scholarly journals Structural and functional analysis of a promoter of the human granulin/epithelin gene

1996 ◽  
Vol 319 (2) ◽  
pp. 441-447 ◽  
Author(s):  
Vijay BHANDARI ◽  
Rachael DANIEL ◽  
Pheng Siew LIM ◽  
Andrew BATEMAN
Keyword(s):  
Promoter Activity ◽  
Biologically Active ◽  
Gene Products ◽  
High Level Expression ◽  
Haematopoietic Cells ◽  
Molecular Masses ◽  
Chloramphenicol Acetyltransferase Gene ◽  
High Level

Granulins (grns) or epithelins (epis) are peptides with molecular masses of approx. 6 kDa that modulate the growth of cells. The precursor for the grns/epis, which might itself be biologically active, is a secreted glycoprotein containing multiple repeats of the grn/epi motif. Grn/epi mRNA occurs widely in vivo, particularly in tissues rich in epithelial and haematopoietic cells. To understand better the role of the gene products for grn/epi it is important to determine the patterns of grn/epi gene expression and how this is regulated. To assist in this we have obtained the 5´ sequence of the human grn/epi gene, and using chimaeras of the grn/epi -5´ sequence and the chloramphenicol acetyltransferase gene we have shown a strong promoter activity associated with the 5´ sequence of the human grn/epi gene. We have further delineated regions of the 5´ sequence that confer high-level expression on the chimaeric gene.

scholarly journals A Dominant Interfering Bub1 Mutant Is Insufficient To Induce or Alter Thymic Tumorigenesis In Vivo, Even in a Sensitized Genetic Background

2005 ◽  
Vol 25 (17) ◽  
pp. 7796-7802 ◽  
Author(s):  
Dale O. Cowley ◽  
Ginger W. Muse ◽  
Terry Van Dyke
Keyword(s):  
Mitotic Spindle ◽  
Genetic Background ◽  
Cultured Cells ◽  
Spindle Checkpoint ◽  
Transgenic Animals ◽  
Dominant Negative ◽  
High Level Expression ◽  
High Level

ABSTRACT Aneuploidy is a common feature of human tumors, often correlating with poor prognosis. The mitotic spindle checkpoint is thought to play a major role in aneuploidy suppression. To investigate the role of the spindle checkpoint in tumor suppression in vivo, we developed transgenic mice in which thymocytes express a dominant interfering fragment of Bub1, a kinase regulator of the spindle checkpoint. We report that, despite high-level expression of dominant-negative Bub1 (Bub1DN), a protein known to inhibit spindle checkpoint activity in cultured cells, thymocytes show no evidence of spindle checkpoint impairment. Transgenic animals also failed to show an increased predisposition to spontaneous tumors. Moreover, the Bub1DN transgene failed to alter the timing or characteristics of thymic lymphoma development in p53 heterozygous or homozygous null backgrounds, indicating that the lack of tumorigenesis is not due to suppression by p53-dependent checkpoints. These results indicate that overexpression of a Bub1 N-terminal fragment is insufficient to impair the spindle checkpoint in vivo or to drive tumorigenesis in the highly susceptible murine thymocyte system, either alone or in combination with G1 checkpoint disruption.

Endothelial progenitor cell homing: prominent role of the IGF2-IGF2R-PLCβ2 axis

Blood ◽  
2009 ◽  
Vol 113 (1) ◽  
pp. 233-243 ◽  
Author(s):  
Yong-Sun Maeng ◽  
Hyun-Jung Choi ◽  
Ja-Young Kwon ◽  
Yong-Won Park ◽  
Kyu-Sil Choi ◽  
...  
Keyword(s):  
Postnatal Life ◽  
Protein Signaling ◽  
Vascular Networks ◽  
High Level Expression ◽  
Endothelial Progenitor ◽  
Hypoxic Conditions ◽  
High Level

Abstract Homing of endothelial progenitor cells (EPCs) to the neovascular zone is now considered to be an essential step in the formation of vascular networks during embryonic development and also for neovascularization in postnatal life. We report here the prominent role of the insulin-like growth factor 2 (IGF2)/IGF2 receptor (IGF2R) system in promoting EPC homing. With high-level expression of IGF2R in EPCs, IGF2-induced hypoxic conditions stimulated multiple steps of EPC homing in vitro and promoted both EPC recruitment and incorporation into the neovascular area, resulting in enhanced angiogenesis in vivo. Remarkably, all IGF2 actions were exerted predominantly through IGF2R-linked G(i) protein signaling and required intracellular Ca2+ mobilization induced by the β2 isoform of phospholipase C. Together, these findings indicate that locally generated IGF2 at either ischemic or tumor sites may contribute to postnatal vasculogenesis by augmenting the recruitment of EPCs. The utilization of the IGF2/IGF2R system may therefore be useful for the development of novel means to treat angiogenesis-dependent diseases.

Differential effects of Cdc68 on cell cycle-regulated promoters in Saccharomyces cerevisiae

1994 ◽  
Vol 14 (11) ◽  
pp. 7455-7465 ◽  
Author(s):  
D Lycan ◽  
G Mikesell ◽  
M Bunger ◽  
L Breeden
Keyword(s):  
Cell Cycle ◽  
Chromatin Structure ◽  
Gene Activation ◽  
High Level Expression ◽  
Specific Component ◽  
Allele Specific ◽  
High Level ◽  
Cyclin Genes ◽  
Regulated Promoters

Swi4 and Swi6 form a complex which is required for Start-dependent activation of HO and for high-level expression of G1 cyclin genes CLN1 and CLN2. To identify other regulators of this pathway, we screened for dominant, recessive, conditional, and allele-specific suppressors of swi4 mutants. We isolated 16 recessive suppressors that define three genes, SSF1, SSF5, and SSF9 (suppressor of swi four). Mutations in all three genes bypass the requirement for both Swi4 and Swi6 for HO transcription and activate transcription from reporter genes lacking upstream activating sequences (UASs). SSF5 is allelic with SIN4 (TSF3), a gene implicated in global repression of transcription and chromatin structure, and SSF9 is likely to be a new global repressor of transcription. SSF1 is allelic with CDC68 (SPT16). cdc68 mutations have been shown to increase expression from defective promoters, while preventing transcription from other intact promoters, including CLN1 and CLN2. We find that CDC68 is a required activator of both SWI4 and SWI6, suggesting that CDC68's role at the CLN promoters may be indirect. The target of CDC68 within the SWI4 promoter is complex in that known activating elements (MluI cell cycle boxes) in the SWI4 promoter are required for CDC68 dependence but only within the context of the full-length promoter. This result suggests that there may be both a chromatin structure and a UAS-specific component to Cdc68 function at SWI4. We suggest that Cdc68 functions both in the assembly of repressive complexes that form on many intact promoters in vivo and in the relief of this repression during gene activation.

High-Level Expression of Biologically Active Human Prolactin from Recombinant Baculovirus in Insect Cells

2000 ◽  
Vol 20 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Tapas Das ◽  
Paul W. Johns ◽  
Vincent Goffin ◽  
Paul Kelly ◽  
Bruce Kelder ◽  
...  
Keyword(s):  
Insect Cells ◽  
Recombinant Baculovirus ◽  
Biologically Active ◽  
High Level Expression ◽  
Human Prolactin ◽  
High Level

scholarly journals Study of Staphylococcus aureusPathogenic Genes by Transfer and Expression in the Less Virulent Organism Streptococcus gordonii

2001 ◽  
Vol 69 (2) ◽  
pp. 657-664 ◽  
Author(s):  
P. Stutzmann Meier ◽  
J. M. Entenza ◽  
P. Vaudaux ◽  
P. Francioli ◽  
M. P. Glauser ◽  
...  
Keyword(s):  
Single Gene ◽  
Individual Factors ◽  
Gene Products ◽  
Streptococcus Gordonii ◽  
Pathogenic Role ◽  
Gain Of Function ◽  
Function Strategy

ABSTRACT Because Staphylococcus aureus strains contain multiple virulence factors, studying their pathogenic role by single-gene inactivation generated equivocal results. To circumvent this problem, we have expressed specific S. aureus genes in the less virulent organism Streptococcus gordonii and tested the recombinants for a gain of function both in vitro and in vivo. Clumping factor A (ClfA) and coagulase were investigated. Both gene products were expressed functionally and with similar kinetics during growth by streptococci and staphylococci. ClfA-positive S. gordoniiwas more adherent to platelet-fibrin clots mimicking cardiac vegetations in vitro and more infective in rats with experimental endocarditis (P < 0.05). Moreover, deletingclfA from clfA-positive streptococcal transformants restored both the low in vitro adherence and the low in vivo infectivity of the parent. Coagulase-positive transformants, on the other hand, were neither more adherent nor more infective than the parent. Furthermore, coagulase did not increase the pathogenicity ofclfA-positive streptococci when both clfA andcoa genes were simultaneously expressed in an artificial minioperon in streptococci. These results definitively attribute a role for ClfA, but not coagulase, in S. aureus endovascular infections. This gain-of-function strategy might help solve the role of individual factors in the complex the S. aureus-host relationship.

scholarly journals Mutations affecting the tRNA-splicing endonuclease activity of Saccharomyces cerevisiae.

Genetics ◽  
1988 ◽  
Vol 118 (4) ◽  
pp. 609-617
Author(s):  
M Winey ◽  
M R Culbertson
Keyword(s):  
Growth Defect ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Endonuclease Activity ◽  
Temperature Dependent ◽  
Direct Role ◽  
Trna Splicing

Abstract Two unlinked mutations that alter the enzyme activity of tRNA-splicing endonuclease have been identified in yeast. The sen1-1 mutation, which maps on chromosome 12, causes temperature-sensitive growth, reduced in vitro endonuclease activity, and in vivo accumulation of unspliced pre-tRNAs. The sen2-1 mutation does not confer a detectable growth defect, but causes a temperature-dependent reduction of in vitro endonuclease activity. Pre-tRNAs do not accumulate in sen2-1 strains. The in vitro enzyme activities of sen1-1 and sen2-1 complement in extracts from a heterozygous diploid, but fail to complement in mixed extracts from separate sen1-1 and sen2-1 haploid strains. These results suggest a direct role for SEN gene products in the enzymatic removal of introns from tRNA that is distinct from the role of other products known to affect tRNA splicing.

High Level Expression and Secretion of Biologically Active Leech Hirudin Variant 1 (HV1) by Escherichia coli

1992 ◽  
pp. 62-64 ◽  
Author(s):  
Satoru Misawa ◽  
Hideyuki Furuya ◽  
Hitoshi Matsuda ◽  
Shin-Ichiro Abe ◽  
Hideya Hayashi
Keyword(s):  
Escherichia Coli ◽  
Biologically Active ◽  
High Level Expression ◽  
High Level

scholarly journals HOXA9 is required for survival in human MLL-rearranged acute leukemias

Blood ◽  
2009 ◽  
Vol 113 (11) ◽  
pp. 2375-2385 ◽  
Author(s):  
Joerg Faber ◽  
Andrei V. Krivtsov ◽  
Matthew C. Stubbs ◽  
Renee Wright ◽  
Tina N. Davis ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Profiling ◽  
Therapeutic Option ◽  
Mixed Lineage Leukemia ◽  
High Level Expression ◽  
Acute Leukemias ◽  
Gene Expression Analyses ◽  
High Level ◽  
Novel Therapeutic

Leukemias that harbor translocations involving the mixed lineage leukemia gene (MLL) possess unique biologic characteristics and often have an unfavorable prognosis. Gene expression analyses demonstrate a distinct profile for MLL-rearranged leukemias with consistent high-level expression of select Homeobox genes, including HOXA9. Here, we investigated the effects of HOXA9 suppression in MLL-rearranged and MLL-germline leukemias using RNA interference. Gene expression profiling after HOXA9 suppression demonstrated co–down-regulation of a program highly expressed in human MLL-AML and murine MLL-leukemia stem cells, including HOXA10, MEIS1, PBX3, and MEF2C. We demonstrate that HOXA9 depletion in 17 human AML/ALL cell lines (7 MLL-rearranged, 10 MLL-germline) induces proliferation arrest and apoptosis specifically in MLL-rearranged cells (P = .007). Similarly, assessment of primary AMLs demonstrated that HOXA9 suppression induces apoptosis to a greater extent in MLL-rearranged samples (P = .01). Moreover, mice transplanted with HOXA9-depleted t(4;11) SEMK2 cells revealed a significantly lower leukemia burden, thus identifying a role for HOXA9 in leukemia survival in vivo. Our data indicate an important role for HOXA9 in human MLL-rearranged leukemias and suggest that targeting HOXA9 or downstream programs may be a novel therapeutic option.

High-Level Expression and Purification of Biologically Active Recombinant Pokeweed Antiviral Protein

1999 ◽  
Vol 16 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Francis Rajamohan ◽  
Cherri R. Engstrom ◽  
Tammy J. Denton ◽  
Lisa A. Engen ◽  
Igor Kourinov ◽  
...  
Keyword(s):  
Biologically Active ◽  
Pokeweed Antiviral Protein ◽  
Expression And Purification ◽  
Antiviral Protein ◽  
High Level Expression ◽  
High Level
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