Trp Repressor−Operator Binding: NMR and Electrophoretic Mobility Shift Studies of the Effect of DNA Sequence and Corepressor Binding on Two Trp Repressor−Operator Complexes†

Biochemistry ◽  
2002 ◽  
Vol 41 (50) ◽  
pp. 14866-14878 ◽  
Author(s):  
Mahesh Jaseja ◽  
Mark Jeeves ◽  
Eva I. Hyde
Keyword(s):  
Electrophoretic Mobility ◽  
Dna Sequence ◽  
Mobility Shift ◽  
Trp Repressor ◽  
Operator Binding

scholarly journals Differential regulation of aldosterone synthase and 11beta-hydroxylase transcription by steroidogenic factor-1

2002 ◽  
Vol 28 (2) ◽  
pp. 125-135 ◽  
Author(s):  
MH Bassett ◽  
Y Zhang ◽  
C Clyne ◽  
PC White ◽  
WE Rainey
Keyword(s):  
Electrophoretic Mobility ◽  
Cell Model ◽  
Orphan Receptor ◽  
Luciferase Reporter ◽  
Zona Fasciculata ◽  
Genetic Linkage Analysis ◽  
Mobility Shift ◽  
Steroidogenic Factor 1 ◽  
Aldosterone Synthase ◽  
H295r Cells

11beta-Hydroxylase (hCYP11B1) and aldosterone synthase (hCYP11B2) are closely related isozymes with distinct roles in cortisol and aldosterone production respectively. Aldosterone synthase catalyzes the final step in aldosterone biosynthesis and is expressed only in the zona glomerulosa of the normal adrenal. 11beta-Hydroxylase catalyzes the final reaction in the production of cortisol and is expressed at higher levels in the zona fasciculata. The mechanisms causing differential expression of these genes are not well defined. Herein, we demonstrate contrasting roles for the orphan receptor steroidogenic factor-1 (SF-1) in the regulation of human (h) CYP11B1 and hCYP11B2. Human NCI-H295R (H295R) or mouse Y-1 cells were transiently transfected with luciferase reporter constructs containing 5'-flanking regions of hCYP11B1, hCYP11B2, human 17alpha-hydroxylase (hCYP17), human cholesterol side-chain cleavage (hCYP11A1) or mouse (m) cyp11b2 (mcyp11b2). Co-transfection of vectors encoding SF-1 increased expression of hCYP11B1, hCYP11A1 and hCYP17 constructs, but inhibited hCYP11B2 reporter activity. Murine, bovine and human SF-1 were unable to increase transcription of hCYP11B2 in H295R cells. Both hCYP11B2 and mcyp11b2 promoter constructs were inhibited similarly by human SF-1. In mouse Y-1 cells, reporter expression of hCYP11B2 and mcyp11b2 was very low compared with hCYP11B1 constructs, suggesting that this adrenal cell model may not be appropriate for studies of CYP11B2. Electrophoretic mobility shift assay demonstrated that SF-1 interacted with an element from both hCYP11B1 and hCYP11B2. However, mutation of this element, termed Ad4, did not prevent agonist stimulation of hCYP11B2 by angiotensin II or forskolin but blocked activity of hCYP11B1. In some, but not all, reports of genetic linkage analysis, a naturally occurring single nucleotide polymorphism within the Ad4 element of hCYP11B2 (-344C/T) has been associated with cardiovascular disease. Herein, we have demonstrated that this polymorphism influenced binding of SF-1 in electrophoretic mobility shift assays, with the C allele binding SF-1 more strongly than the T allele. However, when hCYP11B2 constructs containing these alleles were transfected into H295R cells, there was no difference in agonist-stimulated expression or the response of either reporter construct to co-expression with human SF-1. Taken together, these data suggest that SF-1 and the Ad4 element are not major regulators of adrenal hCYP11B2 gene expression. Thus far, hCYP11B2 is the first steroid hydroxylase gene which is not positively regulated by SF-1.

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.

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