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Hossain MJ, Bakhsh A, Joyia FA, Aksoy E, Gökçe NZÖ, Khan MS. Engineering of insecticidal hybrid gene into potato chloroplast genome exhibits promising control of Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae). Transgenic Res 2023; 32:497-512. [PMID: 37707659 DOI: 10.1007/s11248-023-00366-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/30/2023] [Indexed: 09/15/2023]
Abstract
The potato chloroplast was transformed with codon optimized synthetic hybrid cry gene (SN19) to mitigate crop losses by Colorado potato beetle (CPB). The bombarded explants (leaves and internode) were cultured on MS medium supplemented with BAP (2.0 mg/l), NAA (0.2 mg/l), TDZ (2.0 mg/l) and GA3 (0.1 mg/l); spectinomycin 50 mg/l was used as a selection agent in the medium. Leaf explants of cultivar Kuroda induced highest percentage (92%) of callus where cultivar Santae produced the highest percentage (85.7%) of transplastomic shoots. Sante and Challenger showed 9.6% shoot regeneration efficiency followed by cultivar Simply Red (8.8%). PCR amplification yielded 16 postive transplastomic plantlets out of 21 spectinomycin resistant ones. Target gene integration was confirmed by PCR and Southern blot, whereas RT-qPCR was used to assess the expression level of transgene. The localization of visual marker gene gfp was tracked by laser scanning confocal microscopy which confirmed its expression in chloroplasts of leaf cells. The transplastomic plants ensured high mortality to both larvae and adult CPB. Foliage consumption and weight gain of CPB fed on transplastomic leaves were lower compared to the control plants. Sucessful implementation of current research findings can lead to a viable solution to CPB mediated potato losses globally.
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Affiliation(s)
- Md Jakir Hossain
- Department of Agricultural Genetic Engineering, Faculty of Agricultural Sciences and Technologies, Nigde Omer Halisdemir University, 51240, Nigde, Turkey
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Dhaka, 1207, Bangladesh
| | - Allah Bakhsh
- Department of Agricultural Genetic Engineering, Faculty of Agricultural Sciences and Technologies, Nigde Omer Halisdemir University, 51240, Nigde, Turkey.
- Center of Excellence in Molecular Biology (CEMB), University of Punjab, Lahore, Pakistan.
| | - Faiz Ahmad Joyia
- Center of Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture, Faisalabad, Pakistan
| | - Emre Aksoy
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
| | - Neslihan Zahide Özturk Gökçe
- Department of Agricultural Genetic Engineering, Faculty of Agricultural Sciences and Technologies, Nigde Omer Halisdemir University, 51240, Nigde, Turkey
| | - Muhammad Sarwar Khan
- Center of Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture, Faisalabad, Pakistan
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High-Throughput Single-Cell Transcriptome Profiling of Plant Cell Types. Cell Rep 2020; 27:2241-2247.e4. [PMID: 31091459 PMCID: PMC6758921 DOI: 10.1016/j.celrep.2019.04.054] [Citation(s) in RCA: 207] [Impact Index Per Article: 51.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/14/2019] [Accepted: 04/11/2019] [Indexed: 11/25/2022] Open
Abstract
Single-cell transcriptome profiling of heterogeneous tissues can provide high-resolution windows into developmental dynamics and environmental responses, but its application to plants has been limited. Here, we used the high-throughput Drop-seq approach to profile >12,000 cells from Arabidopsis roots. This identified numerous distinct cell types, covering all major root tissues and developmental stages, and illuminated specific marker genes for these populations. In addition, we demonstrate the utility of this approach to study the impact of environmental conditions on developmental processes. Analysis of roots grown with or without sucrose supplementation uncovers changes in the relative frequencies of cell types in response to sucrose. Finally, we characterize the transcriptome changes that occur across endodermis development and identify nearly 800 genes with dynamic expression as this tissue differentiates. Collectively, we demonstrate that single-cell RNA-seq can be used to profile developmental processes in plants and show how they can be altered by external stimuli. The application of single-cell transcriptome profiling to plants has been limited. Shulse et al. performed Drop-seq on Arabidopsis roots, generating a transcriptional resource for >12,000 cells across major populations. This revealed marker genes for distinct cell types, cell frequency changes resulting from sucrose addition, and genes dynamically regulated during development.
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Jang CW, Shibata Y, Starmer J, Yee D, Magnuson T. Histone H3.3 maintains genome integrity during mammalian development. Genes Dev 2015; 29:1377-92. [PMID: 26159997 PMCID: PMC4511213 DOI: 10.1101/gad.264150.115] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 06/16/2015] [Indexed: 12/19/2022]
Abstract
Histone H3.3 is a highly conserved histone H3 replacement variant in metazoans and has been implicated in many important biological processes, including cell differentiation and reprogramming. Germline and somatic mutations in H3.3 genomic incorporation pathway components or in H3.3 encoding genes have been associated with human congenital diseases and cancers, respectively. However, the role of H3.3 in mammalian development remains unclear. To address this question, we generated H3.3-null mouse models through classical genetic approaches. We found that H3.3 plays an essential role in mouse development. Complete depletion of H3.3 leads to developmental retardation and early embryonic lethality. At the cellular level, H3.3 loss triggers cell cycle suppression and cell death. Surprisingly, H3.3 depletion does not dramatically disrupt gene regulation in the developing embryo. Instead, H3.3 depletion causes dysfunction of heterochromatin structures at telomeres, centromeres, and pericentromeric regions of chromosomes, leading to mitotic defects. The resulting karyotypical abnormalities and DNA damage lead to p53 pathway activation. In summary, our results reveal that an important function of H3.3 is to support chromosomal heterochromatic structures, thus maintaining genome integrity during mammalian development.
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Affiliation(s)
- Chuan-Wei Jang
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA
| | - Yoichiro Shibata
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA
| | - Joshua Starmer
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA
| | - Della Yee
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA
| | - Terry Magnuson
- Department of Genetics, Carolina Center for Genome Sciences, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA
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4
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Saito S, Ura K, Kodama M, Adachi N. Construction and applications of exon-trapping gene-targeting vectors with a novel strategy for negative selection. BMC Res Notes 2015; 8:278. [PMID: 26123730 PMCID: PMC4486125 DOI: 10.1186/s13104-015-1241-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 06/17/2015] [Indexed: 12/11/2022] Open
Abstract
Background Targeted gene modification by homologous recombination provides a powerful tool for studying gene function in cells and animals. In higher eukaryotes, non-homologous integration of targeting vectors occurs several orders of magnitude more frequently than does targeted integration, making the gene-targeting technology highly inefficient. For this reason, negative-selection strategies have been employed to reduce the number of drug-resistant clones associated with non-homologous vector integration, particularly when artificial nucleases to introduce a DNA break at the target site are unavailable or undesirable. As such, an exon-trap strategy using a promoterless drug-resistance marker gene provides an effective way to counterselect non-homologous integrants. However, constructing exon-trapping targeting vectors has been a time-consuming and complicated process. Results By virtue of highly efficient att-mediated recombination, we successfully developed a simple and rapid method to construct plasmid-based vectors that allow for exon-trapping gene targeting. These exon-trap vectors were useful in obtaining correctly targeted clones in mouse embryonic stem cells and human HT1080 cells. Most importantly, with the use of a conditionally cytotoxic gene, we further developed a novel strategy for negative selection, thereby enhancing the efficiency of counterselection for non-homologous integration of exon-trap vectors. Conclusions Our methods will greatly facilitate exon-trapping gene-targeting technologies in mammalian cells, particularly when combined with the novel negative selection strategy. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1241-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shinta Saito
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan.
| | - Kiyoe Ura
- Graduate School of Science, Chiba University, Chiba, 263-8522, Japan.
| | - Miho Kodama
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan.
| | - Noritaka Adachi
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, 236-0027, Japan. .,Advanced Medical Research Center, Yokohama City University, Yokohama, 236-0004, Japan.
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Dickel DE, Zhu Y, Nord AS, Wylie JN, Akiyama JA, Afzal V, Plajzer-Frick I, Kirkpatrick A, Göttgens B, Bruneau BG, Visel A, Pennacchio LA. Function-based identification of mammalian enhancers using site-specific integration. Nat Methods 2014; 11:566-71. [PMID: 24658141 PMCID: PMC4008384 DOI: 10.1038/nmeth.2886] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 02/03/2014] [Indexed: 01/22/2023]
Abstract
The accurate and comprehensive identification of functional regulatory sequences in mammalian genomes remains a major challenge. Here we describe site-specific integration fluorescence-activated cell sorting followed by sequencing (SIF-seq), an unbiased, medium-throughput functional assay for the discovery of distant-acting enhancers. Targeted single-copy genomic integration into pluripotent cells, reporter assays and flow cytometry are coupled with high-throughput DNA sequencing to enable parallel screening of large numbers of DNA sequences. By functionally interrogating >500 kilobases (kb) of mouse and human sequence in mouse embryonic stem cells for enhancer activity we identified enhancers at pluripotency loci including NANOG. In in vitro-differentiated cardiomyocytes and neural progenitor cells, we identified cardiac enhancers and neuronal enhancers, respectively. SIF-seq is a powerful and flexible method for de novo functional identification of mammalian enhancers in a potentially wide variety of cell types.
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Affiliation(s)
- Diane E Dickel
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Yiwen Zhu
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Alex S Nord
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - John N Wylie
- 1] Gladstone Institute of Cardiovascular Disease, San Francisco, California, USA. [2] Roddenberry Center for Stem Cell Biology and Medicine at Gladstone Institutes, San Francisco, California, USA
| | - Jennifer A Akiyama
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Veena Afzal
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Ingrid Plajzer-Frick
- Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Aileen Kirkpatrick
- 1] Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK. [2] Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Berthold Göttgens
- 1] Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK. [2] Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Benoit G Bruneau
- 1] Gladstone Institute of Cardiovascular Disease, San Francisco, California, USA. [2] Roddenberry Center for Stem Cell Biology and Medicine at Gladstone Institutes, San Francisco, California, USA. [3] Department of Pediatrics, University of California, San Francisco, San Francisco, California, USA. [4] Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
| | - Axel Visel
- 1] Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. [2] US Department of Energy Joint Genome Institute, Walnut Creek, California, USA. [3] School of Natural Sciences, University of California, Merced, Merced, California, USA
| | - Len A Pennacchio
- 1] Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. [2] US Department of Energy Joint Genome Institute, Walnut Creek, California, USA
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Taglieri DM, Johnson KR, Burmeister BT, Monasky MM, Spindler MJ, DeSantiago J, Banach K, Conklin BR, Carnegie GK. The C-terminus of the long AKAP13 isoform (AKAP-Lbc) is critical for development of compensatory cardiac hypertrophy. J Mol Cell Cardiol 2014; 66:27-40. [PMID: 24161911 PMCID: PMC4074493 DOI: 10.1016/j.yjmcc.2013.10.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 09/24/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
Abstract
The objective of this study was to determine the role of A-Kinase Anchoring Protein (AKAP)-Lbc in the development of heart failure, by investigating AKAP-Lbc-protein kinase D1 (PKD1) signaling in vivo in cardiac hypertrophy. Using a gene-trap mouse expressing a truncated version of AKAP-Lbc (due to disruption of the endogenous AKAP-Lbc gene), that abolishes PKD1 interaction with AKAP-Lbc (AKAP-Lbc-ΔPKD), we studied two mouse models of pathological hypertrophy: i) angiotensin (AT-II) and phenylephrine (PE) infusion and ii) transverse aortic constriction (TAC)-induced pressure overload. Our results indicate that AKAP-Lbc-ΔPKD mice exhibit an accelerated progression to cardiac dysfunction in response to AT-II/PE treatment and TAC. AKAP-Lbc-ΔPKD mice display attenuated compensatory cardiac hypertrophy, increased collagen deposition and apoptosis, compared to wild-type (WT) control littermates. Mechanistically, reduced levels of PKD1 activation are observed in AKAP-Lbc-ΔPKD mice compared to WT mice, resulting in diminished phosphorylation of histone deacetylase 5 (HDAC5) and decreased hypertrophic gene expression. This is consistent with a reduced compensatory hypertrophy phenotype leading to progression of heart failure in AKAP-Lbc-ΔPKD mice. Overall, our data demonstrates a critical in vivo role for AKAP-Lbc-PKD1 signaling in the development of compensatory hypertrophy to enhance cardiac performance in response to TAC-induced pressure overload and neurohumoral stimulation by AT-II/PE treatment.
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Affiliation(s)
- Domenico M Taglieri
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Keven R Johnson
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Brian T Burmeister
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Michelle M Monasky
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA; Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Matthew J Spindler
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Jaime DeSantiago
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Kathrin Banach
- Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA
| | - Bruce R Conklin
- Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Graeme K Carnegie
- Department of Pharmacology, College of Medicine, University of Illinois at Chicago, Chicago, 60612 IL, USA.
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Horton JS, Buckley CL, Alvarez EM, Schorlemmer A, Stokes AJ. The calcium release-activated calcium channel Orai1 represents a crucial component in hypertrophic compensation and the development of dilated cardiomyopathy. Channels (Austin) 2013; 8:35-48. [PMID: 24135962 DOI: 10.4161/chan.26581] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
As exceptionally calcium selective store-operated channels, Orai channels play a prominent role in cellular calcium signaling. While most studied in the immune system, we are beginning to recognize that Orai1 provides unique calcium signaling pathways in numerous tissue contexts. To assess the involvement of Orai1 in cardiac hypertrophy we used transverse aortic constriction to model pressure overload cardiac hypertrophy and heart failure in Orai1 deficient mice. We demonstrate that Orai1 deficient mice have significantly decreased survival in this pressure overload model. Transthoracic echocardiography reveals that Orai1 deficient mice develop rapid dilated cardiomyopathy, with greater loss of function, and histological and molecular data indicate that this pathology is associated with significant apoptosis, but not major differences in cellular hypertrophy, fibrosis, and some major hypertrophic makers. Orai1 represents a crucial calcium entry mechanism in the compensation of the heart to pressure overload over-load, and the development of dilated cardiomyopathy.
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Affiliation(s)
- Jaime S Horton
- Laboratory of Experimental Medicine; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Cell & Molecular Biology; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA
| | - Cadie L Buckley
- Laboratory of Experimental Medicine; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Molecular Biosciences & Bioengineering; University of Hawaii; Honolulu, HI USA
| | - Ernest M Alvarez
- Laboratory of Experimental Medicine; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Cell & Molecular Biology; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA
| | - Anita Schorlemmer
- Laboratory of Experimental Medicine; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Molecular Biosciences & Bioengineering; University of Hawaii; Honolulu, HI USA
| | - Alexander J Stokes
- Laboratory of Experimental Medicine; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Cell & Molecular Biology; John A. Burns School of Medicine; University of Hawaii; Honolulu, HI USA; Department of Molecular Biosciences & Bioengineering; University of Hawaii; Honolulu, HI USA; Chaminade University; Honolulu, HI USA
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8
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Spindler MJ, Burmeister BT, Huang Y, Hsiao EC, Salomonis N, Scott MJ, Srivastava D, Carnegie GK, Conklin BR. AKAP13 Rho-GEF and PKD-binding domain deficient mice develop normally but have an abnormal response to β-adrenergic-induced cardiac hypertrophy. PLoS One 2013; 8:e62705. [PMID: 23658642 PMCID: PMC3637253 DOI: 10.1371/journal.pone.0062705] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 03/28/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND A-kinase anchoring proteins (AKAPs) are scaffolding molecules that coordinate and integrate G-protein signaling events to regulate development, physiology, and disease. One family member, AKAP13, encodes for multiple protein isoforms that contain binding sites for protein kinase A (PKA) and D (PKD) and an active Rho-guanine nucleotide exchange factor (Rho-GEF) domain. In mice, AKAP13 is required for development as null embryos die by embryonic day 10.5 with cardiovascular phenotypes. Additionally, the AKAP13 Rho-GEF and PKD-binding domains mediate cardiomyocyte hypertrophy in cell culture. However, the requirements for the Rho-GEF and PKD-binding domains during development and cardiac hypertrophy are unknown. METHODOLOGY/PRINCIPAL FINDINGS To determine if these AKAP13 protein domains are required for development, we used gene-trap events to create mutant mice that lacked the Rho-GEF and/or the protein kinase D-binding domains. Surprisingly, heterozygous matings produced mutant mice at Mendelian ratios that had normal viability and fertility. The adult mutant mice also had normal cardiac structure and electrocardiograms. To determine the role of these domains during β-adrenergic-induced cardiac hypertrophy, we stressed the mice with isoproterenol. We found that heart size was increased similarly in mice lacking the Rho-GEF and PKD-binding domains and wild-type controls. However, the mutant hearts had abnormal cardiac contractility as measured by fractional shortening and ejection fraction. CONCLUSIONS These results indicate that the Rho-GEF and PKD-binding domains of AKAP13 are not required for mouse development, normal cardiac architecture, or β-adrenergic-induced cardiac hypertrophic remodeling. However, these domains regulate aspects of β-adrenergic-induced cardiac hypertrophy.
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Affiliation(s)
- Matthew J Spindler
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, USA.
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9
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Baines AC, Adams EJ, Zhang B, Ginsburg D. Disruption of the Sec24d gene results in early embryonic lethality in the mouse. PLoS One 2013; 8:e61114. [PMID: 23596517 PMCID: PMC3626607 DOI: 10.1371/journal.pone.0061114] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Accepted: 03/04/2013] [Indexed: 11/19/2022] Open
Abstract
Transport of newly synthesized proteins from the endoplasmic reticulum (ER) to the Golgi is mediated by the coat protein complex COPII. The inner coat of COPII is assembled from heterodimers of SEC23 and SEC24. Though mice with mutations in one of the four Sec24 paralogs, Sec24b, exhibit a neural tube closure defect, deficiency in humans or mice has not yet been described for any of the other Sec24 paralogs. We now report characterization of mice with targeted disruption of Sec24d. Early embryonic lethality is observed in mice completely deficient in SEC24D, while a hypomorphic Sec24d allele permits survival to mid-embryogenesis. Mice haploinsufficient for Sec24d exhibit no phenotypic abnormality. A BAC transgene containing Sec24d rescues the embryonic lethality observed in Sec24d-null mice. These results demonstrate an absolute requirement for SEC24D expression in early mammalian development that is not compensated by the other three Sec24 paralogs. The early embryonic lethality resulting from loss of SEC24D in mice contrasts with the previously reported mild skeletal phenotype of SEC24D deficiency in zebrafish and restricted neural tube phenotype of SEC24B deficiency in mice. Taken together, these observations suggest that the multiple Sec24 paralogs have developed distinct functions over the course of vertebrate evolution.
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Affiliation(s)
- Andrea C. Baines
- Johns Hopkins Bayview Internal Medicine Residency Program, The Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Elizabeth J. Adams
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Bin Zhang
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - David Ginsburg
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Departments of Internal Medicine, Human Genetics, and Pediatrics and the Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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10
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Wang Y, Zhao L, Suzuki A, Lian L, Min SH, Wang Z, Litvinov RI, Stalker TJ, Yago T, Klopocki AG, Schmidtke DW, Yin H, Choi JK, McEver RP, Weisel JW, Hartwig JH, Abrams CS. Platelets lacking PIP5KIγ have normal integrin activation but impaired cytoskeletal-membrane integrity and adhesion. Blood 2013; 121:2743-52. [PMID: 23372168 PMCID: PMC3617636 DOI: 10.1182/blood-2012-07-445205] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 01/20/2013] [Indexed: 11/20/2022] Open
Abstract
Three isoforms of phosphatidylinositol-4-phosphate 5-kinase (PIP5KIα, PIP5KIβ, and PIP5KIγ) can each catalyze the final step in the synthesis of phosphatidylinositol-4,5-bisphosphate (PIP2), which in turn can be either converted to second messengers or bind directly to and thereby regulate proteins such as talin. A widely quoted model speculates that only p90, a longer splice form of platelet-specific PIP5KIγ, but not the shorter p87 PIP5KIγ, regulates the ligand-binding activity of integrins via talin. However, when we used mice genetically engineered to lack only p90 PIP5KIγ, we found that p90 PIP5KIγ is not critical for integrin activation or platelet adhesion on collagen. However, p90 PIP5KIγ-null platelets do have impaired anchoring of their integrins to the underlying cytoskeleton. Platelets lacking both the p90 and p87 PIP5KIγ isoforms had normal integrin activation and actin dynamics, but impaired anchoring of their integrins to the cytoskeleton. Most importantly, they formed weak shear-resistant adhesions ex vivo and unstable vascular occlusions in vivo. Together, our studies demonstrate that, although PIP5KIγ is essential for normal platelet function, individual isoforms of PIP5KIγ fulfill unique roles for the integrin-dependent integrity of the membrane cytoskeleton and for the stabilization of platelet adhesion.
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Affiliation(s)
- Yanfeng Wang
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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11
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Fan H, Zhao X, Sun S, Luo M, Guan JL. Function of focal adhesion kinase scaffolding to mediate endophilin A2 phosphorylation promotes epithelial-mesenchymal transition and mammary cancer stem cell activities in vivo. J Biol Chem 2012; 288:3322-33. [PMID: 23255596 DOI: 10.1074/jbc.m112.420497] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tyrosine kinases have been shown to play critical roles in cancer development and progression, and their inhibitors hold the potential as effective targeted therapies for breast and other cancers. However, some of these kinases like focal adhesion kinase (FAK) also possess scaffolding functions in intracellular signaling, but such kinase-independent functions of FAK or other kinases have not been examined in cancer directly in vivo. Here, we report that disruption of the function of FAK scaffolding through its Pro-878/881 motif suppressed mammary tumor growth and metastasis in a well characterized murine model of human breast cancer. P878A/P881A mutation in the endogenous FAK gene decreased the expression of markers for epithelial-mesenchymal transition (EMT) and mammary cancer stem cell (MaCSC) activities in tumors derived from mutant mice. This mutation disrupted the function of FAK scaffolding to mediate endophilin A2 phosphorylation at Tyr-315 by Src, leading to the decreased surface expression of MT1-MMP, as observed previously in transformed fibroblasts in vitro. Inhibition of the downstream components of this FAK scaffolding function by Y315F endophilin A2 mutant or MT1-MMP knockdown reduced markers for EMT and MaCSC activities. Conversely, bypass of the scaffolding function using the phosphorylation mimic mutant Y315E endophilin A2 or endophilin A2 knockdown rescued the decreased markers for EMT and MaCSCs as well as surface expression of MT1-MMP in tumor cells harboring the P878A/P881A mutation. Together, these results identify a novel role of FAK scaffolding function in breast cancer, which could serve as a new target in combination with kinase inhibition for more effective treatment strategies.
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Affiliation(s)
- Huaping Fan
- Division of Molecular Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-2200, USA
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12
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Onodera CS, Underwood JG, Katzman S, Jacobs F, Greenberg D, Salama SR, Haussler D. Gene isoform specificity through enhancer-associated antisense transcription. PLoS One 2012; 7:e43511. [PMID: 22937057 PMCID: PMC3427357 DOI: 10.1371/journal.pone.0043511] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 07/25/2012] [Indexed: 12/22/2022] Open
Abstract
Enhancers and antisense RNAs play key roles in transcriptional regulation through differing mechanisms. Recent studies have demonstrated that enhancers are often associated with non-coding RNAs (ncRNAs), yet the functional role of these enhancer:ncRNA associations is unclear. Using RNA-Sequencing to interrogate the transcriptomes of undifferentiated mouse embryonic stem cells (mESCs) and their derived neural precursor cells (NPs), we identified two novel enhancer-associated antisense transcripts that appear to control isoform-specific expression of their overlapping protein-coding genes. In each case, an enhancer internal to a protein-coding gene drives an antisense RNA in mESCs but not in NPs. Expression of the antisense RNA is correlated with expression of a shorter isoform of the associated sense gene that is not present when the antisense RNA is not expressed. We demonstrate that expression of the antisense transcripts as well as expression of the short sense isoforms correlates with enhancer activity at these two loci. Further, overexpression and knockdown experiments suggest the antisense transcripts regulate expression of their associated sense genes via cis-acting mechanisms. Interestingly, the protein-coding genes involved in these two examples, Zmynd8 and Brd1, share many functional domains, yet their antisense ncRNAs show no homology to each other and are not present in non-murine mammalian lineages, such as the primate lineage. The lack of homology in the antisense ncRNAs indicates they have evolved independently of each other and suggests that this mode of lineage-specific transcriptional regulation may be more widespread in other cell types and organisms. Our findings present a new view of enhancer action wherein enhancers may direct isoform-specific expression of genes through ncRNA intermediates.
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Affiliation(s)
- Courtney S. Onodera
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Jason G. Underwood
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Center for Biomolecular Sciences and Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Sol Katzman
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Center for Biomolecular Sciences and Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Frank Jacobs
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Center for Biomolecular Sciences and Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - David Greenberg
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Sofie R. Salama
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Center for Biomolecular Sciences and Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, United States of America
- * E-mail:
| | - David Haussler
- Department of Biomolecular Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Center for Biomolecular Sciences and Engineering, University of California Santa Cruz, Santa Cruz, California, United States of America
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, United States of America
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Large-scale identification of microRNA targets in murine Dgcr8-deficient embryonic stem cell lines. PLoS One 2012; 7:e41762. [PMID: 22912678 PMCID: PMC3422281 DOI: 10.1371/journal.pone.0041762] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 06/25/2012] [Indexed: 01/04/2023] Open
Abstract
Small RNAs such as microRNAs play important roles in embryonic stem cell maintenance and differentiation. A broad range of microRNAs is expressed in embryonic stem cells while only a fraction of their targets have been identified. We have performed large-scale identification of embryonic stem cell microRNA targets using a murine embryonic stem cell line deficient in the expression of Dgcr8. These cells are heavily depleted for microRNAs, allowing us to reintroduce specific microRNA duplexes and identify refined target sets. We used deep sequencing of small RNAs, mRNA expression profiling and bioinformatics analysis of microRNA seed matches in 3' UTRs to identify target transcripts. Consequently, we have identified a network of microRNAs that converge on the regulation of several important cellular pathways. Additionally, our experiments have revealed a novel candidate for Dgcr8-independent microRNA genesis and highlighted the challenges currently facing miRNA annotation.
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Yun EJ, Vu TH. mSmile is necessary for bronchial smooth muscle and alveolar myofibroblast development. Anat Rec (Hoboken) 2011; 295:167-76. [PMID: 21956870 DOI: 10.1002/ar.21475] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Revised: 05/31/2011] [Accepted: 07/06/2011] [Indexed: 11/10/2022]
Abstract
Disrupted lung alveolar myofibroblast and bronchial smooth muscle (BSM) cell development may lead to pulmonary disorders such as bronchopulmonary dysplasia. The molecular mechanisms that regulate BSM and alveolar myofibroblast development are not fully understood. Here we show that mSmile (murine Smile), a novel transmembrane protein with tetratricopeptide repeats, functions in lung alveolar myofibroblast and BSM cell development. mSmile mutant mice exhibit early neonatal lethality with few mice surviving up to 3 weeks. Mutant lungs display both airway branching morphogenesis defect during fetal lung development and alveolarization defect after birth. These defects are associated with reduced numbers of BSM cells in the peribronchial subepithelial region and clefts and myofibroblasts in alveolar septae. Expression of fibroblast growth factor-10 and its down stream target Bmp-4, which are important for BSM formation, is decreased. In vitro, mSmile mutant embryonic fibroblasts show reduced receptor activation and induction of myofibroblast formation in response to Transforming growth factor-β (Tgf-β), indicating that mSmile may mediate myofibroblast development through modulation of Tgf-β signaling. These studies identify mSmile as a novel gene specifying both the BSM and lung alveolar myofibroblast lineages, contributing to our understanding of the biological control of the development of these cells, and may provide insights into the aberrant smooth muscle and alveolar myofibroblast development that occur in pathological conditions.
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Affiliation(s)
- Eun Jun Yun
- Department of Medicine and Lung Biology Center, University of California, San Francisco, 94143-2911, USA
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15
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Hsiao EC, Nguyen TD, Ng JK, Scott MJ, Chang WC, Zahed H, Conklin BR. Constitutive Gs activation using a single-construct tetracycline-inducible expression system in embryonic stem cells and mice. Stem Cell Res Ther 2011; 2:11. [PMID: 21375737 PMCID: PMC3226282 DOI: 10.1186/scrt52] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Accepted: 03/04/2011] [Indexed: 01/19/2023] Open
Abstract
INTRODUCTION The controlled expression of many genes, including G-protein coupled receptors (GPCRs), is important for delineating gene functions in complex model systems. Binary systems for inducible regulation of transgene expression are widely used in mice. One system is the tTA/TRE expression system, composed of a tetracycline-dependent DNA binding factor and a separate tetracycline operon. However, the requirement for two separate transgenes (one for each tTA or TRE component) makes this system less amenable to models requiring directed cell targeting, increases the risk of multiple transgene integration sites, and requires extensive screening for appropriately-functioning clones. METHODS We developed a single, polycistronic tetracycline-inducible expression platform to control the expression of multiple cistrons in mammalian cells. This platform has three basic constructs: regulator, responder, and destination vectors. The modular platform is compatible with both the TetOff (tTA) and TetOn (rtTA) systems. The modular Gateway recombineering-compatible components facilitate rapidly generating vectors to genetically modify mammalian cells. We apply this system to use the elongation factor 1α (EF1α) promoter to drive doxycycline-regulated expression of both the fluorescent marker mCherry and an engineered Gs-coupled GPCR "Rs1" separated by a 2A ribosomal skip site. RESULTS We show that our combined expression construct drives expression of both the mCherry and Rs1 transgenes in a doxycycline-dependent manner. We successfully target the expression construct into the Rosa26 locus of mouse embryonic stem (ES) cells. Rs1 expression in mouse ES cells increases cAMP accumulation via both basal and ligand-induced Gs mechanisms and is associated with increased embryoid body size. Heterozygous mice carrying the Rs1 expression construct showed normal growth and weight, and developed small increases in bone formation that could be observed in the calvaria. CONCLUSIONS Our results demonstrate the feasibility of a single-vector strategy that combines both the tTA and TRE tetracycline-regulated components for use in cells and mouse models. Although the EF1α promoter is useful for driving expression in pluripotent cells, a single copy of the EF1α promoter did not drive high levels of mCherry and Rs1 expression in the differentiated tissues of adult mice. These findings indicate that promoter selection is an important factor when developing transgene expression models.
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Affiliation(s)
- Edward C Hsiao
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St., San Francisco, CA 94158, USA
- Division of Endocrinology and Metabolism, Department of Medicine, 400 Parnassus Ave., University of California, San Francisco, CA 94143-1222, USA
| | - Trieu D Nguyen
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St., San Francisco, CA 94158, USA
| | - Jennifer K Ng
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St., San Francisco, CA 94158, USA
| | - Mark J Scott
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St., San Francisco, CA 94158, USA
| | - Wei Chun Chang
- Department of Cellular and Molecular Pharmacology, 600 16th Street Rm. S-222, University of California, San Francisco, CA 94158-2140, USA
| | - Hengameh Zahed
- Gladstone Institute of Neurological Disease, 1650 Owens St., San Francisco, CA 94158, USA
- Biomedical Sciences Graduate Program, 513 Parnassus Ave. Rm. HSE-1285, University of California, San Francisco, CA 94158-0505, USA
| | - Bruce R Conklin
- Gladstone Institute of Cardiovascular Disease, 1650 Owens St., San Francisco, CA 94158, USA
- Department of Medicine, 505 Parnassus Ave., University of California, San Francisco, CA 94143, USA
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16
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Underwood JG, Uzilov AV, Katzman S, Onodera CS, Mainzer JE, Mathews DH, Lowe TM, Salama SR, Haussler D. FragSeq: transcriptome-wide RNA structure probing using high-throughput sequencing. Nat Methods 2010; 7:995-1001. [PMID: 21057495 PMCID: PMC3247016 DOI: 10.1038/nmeth.1529] [Citation(s) in RCA: 242] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 10/13/2010] [Indexed: 01/07/2023]
Abstract
Previous efforts to determine structures of non-coding RNA (ncRNA) probed only one RNA at a time with enzymes and chemicals, using gel electrophoresis to identify reactive positions. To accelerate RNA structure inference, we have developed FragSeq, a high-throughput RNA structure probing method that uses high-throughput RNA sequencing on fragments generated by nuclease P1, which specifically cleaves single stranded nucleic acids. In experiments probing the entire mouse nuclear transcriptome, we show that we can accurately and simultaneously map single-stranded regions (ssRNA) in multiple ncRNAs with known structure. We carried out probing in two cell types to demonstrate reproducibility. We also identified and experimentally validated structured regions in ncRNAs never previously probed.
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Affiliation(s)
- Jason G Underwood
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, California, USA
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17
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Glypican-1, phosphacan/receptor protein-tyrosine phosphatase-ζ/β and its ligand, tenascin-C, are expressed by neural stem cells and neural cells derived from embryonic stem cells. ASN Neuro 2010; 2:e00039. [PMID: 20689858 PMCID: PMC2914431 DOI: 10.1042/an20100001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 05/11/2010] [Accepted: 05/26/2010] [Indexed: 12/01/2022] Open
Abstract
The heparan sulfate proteoglycan glypican-1, the chondroitin sulfate proteoglycan
phosphacan/RPTP (receptor protein-tyrosine
phosphatase)-ζ/β and the extracellular matrix protein
tenascin-C were all found to be expressed by neural stem cells and by neural
cells derived from them. Expression of proteoglycans and tenascin-C increased
after retinoic acid induction of SSEA1-positive ES (embryonic stem) cells to
nestin-positive neural stem cells, and after neural differentiation,
proteoglycans and tenascin-C are expressed by both neurons and astrocytes, where
they surround cell bodies and processes and in certain cases show distinctive
expression patterns. With the exception of tenascin-C (whose expression may
decrease somewhat), expression levels do not change noticeably during the
following 2 weeks in culture. The significant expression, by neural stem cells
and neurons and astrocytes derived from them, of two major heparan sulfate and
chondroitin sulfate proteoglycans of nervous tissue and of tenascin-C, a
high-affinity ligand of phosphacan/RPTP-ζ/β, indicates
that an understanding of their specific functional roles in stem cell
neurobiology will be important for the therapeutic application of this new
technology in facilitating nervous tissue repair and regeneration.
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18
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Zhao X, Peng X, Sun S, Park AY, Guan JL. Role of kinase-independent and -dependent functions of FAK in endothelial cell survival and barrier function during embryonic development. J Cell Biol 2010; 189:955-65. [PMID: 20530207 PMCID: PMC2886345 DOI: 10.1083/jcb.200912094] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 05/13/2010] [Indexed: 11/22/2022] Open
Abstract
Focal adhesion kinase (FAK) is essential for vascular development as endothelial cell (EC)-specific knockout of FAK (conditional FAK knockout [CFKO] mice) leads to embryonic lethality. In this study, we report the differential kinase-independent and -dependent functions of FAK in vascular development by creating and analyzing an EC-specific FAK kinase-defective (KD) mutant knockin (conditional FAK knockin [CFKI]) mouse model. CFKI embryos showed apparently normal development through embryonic day (E) 13.5, whereas the majority of CFKO embryos died at the same stage. Expression of KD FAK reversed increased EC apoptosis observed with FAK deletion in embryos and in vitro through suppression of up-regulated p21. However, vessel dilation and defective angiogenesis of CFKO embryos were not rescued in CFKI embryos. ECs without FAK or expressing KD FAK showed increased permeability, abnormal distribution of vascular endothelial cadherin (VE-cadherin), and reduced VE-cadherin Y658 phosphorylation. Together, our data suggest that kinase-independent functions of FAK can support EC survival in vascular development through E13.5 but are insufficient for maintaining EC function to allow for completion of embryogenesis.
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Affiliation(s)
- Xiaofeng Zhao
- Division of Molecular Medicine and Genetics, Department of Internal Medicine and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
- Graduate Field of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, NY 14853
| | - Xu Peng
- Division of Molecular Medicine and Genetics, Department of Internal Medicine and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Shaogang Sun
- Division of Molecular Medicine and Genetics, Department of Internal Medicine and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Ann Y.J. Park
- Division of Molecular Medicine and Genetics, Department of Internal Medicine and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Jun-Lin Guan
- Division of Molecular Medicine and Genetics, Department of Internal Medicine and Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
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19
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Galvin KE, Travis ED, Yee D, Magnuson T, Vivian JL. Nodal signaling regulates the bone morphogenic protein pluripotency pathway in mouse embryonic stem cells. J Biol Chem 2010; 285:19747-56. [PMID: 20427282 DOI: 10.1074/jbc.m109.077347] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Members of the transforming growth factor-beta superfamily play essential roles in both the pluripotency and differentiation of embryonic stem (ES) cells. Although bone morphogenic proteins (BMPs) maintain pluripotency of undifferentiated mouse ES cells, the role of autocrine Nodal signaling is less clear. Pharmacological, molecular, and genetic methods were used to further understand the roles and potential interactions of these pathways. Treatment of undifferentiated ES cells with SB431542, a pharmacological inhibitor of Smad2 signaling, resulted in a rapid reduction of phosphorylated Smad2 and altered the expression of several putative downstream targets. Unexpectedly, inhibition of the Nodal signaling pathway resulted in enhanced BMP signaling, as assessed by Smad1/5 phosphorylation. SB431542-treated cells also demonstrated significant induction of the Id genes, which are known direct targets of BMP signaling and important factors in ES cell pluripotency. Inhibition of BMP signaling decreased the SB431542-mediated phosphorylation of Smad1/5 and induction of Id genes, suggesting that BMP signaling is necessary for some Smad2-mediated activity. Because Smad7, a known inhibitory factor to both Nodal and BMP signaling, was down-regulated following inhibition of Nodal-Smad2 signaling, the contribution of Smad7 to the cross-talk between the transforming growth factor-beta pathways in ES cells was examined. Biochemical manipulation of Smad7 expression, through shRNA knockdown or inducible gene expression, significantly reduced the SB431542-mediated phosphorylation of Smad1/5 and induction of the Id genes. We conclude that autocrine Nodal signaling in undifferentiated mouse ES cells modulates the vital pluripotency pathway of BMP signaling.
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Affiliation(s)
- Katherine E Galvin
- Department of Pathology and Laboratory Medicine and Division of Cancer and Developmental Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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20
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Abaskharoun M, Bellemare M, Lau E, Margolis RU. Expression of hyaluronan and the hyaluronan-binding proteoglycans neurocan, aggrecan, and versican by neural stem cells and neural cells derived from embryonic stem cells. Brain Res 2010; 1327:6-15. [PMID: 20176001 DOI: 10.1016/j.brainres.2010.02.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 02/09/2010] [Accepted: 02/12/2010] [Indexed: 01/16/2023]
Abstract
We have examined the expression and localization patterns of hyaluronan and hyaluronan-binding chondroitin sulfate proteoglycans in neural stem cells and differentiated neural cells derived from mouse embryonic stem cells. Expression of proteoglycans and hyaluronan was weak in the SSEA1-positive embryonic stem cells but increased noticeably after retinoic acid induction to nestin-positive neural stem cells. After subsequent plating, the hyaluronan-binding chondroitin sulfate proteoglycans aggrecan, neurocan, and versican are expressed by cells in both the astrocytic and neuronal lineages. During the time period that hyaluronan was present, it co-localized with each of the hyaluronan-binding proteoglycans studied and was found to be clearly associated with beta-III tubulin-expressing neurons and oligodendrocytes expressing the O4 sulfatide marker. Although proteoglycan expression levels increased to varying degrees following neural differentiation, they did not change noticably during the following 2 weeks in culture, but there was a significant decrease in hyaluronan expression. Our studies therefore demonstrate the expression by neural stem cells and neural cells derived from them of hyaluronan and its associated proteoglycans, thereby providing a necessary foundation for integrating their specific properties into developing strategies for therapeutic applications.
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Affiliation(s)
- Mary Abaskharoun
- Department of Pharmacology, New York University Medical Center, 550 First Avenue, New York, NY 10016, USA
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21
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Schebelle L, Wolf C, Stribl C, Javaheri T, Schnütgen F, Ettinger A, Ivics Z, Hansen J, Ruiz P, von Melchner H, Wurst W, Floss T. Efficient conditional and promoter-specific in vivo expression of cDNAs of choice by taking advantage of recombinase-mediated cassette exchange using FlEx gene traps. Nucleic Acids Res 2010; 38:e106. [PMID: 20139417 PMCID: PMC2875000 DOI: 10.1093/nar/gkq044] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Recombinase-mediated cassette exchange (RMCE) exploits the possibility to unidirectionally exchange any genetic material flanked by heterotypic recombinase recognition sites (RRS) with target sites in the genome. Due to a limited number of available pre-fabricated target sites, RMCE in mouse embryonic stem (ES) cells has not been tapped to its full potential to date. Here, we introduce a universal system, which allows the targeted insertion of any given transcriptional unit into 85 742 previously annotated retroviral conditional gene trap insertions, representing 7013 independent genes in mouse ES cells, by RMCE. This system can be used to express any given cDNA under the control of endogenous trapped promoters in vivo, as well as for the generation of transposon ‘launch pads’ for chromosomal region-specific ‘Sleeping Beauty’ insertional mutagenesis. Moreover, transcription of the gene-of-interest is only activated upon Cre-recombinase activity, a feature that adds conditionality to this expression system, which is demonstrated in vivo. The use of the RMCE system presented in this work requires one single-cloning step followed by one overnight gateway clonase reaction and subsequent cassette exchange in ES cells with efficiencies of 40% in average.
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Affiliation(s)
- Laura Schebelle
- Helmholtz Zentrum München, Technische Universität München, Institut für Entwicklungsgenetik, Ingolstädter Landstrasse 1, 85764 München, Neuherberg, Germany
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22
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Aurora-A kinase is essential for bipolar spindle formation and early development. Mol Cell Biol 2008; 29:1059-71. [PMID: 19075002 DOI: 10.1128/mcb.01062-08] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Aurora-A is a conserved kinase implicated in mitotic regulation and carcinogenesis. Aurora-A was previously implicated in mitotic entry and spindle assembly, although contradictory results prevented a clear understanding of the roles of Aurora-A in mammals. We developed a conditional null mutation in the mouse Aurora-A gene to investigate Aurora-A functions in primary cells ex vivo and in vivo. We show here that conditional Aurora-A ablation in cultured embryonic fibroblasts causes impaired mitotic entry and mitotic arrest with a profound defect in bipolar spindle formation. Germ line Aurora-A deficiency causes embryonic death at the blastocyst stage with pronounced cell proliferation failure, mitotic arrest, and monopolar spindle formation. Aurora-A deletion in mid-gestation embryos causes an increase in mitotic and apoptotic cells. These results indicate that murine Aurora-A facilitates, but is not absolutely required for, mitotic entry in murine embryonic fibroblasts and is essential for centrosome separation and bipolar spindle formation in vitro and in vivo. Aurora-A deletion increases apoptosis, suggesting that molecular therapies targeting Aurora-A may be effective in inducing tumor cell apoptosis. Aurora-A conditional mutant mice provide a valuable system for further defining Aurora-A functions and for predicting effects of Aurora-A therapeutic intervention.
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23
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MacFarlane AJ, Perry CA, Girnary HH, Gao D, Allen RH, Stabler SP, Shane B, Stover PJ. Mthfd1 is an essential gene in mice and alters biomarkers of impaired one-carbon metabolism. J Biol Chem 2008; 284:1533-9. [PMID: 19033438 DOI: 10.1074/jbc.m808281200] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytoplasmic folate-mediated one carbon (1C) metabolism functions to carry and activate single carbons for the de novo synthesis of purines, thymidylate, and for the remethylation of homocysteine to methionine. C1 tetrahydrofolate (THF) synthase, encoded by Mthfd1, is an entry point of 1Cs into folate metabolism through its formyl-THF synthetase (FTHFS) activity that catalyzes the ATP-dependent conversion of formate and THF to 10-formyl-THF. Disruption of FTHFS activity by the insertion of a gene trap vector into the Mthfd1 gene results in embryonic lethality in mice. Mthfd1gt/+ mice demonstrated lower hepatic adenosylmethionine levels, which is consistent with formate serving as a source of 1Cs for cellular methylation reactions. Surprisingly, Mthfd1gt/+ mice exhibited decreased levels of uracil in nuclear DNA, indicating enhanced de novo thymidylate synthesis, and suggesting that serine hydroxymethyltransferase and FTHFS compete for a limiting pool of unsubstituted THF. This study demonstrates the essentiality of the Mthfd1 gene and indicates that formate-derived 1Cs are utilized for de novo purine synthesis and the remethylation of homocysteine in liver. Further, the depletion of cytoplasmic FTHFS activity enhances thymidylate synthesis, affirming the competition between thymidylate synthesis and homocysteine remethylation for THF cofactors.
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Affiliation(s)
- Amanda J MacFarlane
- Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA
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Loss of PIP5KIbeta demonstrates that PIP5KI isoform-specific PIP2 synthesis is required for IP3 formation. Proc Natl Acad Sci U S A 2008; 105:14064-9. [PMID: 18772378 DOI: 10.1073/pnas.0804139105] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The three isoforms of PIP5KI (alpha, beta, and gamma) synthesize PI4,5P(2) (PIP(2)) by phosphorylating PI4P. Therefore, it is not clear why platelets, like all eukaryotic cells, have more than one isoform. To test the hypothesis that PIP5KI isoforms have nonoverlapping functions, we generated a murine line containing a null mutation of PIP5KIbeta and analyzed the effect on platelet signaling. PIP5KIbeta-null mice had normal platelet counts. In contrast to platelets lacking PIP5KIalpha, platelets lacking PIP5KIbeta exhibited impaired aggregation accompanied by disaggregation. Although platelets lacking PIP5KIbeta had only a moderate deficiency of PIP(2) under basal conditions, they had a striking deficiency in PIP(2) synthesis and IP(3) formation after thrombin stimulation. We have also observed that platelets lacking both PIP5KIalpha and PIP5KIbeta have a complete loss of thrombin-induced IP(3) synthesis even though they still contain PIP5KIgamma, the predominant PIP5KI isoform in platelets. These results demonstrate that PIP5KIbeta, like PIP5KIalpha, contributes to the rapid synthesis of a pool of PIP(2) that is required for second-messenger formation, whereas the pool of PIP(2) synthesized by PIP5KIgamma does not contribute to this process. Additionally, we found that PIP5KIbeta-null platelets failed to form arterial thrombi properly in vivo. Together, these data demonstrate that PIP5KIbeta is required for rapid PIP(2) synthesis, second-messenger production, and stable platelet adhesion under shear in vivo. These results also demonstrate that after stimulation of a G protein-coupled receptor, IP(3) is completely derived from a rapidly synthesized discrete pool of PIP(2) synthesized by PIP5KIalpha and PIP5KIbeta.
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Hsiao EC, Yoshinaga Y, Nguyen TD, Musone SL, Kim JE, Swinton P, Espineda I, Manalac C, deJong PJ, Conklin BR. Marking embryonic stem cells with a 2A self-cleaving peptide: a NKX2-5 emerald GFP BAC reporter. PLoS One 2008; 3:e2532. [PMID: 18596956 PMCID: PMC2430532 DOI: 10.1371/journal.pone.0002532] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 05/23/2008] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Fluorescent reporters are useful for assaying gene expression in living cells and for identifying and isolating pure cell populations from heterogeneous cultures, including embryonic stem (ES) cells. Multiple fluorophores and genetic selection markers exist; however, a system for creating reporter constructs that preserve the regulatory sequences near a gene's native ATG start site has not been widely available. METHODOLOGY Here, we describe a series of modular marker plasmids containing independent reporter, bacterial selection, and eukaryotic selection components, compatible with both Gateway recombination and lambda prophage bacterial artificial chromosome (BAC) recombineering techniques. A 2A self-cleaving peptide links the reporter to the native open reading frame. We use an emerald GFP marker cassette to create a human BAC reporter and ES cell reporter line for the early cardiac marker NKX2-5. NKX2-5 expression was detected in differentiating mouse ES cells and ES cell-derived mice. CONCLUSIONS Our results describe a NKX2-5 ES cell reporter line for studying early events in cardiomyocyte formation. The results also demonstrate that our modular marker plasmids could be used for generating reporters from unmodified BACs, potentially as part of an ES cell reporter library.
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Affiliation(s)
- Edward C Hsiao
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America.
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Shafee N, Smith CR, Wei S, Kim Y, Mills GB, Hortobagyi GN, Stanbridge EJ, Lee EYHP. Cancer stem cells contribute to cisplatin resistance in Brca1/p53-mediated mouse mammary tumors. Cancer Res 2008; 68:3243-50. [PMID: 18451150 PMCID: PMC2929908 DOI: 10.1158/0008-5472.can-07-5480] [Citation(s) in RCA: 227] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The majority of BRCA1-associated breast cancers are basal cell-like, which is associated with a poor outcome. Using a spontaneous mouse mammary tumor model, we show that platinum compounds, which generate DNA breaks during the repair process, are more effective than doxorubicin in Brca1/p53-mutated tumors. At 0.5 mg/kg of daily cisplatin treatment, 80% primary tumors (n = 8) show complete pathologic response. At greater dosages, 100% show complete response (n = 19). However, after 2 to 3 months of complete remission following platinum treatment, tumors relapse and become refractory to successive rounds of treatment. Approximately 3.8% to 8.0% (mean, 5.9%) of tumor cells express the normal mammary stem cell markers, CD29(hi)24(med), and these cells are tumorigenic, whereas CD29(med)24(-/lo) and CD29(med)24(hi) cells have diminished tumorigenicity or are nontumorigenic, respectively. In partially platinum-responsive primary transplants, 6.6% to 11.0% (mean, 8.8%) tumor cells are CD29(hi)24(med); these populations significantly increase to 16.5% to 29.2% (mean, 22.8%; P < 0.05) in platinum-refractory secondary tumor transplants. Further, refractory tumor cells have greater colony-forming ability than the primary transplant-derived cells in the presence of cisplatin. Expression of a normal stem cell marker, Nanog, is decreased in the CD29(hi)24(med) populations in the secondary transplants. Top2A expression is also down-regulated in secondary drug-resistant tumor populations and, in one case, was accompanied by genomic deletion of Top2A. These studies identify distinct cancer cell populations for therapeutic targeting in breast cancer and implicate clonal evolution and expansion of cancer stem-like cells as a potential cause of chemoresistance.
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Affiliation(s)
- Norazizah Shafee
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, California
| | - Christopher R. Smith
- Department of Biological Chemistry and Developmental and Cell Biology, College of Medicine, University of California, Irvine, California
| | - Shuanzeng Wei
- Department of Biological Chemistry and Developmental and Cell Biology, College of Medicine, University of California, Irvine, California
| | - Yoon Kim
- Department of Biological Chemistry and Developmental and Cell Biology, College of Medicine, University of California, Irvine, California
| | - Gordon B. Mills
- Department of System Biology, University of Texas M. D. Anderson Cancer Center, Houston, Texas,Department of Breast Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Gabriel N. Hortobagyi
- Department of Breast Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas
| | - Eric J. Stanbridge
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Irvine, California
| | - Eva Y-H. P. Lee
- Department of Biological Chemistry and Developmental and Cell Biology, College of Medicine, University of California, Irvine, California
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ES cell pluripotency and germ-layer formation require the SWI/SNF chromatin remodeling component BAF250a. Proc Natl Acad Sci U S A 2008; 105:6656-61. [PMID: 18448678 DOI: 10.1073/pnas.0801802105] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
ATP-dependent chromatin remodeling complexes are a notable group of epigenetic modifiers that use the energy of ATP hydrolysis to change the structure of chromatin, thereby altering its accessibility to nuclear factors. BAF250a (ARID1a) is a unique and defining subunit of the BAF chromatin remodeling complex with the potential to facilitate chromosome alterations critical during development. Our studies show that ablation of BAF250a in early mouse embryos results in developmental arrest (about embryonic day 6.5) and absence of the mesodermal layer, indicating its critical role in early germ-layer formation. Moreover, BAF250a deficiency compromises ES cell pluripotency, severely inhibits self-renewal, and promotes differentiation into primitive endoderm-like cells under normal feeder-free culture conditions. Interestingly, this phenotype can be partially rescued by the presence of embryonic fibroblast cells. DNA microarray, immunostaining, and RNA analyses revealed that BAF250a-mediated chromatin remodeling contributes to the proper expression of numerous genes involved in ES cell self-renewal, including Sox2, Utf1, and Oct4. Furthermore, the pluripotency defects in BAF250a mutant ES cells appear to be cell lineage-specific. For example, embryoid body-based analyses demonstrated that BAF250a-ablated stem cells are defective in differentiating into fully functional mesoderm-derived cardiomyocytes and adipocytes but are capable of differentiating into ectoderm-derived neurons. Our results suggest that BAF250a is a key component of the gene regulatory machinery in ES cells controlling self-renewal, differentiation, and cell lineage decisions.
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Wang Y, Litvinov RI, Chen X, Bach TL, Lian L, Petrich BG, Monkley SJ, Kanaho Y, Critchley DR, Sasaki T, Birnbaum MJ, Weisel JW, Hartwig J, Abrams CS. Loss of PIP5KIgamma, unlike other PIP5KI isoforms, impairs the integrity of the membrane cytoskeleton in murine megakaryocytes. J Clin Invest 2008; 118:812-9. [PMID: 18188447 DOI: 10.1172/jci34239] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Accepted: 11/26/2007] [Indexed: 01/11/2023] Open
Abstract
Phosphatidylinositol-4,5-bisphosphate (PIP(2)) is an abundant phospholipid that contributes to second messenger formation and has also been shown to contribute to the regulation of cytoskeletal dynamics in all eukaryotic cells. Although the alpha, beta, and gamma isoforms of phosphatidylinositol-4-phosphate-5-kinase I (PIP5KI) all synthesize PIP2, mammalian cells usually contain more than one PIP5KI isoform. This raises the question of whether different isoforms of PIP5KI fulfill different functions. Given the speculated role of PIP(2) in platelet and megakaryocyte actin dynamics, we analyzed murine megakaryocytes lacking individual PIP5KI isoforms. PIP5KIgamma(-/-) megakaryocytes exhibited plasma membrane blebbing accompanied by a decreased association of the membrane with the cytoskeleton. This membrane defect was rescued by adding back wild-type PIP5KIgamma, but not by adding a catalytically inactive mutant or a splice variant lacking the talin-binding motif. Notably, both PIP5KIbeta- and PIP5KIgamma(-/-) cells had impaired PIP(2) synthesis. However, PIP5KIbeta-null cells lacked the membrane-cytoskeleton defect. Furthermore, overexpressing PIP5KIbeta in PIP5KIgamma(-/-) cells failed to revert this defect. Megakaryocytes lacking the PIP5KIgamma-binding partner, talin1, mimicked the membrane-cytoskeleton defect phenotype seen in PIP5KIgamma(-/-) cells. These findings demonstrate a unique role for PIP5KIgamma in the anchoring of the cell membrane to the cytoskeleton in megakaryocytes, probably through a pathway involving talin. These observations further demonstrate that individual PIP5KI isoforms fulfill distinct functions within cells.
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Affiliation(s)
- Yanfeng Wang
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Defective mast cell effector functions in mice lacking the CRACM1 pore subunit of store-operated calcium release-activated calcium channels. Nat Immunol 2007; 9:89-96. [PMID: 18059270 DOI: 10.1038/ni1550] [Citation(s) in RCA: 333] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 11/12/2007] [Indexed: 01/04/2023]
Abstract
CRACM1 (also called Orai1) constitutes the pore subunit of store-operated calcium release-activated calcium channels. A point mutation in the gene encoding CRACM1 is associated with severe combined immunodeficiency disease in humans. Here we generated CRACM1-deficient mice in which beta-galactosidase activity 'reported' CRACM1 expression. CRACM1-deficient mice were smaller in size. Mast cells derived from CRACM1-deficient mice showed grossly defective degranulation and cytokine secretion, and the allergic reactions elicited in vivo were inhibited in CRACM1-deficient mice. We detected robust CRACM1 expression in skeletal muscles and some regions of the brain, heart and kidney but not in the lymphoid regions of thymus and spleen. In contrast, we found CRACM2 expression to be much higher in mouse T cells. In agreement with those findings, the store-operated calcium influx and development and proliferation of CRACM1-deficient T cells was unaffected. Thus, CRACM1 is crucial in mouse mast cell effector function, but mouse T cell calcium release-activated calcium channels are functional in the absence of CRACM1.
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Abstract
The plasma kallikrein-kinin system consists of the proteins factor XII (FXII), prekallikrein (PK), and high molecular weight kininogen. It was first recognized as a surface-activated coagulation system that is activated when blood or plasma interacts with artificial surfaces. Although surface-activated contact activation occurs in vivo in the case of tissue destruction or a developing thrombus, the physiologic basis for the activation and function of this system has not been delineated. New investigations indicate that there is a proteolytic pathway on cells for PK activation independent of FXII. This pathway for PK with subsequent FXII activation indicates physiologic activities. These activities include blood pressure regulation and modulation of thrombosis risk independently of hemostasis. Furthermore, they include regulation of endothelial cell proliferation, angiogenesis and apoptosis through a cellular-based, outside-in signaling system. The present characterizations of this system, which incorrectly had been thought to initiate coagulation, represent an evolution of understanding in this field.
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Affiliation(s)
- A H Schmaier
- Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University and University Hospitals Case Medical Center, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
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Elliott AM, de Miguel MP, Rebel VI, Donovan PJ. Identifying genes differentially expressed between PGCs and ES cells reveals a role for CREB-binding protein in germ cell survival. Dev Biol 2007; 311:347-58. [DOI: 10.1016/j.ydbio.2007.08.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 08/11/2007] [Accepted: 08/14/2007] [Indexed: 12/30/2022]
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Hughes ED, Qu YY, Genik SJ, Lyons RH, Pacheco CD, Lieberman AP, Samuelson LC, Nasonkin IO, Camper SA, Van Keuren ML, Saunders TL. Genetic variation in C57BL/6 ES cell lines and genetic instability in the Bruce4 C57BL/6 ES cell line. Mamm Genome 2007; 18:549-58. [PMID: 17828574 DOI: 10.1007/s00335-007-9054-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Accepted: 05/09/2007] [Indexed: 01/12/2023]
Abstract
Genetically modified mouse strains derived from embryonic stem (ES) cells are powerful tools for gene function analysis. ES cells from the C57BL/6 mouse strain are not widely used to generate mouse models despite the advantage of a defined genetic background. We assessed genetic variation in six such ES cell lines with 275 SSLP markers. Compared to C57BL/6, Bruce4 differed at 34 SSLP markers and had significant heterozygosity on three chromosomes. BL/6#3 and Dale1 ES cell lines differed at only 3 SSLP makers. The C2 and WB6d ES cell lines differed at 6 SSLP markers. It is important to compare the efficiency of producing mouse models with available C57BL/6 ES cells relative to standard 129 mouse strain ES cells. We assessed genetic stability (the tendency of cells to become aneuploid) in 110 gene-targeted ES cell clones from the most widely used C57BL/6 ES cell line, Bruce4, and 710 targeted 129 ES cell clones. Bruce4 clones were more likely to be aneuploid and unsuitable for ES cell-mouse chimera production. Despite their tendency to aneuploidy and consequent inefficiency, use of Bruce4 ES cells can be valuable for models requiring behavioral studies and other mouse models that benefit from a defined C57BL/6 background.
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Affiliation(s)
- Elizabeth D Hughes
- Transgenic Animal Model Core, Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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Assembly, activation, and physiologic influence of the plasma kallikrein/kinin system. Int Immunopharmacol 2007; 8:161-5. [PMID: 18182220 DOI: 10.1016/j.intimp.2007.08.022] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/24/2007] [Accepted: 08/28/2007] [Indexed: 01/09/2023]
Abstract
The plasma kallikrein/kinin system that consists of the proteins factor XII, prekallikrein, and high molecular weight kininogen was first recognized as a surface-activated coagulation system arising when blood or plasma interacts with artificial surfaces. Although surface-activated contact activation occurs in vivo when various negatively charged surfaces become exposed, including a developing platelet thrombus, a physiologic, non-injury mechanism for activation, regulation, and function of this system has been elusive. Recent investigations have shown that there is a physiologic pathway for assembly and activation of this system independent of factor XII. Gene deficient mice of the bradykinin B2 receptor and factor XII have been recognized to have reduced risk for arterial thrombosis. This plasma proteolytic system influences arterial thrombosis independent of influencing hemostasis. Thus, the plasma kallikrein/kinin system has two mechanisms for its activation: one that is dependent and another independent of factor XII. Better understanding of this system may lead to insight into mechanisms for arterial thrombosis, independent of hemostasis.
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Li X, Leder P. Identifying genes preferentially expressed in undifferentiated embryonic stem cells. BMC Cell Biol 2007; 8:37. [PMID: 17725840 PMCID: PMC1995199 DOI: 10.1186/1471-2121-8-37] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Accepted: 08/28/2007] [Indexed: 12/28/2022] Open
Abstract
Background The mechanism involved in the maintenance and differentiation of embryonic stem (ES) cells is incompletely understood. Results To address this issue, we have developed a retroviral gene trap vector that can target genes expressed in undifferentiated ES cells. This gene trap vector harbors both GFP and Neo reporter genes. G-418 drug resistance was used to select ES clones in which the vector was integrated into transcriptionally active loci. This was then followed by GFP FACS profiling to identify ES clones with reduced GFP fluorescence and, hence, reduced transcriptional activity when ES cells differentiate. Reduced expression of the GFP reporter in six of three hundred ES clones in our pilot screening was confirmed to be down-regulated by Northern blot analysis during ES cell differentiation. These six ES clones represent four different genes. Among the six integration sites, one was at Zfp-57 whose gene product is known to be enriched in undifferentiated ES cells. Three were located in an intron of a novel isoform of CSL/RBP-Jkappa which encodes the key transcription factor of the LIN-12/Notch pathway. Another was inside a gene that may encode noncoding RNA transcripts. The last integration event occurred at a locus that may harbor a novel gene. Conclusion Taken together, we demonstrate the use of a novel retroviral gene trap vector in identifying genes preferentially expressed in undifferentiated ES cells.
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Affiliation(s)
- Xiajun Li
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Philip Leder
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
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Wang Y, Lian L, Golden JA, Morrisey EE, Abrams CS. PIP5KI gamma is required for cardiovascular and neuronal development. Proc Natl Acad Sci U S A 2007; 104:11748-53. [PMID: 17609388 PMCID: PMC1913884 DOI: 10.1073/pnas.0700019104] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
All eukaryotic cells contain the phospholipid phosphatidylinositol 4, 5-bisphosphate (PIP2) that serves multiple roles in signal transduction cascades. Type I phosphatidylinositol-4-phosphate 5-kinase (PIP5KI) catalyzes the synthesis of PIP2 by phosphorylating phosphatidylinositol 4 phosphate. Although the classical isoforms of PIP5KI (designated as alpha, beta, and gamma) all generate the same phospholipid product, they have significantly dissimilar primary structures and expression levels in different tissues, and they appear to localize within different compartments within the cell. Therefore, it appears likely that PIP5KI isoforms have overlapping, but not identical, functions. Here we show that targeted disruption of PIP5KIgamma causes widespread developmental and cellular defects. PIP5KIgamma-null embryos have myocardial developmental defects associated with impaired intracellular junctions that lead to heart failure and extensive prenatal lethality at embryonic day 11.5 of development. Loss of PIP5KIgamma also results in neural tube closure defects that were associated with impaired PIP2 production, adhesion junction formation, and neuronal cell migration. These data, along with those of other PIP5KI isoforms, indicate that individual PIP5KI isoenzymes fulfill specific roles in embryonic development.
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Affiliation(s)
| | | | | | | | - Charles S. Abrams
- Departments of *Medicine and
- To whom correspondence should be addressed. E-mail:
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Tingley WG, Pawlikowska L, Zaroff JG, Kim T, Nguyen T, Young SG, Vranizan K, Kwok PY, Whooley MA, Conklin BR. Gene-trapped mouse embryonic stem cell-derived cardiac myocytes and human genetics implicate AKAP10 in heart rhythm regulation. Proc Natl Acad Sci U S A 2007; 104:8461-6. [PMID: 17485678 PMCID: PMC1866184 DOI: 10.1073/pnas.0610393104] [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: 11/18/2022] Open
Abstract
Sudden cardiac death due to abnormal heart rhythm kills 400,000-460,000 Americans each year. To identify genes that regulate heart rhythm, we are developing a screen that uses mouse embryonic stem cells (mESCs) with gene disruptions that can be differentiated into cardiac cells for phenotyping. Here, we show that the heterozygous disruption of the Akap10 (D-AKAP2) gene that disrupts the final 51 aa increases the contractile response of cultured cardiac cells to cholinergic signals. In both heterozygous and homozygous mutant mice derived from these mESCs, the same Akap10 disruption increases the cardiac response to cholinergic signals, suggesting a dominant interfering effect of the Akap10 mutant allele. The mutant mice have cardiac arrhythmias and die prematurely. We also found that a common variant of AKAP10 in humans (646V, 40% of alleles) was associated with increased basal heart rate and decreased heart rate variability (markers of low cholinergic/vagus nerve sensitivity). These markers predict an increased risk of sudden cardiac death. Although the molecular mechanism remains unknown, our findings in mutant mESCs, mice, and a common human AKAP10 SNP all suggest a role for AKAP10 in heart rhythm control. Our stem cell-based screen may provide a means of identifying other genes that control heart rhythm.
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Affiliation(s)
- Whittemore G. Tingley
- *Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158
- Departments of Medicine and
| | | | | | - Taeryn Kim
- *Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158
| | - Trieu Nguyen
- *Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158
| | - Stephen G. Young
- Department of Medicine, University of California, Los Angeles, CA 90095
| | - Karen Vranizan
- *Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158
- Functional Genomics Laboratory, University of California, Berkeley, CA 94720; and
| | | | - Mary A. Whooley
- Departments of Medicine and
- **Veterans Affairs Medical Center, San Francisco, CA 94143
| | - Bruce R. Conklin
- *Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158
- Departments of Medicine and
- Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143
- To whom correspondence should be addressed at:
Gladstone Institute of Cardiovascular Disease, 1650 Owens Street, San Francisco, CA 94158. E-mail:
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Aslanukov A, Bhowmick R, Guruju M, Oswald J, Raz D, Bush RA, Sieving PA, Lu X, Bock CB, Ferreira PA. RanBP2 modulates Cox11 and hexokinase I activities and haploinsufficiency of RanBP2 causes deficits in glucose metabolism. PLoS Genet 2006; 2:e177. [PMID: 17069463 PMCID: PMC1626108 DOI: 10.1371/journal.pgen.0020177] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 09/01/2006] [Indexed: 11/19/2022] Open
Abstract
The Ran-binding protein 2 (RanBP2) is a large multimodular and pleiotropic protein. Several molecular partners with distinct functions interacting specifically with selective modules of RanBP2 have been identified. Yet, the significance of these interactions with RanBP2 and the genetic and physiological role(s) of RanBP2 in a whole-animal model remain elusive. Here, we report the identification of two novel partners of RanBP2 and a novel physiological role of RanBP2 in a mouse model. RanBP2 associates in vitro and in vivo and colocalizes with the mitochondrial metallochaperone, Cox11, and the pacemaker of glycolysis, hexokinase type I (HKI) via its leucine-rich domain. The leucine-rich domain of RanBP2 also exhibits strong chaperone activity toward intermediate and mature folding species of Cox11 supporting a chaperone role of RanBP2 in the cytosol during Cox11 biogenesis. Cox11 partially colocalizes with HKI, thus supporting additional and distinct roles in cell function. Cox11 is a strong inhibitor of HKI, and RanBP2 suppresses the inhibitory activity of Cox11 over HKI. To probe the physiological role of RanBP2 and its role in HKI function, a mouse model harboring a genetically disrupted RanBP2 locus was generated. RanBP2−/− are embryonically lethal, and haploinsufficiency of RanBP2 in an inbred strain causes a pronounced decrease of HKI and ATP levels selectively in the central nervous system. Inbred RanBP2+/− mice also exhibit deficits in growth rates and glucose catabolism without impairment of glucose uptake and gluconeogenesis. These phenotypes are accompanied by a decrease in the electrophysiological responses of photosensory and postreceptoral neurons. Hence, RanBP2 and its partners emerge as critical modulators of neuronal HKI, glucose catabolism, energy homeostasis, and targets for metabolic, aging disorders and allied neuropathies. The Ran-binding protein 2 (RanBP2) is a large protein with several domains. Although several protein partners were found to interact with selective domains of RanBP2, none to this date were found toward its large leucine-rich domain (LD). Cell-based experiments support several roles of RanBP2 in cell function, such as the production of functional proteins, control of protein trafficking between the nuclear and cytosol compartments, and control of multiple facets underlying cell division. Still, the genetic and physiological implications of the interactions between RanBP2 and its partners and of the function of RanBP2 in a whole-animal model remain elusive. The authors report the identification of two novel mitochondrial partners of the LD of RanBP2, Cox11 and hexokinase type I (HKI); and with multidisciplinary approaches probe the role of RanBP2 and its LD on Cox11, HKI, and functions allied to these. The authors found that RanBP2 exhibits chaperone activity toward HKI and Cox11. RanBP2 and Cox11 profoundly modulate HKI activity. Moreover, partial loss-of-function of RanBP2 in a mouse model induces deficits in growth rates and breakdown of glucose, promotes the down-regulation of HKI and ATP levels selectively in the central nervous system, and impairs visual function. These findings support a critical role of RanBP2 and its partners in metabolic processes and allied disease states.
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Affiliation(s)
- Azamat Aslanukov
- Third Wave Technologies, Madison, Wisconsin, United States of America
| | - Reshma Bhowmick
- Department of Anatomy, Cell Biology, and Neurobiology, Medical College of Wisconsin, Milwaukee, United States of America
| | - Mallikarjuna Guruju
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - John Oswald
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Dorit Raz
- National Institutes of Health, National Institute on Deafness and Other Communication Disorders/National Eye Institute, Bethesda, Maryland, United States of America
| | - Ronald A Bush
- National Institutes of Health, National Institute on Deafness and Other Communication Disorders/National Eye Institute, Bethesda, Maryland, United States of America
| | - Paul A Sieving
- National Institutes of Health, National Eye Institute, Bethesda, Maryland, United States of America
| | - Xinrong Lu
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Cheryl B Bock
- Duke Comprehensive Cancer Center, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Paulo A Ferreira
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * To whom correspondence should be addressed. E-mail:
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Geurts AM, Wilber A, Carlson CM, Lobitz PD, Clark KJ, Hackett PB, McIvor RS, Largaespada DA. Conditional gene expression in the mouse using a Sleeping Beauty gene-trap transposon. BMC Biotechnol 2006; 6:30. [PMID: 16800892 PMCID: PMC1557845 DOI: 10.1186/1472-6750-6-30] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 06/26/2006] [Indexed: 11/24/2022] Open
Abstract
Background Insertional mutagenesis techniques with transposable elements have been popular among geneticists studying model organisms from E. coli to Drosophila and, more recently, the mouse. One such element is the Sleeping Beauty (SB) transposon that has been shown in several studies to be an effective insertional mutagen in the mouse germline. SB transposon vector studies have employed different functional elements and reporter molecules to disrupt and report the expression of endogenous mouse genes. We sought to generate a transposon system that would be capable of reporting the expression pattern of a mouse gene while allowing for conditional expression of a gene of interest in a tissue- or temporal-specific pattern. Results Here we report the systematic development and testing of a transposon-based gene-trap system incorporating the doxycycline-repressible Tet-Off (tTA) system that is capable of activating the expression of genes under control of a Tet response element (TRE) promoter. We demonstrate that the gene trap system is fully functional in vitro by introducing the "gene-trap tTA" vector into human cells by transposition and identifying clones that activate expression of a TRE-luciferase transgene in a doxycycline-dependent manner. In transgenic mice, we mobilize gene-trap tTA vectors, discover parameters that can affect germline mobilization rates, and identify candidate gene insertions to demonstrate the in vivo functionality of the vector system. We further demonstrate that the gene-trap can act as a reporter of endogenous gene expression and it can be coupled with bioluminescent imaging to identify genes with tissue-specific expression patterns. Conclusion Akin to the GAL4/UAS system used in the fly, we have made progress developing a tool for mutating and revealing the expression of mouse genes by generating the tTA transactivator in the presence of a secondary TRE-regulated reporter molecule. A vector like the gene-trap tTA could provide a means for both annotating mouse genes and creating a resource of mice that express a regulable transcription factor in temporally- and tissue-specific patterns for conditional gene expression studies. These mice would be a valuable resource to the mouse genetics community for purpose of dissecting mammalian gene function.
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Affiliation(s)
- Aron M Geurts
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
| | - Andrew Wilber
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Human Genetics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Corey M Carlson
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - Paul D Lobitz
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
| | - Karl J Clark
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
| | - Perry B Hackett
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Human Genetics, University of Minnesota, Minneapolis, MN 55455, USA
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - R Scott McIvor
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Human Genetics, University of Minnesota, Minneapolis, MN 55455, USA
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
| | - David A Largaespada
- Department of Genetics, Cell Biology, and Development and The Arnold and Mabel Beckman Center for Transposon Research at the University of Minnesota, Minneapolis, MN 55455, USA
- Institute of Human Genetics, University of Minnesota, Minneapolis, MN 55455, USA
- University of Minnesota Cancer Center, Minneapolis, MN 55455, USA
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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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Braud S, Moutiez M, Belin P, Abello N, Drevet P, Zinn-Justin S, Courçon M, Masson C, Dassa J, Charbonnier JB, Boulain JC, Ménez A, Genet R, Gondry M. Dual expression system suitable for high-throughput fluorescence-based screening and production of soluble proteins. J Proteome Res 2006; 4:2137-47. [PMID: 16335960 DOI: 10.1021/pr050230i] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many studies that aim to characterize the proteome structurally or functionally require the production of pure protein in a high-throughput format. We have developed a fast and flexible integrated system for cloning, protein expression in Escherichia coli, solubility screening and purification that can be completely automated in a 96-well microplate format. We used recombination cloning in custom-designed vectors including (i) a (His)(6) tag-encoding sequence, (ii) a variable solubilizing partner gene, (iii) the DNA sequence corresponding to the TEV protease cleavage site, (iv) the gene (or DNA fragment) of interest, (v) a suppressible amber stop codon, and (vi) an S.tag peptide-encoding sequence. First, conditions of bacterial culture in microplates (250 microL) were optimized to obtain expression and solubility patterns identical to those obtained in a 1-L flask (100-mL culture). Such conditions enabled the screening of various parameters in addition to the fusion partners (E. coli strains, temperature, inducer...). Second, expression of fusion proteins in amber suppressor strains allowed quantification of soluble and insoluble proteins by fluorescence through the detection of the S.tag. This technique is faster and more sensitive than other commonly used methods (dot blots, Western blots, SDS-PAGE). The presence of the amber suppressor tRNA was shown to affect neither the expression pattern nor the solubility of the target proteins. Third, production of the most interesting soluble fusion proteins, as detected by our screening method, could be performed in nonsuppressor strains. After cleavage with the TEV protease, the target proteins were obtained in a native form with a unique additional N-terminal glycine.
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Affiliation(s)
- Sandrine Braud
- CEA/Saclay, Département d'Ingénierie et d'Etudes des Protéines, F-91191 Gif-sur-Yvette Cedex, France
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41
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Shariat-Madar Z, Rahimy E, Mahdi F, Schmaier AH. Overexpression of prolylcarboxypeptidase enhances plasma prekallikrein activation on Chinese hamster ovary cells. Am J Physiol Heart Circ Physiol 2005; 289:H2697-703. [PMID: 16113074 DOI: 10.1152/ajpheart.00715.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Plasma prekallikrein (PK) complexes with its receptor, high-molecular-weight kininogen (HK), on human umbilical vein endothelial cells (HUVEC). When assembled on endothelial cells, PK is activated to plasma kallikrein independent of factor XIIa by the serine protease prolylcarboxypeptidase (PRCP, Km= 9 nM). PRCP was shown to be a PK activator when isolated from HUVEC ( J Biol Chem 277: 17962–17969, 2002) and produced as a recombinant protein ( Blood 103: 4554–4561, 2004). To additionally confirm that human PRCP is a physiological PK activator, PRCP was overexpressed in Chinese hamster ovary (CHO) cells. CHO cells were transfected with full-length PRCP under the control of a cytomegalovirus promoter, and CHO recombinant PRCP was expressed as a fusion protein with COOH-terminal enhanced green fluorescence protein (EGFP). The presence of recombinant PRCP in transfected CHO cells was detected by real-time RT-PCR, immunoblot, and immunoprecipitation. PRCP mRNA and PK activation were two- to threefold higher in transfected than in control CHO cells. The increase in PRCP-induced PK activation in the transfected CHO cells paralleled the increase in PRCP antigen expression, as determined by anti-PRCP and anti-green fluorescence protein antibodies. PK activation of the transfected cells was blocked by small interfering RNA to PRCP. Anti-PRCP antibody and Z-Pro-Pro-aldehyde dimethyl acetate also blocked PK activation (IC50= 0.01 and 7.0 mM, respectively). Localization of PRCP in intact cells observed via confocal microscopy and flow cytometry also confirmed overexpression of PRCP on the external membrane. These investigations independently confirm that PRCP is expressed on cell membranes and that PRCP expression increases PK activation.
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Affiliation(s)
- Z Shariat-Madar
- Hematology/Oncology Division, Department of Internal Medicine, Univ. of Michigan, 5301 MSRB III, 1150 West Medical Center Dr., Ann Arbor, MI 48109-0640, USA.
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42
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Chen NT, Lo SH. The N-terminal half of talin2 is sufficient for mouse development and survival. Biochem Biophys Res Commun 2005; 337:670-6. [PMID: 16202389 DOI: 10.1016/j.bbrc.2005.09.100] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Accepted: 09/16/2005] [Indexed: 10/25/2022]
Abstract
Using a talin2 gene-trapped embryonic stem cell clone, we have developed a talin2 mutant mouse line that expresses the N-terminal half (1-1295) of talin2 fused with beta-galactosidase. The homozygous mutant mice appear to be normal and healthy. In the testis, talin2 expresses as a shorter form with a unique 30 residues at N-terminus linking to a common C-terminus from 1122 to 2453 of the long form. The resulting talin2 in the mutant testis only contains 204 residues of the wild-type testis talin2. However, it did not seem to affect the morphology of testis or reproduction of male mice. In fact, male and female mutant mice are fertile. Utilizing the expression of talin2(1-1295)/beta-galactosidase fusion protein, we have examined the distribution of talin2 in tissues. In contrast to talin1, talin2 expression is more restricted in tissues and cell types.
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Affiliation(s)
- Nien-Tsu Chen
- Center for Tissue Regeneration and Repair, Department of Orthopaedic Surgery and Cancer Center, University of California-Davis, Sacramento, 95817, USA
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43
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Abstract
Over the past two decades, molecular genetic studies have enabled a common conceptual framework for the development and basic function of the nervous system. These studies, and the pioneering efforts of mouse geneticists and neuroscientists to identify and clone genes for spontaneous mouse mutants, have provided a paradigm for understanding complex processes of the vertebrate brain. Gene cloning for human brain malformations and degenerative disorders identified other important central nervous system (CNS) genes. However, because many debilitating human disorders are genetically complex, phenotypic screens are difficult to design. This difficulty has led to large-scale, genomic approaches to discover genes that are uniquely expressed in brain circuits and regions that control complex behaviors. In this review, we summarize current phenotype- and genotype-driven approaches to discover novel CNS-expressed genes, as well as current approaches to carry out large-scale, gene-expression screens in the CNS.
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Affiliation(s)
- Mary E Hatten
- Laboratory of Developmental Neurobiology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10021, USA.
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Forrai A, Robb L. The gene trap resource: a treasure trove for hemopoiesis research. Exp Hematol 2005; 33:845-56. [PMID: 16038776 DOI: 10.1016/j.exphem.2005.03.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Accepted: 03/23/2005] [Indexed: 11/16/2022]
Abstract
The laboratory mouse is an invaluable tool for functional gene discovery because of its genetic malleability and a biological similarity to human systems that facilitates identification of human models of disease. A number of mutagenic technologies are being used to elucidate gene function in the mouse. Gene trapping is an insertional mutagenesis strategy that is being undertaken by multiple research groups, both academic and private, in an effort to introduce mutations across the mouse genome. Large-scale, publicly funded gene trap programs have been initiated in several countries with the International Gene Trap Consortium coordinating certain efforts and resources. We outline the methodology of mammalian gene trapping and how it can be used to identify genes expressed in both primitive and definitive blood cells and to discover hemopoietic regulator genes. Mouse mutants with hematopoietic phenotypes derived using gene trapping are described. The efforts of the large-scale gene trapping consortia have now led to the availability of libraries of mutagenized ES cell clones. The identity of the trapped locus in each of these clones can be identified by sequence-based searching via the world wide web. This resource provides an extraordinary tool for all researchers wishing to use mouse genetics to understand gene function.
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Affiliation(s)
- Ariel Forrai
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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45
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Friedel RH, Plump A, Lu X, Spilker K, Jolicoeur C, Wong K, Venkatesh TR, Yaron A, Hynes M, Chen B, Okada A, McConnell SK, Rayburn H, Tessier-Lavigne M. Gene targeting using a promoterless gene trap vector ("targeted trapping") is an efficient method to mutate a large fraction of genes. Proc Natl Acad Sci U S A 2005; 102:13188-93. [PMID: 16129827 PMCID: PMC1193537 DOI: 10.1073/pnas.0505474102] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A powerful tool for postgenomic analysis of mammalian gene function is gene targeting in mouse ES cells. We report that homologous recombination using a promoterless gene trap vector ("targeting trapping") yields targeting frequencies averaging above 50%, a significant increase compared with current approaches. These high frequencies appear to be due to the stringency of selection with promoterless constructs, because most random insertions are silent and eliminated by drug selection. The promoterless design requires that the targeted gene be expressed in ES cells at levels exceeding a certain threshold (which we estimate to be approximately 1% of the transferrin receptor gene expression level, for the secretory trap vector used here). Analysis of 127 genes that had been trapped by random (nontargeted) gene trapping with the same vector shows that virtually all are expressed in ES cells above this threshold, suggesting that targeted and random trapping share similar requirements for expression levels. In a random sampling of 130 genes encoding secretory proteins, about half were expressed above threshold, suggesting that about half of all secretory genes are accessible by either targeted or random gene trapping. The simplicity and high efficiency of the method facilitate systematic targeting of a large fraction of the genome by individual investigators and large-scale consortia alike.
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Affiliation(s)
- Roland H Friedel
- Department of Biological Sciences, Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
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46
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Chiang MK, Liao YC, Kuwabara Y, Lo SH. Inactivation of tensin3 in mice results in growth retardation and postnatal lethality. Dev Biol 2005; 279:368-77. [PMID: 15733665 DOI: 10.1016/j.ydbio.2004.12.027] [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: 07/12/2004] [Revised: 12/15/2004] [Accepted: 12/21/2004] [Indexed: 01/22/2023]
Abstract
Tensin family is a group of focal adhesion proteins that interact with integrins, actin, and phosphotyrosine-containing proteins. To explore the in vivo functions of a new member of the family, tensin3, we have generated mutant mice with a disrupted tensin3 gene. Inactivation of tensin3 resulted in growth retardation and postnatal lethality in one third of the homozygous mutants. Histological analysis of those mutants showed incomplete development of the small intestine, lung, and bone. Villus formation in the small intestine was affected and cells migrated slower in the runt mutants. Their lungs also displayed enlarged air space suggesting defects in alveogenesis. In addition, the resting zone was thicker and fewer proliferating cells were present in the growth plates of tensin3(-/-) tibiae. These observations indicate that tensin3 is essential for normal development and functions of the small intestine, lung, and bone. These phenotypes of the runt tensin3(-/-) mice are similar to some clinical features of Silver-Russell syndrome (SRS) which is a genetically inherited defect. About 10% of SRS cases have been linked to abnormality in chromosome 7p11.2-13, where human tensin3 gene is located, suggesting a potential link between tensin3 and SRS.
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Affiliation(s)
- Ming-Ko Chiang
- Center for Tissue Regeneration and Repair, Department of Orthopaedic Surgery, University of California-Davis, 4635 Second Avenue, Room 2000, Sacramento, CA 95817, USA
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47
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Barrière H, Tauc M, Poujeol P. Use of knock-out mouse models for the study of renal ion channels. J Membr Biol 2005; 198:113-24. [PMID: 15216413 DOI: 10.1007/s00232-004-0665-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Indexed: 12/30/2022]
Affiliation(s)
- H Barrière
- UMR CNRS 6548, Université de Nice-Sophia Antipolis, 06108 Nice Cedex 2, France
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48
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Parrish JR, Limjindaporn T, Hines JA, Liu J, Liu G, Finley RL. High-throughput cloning of Campylobacter jejuni ORfs by in vivo recombination in Escherichia coli. J Proteome Res 2004; 3:582-6. [PMID: 15253440 DOI: 10.1021/pr0341134] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A rate-limiting and costly step in many proteomics analyses is the cloning of all of the ORFs for an organism into technique-specific vectors. Here, we describe the generation of a Campylobacter jejuni expression clone set using a high-throughput cloning approach based on recombination in E. coli. The approach uses native E. coli recombination functions and requires no in vitro enzymatic steps or special strains. Our results indicate that this approach is an efficient and economical alternative for high-throughput cloning.
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Affiliation(s)
- Jodi R Parrish
- Center for Molecular Medicine and Genetics, Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, 540 East Canfield Ave, Detroit, Michigan 48201, USA
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49
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Wang Z, Zhai W, Richardson JA, Olson EN, Meneses JJ, Firpo MT, Kang C, Skarnes WC, Tjian R. Polybromo protein BAF180 functions in mammalian cardiac chamber maturation. Genes Dev 2004; 18:3106-16. [PMID: 15601824 PMCID: PMC535920 DOI: 10.1101/gad.1238104] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2004] [Accepted: 10/12/2004] [Indexed: 11/24/2022]
Abstract
BAF and PBAF are two related mammalian chromatin remodeling complexes essential for gene expression and development. PBAF, but not BAF, is able to potentiate transcriptional activation in vitro mediated by nuclear receptors, such as RXRalpha, VDR, and PPARgamma. Here we show that the ablation of PBAF-specific subunit BAF180 in mouse embryos results in severe hypoplastic ventricle development and trophoblast placental defects, similar to those found in mice lacking RXRalpha and PPARgamma. Embryonic aggregation analyses reveal that in contrast to PPARgamma-deficient mice, the heart defects are likely a direct result of BAF180 ablation, rather than an indirect consequence of trophoblast placental defects. We identified potential target genes for BAF180 in heart development, such as S100A13 as well as retinoic acid (RA)-induced targets RARbeta2 and CRABPII. Importantly, BAF180 is recruited to the promoter of these target genes and BAF180 deficiency affects the RA response for CRABPII and RARbeta2. These studies reveal unique functions of PBAF in cardiac chamber maturation.
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Affiliation(s)
- Zhong Wang
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3204, USA
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50
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Abstract
Embryonic stem (ES) cells are typically derived from the inner cell mass of the preimplantation blastocyst and can both self-renew and differentiate into all the cells and tissues of the embryo. Because they are pluripotent, ES cells have been used extensively to analyze gene function in development via gene targeting. The embryonic stem cell is also an unsurpassed starting material to begin to understand a critical, largely inaccessible period of development. If their differentiation could be controlled, they would also be an important source of cells for transplantation to replace cells lost through disease or injury or to replace missing hormones or genes. Traditionally, ES cells have been differentiated in suspension culture as embryoid bodies, named because of their similarity to the early postimplantation-staged embryo. Unlike the pristine organization of the early embryo, differentiation in embryoid bodies appears to be largely unpatterned, although multiple cell types form. It has recently been possible to separate the desired cell types from differentiating ES cells in embryoid bodies by using cell-type-restricted promoters driving expression of either antibiotic resistance genes or fluorophores such as EGFP. In combination with growth factor exposure, highly differentiated cell types have successfully been derived from ES cells. Recent technological advances such as RNA interference to knock down gene expression in ES cells are also producing enriched populations of cells and elucidating gene function in early development.
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Affiliation(s)
- K Sue O'Shea
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0616, USA.
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