, Ping Gong, Keith Reddig, Mirna Mitra, Peiyi Guo, Hong-Sheng Li

Peiyi Guo

Control of membrane-receptor activity is required not only for the accuracy of sensory responses, but also to protect cells from excitotoxicity. Here we report the isolation of two noncomplementary fly mutants with slow termination of photoresponses. Genetic and electrophysiological analyses of the mutants revealed a defect in the deactivation of rhodopsin, a visual G protein-coupled receptor (GPCR). The mutant gene was identified as the calmodulin-binding transcription activator (dCAMTA). The known rhodopsin regulator Arr2 does not mediate this visual function of dCAMTA. A genome-wide screen identified five dCAMTA target genes. Of these, overexpression of the F box gene dFbxl4 rescued the …

Molecular Basis Of Rna Recognition By The Embryonic Polarity Determinant Mex-5, John Pagano, Brian Farley, Lisa Mccoig, Sean Ryder

Sean P. Ryder

Embryonic development requires maternal proteins and RNA. In Caenorhabditis elegans, a gradient of CCCH tandem zinc finger (TZF) proteins coordinates axis polarization and germline differentiation. These proteins govern expression from maternal mRNAs by an unknown mechanism. Here we show that the TZF protein MEX-5, a primary anterior determinant, is an RNA-binding protein that recognizes linear RNA sequences with high affinity but low specificity. The minimal binding site is a tract of six or more uridines within a 9-13-nucleotide window. This sequence is remarkably abundant in the 3'-untranslated region of C. elegans transcripts, demonstrating that MEX-5 alone cannot specify mRNA target …

Subnuclear Distribution Of The Vitamin D Receptor, Joseph Bidwell, Andre Van Wijnen, Edward Fey, Harold Merriman, Sheldon Penman, Janet Stein, Gary Stein, Jane Lian

Harold L. Merriman

The subnuclear distribution of the vitamin D receptor was investigated to begin addressing the contribution of nuclear architecture to vitamin D-responsive control of gene expression in ROS 17/2.8 rat osteosarcoma cells. The nuclear matrix is an anastomosing network of filaments that is functionally associated with DNA replication, transcription, and RNA processing. The representation of vitamin D receptor in the nuclear matrix and nonmatrix nuclear fractions was determined by the combined application of 1) sequence-specific interactions with the vitamin D receptor binding element of the rat bone-specific osteocalcin gene promoter and 2) Western blot analysis. Both methods confirmed the presence of …

The Tissue-Specific Nuclear Matrix Protein, Nmp-2, Is A Member Of The Aml/Cbf/Pebp2/Runt Domain Transcription Factor Family: Interactions With The Osteocalcin Gene Promoter, Harold Merriman, Andre Van Wijnen, Scott Hiebert, Joseph Bidwell, Edward Fey, Jane Lian, Janet Stein, Gary Stein

Harold L. Merriman

The nuclear matrix protein, NMP-2, was originally identified as an osteoblast-specific DNA-binding complex localized exclusively to the nuclear matrix. NMP-2 was shown to recognize two binding sites, site A (nt-605 to -599) and site B (nt -441 to -435), in the rat bone-specific osteocalcin gene promoter. This study shows that the NMP-2 binding sites A and B as well as a third NMP-2 binding site (nt -135 to -130) constitute a consensus sequence, ATGCTGGT, and represent an AML-1 recognition motif. AML-1 is a member of the AML transcription factor family which is associated with acute myelogenous leukemia and binds to …

Bacterial Rna:Dna Hybrids Are Activators Of The Nlrp3 Inflammasome, Sivapriya Kailasan Vanaja, Vijay A. K. Rathinam, Maninjay K. Atianand, Parisa Kalantari, Brian M. Skehan, Katherine A. Fitzgerald, John M. Leong

Katherine A. Fitzgerald

Enterohemorrhagic Escherichia coli (EHEC) is an extracellular pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome. The proinflammatory cytokine, interleukin-1beta, has been linked to hemolytic uremic syndrome. Here we identify the nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3) inflammasome as an essential mediator of EHEC-induced IL-1beta. Whereas EHEC-specific virulence factors were dispensable for NLRP3 activation, bacterial nucleic acids such as RNA:DNA hybrids and RNA gained cytosolic access and mediated inflammasome-dependent responses. Consistent with a direct role for RNA:DNA hybrids in inflammasome activation, delivery of synthetic EHEC RNA:DNA hybrids into the cytosol triggered NLRP3-dependent responses, …

A Single Base Pair Mutation Encoding A Premature Stop Codon In The Mis Type Ii Receptor Is Responsible For Canine Persistent Mullerian Duct Syndrome, Wenfang Wu, Shengqin Wan, Pujar Shashikant, Mark Haskins, Donald Schlafer, Mary Lee, Vicki Meyers-Wallen

Mary M. Lee

Mullerian inhibiting substance (MIS), a secreted glycoprotein in the transforming growth factor-beta family of growth factors, mediates regression of the Mullerian ducts during embryonic sex differentiation in males. In persistent Mullerian duct syndrome (PMDS), rather than undergoing involution, the Mullerian ducts persist in males, giving rise to the uterus, fallopian tubes, and upper vagina. Genetic defects in MIS or its receptor (MISRII) have been identified in patients with PMDS. The phenotype in the canine model of PMDS derived from the miniature schnauzer breed is strikingly similar to that of human patients. In this model, PMDS is inherited as a sex-limited …

Gel Shift Analysis Of The Empa Promoter Region In Vibrio Anguillarum, Steven Denkin, Pedja Sekaric, David Nelson

David R. Nelson

BACKGROUND: The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements.

RESULTS: Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG)-labeled oligomer containing a lux box-like …

Altered Cytokine Responses Of Dengue-Specific Cd4+ T Cells To Heterologous Serotypes, Maloy Mangada, Alan Rothman

Alan Rothman

The interplay of different inflammatory cytokines induced during a dengue (DEN) virus infection plays a role in either protection or increased disease severity. We measured the frequencies and characterized the cytokine responses of DEN virus-specific memory CD4+ T cells in PBMC of six volunteers who received experimental live attenuated monovalent DEN vaccines. IFN-gamma and TNF-alpha responses to inactivated DEN Ags were detected in up to 0.54 and 1.17% of total circulating CD4+ T cells, respectively. Ags from the homologous serotype elicited the highest IFN-gamma response. The ratio of TNF-alpha- to IFN-gamma-producing CD4+ T cells was higher after stimulation with Ags …

Analysis Of Murine Cd8(+) T-Cell Clones Specific For The Dengue Virus Ns3 Protein: Flavivirus Cross-Reactivity And Influence Of Infecting Serotype, Anne C. Spaulding, Ichiro Kurane, Francis A. Ennis, Alan L. Rothman

Alan Rothman

Serotype-cross-reactive dengue virus-specific cytotoxic T lymphocytes (CTL) induced during a primary dengue virus infection are thought to play a role in the immunopathogenesis of dengue hemorrhagic fever (DHF) during a secondary dengue virus infection. Although there is no animal model of DHF, we previously reported that murine dengue virus-specific CTL responses are qualitatively similar to human dengue virus-specific CTL responses. We used BALB/c mice to study the specificity of the CTL response to an immunodominant epitope on the dengue virus NS3 protein. We mapped the minimal H-2Kd-restricted CTL epitope to residues 298 to 306 of the dengue type 2 virus …

Identification And Analysis For Cross-Reactivity Among Hantaviruses Of H-2b-Restricted Cytotoxic T-Lymphocyte Epitopes In Sin Nombre Virus Nucleocapsid Protein, Ken Maeda, Kim West, Tomoko Toyosaki-Maeda, Alan Rothman, Francis Ennis, Masanori Terajima

Alan Rothman

Sin Nombre virus (SNV) causes hantavirus pulmonary syndrome (HPS), with a high rate of mortality in humans who are infected by the transmission of virus from the natural rodent host. In humans, cytotoxic T lymphocytes (CTL) specific for SNV appear to play an important role in the pathogenicity of HPS. There is a correlation between the frequencies of SNV-specific CTLs and the severity of HPS disease. In order to create a mouse model to study the role of SNV-specific T cells in vivo, T cell responses to SNV nucleocapsid (N) protein in B6.PL Thy1(a)/Cy mice (H-2(b)) immunized with plasmid DNA …

Identification Of Murine Poxvirus-Specific Cd8+ Ctl Epitopes With Distinct Functional Profiles, Anuja Mathew, Masanori Terajima, Kim West, Sharone Green, Alan Rothman, Francis Ennis, Jeffrey Kennedy

Alan Rothman

Murine T cell epitopes against vaccinia virus (VV) have not been characterized to date in part due to the large and complex genome of VV. We have identified and characterized two CD8+ T cell epitopes on the A47L (modified VV Ankara strain (MVA)-029) and J6R (MVA-043) proteins of VV that are Db and Kb restricted, respectively. Following i.p. immunization with VV New York City Board of Health (NYCBH) strain, MVA-029 peptide-stimulated splenocytes secreted IFN-gamma from 7 days to 7 mo postimmunization, and virus-stimulated effectors were also able to lyse MVA-029-pulsed target cells at the same time points. In contrast, MVA-043 …

Identification Of Murine Poxvirus-Specific Cd8+ Ctl Epitopes With Distinct Functional Profiles, Anuja Mathew, Masanori Terajima, Kim West, Sharone Green, Alan Rothman, Francis Ennis, Jeffrey Kennedy

Sharone Green

Murine T cell epitopes against vaccinia virus (VV) have not been characterized to date in part due to the large and complex genome of VV. We have identified and characterized two CD8+ T cell epitopes on the A47L (modified VV Ankara strain (MVA)-029) and J6R (MVA-043) proteins of VV that are Db and Kb restricted, respectively. Following i.p. immunization with VV New York City Board of Health (NYCBH) strain, MVA-029 peptide-stimulated splenocytes secreted IFN-gamma from 7 days to 7 mo postimmunization, and virus-stimulated effectors were also able to lyse MVA-029-pulsed target cells at the same time points. In contrast, MVA-043 …

Definition Of An Hla-Dpw2-Restricted Epitope On Ns3, Recognized By A Dengue Virus Serotype-Cross-Reactive Human Cd4+ Cd8- Cytotoxic T-Cell Clone, Ichiro Kurane, Li Chen Dai, Peter G. Livingston, Elaine Reed, Francis A. Ennis

Li Dai

We previously reported that the clone JK34 was cross-reactive for dengue virus types 1, 2, 3, and 4 and recognized NS3 (I. Kurane, M. A. Brinton, A. L. Samson, and F. A. Ennis, J. Virol. 65:1823-1828, 1991). In the present experiments, we defined the epitope at the amino acid level, with 93 15-mer overlapping peptides which cover the entire NS3. A peptide 4 which contains amino acids 251 to 265 of NS3 sensitized the autologous B lymphoblastoid cell line (LCL) to the lysis by JK34. The smallest peptide recognized by JK34 was a 10-mer peptide which contains amino acids 255 …

Mutation Of Human Immunodeficiency Virus Type 1 At Amino Acid 585 On Gp41 Results In Loss Of Killing By Cd8+ A24-Restricted Cytotoxic T Lymphocytes, Li Chen Dai, Kim West, Rebecca A. Littaua, Kazuo Takahashi, Francis A. Ennis

Li Dai

A human leukocyte antigen A24-restricted CD8+ cytotoxic T-cell clone specific for gp41 of human immunodeficiency virus type 1 was isolated from an infected individual. The epitope was localized to amino acids 584 to 591 (YLKDQQLL, NL43 env sequence) of gp41 by using a panel of recombinant vaccinia viruses that contain truncated env genes and synthetic peptides. The clone killed autologous B-lymphoblastoid cell lines pulsed with a synthetic peptide reflecting the sequence of the IIIB and MN strains. This clone, however, failed to kill target cells pulsed with the peptides that have a mutation from Lys to Arg or Gln at …

A Zebrafish Unc-45-Related Gene Expressed During Muscle Development, Letitiah Etheridge, Philip Diiorio, Charles Sagerstrom

Philip J diIorio Jr

We report the isolation and expression pattern of zebrafish unc45r, a gene related to Caenorhabditis elegans unc-45. UNC-45 is a muscle-specific protein thought to interact with myosin and promote the assembly of muscle thick filaments during C. elegans development. Zebrafish Unc45r shares sequence features with C. elegans UNC-45, including three tetratricopeptide repeats and a CRO1/She4p homology domain. unc45r is expressed in mesoderm adjacent to the dorsal midline during late gastrula stages and is coexpressed with muscle specific genes in somitic mesoderm during development of trunk skeletal muscle. unc45r is also expressed in cranial skeletal muscle as well as in cardiac …

Identification Of Cytoplasmic Residues Of Sec61p Involved In Ribosome Binding And Cotranslational Translocation, Zhiliang Cheng, Ying Jiang, Elisabet Mandon, Reid Gilmore

Elisabet Mandon

The cytoplasmic surface of Sec61p is the binding site for the ribosome and has been proposed to interact with the signal recognition particle receptor during targeting of the ribosome nascent chain complex to the translocation channel. Point mutations in cytoplasmic loops six (L6) and eight (L8) of yeast Sec61p cause reductions in growth rates and defects in the translocation of nascent polypeptides that use the cotranslational translocation pathway. Sec61 heterotrimers isolated from the L8 sec61 mutants have a greatly reduced affinity for 80S ribosomes. Cytoplasmic accumulation of protein precursors demonstrates that the initial contact between the large ribosomal subunit and …

Nitric Oxide-Mediated Inhibition Of Hdm2-P53 Binding, Christopher Schonhoff, Marie-Claire Daou, Stephen Jones, Celia Schiffer, Alonzo Ross

Celia A. Schiffer

It has become increasingly evident that nitric oxide exerts its effects, in part, by S-nitrosylation of cysteine residues. We tested in vitro whether nitric oxide may indirectly control p53 by S-nitrosylation and inactivation of the p53 negative regulator, Hdm2. Treatment of Hdm2 with a nitric oxide donor inhibits Hdm2-p53 binding, a critical step in Hdm2 regulation of p53. The presence of excess amounts of cysteine or dithiothreitol blocks this inhibition of binding. Moreover, nitric oxide inhibition of Hdm2-p53 binding was found to be reversible. Sulfhydryl sensitivity and reversibility are consistent with nitrosylation. Finally, we have identified a critical cysteine residue …

Contribution Of Ser386 And Ser396 To Activation Of Interferon Regulatory Factor 3, Weijun Chen, Hema Srinath, Suvana Lam, Celia Schiffer, William Royer, Kai Lin

Celia A. Schiffer

IRF-3, a member of the interferon regulatory factor (IRF) family of transcription factors, functions in innate immune defense against viral infection. Upon infection, host cell IRF-3 is activated by phosphorylation at its seven C-terminal Ser/Thr residues: (385)SSLENTVDLHISNSHPLSLTS(405). This phosphoactivation triggers IRF-3 to react with the coactivators, CREB-binding protein (CBP)/p300, to form a complex that activates target genes in the nucleus. However, the role of each phosphorylation site for IRF-3 phosphoactivation remains unresolved. To address this issue, all seven Ser/Thr potential phosphorylation sites were screened by mutational studies, size-exclusion chromatography, and isothermal titration calorimetry. Using purified proteins, we show that CBP …

Lps-Tlr4 Signaling To Irf-3/7 And Nf-Kappab Involves The Toll Adapters Tram And Trif, Katherine A. Fitzgerald, Daniel C. Rowe, Betsy J. Barnes, Daniel R. Caffrey, Alberto Visintin, Eicke Latz, Brian G. Monks, Paula M. Pitha, Douglas T. Golenbock

Katherine A. Fitzgerald

Toll-IL-1-resistance (TIR) domain-containing adaptor-inducing IFN-beta (TRIF)-related adaptor molecule (TRAM) is the fourth TIR domain-containing adaptor protein to be described that participates in Toll receptor signaling. Like TRIF, TRAM activates interferon regulatory factor (IRF)-3, IRF-7, and NF-kappaB-dependent signaling pathways. Toll-like receptor (TLR)3 and 4 activate these pathways to induce IFN-alpha/beta, regulated on activation, normal T cell expressed and secreted (RANTES), and gamma interferon-inducible protein 10 (IP-10) expression independently of the adaptor protein myeloid differentiation factor 88 (MyD88). Dominant negative and siRNA studies performed here demonstrate that TRIF functions downstream of both the TLR3 (dsRNA) and TLR4 (LPS) signaling pathways, whereas the …

Regulation Of Alpha 6 Beta 1 Integrin Laminin Receptor Function By The Cytoplasmic Domain Of The Alpha 6 Subunit, Leslie M. Shaw, Arthur M. Mercurio

Arthur M. Mercurio

The alpha 6 beta 1 integrin is expressed on the macrophage surface in an inactive state and requires cellular activation with PMA or cytokines to function as a laminin receptor (Shaw, L. M., J. M. Messier, and A. M. Mercurio. 1990. J. Cell Biol. 110:2167-2174). In the present study, the role of the alpha 6 subunit cytoplasmic domain in alpha 6 beta 1 integrin activation was examined. The use of P388D1 cells, an alpha 6-integrin deficient macrophage cell line, facilitated this analysis because expression of either the alpha 6A or alpha 6B subunit cDNAs restores their activation responsive laminin adhesion …

Patellin1, A Novel Sec14-Like Protein, Localizes To The Cell Plate And Binds Phosphoinositides, T. Peterman, Yamini Ohol, Lisa Mcreynolds, Elizabeth Luna

Elizabeth J. Luna

Membrane trafficking is central to construction of the cell plate during plant cytokinesis. Consequently, a detailed understanding of the process depends on the characterization of molecules that function in the formation, transport, targeting, and fusion of membrane vesicles to the developing plate, as well as those that participate in its consolidation and maturation into a fully functional partition. Here we report the initial biochemical and functional characterization of patellin1 (PATL1), a novel cell-plate-associated protein that is related in sequence to proteins involved in membrane trafficking in other eukaryotes. Analysis of the Arabidopsis genome indicated that PATL1 is one of a …

Supervillin (P205): A Novel Membrane-Associated, F-Actin-Binding Protein In The Villin/Gelsolin Superfamily, Kersi N. Pestonjamasp, Robert K. Pope, J. D. Wulfkuhle, Elizabeth J. Luna

Elizabeth J. Luna

Actin-binding membrane proteins are involved in both adhesive interactions and motile processes. We report here the purification and initial characterization of p205, a 205-kD protein from bovine neutrophil plasma membranes that binds to the sides of actin filaments in blot overlays. p205 is a tightly bound peripheral membrane protein that cosediments with endogenous actin in sucrose gradients and immunoprecipitates. Amino acid sequences were obtained from SDS-PAGE-purified p205 and used to generate antipeptide antibodies, immunolocalization data, and cDNA sequence information. The intracellular localization of p205 in MDBK cells is a function of cell density and adherence state. In subconfluent cells, p205 …

Merlin Differs From Moesin In Binding To F-Actin And In Its Intra- And Intermolecular Interactions, L. Huang, E. Ichimaru, Kersi Pestonjamasp, X. Cui, H. Nakamura, G. Lo, F. Lin, Elizabeth Luna, H. Furthmayr

Elizabeth J. Luna

The neurofibromatosis type 2 (NF2) tumor suppressor gene encodes merlin, a protein with homology to the cell membrane/F-actin linking proteins, moesin, ezrin and radixin. Unlike these closely related proteins, merlin lacks a C-terminal F-actin binding site detectable by actin blot overlays, and the GFP-tagged merlin C-terminal domain co-distributes with neither stress fibers nor cortical actin in NIH3T3 cells. Merlin also differs from the other three proteins in its inter- and intramolecular domain interactions, as shown by in vitro binding and yeast two-hybrid assays. As is true for ezrin, moesin and radixin, the N- and C-terminal domains of merlin type 1 …

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

Elizabeth J. Luna

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 cortex after …

F-Actin And Myosin Ii Binding Domains In Supervillin, Yu Chen, Norio Takizawa, Jessica Crowley, Sang Oh, Cheryl Gatto, Taketoshi Kambara, Osamu Sato, Xiang-Dong Li, Mitsuo Ikebe, Elizabeth Luna

Elizabeth J. Luna

Detergent-resistant membranes contain signaling and integral membrane proteins that organize cholesterol-rich domains called lipid rafts. A subset of these detergent-resistant membranes (DRM-H) exhibits a higher buoyant density ( approximately 1.16 g/ml) because of association with membrane skeleton proteins, including actin, myosin II, myosin 1G, fodrin, and an actin- and membrane-binding protein called supervillin (Nebl, T., Pestonjamasp, K. N., Leszyk, J. D., Crowley, J. L., Oh, S. W., and Luna, E. J. (2002) J. Biol. Chem. 277, 43399-43409). To characterize interactions among DRM-H cytoskeletal proteins, we investigated the binding partners of the novel supervillin N terminus, specifically amino acids 1-830. We …

Archvillin, A Muscle-Specific Isoform Of Supervillin, Is An Early Expressed Component Of The Costameric Membrane Skeleton, Sang W. Oh, Robert K. Pope, Kelly P. Smith, Jessica Lynn Crowley, Thomas Nebl, Jeanne B. Lawrence, Elizabeth J. Luna

Elizabeth J. Luna

The membrane skeleton protein supervillin binds tightly to both F-actin and membranes and can potentiate androgen receptor activity in non-muscle cells. We report that muscle, which constitutes the principal tissue source for supervillin sequences, contains a approximately 250 kDa isoform of supervillin that localizes within nuclei and with dystrophin at costameres, regions of F-actin membrane attachment in skeletal muscle. The gene encoding this protein, 'archvillin' (Latin, archi; Greek, archos; 'principal' or 'chief'), contains an evolutionarily conserved, muscle-specific 5' leader sequence. Archvillin cDNAs also contain four exons that encode approximately 47 kDa of additional muscle-specific protein sequence in the form of …