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Repression of the lac promoter may be achieved in two different ways: either by interference with the action of RNA polymerase or by interference with CAP activation. We investigated cooperative repression of the Escherichia coli lac operon by systematic conversion of its three natural operators (O1, O2 and O3) on the chromosome. We find that cooperative(More)
We tested the effect of systematic destruction of all three lac operators of the chromosomal lac operon of Escherichia coli on repression by Lac repressor. Absence of just one 'pseudo-operator' O2 or O3 decreases repression by wild-type tetrameric Lac repressor approximately 2- to 3-fold; absence of both 'pseudo-operators' decreases repression greater than(More)
Downregulation of E-cadherin is a crucial event for epithelial to mesenchymal transition (EMT) in embryonic development and cancer progression. Using the EpFosER mammary tumour model we show that during EMT, upregulation of the transcriptional regulator deltaEF1 coincided with transcriptional repression of E-cadherin. Ectopic expression of deltaEF1 in(More)
The tetrameric Lac repressor can bind simultaneously to two lac operators on the same DNA molecule, thereby including the formation of a DNA loop. We investigated the phasing dependence of DNA loop formation between lac operator O1 and an auxiliary ideal lac operator (O(id)) on the bacterial chromosome, with inter-operator distances varying from 57.5 to(More)
Plectin, a cytolinker protein greater than 500 kDa in size, has an important role as a mechanical stabiliser of cells. It interlinks the various cytoskeletal filament systems and anchors intermediate filaments to peripheral junctional complexes. In addition, there is increasing evidence that plectin acts as a scaffolding platform that controls the spatial(More)
Based on cDNA cloning and sequencing, human epiplakin has been classified as a member of the plakin protein family of cytolinkers. We report here the characterization of the mouse epiplakin gene locus and the isolation of full-length mouse epiplakin cDNA using BAC vectors. We found that the protein is encoded by a single remarkably large exon (>20 kb) that(More)
BACKGROUND The aim of this study was to evaluate the validity of a three-dimensional (3D) multiple stereo camera system for objective breast assessment. METHODS A multiple stereo camera system, which consisted of four pods and eight cameras, two cameras on each pod, developed by Glasgow University, was used. Nine specially shaped plaster breast models(More)
Insulin-like growth factor (IGF) signaling is a key regulator of breast development and breast cancer. We have analyzed the expression of the IGF signaling cascade in 17 human breast cancer and 4 mammary epithelial cell lines. Five cell lines expressed high levels of IGF1 receptor, insulin (INS)/IGF receptor substrate 1, IGF-binding proteins 2 and 4, as(More)
Exchanges in positions 1 and 2 of the putative recognition helix allow lac repressor to bind to ideal lac operator variants in which base pair 4 has been replaced. We show here that an Arg-22----Asn exchange in position 6 of the putative recognition helix of lac repressor abolishes lac repressor binding to ideal lac operator. This lac repressor variant,(More)
The ability to bind to nitrocellulose is commonly accepted as being a universal property of proteins and has been widely used in many different fields of study. This property was first exploited in the study of DNA-binding proteins 30 years ago, in studies involving DNA binding by the lactose repressor (LacR) of Escherichia coli. Termed the filter-binding(More)