scholarly journals Functions of PIT1 in GATA2-dependent transactivation of the thyrotropin β promoter

2008 ◽  
Vol 42 (3) ◽  
pp. 225-237 ◽  
Author(s):  
Yumiko Kashiwabara ◽  
Shigekazu Sasaki ◽  
Akio Matsushita ◽  
Koji Nagayama ◽  
Kenji Ohba ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Binding Site ◽  
Electrophoretic Mobility Shift Assay ◽  
Electrophoretic Mobility ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Minimal Sequence ◽  
Mobility Shift Assay ◽  
Β Chain

Thyrotropin (TSH) is a heterodimer consisting of α and β chains, and the β chain (TSHβ) is specific to TSH. The coexistence of two transcription factors, PIT1 and GATA2, is known to be essential for TSHβ expression. Using kidney-derived CV1 cells, we investigated the role of PIT1 in the expression of Tshb gene. GATA2 Zn finger domain, which is known to recognize GATA-responsive elements (GATA-REs), is essential for cooperation by PIT1. Transactivation of TSHβ promoter requires PIT1-binding site upstream to GATA-REs (PIT1-US), and the spacing between PIT1-US and GATA-REs strictly determines the cooperation between PIT1 and GATA2. Moreover, truncation of the sequence downstream to GATA-REs enabled GATA2 to transactivate the TSHβ promoter without PIT1. The deleted region (nt −82/−52) designated as a suppressor region (SR) was considered to inhibit transactivation by GATA2. The cooperation of PIT1 with GATA2 was not conventional synergism but rather counteracted SR-induced suppression (derepression). The minimal sequence for SR was mapped to the 9 bp sequence downstream to GATA-REs. Electrophoretic mobility shift assay suggested that some nuclear factor exists in CV1 cells, which binds with SR and this interaction was blocked by recombinant PIT1. Our study indicates that major activator for the TSHβ promoter is GATA2 and that PIT1 protects the function of GATA2 from the inhibition by SR-binding protein.

scholarly journals Regulation of lactase–phlorizin hydrolase gene expression by the caudal-related homoeodomain protein Cdx-2

1997 ◽  
Vol 322 (3) ◽  
pp. 833-838 ◽  
Author(s):  
Jesper T. TROELSEN ◽  
Cathy MITCHELMORE ◽  
Nikolaj SPODSBERG ◽  
Anette M. JENSEN ◽  
Ove NORÉN ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Binding Site ◽  
Electrophoretic Mobility Shift Assay ◽  
Gene Transcription ◽  
Transcriptional Activity ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Cis Element ◽  
Mobility Shift Assay

Lactase–phlorizin hydrolase is exclusively expressed in the small intestine and is often used as a marker for the differentiation of enterocytes. The cis-element CE-LPH1 found in the lactase–phlorizin hydrolase promoter has previously been shown to bind an intestinal-specific nuclear factor. By electrophoretic mobility-shift assay it was shown that the factor Cdx-2 (a homoeodomain-protein related to caudal) binds to a TTTAC sequence in the CE-LPH1. Furthermore it was demonstrated that Cdx-2 is able to activate reporter gene transcription by binding to CE-LPH1. A mutation in CE-LPH1, which does not affect Cdx-2 binding, results in a higher transcriptional activity, indicating that the CE-LPH1 site contains other binding site(s) in addition to the Cdx-2-binding site.

scholarly journals The orphan receptor hepatic nuclear factor 4 functions as a transcriptional activator for tissue-specific and hypoxia-specific erythropoietin gene expression and is antagonized by EAR3/COUP-TF1.

1995 ◽  
Vol 15 (4) ◽  
pp. 2135-2144 ◽  
Author(s):  
D L Galson ◽  
T Tsuchiya ◽  
D S Tendler ◽  
L E Huang ◽  
Y Ren ◽  
...  
Keyword(s):  
Electrophoretic Mobility Shift Assay ◽  
Electrophoretic Mobility ◽  
Hela Cells ◽  
Hormone Receptor ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Response Elements ◽  
Nuclear Extracts ◽  
Hep3b Cells ◽  
Mobility Shift Assay

The erythropoietin (Epo) gene is regulated by hypoxia-inducible cis-acting elements in the promoter and in a 3' enhancer, both of which contain consensus hexanucleotide hormone receptor response elements which are important for function. A group of 11 orphan nuclear receptors, transcribed and translated in vitro, were screened by the electrophoretic mobility shift assay. Of these, hepatic nuclear factor 4 (HNF-4), TR2-11, ROR alpha 1, and EAR3/COUP-TF1 bound specifically to the response elements in the Epo promoter and enhancer and, except for ROR alpha 1, formed DNA-protein complexes that had mobilities similar to those observed in nuclear extracts of the Epo-producing cell line Hep3B. Moreover, both anti-HNF-4 and anti-COUP antibodies were able to supershift complexes in Hep3B nuclear extracts. Like Epo, HNF-4 is expressed in kidney, liver, and Hep3B cells but not in HeLa cells. Transfection of a plasmid expressing HNF-4 into HeLa cells enabled an eightfold increase in the hypoxic induction of a luciferase reporter construct which contains the minimal Epo enhancer and Epo promoter, provided that the nuclear hormone receptor consensus DNA elements in both the promoter and the enhancer were intact. The augmentation by HNF-4 in HeLa cells could be abrogated by cotransfection with HNF-4 delta C, which retains the DNA binding domain of HNF-4 but lacks the C-terminal activation domain. Moreover, the hypoxia-induced expression of the endogenous Epo gene was significantly inhibited in Hep3B cells stably transfected with HNF-4 delta C. On the other hand, cotransfection of EAR3/COUP-TF1 and the Epo reporter either with HNF-4 into HeLa cells or alone into Hep3B cells suppressed the hypoxia induction of the Epo reporter. These electrophoretic mobility shift assay and functional experiments indicate that HNF-4 plays a critical positive role in the tissue-specific and hypoxia-inducible expression of the Epo gene, whereas the COUP family has a negative modulatory role.

scholarly journals From an electrophoretic mobility shift assay to isolated transcription factors: a fast genomic-proteomic approach

BMC Genomics ◽  
2010 ◽  
Vol 11 (1) ◽  
Author(s):  
Astrid R Mach-Aigner ◽  
Karin Grosstessner-Hain ◽  
Marcio J Poças-Fonseca ◽  
Karl Mechtler ◽  
Robert L Mach
Keyword(s):  
Transcription Factors ◽  
Electrophoretic Mobility Shift Assay ◽  
Electrophoretic Mobility ◽  
Mobility Shift ◽  
Proteomic Approach ◽  
Mobility Shift Assay

A fluorescence based non-radioactive electrophoretic mobility shift assay

2000 ◽  
Vol 78 (2) ◽  
pp. 163-170 ◽  
Author(s):  
K Ruscher ◽  
M Reuter ◽  
D Kupper ◽  
G Trendelenburg ◽  
U Dirnagl ◽  
...  
Keyword(s):  
Electrophoretic Mobility Shift Assay ◽  
Electrophoretic Mobility ◽  
Mobility Shift ◽  
Mobility Shift Assay

scholarly journals Human replication-dependent histone H3 genes are activated by a tandemly arranged pair of two CCAAT boxes

2004 ◽  
Vol 384 (2) ◽  
pp. 317-326 ◽  
Author(s):  
Heiner KOESSLER ◽  
Joerg KAHLE ◽  
Christa BODE ◽  
Detlef DOENECKE ◽  
Werner ALBIG
Keyword(s):  
Electrophoretic Mobility Shift Assay ◽  
Electrophoretic Mobility ◽  
Histone H3 ◽  
Maximal Activity ◽  
Significant Loss ◽  
Tata Box ◽  
Mobility Shift ◽  
Nuclear Factor Y ◽  
Binding Factor ◽  
Mobility Shift Assay

We have analysed the transcriptional regulation of the human histone H3 genes using promoter deletion series, scanning mutagenesis, specific mutagenesis and electrophoretic mobility-shift assay experiments. The promoters of five of the six examined histone H3 genes showed near-maximal activity at lengths of 133–227 bp: H3/d 198 bp, H3/h 147 bp, H3/k 133 bp, H3/m 227 bp, H3/n 140 bp (exception H3/i). To search for functional cis-elements within these regions, we performed scanning mutagenesis of the two histone H3 promoters H3/k and H3/m. Mutagenesis revealed that the functional framework of the histone H3 promoters consists of a TATA box and two tandemly arranged CCAAT boxes in relatively fixed positions. Alterations of the distance between the CCAAT boxes and of the distance between the CCAAT boxes and the TATA box resulted in significant loss of activity. In electrophoretic mobility-shift assay experiments, the factor CBF (CCAAT-binding factor)/NF-Y (nuclear factor-Y) bound to isolated CCAAT boxes of the H3/k promoter. This suggests that an initiation complex is formed on the histone H3 promoter that has a defined structure and limited flexibility, consisting of two molecules of CBF/NF-Y and further (general or specific) transcription factors.

Sign in / Sign up

Export Citation Format

Share Document