201
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Hisamoto N, Moriguchi T, Urushiyama S, Mitani S, Shibuya H, Matsumoto K. Caenorhabditis elegans WNK-STE20 pathway regulates tube formation by modulating ClC channel activity. EMBO Rep 2007; 9:70-5. [PMID: 18049475 DOI: 10.1038/sj.embor.7401128] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 10/23/2007] [Accepted: 10/23/2007] [Indexed: 11/09/2022] Open
Abstract
WNK kinases are a small group of unique serine/threonine protein kinases that are conserved among multicellular organisms. Mutations in WNK1-4 cause pseudohypoaldosteronism type II-a form of hypertension. WNKs have been linked to the STE20 kinases and ion carriers, but the underlying molecular mechanisms by which WNKs regulate cellular processes in whole animals are unknown. The Caenorhabditis elegans WNK-like kinase WNK-1 interacts with and phosphorylates germinal centre kinase (GCK)-3--a STE20-like kinase--which is known to inactivate CLH-3, a CIC chloride channel. The wnk-1 or gck-3 deletion mutation causes an Exc phenotype, a defect in the tubular extension of excretory canals. Expression of the activated form of GCK-3 or the clh-3 deletion mutation can partly suppress wnk-1 or gck-3 defects, respectively. These results indicate that WNK-1 controls the tubular formation of excretory canals by activating GCK-3, resulting in downregulation of CIC channel activity.
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Affiliation(s)
- Naoki Hisamoto
- Department of Molecular Biology, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, Japan
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202
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Roma G, Sardiello M, Cobellis G, Cruz P, Lago G, Sanges R, Stupka E. The UniTrap resource: tools for the biologist enabling optimized use of gene trap clones. Nucleic Acids Res 2007; 36:D741-6. [PMID: 17942430 PMCID: PMC2238955 DOI: 10.1093/nar/gkm825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We have developed a comprehensive resource devoted to biologists wanting to optimize the use of gene trap clones in their experiments. We have processed 300 602 such clones from both public and private projects to generate 28 199 ‘UniTraps’, i.e. distinct collections of unambiguous insertions at the same subgenic region of annotated genes. The UniTrap resource contains data relative to 9583 trapped genes, which represent 42.3% of the mouse gene content. Among the trapped genes, 7 728 have a counterpart in humans, and 677 are known to be involved in the pathogenesis of human diseases. The aim of this analysis is to provide the wet lab researchers with a comprehensive database and curated tools for (i) identifying and comparing the clones carrying a trap into the genes of interest, (ii) evaluating the severity of the mutation to the protein function in each independent trapping event and (iii) supplying complete information to perform PCR, RT-PCR and restriction experiments to verify the clone and identify the exact point of vector insertion. To share this unique resource with the scientific community, we have designed and implemented a web interface that is freely accessible at http://unitrap.cbm.fvg.it/.
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Affiliation(s)
- Guglielmo Roma
- Telethon Institute of Genetics and Medicine (TIGEM), Via P. Castellino, 111, 80131, Napoli, Italy
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203
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Horn C, Hansen J, Schnütgen F, Seisenberger C, Floss T, Irgang M, De-Zolt S, Wurst W, von Melchner H, Noppinger PR. Splinkerette PCR for more efficient characterization of gene trap events. Nat Genet 2007; 39:933-4. [PMID: 17660805 DOI: 10.1038/ng0807-933] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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204
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Oh E, Heise CJ, English JM, Cobb MH, Thurmond DC. WNK1 is a novel regulator of Munc18c-syntaxin 4 complex formation in soluble NSF attachment protein receptor (SNARE)-mediated vesicle exocytosis. J Biol Chem 2007; 282:32613-22. [PMID: 17848561 PMCID: PMC2423411 DOI: 10.1074/jbc.m706591200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Defects in soluble NSF attachment protein receptor (SNARE)-mediated granule exocytosis occur in islet beta cells, adipocytes, and/or skeletal muscle cells correlate with increased susceptibility to insulin resistance and diabetes. The serine/threonine kinase WNK1 (with no K (lysine)) has recently been implicated in exocytosis and is expressed in all three of these cell types. To search for WNK1 substrates related to exocytosis, we conducted a WNK1 two-hybrid screen, which yielded Munc18c. Munc18c is known to be a key regulator of accessibility of the target membrane (t-SNARE) protein syntaxin 4 to participate in SNARE core complex assembly, although a paucity of Munc18c-binding factors has precluded discovery of its precise functions. To validate WNK1 as a new Munc18c-interacting partner, the direct interaction between WNK1 and Munc18c was confirmed using in vitro binding analysis, and endogenous WNK1-Munc18c complexes were detected in the cytosolic and plasma membrane compartments of the islet beta cell line MIN6. This binding interaction is mediated through the N-terminal 172 residues of Munc18c and the kinase domain residues of WNK1 (residues 159-491). Expression of either of these two minimal interaction domains resulted in inhibition of glucose-stimulated insulin secretion, consistent with a functional importance for the endogenous WNK1-Munc18c complex in exocytosis. Interestingly, Munc18c failed to serve as a WNK1 substrate in kinase activity assays, suggesting that WNK1 functions in SNARE complex assembly outside its role as a kinase. Taken together, these data support a novel role for WNK1 and a new mechanism for the regulation of SNARE complex assembly by WNK1-Munc18c complexes.
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Affiliation(s)
- Eunjin Oh
- Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Charles J. Heise
- Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239
| | | | - Melanie H. Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390
| | - Debbie C. Thurmond
- Department of Biochemistry and Molecular Biology, Center for Diabetes Research, Indiana University School of Medicine, Indianapolis, Indiana 46202
- To whom correspondence and reprint requests should be addressed: 635 Barnhill Dr., MS4053, Dept. of Biochemistry and Molecular Biology, Indianapolis, IN 46202. Tel.: 317-274-1551; Fax: 317-274-4686; E-mail:
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205
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Lee WS, Payne BJ, Gelfman CM, Vogel P, Kornfeld S. Murine UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase lacking the gamma-subunit retains substantial activity toward acid hydrolases. J Biol Chem 2007; 282:27198-27203. [PMID: 17652091 DOI: 10.1074/jbc.m704067200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase) mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on acid hydrolases. The transferase exists as an alpha(2)beta(2)gamma(2) hexameric complex with the alpha- and beta-subunits derived from a single precursor molecule. The catalytic function of the transferase is attributed to the alpha- and beta-subunits, whereas the gamma-subunit is believed to be involved in the recognition of a conformation-dependent protein determinant common to acid hydrolases. Using knock-out mice with mutations in either the alpha/beta gene or the gamma gene, we show that disruption of the alpha/beta gene completely abolishes phosphorylation of high mannose oligosaccharides on acid hydrolases whereas knock-out of the gamma gene results in only a partial loss of phosphorylation. These findings demonstrate that the alpha/beta-subunits, in addition to their catalytic function, have some ability to recognize acid hydrolases as specific substrates. This process is enhanced by the gamma-subunit.
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Affiliation(s)
- Wang-Sik Lee
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110 and
| | | | | | - Peter Vogel
- Lexicon Pharmaceuticals, Inc., The Woodlands, Texas 77381
| | - Stuart Kornfeld
- Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110 and.
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206
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Nord AS, Vranizan K, Tingley W, Zambon AC, Hanspers K, Fong LG, Hu Y, Bacchetti P, Ferrin TE, Babbitt PC, Doniger SW, Skarnes WC, Young SG, Conklin BR. Modeling insertional mutagenesis using gene length and expression in murine embryonic stem cells. PLoS One 2007; 2:e617. [PMID: 17637833 PMCID: PMC1910612 DOI: 10.1371/journal.pone.0000617] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 05/31/2007] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND High-throughput mutagenesis of the mammalian genome is a powerful means to facilitate analysis of gene function. Gene trapping in embryonic stem cells (ESCs) is the most widely used form of insertional mutagenesis in mammals. However, the rules governing its efficiency are not fully understood, and the effects of vector design on the likelihood of gene-trapping events have not been tested on a genome-wide scale. METHODOLOGY/PRINCIPAL FINDINGS In this study, we used public gene-trap data to model gene-trap likelihood. Using the association of gene length and gene expression with gene-trap likelihood, we constructed spline-based regression models that characterize which genes are susceptible and which genes are resistant to gene-trapping techniques. We report results for three classes of gene-trap vectors, showing that both length and expression are significant determinants of trap likelihood for all vectors. Using our models, we also quantitatively identified hotspots of gene-trap activity, which represent loci where the high likelihood of vector insertion is controlled by factors other than length and expression. These formalized statistical models describe a high proportion of the variance in the likelihood of a gene being trapped by expression-dependent vectors and a lower, but still significant, proportion of the variance for vectors that are predicted to be independent of endogenous gene expression. CONCLUSIONS/SIGNIFICANCE The findings of significant expression and length effects reported here further the understanding of the determinants of vector insertion. Results from this analysis can be applied to help identify other important determinants of this important biological phenomenon and could assist planning of large-scale mutagenesis efforts.
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Affiliation(s)
- Alex S. Nord
- Department of Medicine, MacDonald Medical Research Laboratories, University of California at Los Angeles, California, United States of America
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry, University of California at San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail: (AN); (BC)
| | - Karen Vranizan
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Functional Genomics Laboratory, University of California at Berkeley, California, United States of America
| | - Whittemore Tingley
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, California, United States of America
| | - Alexander C. Zambon
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, California, United States of America
| | - Kristina Hanspers
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, California, United States of America
| | - Loren G. Fong
- Department of Medicine, MacDonald Medical Research Laboratories, University of California at Los Angeles, California, United States of America
| | - Yan Hu
- Department of Medicine, MacDonald Medical Research Laboratories, University of California at Los Angeles, California, United States of America
| | - Peter Bacchetti
- Department of Epidemiology and Biostatistics, University of California at San Francisco, California, United States of America
| | - Thomas E. Ferrin
- Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry, University of California at San Francisco, California, United States of America
| | - Patricia C. Babbitt
- Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry, University of California at San Francisco, California, United States of America
| | - Scott W. Doniger
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Washington University School of Medicine, St. Louis, Missouri, United States of America
| | | | - Stephen G. Young
- Department of Medicine, MacDonald Medical Research Laboratories, University of California at Los Angeles, California, United States of America
| | - Bruce R. Conklin
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America
- Department of Medicine, University of California at San Francisco, California, United States of America
- Department of Molecular and Cellular Pharmacology, University of California at San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail: (AN); (BC)
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207
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Abstract
Point mutations in WNK4 [for With No K (lysine)], a serine-threonine kinase that is expressed in the distal nephron of the kidney, are linked to familial hyperkalemic hypertension (FHH). The imbalanced electrolyte homeostasis in FHH has led to studies toward an understanding of WNK4-mediated regulation of ion transport proteins in the kidney. A growing number of ion transport proteins for Na(+), K(+), Ca(2+), and Cl(-), including ion channels and transporters in the transcellular pathway and claudins in the paracellular pathway, are shown to be regulated by WNK4 from studies using models ranging from Xenopus laevis oocytes to transgenic and knockin mice. WNK4 regulates these transport proteins in different directions and by different cellular mechanisms. The common theme of WNK4-mediated regulation is to alter the abundance of ion transport proteins at the plasma membrane, with the exception of claudins, which are phosphorylated in the presence of WNK4. The regulation of WNK4 can be blocked by the full-length WNK1, whose action is in turn antagonized by a kidney-specific WNK1 variant lacking the kinase domain. In addition, WNK4 also activates stress-related serine-threonine kinases to regulate members of the SLC12 family members of cation-chloride cotransporters. In many cases, the FHH-causing mutants of WNK4 exhibit differences from wild-type WNK4 in regulating ion transport proteins. These regulations well explain the clinical features of FHH and provide insights into the multilayered regulation of ion transport processes in the distal nephron.
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Affiliation(s)
- Ji-Bin Peng
- Nephrology Research and Training Center, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294-0006, USA.
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208
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Schmidt M, Paes K, De Mazière A, Smyczek T, Yang S, Gray A, French D, Kasman I, Klumperman J, Rice DS, Ye W. EGFL7 regulates the collective migration of endothelial cells by restricting their spatial distribution. Development 2007; 134:2913-23. [PMID: 17626061 DOI: 10.1242/dev.002576] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
During sprouting angiogenesis, groups of endothelial cells (ECs) migrate together in units called sprouts. In this study, we demonstrate that the vascular-specific secreted factor EGFL7 regulates the proper spatial organization of ECs within each sprout and influences their collective movement. In the homozygous Egfl7-knockout mice, vascular development is delayed in many organs despite normal EC proliferation, and 50% of the knockout embryos die in utero. ECs in the mutant vasculatures form abnormal aggregates and the vascular basement membrane marker collagen IV is mislocalized, suggesting that ECs fail to recognize the proper spatial position of their neighbors. Although the migratory ability of individual ECs in isolation is not affected by the loss of EGFL7, the aberrant spatial organization of ECs in the mutant tissues decreases their collective movement. Using in vitro and in vivo analyses, we showed that EGFL7 is a component of the interstitial extracellular matrix deposited on the basal sides of sprouts, a location suitable for conveying positional information to neighboring ECs. Taken together, we propose that EGFL7 defines the optimal path of EC movement by assuring the correct positioning of each EC in a nascent sprout.
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Affiliation(s)
- Maike Schmidt
- Tumor Biology and Angiogenesis Department, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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209
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Desai U, Lee EC, Chung K, Gao C, Gay J, Key B, Hansen G, Machajewski D, Platt KA, Sands AT, Schneider M, Van Sligtenhorst I, Suwanichkul A, Vogel P, Wilganowski N, Wingert J, Zambrowicz BP, Landes G, Powell DR. Lipid-lowering effects of anti-angiopoietin-like 4 antibody recapitulate the lipid phenotype found in angiopoietin-like 4 knockout mice. Proc Natl Acad Sci U S A 2007; 104:11766-71. [PMID: 17609370 PMCID: PMC1913890 DOI: 10.1073/pnas.0705041104] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We used gene knockout mice to explore the role of Angiopoietin-like-4 (Angptl4) in lipid metabolism as well as to generate anti-Angptl4 mAbs with pharmacological activity. Angptl4 -/- mice had lower triglyceride (TG) levels resulting both from increased very low-density lipoprotein (VLDL) clearance and decreased VLDL production and had modestly lower cholesterol levels. Also, both Angptl4 -/- suckling mice and adult mice fed a high-fat diet showed reduced viability associated with lipogranulomatous lesions of the intestines and their draining lymphatics and mesenteric lymph nodes. Treating C57BL/6J, ApoE -/-, LDLr -/-, and db/db mice with the anti-Angptl4 mAb 14D12 recapitulated the lipid and histopathologic phenotypes noted in Angptl4 -/- mice. This demonstrates that the knockout phenotype reflects not only the physiologic function of the Angptl4 gene but also predicts the pharmacologic consequences of Angptl4 protein inhibition with a neutralizing antibody in relevant models of human disease.
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Affiliation(s)
| | | | | | | | - Jason Gay
- Departments of *Pharmaceutical Biology
| | | | - Gwenn Hansen
- Genetics, Lexicon Pharmaceuticals, Inc., 8800 Technology Forest Place, The Woodlands, TX, 77381
| | | | - Kenneth A. Platt
- Genetics, Lexicon Pharmaceuticals, Inc., 8800 Technology Forest Place, The Woodlands, TX, 77381
| | - Arthur T. Sands
- Departments of *Pharmaceutical Biology
- Biotherapeutics, and
- Genetics, Lexicon Pharmaceuticals, Inc., 8800 Technology Forest Place, The Woodlands, TX, 77381
| | | | | | - Adisak Suwanichkul
- Genetics, Lexicon Pharmaceuticals, Inc., 8800 Technology Forest Place, The Woodlands, TX, 77381
| | | | | | | | - Brian P. Zambrowicz
- Departments of *Pharmaceutical Biology
- Biotherapeutics, and
- Genetics, Lexicon Pharmaceuticals, Inc., 8800 Technology Forest Place, The Woodlands, TX, 77381
| | | | - David R. Powell
- Departments of *Pharmaceutical Biology
- To whom correspondence should be addressed. E-mail:
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210
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Anderson SJ, Lauritsen JPH, Hartman MG, Foushee AMD, Lefebvre JM, Shinton SA, Gerhardt B, Hardy RR, Oravecz T, Wiest DL. Ablation of ribosomal protein L22 selectively impairs alphabeta T cell development by activation of a p53-dependent checkpoint. Immunity 2007; 26:759-72. [PMID: 17555992 DOI: 10.1016/j.immuni.2007.04.012] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 02/27/2007] [Accepted: 04/10/2007] [Indexed: 10/23/2022]
Abstract
The alphabeta and gammadelta T lineages are thought to arise from a common precursor; however, the regulation of separation and development of these lineages is not fully understood. We report here that development of alphabeta and gammadelta precursors was differentially affected by elimination of ribosomal protein L22 (Rpl22), which is ubiquitously expressed but not essential for translation. Rpl22 deficiency selectively arrested development of alphabeta-lineage T cells at the beta-selection checkpoint by inducing their death. The death was caused by induction of p53 expression, because p53 deficiency blocked death and restored development of Rpl22-deficient thymocytes. Importantly, Rpl22 deficiency led to selective upregulation of p53 in alphabeta-lineage thymocytes, at least in part by increasing p53 synthesis. Taken together, these data indicate that Rpl22 deficiency activated a p53-dependent checkpoint that produced a remarkably selective block in alphabeta T cell development but spared gammadelta-lineage cells, suggesting that some ribosomal proteins may perform cell-type-specific or stage-specific functions.
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Affiliation(s)
- Stephen J Anderson
- Division of Immunology and Hematology, Lexicon Genetics, Inc., 8800 Technology Forest Place, The Woodlands, TX 77381, USA
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211
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Lee BH, Chen W, Stippec S, Cobb MH. Biological Cross-talk between WNK1 and the Transforming Growth Factor β-Smad Signaling Pathway. J Biol Chem 2007; 282:17985-17996. [PMID: 17392271 DOI: 10.1074/jbc.m702664200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
WNKs (with no lysine (K)), unique serine/threonine protein kinases, have been best studied in the context of cell volume regulation and ion homeostasis. Here we describe a biological link between WNKs and transforming growth factor (TGF) beta-Smad signaling. Both WNK1 and WNK4 directly bind to and phosphorylate Smad2. Knockdown of WNK1 in HeLa cells using small interfering RNA reduces Smad2 protein expression; this decrease is at least partially due to down-regulation of Smad2 transcription. In contrast, phosphorylated Smad2 significantly accumulated in the nucleus as a consequence of depletion of WNK1, resulting in Smad-mediated transcriptional responses. In addition, TGFbeta-induced target gene transcripts were increased in WNK1 small interfering RNA cells. These findings suggest WNK1 as a dual modulator of TGFbeta-Smad signaling pathways.
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Affiliation(s)
- Byung-Hoon Lee
- Department of Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041
| | - Wei Chen
- Department of Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041
| | - Steve Stippec
- Department of Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041
| | - Melanie H Cobb
- Department of Pharmacology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9041.
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212
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Roma G, Cobellis G, Claudiani P, Maione F, Cruz P, Tripoli G, Sardiello M, Peluso I, Stupka E. A novel view of the transcriptome revealed from gene trapping in mouse embryonic stem cells. Genome Res 2007; 17:1051-60. [PMID: 17540781 PMCID: PMC1899116 DOI: 10.1101/gr.5720807] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Embryonic stem (ES) cells are pluripotent cell lines with the capacity of self-renewal and the ability to differentiate into specific cell types. We performed the first genome-wide analysis of the mouse ES cell transcriptome using approximately 250,000 gene trap sequence tags deposited in public databases. We unveiled >8000 novel transcripts, mostly non-coding, and >1000 novel alternative and often tissue-specific exons of known genes. Experimental verification of the expression of these genes and exons by RT-PCR yielded a 70% validation rate. A novel non-coding transcript within the set studied showed a highly specific pattern of expression by in situ hybridization. Our analysis also shows that the genome presents gene trapping hotspots, which correspond to 383 known and 87 novel genes. These "hypertrapped" genes show minimal overlap with previously published expression profiles of ES cells; however, we prove by real-time PCR that they are highly expressed in this cell type, thus potentially contributing to the phenotype of ES cells. Although gene trapping was initially devised as an insertional mutagenesis technique, our study demonstrates its impact on the discovery of a substantial and unprecedented portion of the transcriptome.
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Affiliation(s)
- Guglielmo Roma
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Gilda Cobellis
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
- Dipartimento di Patologia Generale, Seconda Universita’ di Napoli, 80100 Napoli, Italy
| | - Pamela Claudiani
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Francesco Maione
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Pedro Cruz
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Gaetano Tripoli
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Marco Sardiello
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Ivana Peluso
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
| | - Elia Stupka
- Telethon Institute of Genetics and Medicine (TIGEM), 80131 Napoli, Italy
- CBM S.c.r.l., Area Science Park, Basovizza- SS14, Km 163,5 Trieste, 34012 Italy
- Corresponding author.E-mail ; fax 39-040-3757710
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213
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Abstract
Despite advancements in genetics, chemistry, and protein engineering, recent years have seen fewer approvals of new drugs, increases in development costs, and high-profile drug withdrawals. This article focuses on technologic methods for improving drug development efficiency. These technologies include high-content cell screening, expression profiling, mass spectroscopy, mouse models of disease, and a post-launch screening program that enables investigations of adverse drug effects. Implementation of these new technologies promises to improve performance in drug development and safety.
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Affiliation(s)
- C Thomas Caskey
- Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA.
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214
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Henderson WR, Chi EY, Bollinger JG, Tien YT, Ye X, Castelli L, Rubtsov YP, Singer AG, Chiang GKS, Nevalainen T, Rudensky AY, Gelb MH. Importance of group X-secreted phospholipase A2 in allergen-induced airway inflammation and remodeling in a mouse asthma model. ACTA ACUST UNITED AC 2007; 204:865-77. [PMID: 17403936 PMCID: PMC2118555 DOI: 10.1084/jem.20070029] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Arachidonic acid metabolites, the eicosanoids, are key mediators of allergen-induced airway inflammation and remodeling in asthma. The availability of free arachidonate in cells for subsequent eicosanoid biosynthesis is controlled by phospholipase A2s (PLA2s), most notably cytosolic PLA2-α. 10 secreted PLA2s (sPLA2s) have also been identified, but their function in eicosanoid generation is poorly understood. We investigated the role of group X sPLA2 (sPLA2-X), the sPLA2 with the highest in vitro cellular phospholipolysis activity, in acute and chronic mouse asthma models in vivo. The lungs of sPLA2-X−/− mice, compared with those of sPLA2-X+/+ littermates, had significant reduction in ovalbumin-induced infiltration by CD4+ and CD8+ T cells and eosinophils, goblet cell metaplasia, smooth muscle cell layer thickening, subepithelial fibrosis, and levels of T helper type 2 cell cytokines and eicosanoids. These data direct attention to sPLA2-X as a novel therapeutic target for asthma.
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Affiliation(s)
- William R Henderson
- Center for Allergy and Inflammation, Department of Medicine, University of Washington, Seattle, WA 98109, USA.
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215
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Elliott-Hunt CR, Pope RJP, Vanderplank P, Wynick D. Activation of the galanin receptor 2 (GalR2) protects the hippocampus from neuronal damage. J Neurochem 2007; 100:780-9. [PMID: 17263796 PMCID: PMC2705497 DOI: 10.1111/j.1471-4159.2006.04239.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Expression of the neuropeptide galanin is up-regulated in many brain regions following nerve injury and in the basal forebrain of patients with Alzheimer's disease. We have previously demonstrated that galanin modulates hippocampal neuronal survival, although it was unclear which receptor subtype(s) mediates this effect. Here we report that the protective role played by galanin in hippocampal cultures is abolished in animals carrying a loss-of-function mutation in the second galanin receptor subtype (GalR2-MUT). Exogenous galanin stimulates the phosphorylation of the serine/threonine kinase Akt and extracellular signal-regulated kinase (ERK) in wild-type (WT) cultures by 435 +/- 5% and 278 +/- 2%, respectively. The glutamate-induced activation of Akt was abolished in cultures from galanin knockout animals, and was markedly attenuated in GalR2-MUT animals, compared with WT controls. In contrast, similar levels of glutamate-induced ERK activation were observed in both loss-of-function mutants, but were further increased in galanin over-expressing animals. Using specific inhibitors of either ERK or Akt confirms that a GalR2-dependent modulation in the activation of the Akt and ERK signalling pathways contributes to the protective effects of galanin. These findings imply that the rise in endogenous galanin observed either after brain injury or in various disease states is an adaptive response that reduces apoptosis by the activation of GalR2, and hence Akt and ERK.
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MESH Headings
- Animals
- Brain Damage, Chronic/genetics
- Brain Damage, Chronic/metabolism
- Brain Damage, Chronic/physiopathology
- Cytoprotection/drug effects
- Cytoprotection/genetics
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Extracellular Signal-Regulated MAP Kinases/drug effects
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Galanin/metabolism
- Galanin/pharmacology
- Glutamic Acid/metabolism
- Glutamic Acid/pharmacology
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hippocampus/physiopathology
- Male
- Mice
- Mice, Knockout
- Nerve Degeneration/genetics
- Nerve Degeneration/metabolism
- Nerve Degeneration/physiopathology
- Neurodegenerative Diseases/genetics
- Neurodegenerative Diseases/metabolism
- Neurodegenerative Diseases/physiopathology
- Neurons/drug effects
- Neurons/metabolism
- Organ Culture Techniques
- Proto-Oncogene Proteins c-akt/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- Receptor, Galanin, Type 2/agonists
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Up-Regulation/drug effects
- Up-Regulation/physiology
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Affiliation(s)
- Caroline R Elliott-Hunt
- Departments of Pharmacology and Clinical Sciences South Bristol, Bristol University, Bristol, UK
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216
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Iwaniec UT, Wronski TJ, Liu J, Rivera MF, Arzaga RR, Hansen G, Brommage R. PTH stimulates bone formation in mice deficient in Lrp5. J Bone Miner Res 2007; 22:394-402. [PMID: 17147489 DOI: 10.1359/jbmr.061118] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
UNLABELLED Lrp5 deficiency decreases bone formation and results in low bone mass. This study evaluated the bone anabolic response to intermittent PTH treatment in Lrp5-deficient mice. Our results indicate that Lrp5 is not essential for the stimulatory effect of PTH on cancellous and cortical bone formation. INTRODUCTION Low-density lipoprotein receptor-related protein 5 (Lrp5), a co-receptor in canonical Wnt signaling, increases osteoblast proliferation, differentiation, and function. The purpose of this study was to use Lrp5-deficient mice to evaluate the potential role of this gene in mediating the bone anabolic effects of PTH. MATERIALS AND METHODS Adult wildtype (WT, 23 male and 25 female) and Lrp5 knockout (KO, 27 male and 26 female) mice were treated subcutaneously with either vehicle or 80 microg/kg human PTH(1-34) on alternate days for 6 weeks. Femoral BMC and BMD were determined using DXA. Lumbar vertebrae were processed for quantitative bone histomorphometry. Bone architecture was evaluated by microCT. Data were analyzed using a multiway ANOVA. RESULTS Cancellous and cortical bone mass were decreased with Lrp5 deficiency. Compared with WT mice, cancellous bone volume in the distal femur and the lumbar vertebra in Lrp5 KO mice was 54% and 38% lower, respectively (p<0.0001), whereas femoral cortical thickness was 11% lower in the KO mice (p<0.0001). The decrease in cancellous bone volume in the lumbar vertebrae was associated with a 45% decrease in osteoblast surface (p<0.0001) and a comparable decrease in bone formation rate (p<0.0001). Osteoclast surface, an index of bone resorption, was 24% lower in Lrp5 KO compared with WT mice (p<0.007). Treatment of mice with PTH for 6 weeks resulted in a 59% increase in osteoblast surface (p<0.0001) and a 19% increase in osteoclast surface (p=0.053) in both genotypes, but did not augment cancellous bone volume in either genotype. Femur cortical thickness was 11% higher in PTH-treated mice in comparison with vehicle-treated mice (p<0.0001), regardless of genotype. CONCLUSIONS Whereas disruption of Lrp5 results in decreased bone mass because of decreased bone formation, Lrp5 does not seem to be essential for the stimulatory effects of PTH on cancellous and cortical bone formation.
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Affiliation(s)
- Urszula T Iwaniec
- Department of Physiological Sciences, University of Florida, Gainesville, USA.
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217
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Flatman PW. Cotransporters, WNKs and hypertension: important leads from the study of monogenetic disorders of blood pressure regulation. Clin Sci (Lond) 2007; 112:203-16. [PMID: 17223794 DOI: 10.1042/cs20060225] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Major advances are being made in identifying the structure and behaviour of regulatory cascades that control the activity of cation-Cl(-) cotransporters and certain Na(+), K(+) and Cl(-) channels. These transporters play key roles in regulating arterial blood pressure as they are not only responsible for NaCl reabsorption in the thick ascending limb and distal tubule of the kidney, but are also involved in regulating smooth muscle Ca(2+) levels. It is now apparent that defects in these transporters, and particularly in the regulatory cascades, cause some monogenetic forms of hypertension and may contribute to essential hypertension and problems with K(+) homoeostasis. Two families of kinases are prominent in these processes: the Ste-20-related kinases [OSR1 (oxidative stress-responsive kinase 1) and SPAK (Ste20/SPS1-related proline/alanine-rich kinase)] and the WNKs [with no lysine kinases]. These kinases affect the behaviour of their targets through both phosphorylation and by acting as scaffolding proteins, bringing together regulatory complexes. This review analyses how these kinases affect transport by activating or inhibiting individual transporters at the cell surface, or by changing the surface density of transporters by altering the rate of insertion or removal of transporters from the cell surface, and perhaps through controlling the rate of transporter degradation. This new knowledge should not only help us target antihypertensive therapy more appropriately, but could also provide the basis for developing new therapeutic approaches to essential hypertension.
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Affiliation(s)
- Peter W Flatman
- Centre for Integrative Physiology, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh EH8 9XD, Scotland, U.K.
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218
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Salojin K, Oravecz T. Regulation of innate immunity by MAPK dual-specificity phosphatases: knockout models reveal new tricks of old genes. J Leukoc Biol 2007; 81:860-9. [PMID: 17289800 DOI: 10.1189/jlb.1006639] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Throughout evolution, mammals have developed an elaborate network of positive and negative regulatory mechanisms, which provide balance between defensive measures against bacterial and viral pathogens and protective measures against unwarranted destruction of the host by the activated immune system. Kinases and phosphatases encompassing the MAPK pathway are key players in the orderly action of pro- and anti-inflammatory processes, forming numerous promiscuous interactions. Several lines of evidence demonstrate that the phosphorylation and activation status of kinases in the MAPK system has crucial impact on the outcome of downstream events that regulate cytokine production. At least 13 members of the family of dual-specificity phosphatases (DUSP) display unique substrate specificities for MAPKs. Despite the considerable amount of information obtained about the contribution of the different DUSP to MAPK-mediated signaling and innate immunity, the interpretation of available data remains problematic. The in vitro and ex vivo findings are often complicated by functional redundancy of signaling molecules and do not always accurately predict the situation in vivo. Until recently, DUSP research has been hampered by the lack of relevant mammalian knockout (KO) models, which is a powerful tool for delineating in vivo function and redundancy in gene families. This situation changed dramatically over the last year, and this review integrates recent insights into the precise biological role of the DUSP family in innate immunity gained from a comprehensive analysis of mammalian KO models.
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Affiliation(s)
- Konstantin Salojin
- Lexicon Genetics Incorporated, 8800 Technology Forest Place, The Woodlands, TX 77381, USA.
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219
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Cardiac Development: Toward a Molecular Basis for Congenital Heart Disease. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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220
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Abstract
Our ability to genetically manipulate the mouse has had a great impact on medical research over the last few decades. Mouse genetics has developed into a powerful tool for dissecting the genetic causes of human disease and identifying potential targets for pharmaceutical intervention. With the recent sequencing of the human and mouse genomes, a large number of novel genes have been identified whose function in normal and disease physiology remains largely unknown. Government-sponsored multinational efforts are underway to analyze the function of all mouse genes through mutagenesis and phenotyping, making the mouse the interpreter of the human genome. A number of technologies are available for the generation of mutant mice, including gene targeting, gene trapping and transposon, chemical or radiation-induced mutagenesis. In this chapter, we review the current status of gene trapping technology, including its applicability to conditional mutagenesis.
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Affiliation(s)
- A Abuin
- Lexicon Genetics, 8800 Technology Forest Place, The Woodlands, TX 77381, USA.
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221
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Zagórska A, Pozo-Guisado E, Boudeau J, Vitari AC, Rafiqi FH, Thastrup J, Deak M, Campbell DG, Morrice NA, Prescott AR, Alessi DR. Regulation of activity and localization of the WNK1 protein kinase by hyperosmotic stress. ACTA ACUST UNITED AC 2006; 176:89-100. [PMID: 17190791 PMCID: PMC2063630 DOI: 10.1083/jcb.200605093] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mutations within the WNK1 (with-no-K[Lys] kinase-1) gene cause Gordon's hypertension syndrome. Little is known about how WNK1 is regulated. We demonstrate that WNK1 is rapidly activated and phosphorylated at multiple residues after exposure of cells to hyperosmotic conditions and that activation is mediated by the phosphorylation of its T-loop Ser382 residue, possibly triggered by a transautophosphorylation reaction. Activation of WNK1 coincides with the phosphorylation and activation of two WNK1 substrates, namely, the protein kinases STE20/SPS1-related proline alanine–rich kinase (SPAK) and oxidative stress response kinase-1 (OSR1). Small interfering RNA depletion of WNK1 impairs SPAK/OSR1 activity and phosphorylation of residues targeted by WNK1. Hyperosmotic stress induces rapid redistribution of WNK1 from the cytosol to vesicular structures that may comprise trans-Golgi network (TGN)/recycling endosomes, as they display rapid movement, colocalize with clathrin, adaptor protein complex 1 (AP-1), and TGN46, but not the AP-2 plasma membrane–coated pit marker nor the endosomal markers EEA1, Hrs, and LAMP1. Mutational analysis suggests that the WNK1 C-terminal noncatalytic domain mediates vesicle localization. Our observations shed light on the mechanism by which WNK1 is regulated by hyperosmotic stress.
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Affiliation(s)
- Anna Zagórska
- Medical Research Council Protein Phosphorylation Unit, School of Life Sciences, Medical Sciences Institute/Wellcome Trust Biocentre Complex, University of Dundee, Dundee DD1 5EH, Scotland, UK
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222
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Hobson SA, Holmes FE, Kerr NCH, Pope RJP, Wynick D. Mice deficient for galanin receptor 2 have decreased neurite outgrowth from adult sensory neurons and impaired pain-like behaviour. J Neurochem 2006; 99:1000-10. [PMID: 17076662 PMCID: PMC2725756 DOI: 10.1111/j.1471-4159.2006.04143.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Expression of the neuropeptide galanin is markedly up-regulated within the adult dorsal root ganglia (DRG) following peripheral nerve injury. We have previously demonstrated that galanin knockout (Gal-KO) mice have a developmental loss of a subset of DRG neurons. Galanin also plays a trophic role in the adult animal, and the rate of peripheral nerve regeneration and neurite outgrowth is reduced in adult Gal-KO mice. Here we describe the characterization of mice with an absence of GalR2 gene transcription (GalR2-MUT) and demonstrate that they have a 15% decrease in the number of calcitonin gene-related peptide (CGRP) expressing neuronal profiles in the adult DRG, associated with marked deficits in neuropathic and inflammatory pain behaviours. Adult GalR2-MUT animals also have a one third reduction in neurite outgrowth from cultured DRG neurons that cannot be rescued by either galanin or a high-affinity GalR2/3 agonist. Galanin activates extracellular signal-regulated kinase (ERK) and Akt in adult wild-type (WT) mouse DRG. Intact adult DRG from GalR2-MUT animals have lower levels of pERK and higher levels of pAkt than are found in WT controls. These data suggest that a lack of GalR2 activation in Gal-KO and GalR2-MUT animals is responsible for the observed developmental deficits in the DRG, and the decrease in neurite outgrowth in the adult.
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MESH Headings
- Animals
- Behavior, Animal/physiology
- Blotting, Western
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Genotype
- Immunohistochemistry
- Male
- Mice
- Mice, Knockout
- Neurites/physiology
- Neurons, Afferent/physiology
- Pain/genetics
- Pain/psychology
- Peripheral Nerve Injuries
- Phenotype
- Phosphorylation
- Proto-Oncogene Proteins c-akt/physiology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction/genetics
- Signal Transduction/physiology
- Transcription, Genetic
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Affiliation(s)
- Sally-Ann Hobson
- Departments of Pharmacology and Clinical Science at South Bristol, Bristol University, Bristol, UK
| | - Fiona E. Holmes
- Departments of Pharmacology and Clinical Science at South Bristol, Bristol University, Bristol, UK
| | - Niall C. H. Kerr
- Departments of Pharmacology and Clinical Science at South Bristol, Bristol University, Bristol, UK
| | - Robert J. P. Pope
- Departments of Pharmacology and Clinical Science at South Bristol, Bristol University, Bristol, UK
| | - David Wynick
- Departments of Pharmacology and Clinical Science at South Bristol, Bristol University, Bristol, UK
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223
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Abstract
Over the past years new vectors and methodologies have been developed to carry out large-scale genome-wide insertional mutagenesis screens in the mouse. Gene trapping, the most commonly used technique, is based on the insertion of a retroviral- or plasmid-based vector into a gene, resulting in a loss-of-function mutation, while simultaneously reporting its expression pattern and providing a molecular tag to facilitate cloning. The discovery of vertebrate DNA transposons in the mouse and recent improvements has also led to their increased use in insertional mutagenesis screens. Several public resources have been set-up recently by the academic community to distribute information and materials generated from these large-scale screens. These new resources should accelerate the study and understanding of biological and developmental processes.
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Affiliation(s)
- Christopher S Raymond
- Program in Developmental Biology, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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224
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Fan B, Brennan J, Grant D, Peale F, Rangell L, Kirchhofer D. Hepatocyte growth factor activator inhibitor-1 (HAI-1) is essential for the integrity of basement membranes in the developing placental labyrinth. Dev Biol 2006; 303:222-30. [PMID: 17174946 DOI: 10.1016/j.ydbio.2006.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Revised: 10/15/2006] [Accepted: 11/06/2006] [Indexed: 11/27/2022]
Abstract
Hepatocyte growth factor activator inhibitor-1 (HAI-1) is a membrane-associated Kunitz-type serine protease inhibitor that regulates cell surface and extracellular serine proteases involved in tissue remodeling and tumorigenesis, such as HGFA, matriptase, prostasin and hepsin. We generated HAI-1 deficient mice, which died in utero due to placental defects. The HAI-1(-/-) placental labyrinth exhibited a complete failure of vascularization and a compact morphology of the trophoblast layer. Immunofluorescent staining of collagen IV and laminin and electron microscopy analysis revealed that this aberrant labyrinth architecture was associated with disrupted basement membranes located at the interface of chorionic trophoblasts and allantoic mesoderm. Unlike the placental labyrinth, basement membranes and vasculogenesis were normal in embryo and yolk sac. Therefore, basement membrane defects appear to be the underlying cause for the greatly impaired vascularization and trophoblast branching in HAI-1(-/-) placentas. In wild-type placentas, the expression of matriptase and prostasin co-localized with their physiological inhibitor HAI-1 to the labyrinthine trophoblast cells in proximity to basement membranes. In HAI-1(-/-) placentas, both the localization and expression of the two proteases remained unchanged, implying uncontrolled proteolytic activities of the two enzymes. Our study demonstrates the important role of HAI-1 in maintaining the integrity of basement membrane most likely by regulating extracellular proteolytic activities during placental development.
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Affiliation(s)
- Bin Fan
- Department of Protein Engineering, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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225
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Lin Q, Donahue SL, Moore-Jarrett T, Cao S, Osipovich AB, Ruley HE. Mutagenesis of diploid mammalian genes by gene entrapment. Nucleic Acids Res 2006; 34:e139. [PMID: 17062627 PMCID: PMC1635309 DOI: 10.1093/nar/gkl728] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The present study describes a genome-wide method for biallelic mutagenesis in mammalian cells. Novel poly(A) gene trap vectors, which contain features for direct cloning vector–cell fusion transcripts and for post-entrapment genome engineering, were used to generate a library of 979 mutant ES cells. The entrapment mutations generally disrupted gene expression and were readily transmitted through the germline, establishing the library as a resource for constructing mutant mice. Cells homozygous for most entrapment loci could be isolated by selecting for enhanced expression of an inserted neomycin-resistance gene that resulted from losses of heterozygosity (LOH). The frequencies of LOH measured at 37 sites in the genome ranged from 1.3 × 10−5 to 1.2 × 10−4 per cell and increased with increasing distance from the centromere, implicating mitotic recombination in the process. The ease and efficiency of obtaining homozygous mutations will (i) facilitate genetic studies of gene function in cultured cells, (ii) permit genome-wide studies of recombination events that result in LOH and mediate a type of chromosomal instability important in carcinogenesis, and (iii) provide new strategies for phenotype-driven mutagenesis screens in mammalian cells.
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Affiliation(s)
| | | | | | | | | | - H. Earl Ruley
- To whom correspondence should be addressed. Tel: +615 343 1379; Fax: +615 343 7392;
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226
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Ohtsuki S, Kikkawa T, Hori S, Terasaki T. Modulation and compensation of the mRNA expression of energy related transporters in the brain of glucose transporter 1-deficient mice. Biol Pharm Bull 2006; 29:1587-91. [PMID: 16880609 DOI: 10.1248/bpb.29.1587] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Facilitative glucose transporter 1 (GLUT1) is the molecule responsible for the entry of glucose into the brain, and its mutation is known as GLUT1 deficiency syndrome (GLUT1DS) in humans. To clarify the effect of GLUT1 gene deficiency, we have produced GLUT1-deficient mice, and investigated the developmental expression of GLUT1, monocarboxylate transporter 1 (MCT1) and MCT2 in the brains of these mice. Since the homozygotes were found to be embryonically lethal and the heterozygotes exhibited no abnormalities, GLUT1deficiency was examined using heterozygote mice. GLUT1 deficiency did not significantly affect the mRNA levels of GLUT1 at P0, P7 and in adults, or the levels of MCTs at P7, P14 and in adults. The GLUT1 level at P14 was reduced by 46.9%, although this was not statistically significant. The MCTs levels at P0 were increased about 2.0-fold in the deficient mice compared with the wild type. Furthermore, at P0, GLUT1 mRNA levels in wild type females were 1.91-fold higher than in wild type males. These results suggest that GLUT1 deficiency affects GLUT1 mRNA expression in the infant brain, and that of MCT1 and MCT2 in the neonatal brain. Furthermore, a compensatory effect of GLUT1 expression was observed in the brain of adult deficient mice. These effects of GLUT1 deficiency in the brain provide a molecular basis to assist in our understanding of the symptoms of GLUT1DS.
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Affiliation(s)
- Sumio Ohtsuki
- Department of Molecular Biopharmacy and Genetics, Graduate School of Pharmaceutical Sciences, Tohoku University, Japan
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227
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Proctor G, Linas S. Type 2 pseudohypoaldosteronism: new insights into renal potassium, sodium, and chloride handling. Am J Kidney Dis 2006; 48:674-93. [PMID: 16997066 DOI: 10.1053/j.ajkd.2006.06.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Accepted: 06/12/2006] [Indexed: 11/11/2022]
Affiliation(s)
- Gregory Proctor
- Division of Nephrology, University of Colorado Health Sciences Center, Denver, CO, USA.
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228
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Sun X, Gao L, Yu RK, Zeng G. Down-regulation of WNK1 protein kinase in neural progenitor cells suppresses cell proliferation and migration. J Neurochem 2006; 99:1114-21. [PMID: 17018027 DOI: 10.1111/j.1471-4159.2006.04159.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
WNK1, a Ser/Thr protein kinase, is widely expressed in many tissues. Its biological functions are largely unknown. Disruption of the WNK1 gene in mice leads to embryonic lethality at day 13, implicating a critical role of WNK1 in embryonic development. To investigate this potential function, we used antisense strategy to knock down the expression of WNK1 in a mouse neural progenitor cell line, C17.2. Down-regulation of WNK1 in C17.2 cells greatly reduced cell growth. Addition of epidermal growth factor (EGF), a mitogen for C17.2 cells, had no effect on growth. The WNK1-knockdown cells showed a flat and rounded morphology, characteristic of the immature and non-differentiated phenotype of the progenitor cells; this was further demonstrated by immunostaining for the progenitor and neuronal markers. Migration of the WNK1-knockdown C17.2 cells was reduced as tested in culture dishes or Matrigel-covered chambers. Moreover, activation of extracellular signal-regulated kinase (ERK1)/2 and ERK5 by EGF in the WNK1-knockdown cells was suppressed. These results demonstrate a novel function of WNK1 in proliferation, migration, and differentiation of neural progenitor cells, likely by mechanisms involving activation of the mitogen-activated protein (MAP) kinase ERK1/2 and/or ERK5 pathways.
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Affiliation(s)
- Xutong Sun
- Developmental Neurobiology Program, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, Georgia 30912, USA.
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229
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Ferretti E, Villaescusa JC, Di Rosa P, Fernandez-Diaz LC, Longobardi E, Mazzieri R, Miccio A, Micali N, Selleri L, Ferrari G, Blasi F. Hypomorphic mutation of the TALE gene Prep1 (pKnox1) causes a major reduction of Pbx and Meis proteins and a pleiotropic embryonic phenotype. Mol Cell Biol 2006; 26:5650-62. [PMID: 16847320 PMCID: PMC1592771 DOI: 10.1128/mcb.00313-06] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The interaction of Prep1 and Pbx homeodomain transcription factors regulates their activity, nuclear localization, and likely, function in development. To understand the in vivo role of Prep1, we have analyzed an embryonic lethal hypomorphic mutant mouse (Prep1(i/i)). Prep1(i/i) embryos die at embryonic day 17.5 (E17.5) to birth with an overall organ hypoplasia, severe anemia, impaired angiogenesis, and eye anomalies, particularly in the lens and retina. The anemia correlates with delayed differentiation of erythroid progenitors and may be, at least in part, responsible for intrauterine death. At E14.5, Prep1 is present in fetal liver (FL) cMyb-positive cells, whose deficiency causes a marked hematopoietic phenotype. Prep1 is also localized to FL endothelial progenitors, consistent with the observed angiogenic phenotype. Likewise, at the same gestational day, Prep1 is present in the eye cells that bear Pax6, implicated in eye development. The levels of cMyb and Pax6 in FL and in the retina, respectively, are significantly decreased in Prep1(i/i) embryos, consistent with the hematopoietic and eye phenotypes. Concomitantly, Prep1 deficiency results in the overall decrease of protein levels of its related family member Meis1 and its partners Pbx1 and Pbx2. As both Prep1 and Meis interact with Pbx, the overall Prep1/Meis-Pbx DNA-binding activity is strongly reduced in whole Prep1(i/i) embryos and their organs. Our data indicate that Prep1 is an essential gene that acts upstream of and within a Pbx-Meis network that regulates multiple aspects of embryonic development.
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Affiliation(s)
- Elisabetta Ferretti
- Laboratory of Molecular Genetics, DIBIT, via Olgettina 58, 20132 Milano, Italy
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230
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Xie J, Craig L, Cobb MH, Huang CL. Role of with-no-lysine [K] kinases in the pathogenesis of Gordon's syndrome. Pediatr Nephrol 2006; 21:1231-6. [PMID: 16683163 DOI: 10.1007/s00467-006-0106-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 01/23/2006] [Indexed: 11/28/2022]
Abstract
Gordon's syndrome, also known as pseudohypoaldosteronism type II (PHA II) or familial hypertension with hyperkalemia, is an autosomal-dominant disease characterized by hypertension, hyperkalemia, hyperchloremic metabolic acidosis, and normal glomerular filtration rate. Recent positional cloning has linked mutations of WNK1 and WNK4 to Gordon's syndrome. With-no-lysine [K] (WNK) kinases are a new family of large serine-threonine protein kinases with an atypical placement of the catalytic lysine. Here, we review the pathogenesis of PHA II based on current understanding of the actions of WNK1 and WNK4 on Na+ and K+ handling in the renal distal tubule.
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Affiliation(s)
- Jian Xie
- Department of Medicine, Room J5-104, MC-8856, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-8856, USA
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231
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Delaloy C, Hadchouel J, Imbert-Teboul M, Clemessy M, Houot AM, Jeunemaitre X. Cardiovascular expression of the mouse WNK1 gene during development and adulthood revealed by a BAC reporter assay. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 169:105-18. [PMID: 16816365 PMCID: PMC1698764 DOI: 10.2353/ajpath.2006.051290] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Large deletions in WNK1 are associated with inherited arterial hypertension. WNK1 encodes two types of protein: a kidney-specific isoform (KS-WNK1) lacking kinase activity and a ubiquitously expressed full-length isoform (L-WNK1) with serine threonine kinase activity. Disease is thought to result from hypermorphic mutations increasing the production of one or both isoforms. However, the pattern of L-WNK1 expression remains poorly characterized. We generated transgenic mice bearing a murine WNK1 BAC containing the nlacZ reporter gene for monitoring L-WNK1 expression during development and adulthood. We observed previously unsuspected early expression in the vessels and primitive heart during embryogenesis, consistent with the early death of WNK1(-/-) mice. The generalized cardiovascular expression observed in adulthood may also suggest a possible kidney-independent role in blood pressure regulation. The second unsuspected site of L-WNK1 expression was the granular layer and Purkinje cells of the cerebellum, suggesting a role in local ion balance or cell trafficking. In the kidney, discordance between endogenous L-WNK1 and transgene expression suggests that either cis-regulatory elements important for physiological renal expression lie outside the BAC sequence or that illegitimate interactions occur between promoters. Despite this limitation, this transgenic model is a potentially valuable tool for the analysis of spatial and temporal aspects of WNK1 expression and regulation.
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232
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O'Reilly M, Marshall E, Macgillivray T, Mittal M, Xue W, Kenyon CJ, Brown RW. Dietary electrolyte-driven responses in the renal WNK kinase pathway in vivo. J Am Soc Nephrol 2006; 17:2402-13. [PMID: 16899520 DOI: 10.1681/asn.2005111197] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
WNK1 and WNK4 are unusual serine/threonine kinases with atypical positioning of the catalytic active-site lysine (WNK: With-No-K[lysine]). Mutations in these WNK kinase genes can cause familial hyperkalemic hypertension (FHHt), an autosomal dominant, hypertensive, hyperkalemic disorder, implicating this novel WNK pathway in normal regulation of BP and electrolyte balance. Full-length (WNK1-L) and short (WNK1-S) kinase-deficient WNK1 isoforms previously have been identified. Importantly, WNK1-S is overwhelmingly predominant in kidney. Recent Xenopus oocyte studies implicate WNK4 in inhibition of both thiazide-sensitive co-transporter-mediated Na+ reabsorption and K+ secretion via renal outer medullary K+ channel and now suggest that WNK4 is inhibited by WNK1-L, itself inhibited by WNK1-S. This study examined WNK pathway gene expression in mouse kidney and its regulation in vivo. Expression of WNK1-S and WNK4 is strongest in distal tubule, dropping sharply in collecting duct and with WNK4 also expressed in thick ascending limb and the macula densa. These nephron segments that express WNK1-S and WNK4 mRNA have major influence on long-term NaCl reabsorption, BP, K+, and acid-base balance, processes that all are disrupted in FHHt. In vivo, this novel WNK pathway responds with significant upregulation of WNK1-S and WNK4 with high K+ intake and reduction in WNK1-S on chronic lowering of K+ or Na+ intake. A two-compartment distal nephron model explains these in vivo findings and the pathophysiology of FHHt well, with WNK and classic aldosterone pathways responding to drivers from K+ balance, extracellular volume, and aldosterone and cross-talk through distal Na+ delivery regulating electrolyte balance and BP.
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Affiliation(s)
- Michelle O'Reilly
- Centre for Cardiovascular Science, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, UK EH16 4TJ
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233
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Anselmo AN, Earnest S, Chen W, Juang YC, Kim SC, Zhao Y, Cobb MH. WNK1 and OSR1 regulate the Na+, K+, 2Cl- cotransporter in HeLa cells. Proc Natl Acad Sci U S A 2006; 103:10883-8. [PMID: 16832045 PMCID: PMC1544143 DOI: 10.1073/pnas.0604607103] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Oxidative stress-responsive kinase (OSR) 1 and sterile20-related, proline-, alanine-rich kinase (SPAK) are Ste20p-related protein kinases that bind to the sodium, potassium, two chloride cotransporter, NKCC. Here we present evidence that the protein kinase with no lysine [K] (WNK) 1 regulates OSR1, SPAK, and NKCC activities. OSR1 exists in a complex with WNK1 in cells, is activated by recombinant WNK1 in vitro, and is phosphorylated in a WNK1-dependent manner in cells. Depletion of WNK1 from HeLa cells by using small interfering RNA reduces OSR1 kinase activity. In addition, depletion of either WNK1 or OSR1 reduces NKCC activity, indicating that WNK1 and OSR1 are both required for NKCC function. OSR1 and SPAK are likely links between WNK1 and NKCC in a pathway that contributes to volume regulation and blood pressure homeostasis in mammals.
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Affiliation(s)
| | | | - Wei Chen
- Departments of *Pharmacology and
| | | | - Sung Chan Kim
- Departments of *Pharmacology and
- Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Yingming Zhao
- Departments of *Pharmacology and
- Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Melanie H. Cobb
- Departments of *Pharmacology and
- To whom correspondence should be addressed. E-mail:
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234
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Vitari AC, Thastrup J, Rafiqi FH, Deak M, Morrice NA, Karlsson HKR, Alessi DR. Functional interactions of the SPAK/OSR1 kinases with their upstream activator WNK1 and downstream substrate NKCC1. Biochem J 2006; 397:223-31. [PMID: 16669787 PMCID: PMC1479760 DOI: 10.1042/bj20060220] [Citation(s) in RCA: 242] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The SPAK (STE20/SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase-1) kinases interact and phosphorylate NKCC1 (Na+-K+-2Cl- co-transporter-1), leading to its activation. Recent studies indicated that SPAK and OSR1 are phosphorylated and activated by the WNK1 [with no K (lysine) protein kinase-1] and WNK4, genes mutated in humans affected by Gordon's hypertension syndrome. In the present study, we have identified three residues in NKCC1 (Thr175/Thr179/Thr184 in shark or Thr203/Thr207/Thr212 in human) that are phosphorylated by SPAK and OSR1, and have developed a peptide substrate, CATCHtide (cation chloride co-transporter peptide substrate), to assess SPAK and OSR1 activity. Exposure of HEK-293 (human embryonic kidney) cells to osmotic stress, which leads to phosphorylation and activation of NKCC1, increased phosphorylation of NKCC1 at the sites targeted by SPAK/OSR1. The residues on NKCC1, phosphorylated by SPAK/OSR1, are conserved in other cation co-transporters, such as the Na+-Cl- co-transporter, the target of thiazide drugs that lower blood pressure in humans with Gordon's syndrome. Furthermore, we characterize the properties of a 92-residue CCT (conserved C-terminal) domain on SPAK and OSR1 that interacts with an RFXV (Arg-Phe-Xaa-Val) motif present in the substrate NKCC1 and its activators WNK1/WNK4. A peptide containing the RFXV motif interacts with nanomolar affinity with the CCT domains of SPAK/OSR1 and can be utilized to affinity-purify SPAK and OSR1 from cell extracts. Mutation of the arginine, phenylalanine or valine residue within this peptide abolishes binding to SPAK/OSR1. We have identified specific residues within the CCT domain that are required for interaction with the RFXV motif and have demonstrated that mutation of these in OSR1 inhibited phosphorylation of NKCC1, but not of CATCHtide which does not possess an RFXV motif. We establish that an intact CCT domain is required for WNK1 to efficiently phosphorylate and activate OSR1. These data establish that the CCT domain functions as a multipurpose docking site, enabling SPAK/OSR1 to interact with substrates (NKCC1) and activators (WNK1/WNK4).
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Affiliation(s)
- Alberto C Vitari
- MRC Protein Phosphorylation Unit, School of Life Sciences, MSI/WTB complex, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.
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235
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Schrick JJ, Vogel P, Abuin A, Hampton B, Rice DS. ADP-ribosylation factor-like 3 is involved in kidney and photoreceptor development. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1288-98. [PMID: 16565502 PMCID: PMC1606550 DOI: 10.2353/ajpath.2006.050941] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
ADP-ribosylation factor-like 3 (Arl3) is a member of a small subfamily of G-proteins involved in membrane-associated vesicular and intracellular trafficking processes. Genetic studies in Leishmania have shown that the Arl3 homolog is essential for flagellum biogenesis. Mutations in a related human family member, Arl6, result in Bardet-Biedl syndrome in humans, which is characterized by genital, renal, and retinal abnormalities, obesity, and learning deficits. As part of our large-scale phenotypic screen, mice deficient for the Arl3 gene were generated and analyzed. Arl3 (-/-) mice were born at a sub-Mendelian ratio, were small and sickly, and had markedly swollen abdomens. These mutants failed to thrive, and all died by 3 weeks of age. The (-/-) mice exhibited abnormal development of renal, hepatic, and pancreatic epithelial tubule structures, which is characteristic of the renal-hepatic-pancreatic dysplasia found in autosomal recessive polycystic kidney disease. Absence of Arl3 was associated with abnormal epithelial cell proliferation and cyst formation. Moreover, mice lacking Arl3 exhibited photoreceptor degeneration as early as postnatal day 14. These results are the first to implicate Arl3 in a ciliary disease affecting the kidney, biliary tract, pancreas, and retina.
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Affiliation(s)
- Jeffrey J Schrick
- Lexicon Genetics Inc., 8800 Technology Forest Pl., The Woodlands, TX 77381, USA.
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236
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Parker LL, Gao J, Zuo J. Absence of hearing loss in a mouse model for DFNA17 and MYH9-related disease: the use of public gene-targeted ES cell resources. Brain Res 2006; 1091:235-42. [PMID: 16630581 DOI: 10.1016/j.brainres.2006.03.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 02/14/2006] [Accepted: 03/10/2006] [Indexed: 11/22/2022]
Abstract
Multiple mouse embryonic stem (ES) cell banks expand the capability to characterize functions of genes implicated in human disease and to develop mouse models for the further understanding of disease pathology. Genetic diseases that result in hearing loss can provide insight into causative molecular mechanisms for deafness. We utilized BayGenomics, the public mouse ES cell bank, to identify gene-trapped ES cell lines associated with hearing loss. We identified two gene-trapped ES cell lines specific for the non-muscle myosin heavy chain class IIA or myosin heavy chain IX (Myh9). Inherited mutations in the Myh9 gene have been linked to non-syndromic hereditary hearing impairment DFNA17 as well as 'MYH9-related disease' characterized by macrothrombocytopenia, leukocyte inclusions, and in some patients deafness. Mutant Myh9 mice were derived from one of these ES cell lines that underwent germline transmission for in-depth otological examination. No homozygous mice however were identified at birth, consistent with recently published data describing the embryonic lethality of homozygous mutations in Myh9. We provide evidence that adult heterozygous Myh9 mouse inner ears contain half wild-type levels of Myh9 mRNA. Hearing loss however was not observed in heterozygous Myh9 mice in contrast to human Myh9-related diseases. Aged heterozygous Myh9 mice also did not show signs of cochleosaccular degeneration common in DFNA17. Although inheritance of Myh9 mutations in humans is dominant, we conclude that heterozygous loss of Myh9 is not critical to hearing function in mice by itself.
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Affiliation(s)
- Lisan L Parker
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN 38105-2794, USA
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237
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Salojin KV, Owusu IB, Millerchip KA, Potter M, Platt KA, Oravecz T. Essential role of MAPK phosphatase-1 in the negative control of innate immune responses. THE JOURNAL OF IMMUNOLOGY 2006; 176:1899-907. [PMID: 16424221 DOI: 10.4049/jimmunol.176.3.1899] [Citation(s) in RCA: 281] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TLR-induced innate immunity and inflammation are mediated by signaling cascades leading to activation of the MAPK family of Ser/Thr protein kinases, including p38 MAPK, which controls cytokine release during innate and adoptive immune responses. Failure to terminate such inflammatory reactions may lead to detrimental systemic effects, including septic shock and autoimmunity. In this study, we provide genetic evidence of a critical and nonredundant role of MAPK phosphatase (MKP)-1 in the negative control of MAPK-regulated inflammatory reactions in vivo. MKP-1-/- mice are hyperresponsive to low-dose LPS-induced toxicity and exhibit significantly increased serum TNF-alpha, IL-6, IL-12, MCP-1, IFN-gamma, and IL-10 levels after systemic administration of LPS. Furthermore, absence of MKP-1 increases systemic levels of proinflammatory cytokines and exacerbates disease development in a mouse model of rheumatoid arthritis. When activated through TLR2, TLR3, TLR4, TLR5, and TLR9, bone marrow-derived MKP-1-/- macrophages exhibit increased cytokine production and elevated expression of the differentiation markers B7.2 (CD86) and CD40. MKP-1-deficient macrophages also show enhanced constitutive and TLR-induced activation of p38 MAPK. Based on these findings, we propose that MKP-1 is an essential component of the intracellular homeostasis that controls the threshold and magnitude of p38 MAPK activation in macrophages, and inflammatory conditions accentuate the significance of this regulatory function.
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238
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Yu ASL. WNK signaling in the distal tubule: an inhibitory cascade regulating salt transport. Am J Physiol Renal Physiol 2006; 290:F617-8. [PMID: 16461759 DOI: 10.1152/ajprenal.00409.2005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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239
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Tian Y, James S, Zuo J, Fritzsch B, Beisel KW. Conditional and inducible gene recombineering in the mouse inner ear. Brain Res 2006; 1091:243-54. [PMID: 16488403 PMCID: PMC3901521 DOI: 10.1016/j.brainres.2006.01.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 12/30/2005] [Accepted: 01/05/2006] [Indexed: 12/21/2022]
Abstract
Genetically engineered mice have greatly improved our understanding of gene functions and disease mechanisms. Nevertheless, the traditional knock-out approach has limitations in the overall viability of mutants. The application of the Cre/loxP system in the inner ear can help bypass this difficulty by generation of conditional gene recombineering. However, to do so requires an expression system that allows ear-specific temporally inducible, gene abrogation of one or more of the increasingly available floxed genes. To date, three approaches have been successfully used to create murine inner ear-specific Cre lines: conventional transgenesis, BAC transgenesis, and gene knock-in. Unfortunately, timing of conditional Cre activity does not extend beyond the regulatory range of the gene controlling Cre expression. Rectification of this problem requires the generation of tamoxifen or tetracycline inducible systems in the inner ear. Examination of integrase expression at different loci will facilitate studies on the expression of exogenous transgenes. These genetic applications for the mouse genome will dramatically advance in vivo gene function studies.
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Affiliation(s)
- Yong Tian
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Sally James
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Jian Zuo
- Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Bernd Fritzsch
- Department of Biomedical Sciences, Creighton University, School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
| | - Kirk W. Beisel
- Department of Biomedical Sciences, Creighton University, School of Medicine, 2500 California Plaza, Omaha, NE 68178, USA
- Corresponding author: Fax: +1 402 280 2690. (K.W. Beisel)
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240
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De-Zolt S, Schnütgen F, Seisenberger C, Hansen J, Hollatz M, Floss T, Ruiz P, Wurst W, von Melchner H. High-throughput trapping of secretory pathway genes in mouse embryonic stem cells. Nucleic Acids Res 2006; 34:e25. [PMID: 16478711 PMCID: PMC1369290 DOI: 10.1093/nar/gnj026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
High-throughput gene trapping is a random approach for inducing insertional mutations across the mouse genome. This approach uses gene trap vectors that simultaneously inactivate and report the expression of the trapped gene at the insertion site, and provide a DNA tag for the rapid identification of the disrupted gene. Gene trapping has been used by both public and private institutions to produce libraries of embryonic stem (ES) cells harboring mutations in single genes. Presently, ∼66% of the protein coding genes in the mouse genome have been disrupted by gene trap insertions. Among these, however, genes encoding signal peptides or transmembrane domains (secretory genes) are underrepresented because they are not susceptible to conventional trapping methods. Here, we describe a high-throughput gene trapping strategy that effectively targets secretory genes. We used this strategy to assemble a library of ES cells harboring mutations in 716 unique secretory genes, of which 61% were not trapped by conventional trapping, indicating that the two strategies are complementary. The trapped ES cell lines, which can be ordered from the International Gene Trap Consortium (), are freely available to the scientific community.
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Affiliation(s)
| | | | - Claudia Seisenberger
- Institute of Developmental Genetics, GSF-National Research Center for Environment and HealthNeuherberg, Germany
| | - Jens Hansen
- Institute of Developmental Genetics, GSF-National Research Center for Environment and HealthNeuherberg, Germany
| | - Melanie Hollatz
- Institute of Developmental Genetics, GSF-National Research Center for Environment and HealthNeuherberg, Germany
| | - Thomas Floss
- Institute of Developmental Genetics, GSF-National Research Center for Environment and HealthNeuherberg, Germany
| | - Patricia Ruiz
- Center for Cardiovascular Research, Charité UniversitätsmedizinBerlin, Germany
- Department of Vertebrate Genomics, Max-Planck Institute for Molecular GeneticsBerlin, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, GSF-National Research Center for Environment and HealthNeuherberg, Germany
- Department for Molecular Neurogenetics, Max-Planck Institute of PsychiatryMunich, Germany
| | - Harald von Melchner
- To whom correspondence should be addressed. Tel: +49 69 63016696; Fax: +49 69 63016390;
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241
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Fanzo JC, Yang W, Jang SY, Gupta S, Chen Q, Siddiq A, Greenberg S, Pernis AB. Loss of IRF-4-binding protein leads to the spontaneous development of systemic autoimmunity. J Clin Invest 2006; 116:703-14. [PMID: 16470246 PMCID: PMC1361345 DOI: 10.1172/jci24096] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2004] [Accepted: 12/01/2005] [Indexed: 12/18/2022] Open
Abstract
IFN regulatory factor 4-binding (IRF-4-binding) protein (IBP) is a novel type of activator of Rho GTPases that is recruited to the immunological synapse upon TCR stimulation. Here we demonstrate that loss of IBP leads to the spontaneous development of a systemic autoimmune disorder characterized by the accumulation of effector/memory T cells and IgG+ B cells, profound hypergammaglobulinemia, and autoantibody production. Similar to human SLE, this syndrome primarily affects females. T cells from IBP-deficient mice are resistant to death in vitro as well as in vivo and exhibit selective defects in effector function. In the absence of IBP, T cells respond suboptimally to TCR engagement, as demonstrated by diminished ERK1/2 activation, decreased c-Fos induction, impaired immunological synapse formation, and defective actin polymerization. Transduction of IBP-deficient T cells with a WT IBP protein, but not with an IBP mutant lacking the Dbl-like domain required for Rho GTPase activation, rescues the cytoskeletal defects exhibited by these cells. Collectively, these findings indicate that IBP, a novel regulator of Rho GTPases, is required for optimal T cell effector function, lymphocyte homeostasis, and the prevention of systemic autoimmunity.
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Affiliation(s)
- Jessica C Fanzo
- Department of Medicine, Columbia University, New York, New York 10032, USA
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242
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Lazrak A, Liu Z, Huang CL. Antagonistic regulation of ROMK by long and kidney-specific WNK1 isoforms. Proc Natl Acad Sci U S A 2006; 103:1615-20. [PMID: 16428287 PMCID: PMC1360592 DOI: 10.1073/pnas.0510609103] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
WNK kinases are serine-threonine kinases with an atypical placement of the catalytic lysine. Intronic deletions with increased expression of a ubiquitous long WNK1 transcript cause pseudohypoaldosteronism type 2 (PHA II), characterized by hypertension and hyperkalemia. Here, we report that long WNK1 inhibited ROMK1 by stimulating its endocytosis. Inhibition of ROMK by long WNK1 was synergistic with, but not dependent on, WNK4. A smaller transcript of WNK1 lacking the N-terminal 1-437 amino acids is expressed highly in the kidney. Whether expression of the KS-WNK1 (kidney-specific, KS) is altered in PHA II is not known. We found that KS-WNK1 did not inhibit ROMK1 but reversed the inhibition of ROMK1 caused by long WNK1. Consistent with the lack of inhibition by KS-WNK1, we found that amino acids 1-491 of the long WNK1 were sufficient for inhibiting ROMK. Dietary K(+) restriction decreases ROMK abundance in the renal cortical-collecting ducts by stimulating endocytosis, an adaptative response important for conservation of K(+) during K(+) deficiency. We found that K(+) restriction in rats increased whole-kidney transcript of long WNK1 while decreasing that of KS-WNK1. Thus, KS-WNK1 is a physiological antagonist of long WNK1. Hyperkalemia in PHA II patients with PHA II mutations may be caused, at least partially, by increased expression of long WNK1 with or without decreased expression of KS-WNK1.
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Affiliation(s)
- Ahmed Lazrak
- Department of Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-8856, USA
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243
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Vitari AC, Deak M, Morrice NA, Alessi DR. The WNK1 and WNK4 protein kinases that are mutated in Gordon's hypertension syndrome phosphorylate and activate SPAK and OSR1 protein kinases. Biochem J 2006; 391:17-24. [PMID: 16083423 PMCID: PMC1237134 DOI: 10.1042/bj20051180] [Citation(s) in RCA: 404] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mutations in the human genes encoding WNK1 [with no K (lysine) protein kinase-1] and the related protein kinase WNK4 are the cause of Gordon's hypertension syndrome. Little is known about the molecular mechanism by which WNK isoforms regulate cellular processes. We immunoprecipitated WNK1 from extracts of rat testis and found that it was specifically associated with a protein kinase of the STE20 family termed 'STE20/SPS1-related proline/alanine-rich kinase' (SPAK). We demonstrated that WNK1 and WNK4 both interacted with SPAK as well as a closely related kinase, termed 'oxidative stress response kinase-1' (OSR1). Wildtype (wt) but not catalytically inactive WNK1 and WNK4 phosphorylated SPAK and OSR1 to a much greater extent than with other substrates utilized previously, such as myelin basic protein and claudin-4. Phosphorylation by WNK1 or WNK4 markedly increased SPAK and OSR1 activity. Phosphopeptide mapping studies demonstrated that WNK1 phosphorylated kinase-inactive SPAK and OSR1 at an equivalent residue located within the T-loop of the catalytic domain (Thr233 in SPAK, Thr185 in OSR1) and a serine residue located within a C-terminal non-catalytic region (Ser373 in SPAK, Ser325 in OSR1). Mutation of Thr185 to alanine prevented the activation of OSR1 by WNK1, whereas mutation of Thr185 to glutamic acid (to mimic phosphorylation) increased the basal activity of OSR1 over 20-fold and prevented further activation by WNK1. Mutation of Ser325 in OSR1 to alanine or glutamic acid did not affect the basal activity of OSR1 or its ability to be activated by WNK1. These findings suggest that WNK isoforms operate as protein kinases that activate SPAK and OSR1 by phosphorylating the T-loops of these enzymes, resulting in their activation. Our analysis also describes the first facile assay that can be employed to quantitatively assess WNK1 and WNK4 activity.
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Affiliation(s)
- Alberto C Vitari
- MRC Protein Phosphorylation Unit, School of Life Sciences, MSI/WTB Complex, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.
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244
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Abstract
The mouse is the foremost vertebrate experimental model because its genome can be precisely and variously engineered. Now that the mouse genome has been sequenced and annotated, the task of mutating each gene is feasible, and an international cooperation is providing mutated embryonic stem cells and mice as readily available resources. Because these resources will change biomedical research, decisions about their nature will have far-reaching effects. It is therefore timely to consider topical issues for mouse genome engineering, such as the background genotype; homologous, site-specific and transpositional recombination; conditional mutagenesis; RNA-mediated interference; and functional genomics with embryonic stem cells.
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Affiliation(s)
- Stefan Glaser
- Genomics, BioInnovationsZentrum, Dresden University of Technology, Am Tatzberg 47, 01307, Dresden, Germany
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245
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Abstract
Gene trapping in embryonic stem cells (ESCs) generates random, sequence-tagged insertional mutations, which can often report the gene expression pattern of the mutated gene. This mutagenesis strategy has often been coupled to expression or function-based assays in gene discovery screens. The availability of the mouse genome sequence has shifted gene trapping from a gene discovery platform to a high-throughput mutagenesis platform. At present, a concerted worldwide effort is underway to develop a library of loss-of-function mutations in all mouse genes. The International Gene Trap Consortium (IGTC) is leading the way by making a first pass of the genome by random mutagenesis before a high-throughput gene targeting program takes over. In this chapter, we provide a methods guidebook to exploring and using the IGTC resource, explain the different kinds of vectors and insertions that reside in the different libraries, and provide advice and methods for investigators to design novel expression-based "cottage industry" screens.
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Affiliation(s)
- William L Stanford
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
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246
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Zhao S, Edwards J, Carroll J, Wiedholz L, Millstein RA, Jaing C, Murphy DL, Lanthorn TH, Holmes A. Insertion mutation at the C-terminus of the serotonin transporter disrupts brain serotonin function and emotion-related behaviors in mice. Neuroscience 2006; 140:321-34. [PMID: 16542782 DOI: 10.1016/j.neuroscience.2006.01.049] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2005] [Revised: 01/23/2006] [Accepted: 01/27/2006] [Indexed: 11/17/2022]
Abstract
The 5-hydroxytryptamine transporter (5-HTT) regulates 5-hydroxytryptamine (5-HT) neurotransmission by removing 5-HT from the synaptic cleft. Emerging evidence from clinical and genetic studies implicates the 5-HTT in various neuropsychiatric conditions, including anxiety and depression. Here we report that a 5-HTT null mutant mouse line was generated by gene trapping that disrupted the sequence encoding the C-terminus of 5-HTT. This mutation resulted in significant reduction of 5-HTT mRNA and loss of 5-HTT protein. Brain levels of 5-HT and its major metabolite, 5-hydroxyindoleacetic acid, were markedly decreased in C-terminus 5-HTT -/- mice, while 5-HT uptake or 5-HT content in platelets was absent. Behavioral phenotyping showed that C-terminus 5-HTT -/- mice were normal on a screen for gross behavioral, neurological, and sensory functions. In the tail suspension test for depression-related behavior, C-terminus 5-HTT -/- mice showed increased immobility relative to their +/+ controls. By comparison, a previously generated line of 5-HTT -/- mice lacking exon 2, encoding the N-terminus of the 5-HTT, showed abnormally high immobility in response to repeated, but not acute, exposure to the tail suspension test. In a novel, brightly-lit open field, both C-terminus 5-HTT -/- mice and N-terminus 5-HTT -/- mice displayed decreased center time and reduced locomotor activity compared with their +/+ controls. Both mutant lines buried significantly fewer marbles than their +/+ controls in the marble burying test. These findings further demonstrate the neurobiological functions of the 5-HTT and add to a growing literature linking genetic variation in 5-HTT function with emotional abnormalities.
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Affiliation(s)
- S Zhao
- Lexicon Genetics Incorporated, 8800 Technology Forest Place, The Woodlands, TX 77381, USA.
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247
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Bundschu K, Gattenlöhner S, Knobeloch KP, Walter U, Schuh K. Tissue-specific Spred-2 promoter activity characterized by a gene trap approach. Gene Expr Patterns 2005; 6:247-55. [PMID: 16378760 DOI: 10.1016/j.modgep.2005.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 08/11/2005] [Accepted: 08/12/2005] [Indexed: 01/17/2023]
Abstract
Spreds (Sprouty-related proteins with an Ena/Vasodilator-stimulated phosphoprotein homology-1 domain) are a new protein family inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway. Different RNA and protein studies already revealed an almost ubiquitous Spred-2 expression pattern. But until now, only few data were available on the in situ Spred-2 promoter activity. Here, we show a detailed in situ analysis of a mouse strain with a trapped Spred-2 gene, bringing a beta-galactosidase and neomycin fusion gene (beta-geo) under the control of the endogenous Spred-2 promoter. This allowed us to monitor Spred-2 promoter activity in practically every organ and their corresponding sub-compartments. X-Gal staining of newborn and adult mice revealed a nearly congruent Spred-2 promoter activity pattern. Our detailed data provide information for further studies of the still enigmatic physiological functions of Spred-2 in various organs by identifying the tissues with strong Spred-2 promoter activity.
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MESH Headings
- Animals
- Animals, Newborn
- Cell Line
- Crosses, Genetic
- DNA, Complementary/genetics
- Exons
- Female
- Galactosides/metabolism
- Gene Expression Regulation, Developmental
- Gene Targeting
- Genes, Reporter
- Genetic Vectors
- Immunohistochemistry
- Indoles/metabolism
- Introns
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitogen-Activated Protein Kinases/antagonists & inhibitors
- Muscle, Smooth/metabolism
- Promoter Regions, Genetic
- Protein Structure, Tertiary
- Repressor Proteins/chemistry
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Stem Cells/cytology
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Affiliation(s)
- Karin Bundschu
- Institut für Klinische Biochemie und Pathobiochemie, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany
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248
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Cusick JK, Xu LG, Bin LH, Han KJ, Shu HB. Identification of RELT homologues that associate with RELT and are phosphorylated by OSR1. Biochem Biophys Res Commun 2005; 340:535-43. [PMID: 16389068 DOI: 10.1016/j.bbrc.2005.12.033] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Accepted: 12/03/2005] [Indexed: 11/25/2022]
Abstract
RELL1 and RELL2 are two newly identified RELT homologues that bind to the TNF receptor family member RELT. The expression of RELL1 at the mRNA level is ubiquitous, whereas expression of RELL2 mRNA is more restricted to particular tissues. RELT, RELL1, and RELL2 co-localized with one another at the plasma membrane. The three proteins interacted with one another as demonstrated by in vitro co-immunoprecipitation experiments. We propose that RELL1 and RELL2 be considered RELT family members based on their similar amino acid sequences and on their ability to physically interact with one another. OSR1 was identified through a yeast two-hybrid screen utilizing the intracellular portion of RELL1 as bait, and OSR1 was shown to interact with the three RELT family members by in vitro co-immunoprecipitation experiments. Additionally, OSR1 phosphorylated the RELT family members in an in vitro kinase assay. These results report two novel homologues of RELT that interact with RELT and are phosphorylated by the OSR1 kinase.
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Affiliation(s)
- John K Cusick
- National Jewish Research Center, Department of Immunology, 1400 Jackson Street, Denver, CO 80220, USA.
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249
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Moriguchi T, Urushiyama S, Hisamoto N, Iemura SI, Uchida S, Natsume T, Matsumoto K, Shibuya H. WNK1 Regulates Phosphorylation of Cation-Chloride-coupled Cotransporters via the STE20-related Kinases, SPAK and OSR1. J Biol Chem 2005; 280:42685-93. [PMID: 16263722 DOI: 10.1074/jbc.m510042200] [Citation(s) in RCA: 375] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The WNK1 and WNK4 genes have been found to be mutated in some patients with hyperkalemia and hypertension caused by pseudohypoaldosteronism type II. The clue to the pathophysiology of pseudohypoaldosteronism type II was its striking therapeutic response to thiazide diuretics, which are known to block the sodium chloride cotransporter (NCC). Although this suggests a role for WNK1 in hypertension, the precise molecular mechanisms are largely unknown. Here we have shown that WNK1 phosphorylates and regulates the STE20-related kinases, Ste20-related proline-alanine-rich kinase (SPAK) and oxidative stress response 1 (OSR1). WNK1 was observed to phosphorylate the evolutionary conserved serine residue located outside the kinase domains of SPAK and OSR1, and mutation of the OSR1 serine residue caused enhanced OSR1 kinase activity. In addition, hypotonic stress was shown to activate SPAK and OSR1 and induce phosphorylation of the conserved OSR1 serine residue, suggesting that WNK1 may be an activator of the SPAK and OSR1 kinases. Moreover, SPAK and OSR1 were found to directly phosphorylate the N-terminal regulatory regions of cation-chloride-coupled cotransporters including NKCC1, NKCC2, and NCC. Phosphorylation of NCC was induced by hypotonic stress in cells. These results suggested that WNK1 and SPAK/OSR1 mediate the hypotonic stress signaling pathway to the transporters and may provide insights into the mechanisms by which WNK1 regulates ion balance.
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Affiliation(s)
- Tetsuo Moriguchi
- Department of Molecular Cell Biology, Medical Research Institute and School of Biomedical Science, Tokyo Medical and Dental University, and CREST, JST, Chiyoda, Tokyo 101-0062
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250
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Zhang H, Staessen JA. Association of Blood Pressure With Genetic Variation inWNKKinases in a White European Population. Circulation 2005; 112:3371-2. [PMID: 16316962 DOI: 10.1161/circulationaha.105.585737] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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