The potential of electrophoretic mobility shift assays for clinical mutation detection

2006 ◽  
Vol 27 (19) ◽  
pp. 3805-3815 ◽  
Author(s):  
Christa N. Hestekin ◽  
Annelise E. Barron
Keyword(s):  
Electrophoretic Mobility ◽  
Mutation Detection ◽  
Mobility Shift ◽  
Electrophoretic Mobility Shift Assays

scholarly journals Granulocyte-macrophage colony-stimulating factor and interleukin-3 signaling pathways converge on the CREB-binding site in the human egr-1 promoter.

1994 ◽  
Vol 14 (9) ◽  
pp. 5975-5985 ◽  
Author(s):  
K M Sakamoto ◽  
J K Fraser ◽  
H J Lee ◽  
E Lehman ◽  
J C Gasson
Keyword(s):  
Binding Site ◽  
Electrophoretic Mobility ◽  
Colony Stimulating Factor ◽  
Mobility Shift ◽  
Response Gene ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Electrophoretic Mobility Shift Assays ◽  
Stimulating Factor

Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates myeloid progenitor cell proliferation and enhances the function of terminally differentiated effector cells. Interleukin-3 (IL-3) stimulation results in the proliferation and maturation of early bone marrow progenitor cells. These activities are mediated by non-tyrosine kinase-containing receptors which consist of ligand-specific alpha subunits that complex with a common beta subunit required for signal transduction. Both GM-CSF and IL-3 rapidly and transiently induce expression of early growth response gene 1 (egr-1) in the human factor-dependent cell line TF-1. To define the mechanism of early response gene induction by GM-CSF and IL-3, growth factor- and serum-starved TF-1 cells transfected with recombinant constructs containing sequences of the human egr-1 promoter were stimulated with GM-CSF or IL-3. A 116-nucleotide (nt) region of the egr-1 promoter which contains sequences inducible by GM-CSF and IL-3 was defined. DNase I footprint analysis identified a 20-nt region, including nt -57 to -76, which contains a potential cyclic AMP (cAMP) response element (CRE). Electrophoretic mobility shift assays performed with CREB antibody confirmed the presence of CREB in the DNA-binding complex. Mutational analysis of the cytokine-responsive region of the egr-1 promoter revealed that both the cAMP response and serum response elements are required for induction by GM-CSF and IL-3. Nuclear extracts from GM-CSF- or IL-3-stimulated but not unstimulated TF-1 cells contain factors which specifically bind to the Egr-1-binding site in the nt -600 to -480 region of the promoter. Electrophoretic mobility shift assays were performed with antibodies against the Egr-1 protein to demonstrate the presence of the protein product in the shifted complex. Our studies suggest that the Egr-1 protein may further stimulate transcription of the egr-1 gene in response to GM-CSF as a secondary event.

Role of Cjun in Gγ-Globin Gene Trans-Activation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1870-1870
Author(s):  
Sirisha Kodeboyina ◽  
Sima Zein ◽  
Moosueng Lee ◽  
Parimaladevi Balamurugan ◽  
Xiao Yao ◽  
...  
Keyword(s):  
Electrophoretic Mobility ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
K562 Cells ◽  
Luciferase Reporter ◽  
Complete Analysis ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Electrophoretic Mobility Shift Assays

Abstract Previous studies from our laboratory demonstrated the role of the G-CRE (Gγ-globin cAMP response element) in drug-mediated fetal hemoglobin induction. The G-CRE located at −1222 to −1229 in the promoter of Gγ-globin gene, contains binding site for trans-factors CREB1, ATF-2 and cJun. We previously demonstrated binding of phosphorylated CREB1 and ATF-2 to this element via p38 MAPK signaling triggered by sodium butyrate (NaB) and trichostatin A (TSA). Electrophoretic mobility shift assays with a probe containing the AC → TG mutation in the G-CRE (TGTGGTCA, m2) abolished trans-factor binding to the G-CRE. Furthermore, Gγ promoter activity was abolished in the PGL3 luciferase reporter vector driven by the Gγ promoter (−1500 to +36) carrying the m2 mutation. (Sangerman et al. Blood108:3590–9, 2006). Subsequent studies in our laboratory were aimed at understanding the role of trans-factor cJun, an AP-1 family member, as a regulator of Gγ-globin expression via the G-CRE site. In K562 cells treated with 2mM NaB or 0.3μM TSA for 48 hrs, cJun phosphorylation increased 2.8-fold and 6.4-fold respectively by western blot analysis. Chromatin immunoprecipitation studies showed 16-fold chromatin enrichment in the −1225 Gγ-globin region compared to IgG control studies indicative of significant cJun binding in vivo at steady state. Electrophoretic mobility shift assays using cJun monoclonal antibody demonstrated a supershifted DNA-protein complex confirming binding of cJun to the G-CRE probe. To gain evidence for a functional role of cJun, we performed enforced expression studies using the pLen-cJun vector. In a concentration dependent manner, over-expression of cJun increased luciferase activity up to 350-fold in the luciferase reporter plasmid controlled by the Gγ-promoter (−1500 to +36). As predicted from binding studies, the m2 mutation in this promoter abolished the cJunmediated trans-activation confirming that the G-CRE is required to mediate effects of cJun. We are currently investigating the ability of cJun to trans-activate the endogenous Gγ-globin gene in K562 cells. To achieve this goal, K562 stable lines were established with the expression vectors pLen-cJun and empty vector. A complete analysis of the stable lines is in progress. Future investigations to identify other components of the functional CREB1/ATF2/cJun enhanceosome complex bound to the G-CRE will be performed using affinity chromatography and mass spectrometry. This information will be used to develop strategies for fetal hemoglobin induction.

scholarly journals Replication from oriP of Epstein-Barr Virus Requires Exact Spacing of Two Bound Dimers of EBNA1 Which Bend DNA

2001 ◽  
Vol 75 (22) ◽  
pp. 10603-10611 ◽  
Author(s):  
Jacqueline M. Bashaw ◽  
John L. Yates
Keyword(s):  
Electrophoretic Mobility ◽  
Binding Sites ◽  
Epstein Barr Virus ◽  
Mobility Shift ◽  
Barr Virus ◽  
Cellular Factors ◽  
Specific Nucleotide Sequence ◽  
Epstein Barr ◽  
Stable Maintenance ◽  
Electrophoretic Mobility Shift Assays

ABSTRACT oriP is a 1.7-kb region of the Epstein-Barr virus (EBV) chromosome that supports replication and stable maintenance of plasmids in human cells that contain EBV-encoded protein EBNA1. Plasmids that depend on oriP are replicated once per cell cycle by cellular factors. The replicator of oriPis an ∼120-bp region called DS which depends on either of two pairs of closely spaced EBNA1 binding sites. Here we report that changing the distance between the EBNA1 sites of a functional pair by inserting or deleting 1 or 2 bp abolished replication activity. The results indicated that, while the distance separating the binding sites is critical, the specific nucleotide sequence between them is unlikely to be important. The use of electrophoretic mobility shift assays to investigate binding by EBNA1 to the sites with normal or altered spacing revealed that EBNA1 induces DNA to bend significantly when it binds, with the center of bending coinciding with the center of binding. EBNA1 binding to a functional pair of sites which are spaced 21 bp apart center to center and which thus are in helical phase induces a larger symmetrical bend, which based on electrophoretic mobility approximates the sum of two separate EBNA1-induced DNA bends. The results imply that replication from oriP requires a precise structure in which DNA forms a large bend around two EBNA1 dimers.

scholarly journals Validation of miRNA-mRNA interactions by electrophoretic mobility shift assays

2013 ◽  
Vol 6 (1) ◽  
pp. 454 ◽  
Author(s):  
Anna Solé ◽  
Núria Mencia ◽  
Xenia Villalobos ◽  
Véronique Noé ◽  
Carlos J Ciudad
Keyword(s):  
Electrophoretic Mobility ◽  
Mobility Shift ◽  
Electrophoretic Mobility Shift Assays
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