This study demonstrates the presence of positive and negative regulatory elements within a 2336-base pair-long region of the rat choline acetyltransferase (ChAT) gene promoter that cooperate to direct cell type-specific expression in cholinergic cells. A 21-base pair-long neuron-restrictive silencer element (NRSE) was identified in the proximal part of this region. This element was recognized b...

The murine B29 (Igbeta) promoter is B cell specific and contains essential SP1, ETS, OCT, and Ikaros motifs. Flanking 5' DNA sequences inhibit B29 promoter activity, suggesting this region contains silencer elements. Two adjacent 5' DNA segments repress transcription by the murine B29 promoter in a position- and orientation-independent manner, analogous to known silencers. Both these 5' segment...

The neuron-restrictive silencer factor [NRSF (RE-1 silencing transcription factor/X box repressor)] is a transcriptional silencer, which we have previously implicated in deregulation of the vasopressin promoter in small cell lung cancer (SCLC). Here we describe a novel splice variant of the NRSF transcript, which is highly expressed in SCLCs. The variant was detected in both established cell li...

Rag1 and Rag2 gene expression in CD4(+)CD8(+) double-positive (DP) thymocytes depends on the activity of a distant anti-silencer element (ASE) that counteracts the activity of an intergenic silencer. However, the mechanistic basis for ASE activity is unknown. Here, we show that the ASE physically interacts with the distant Rag1 and Rag2 gene promoters in DP thymocytes, bringing the two promoter...

The noncoding region of the highly oncogenic, epidermodysplasia verruciformis-associated human papillomavirus type 8 contains a negative regulatory element (NRE). Quantitative RNase protection analysis confirmed that the NRE sequence acts as a silencer of transcription. A 38-bp sequence upstream of late promoter P7535 down-regulated expression from the homologous P7535 promoter, as well as the ...

Mechanisms controlling transcription and its regulation are fundamental to our understanding of molecular biology and, ultimately, cellular biology. Our knowledge of transcription initiation and integral factors such as RNA polymerase is considerable, and more recently our understanding of the involvement of enhancers and complexes such as holoenzyme and mediator has increased dramatically. How...

A portion of the 5”flanking region of the glycoprotein IIb (aI,) integrin gene extending from -598 to +32 base pairs was isolated. This DNA segment is capable of driving low level base-line transcription in undifferentiated K562 cells. It also contains elements which direct the markedly increased expression observed following megakaryocytic differentiation of K562 cells with phorbo1 dibutyr...

The Drosophila germline lineage depends on a complex microenvironment of extrinsic and intrinsic factors that regulate the self-renewing and asymmetric divisions of dedicated stem cells. Germline stem cells (GSCs) must express components of the Dpp cassette and the translational repressors Nanos and Pumilio, whereas cystoblasts require the bam and bgcn genes. Bam is especially attractive as a t...