GAL4-VP16 is an unusually potent transcriptional activator

Abstract

Recent work has defined a class of transcriptional activators, members of which activate transcription in yeast, plant, insect and mammalian cells. These proteins contain two parts: one directs DNA binding and the other, called the activating region, presumably interacts with some component of the transcriptional machinery. Activating regions are typically acidic and require some poorly-understood aspect of structure, probably at least in part an alpha-helix. Here we describe a new member of this class, formed by fusing a DNA-binding fragment of the yeast activator GAL4 to a highly acidic portion of the herpes simplex virus protein VP16 (ref. 11; also called Vmw65). VP16 activates transcription of immediate early viral genes by using its amino-terminal sequences to attach to one or more host-encoded proteins that recognise DNA sequences in their promoters. We show that the hybrid protein (GAL4-VP16) activates transcription unusually efficiently in mammalian cells when bound close to, or at large distances from the gene. We suggest that the activating region of VP16 may be near-maximally potent and that it is not coincidental that such a strong activator is encoded by a virus.

A KRAB-related domain and a novel transcription repression domain in proteins encoded by SSX genes that are disrupted in human sarcomas

“…To date the SSX-KRAB domain itself has not been tested for repression activity. In this study we have used a highly sensitive transcription repressor assay (TRA) ®rst described by Thiesen (1997) to assess the potential dominant repression e ect of protein domains fused to a potent transcriptional activator GAL4-VP16 (Sadowski et al, 1988).…”

A Synthetic Mammalian Therapeutic Gene Circuit for Sensing and Suppressing Inflammation

“…These modules were interconnected via the well-characterized transcriptional activator Gal4-VP16 (GV16), 19 which is orthogonal to mammalian intracellular signaling and transcriptional pathways. To demonstrate the concept of an antiinflammatory device that could be used in patients with inflammatory diseases, we aimed to develop a system that could sense a common signal of inflammation.…”

Cath6, a bHLH atonal family proneural gene, negatively regulates neuronal differentiation in the retina

“…We speculated that Cath6 might function as a transcriptional repressor to counteract the function of these Atonal family genes, although Cath6 did not display significant sequence similarities to known transcriptional repressors. To test this possibility, we generated two types of chimeric constructs of Cath6; one was fused with the transcriptional activation domain of VP16 (Sadowski et al, 1988;Shimizu et al, 2002) and the other one fused with the transcriptional repressor domain of Engrailed (EnR; Fan and Sokol, 1997;Shimizu et al, 2002) (Fig. 5A).…”