Delimitation of far upstream sequences required for maximal in vitro transcription of an H2A histone gene.
AUTOR(ES)
Grosschedl, R
RESUMO
Sea urchin (psammechinus miliaris) H2A histone genes shown to be promoter mutants from oocyte injection experiments were tested for their ability to initiate transcription in vitro. Circular templates were transcribed with HeLa cell extracts, and the transcripts were assayed by mung bean or S1 nuclease mapping of the 5' ends. The transcripts of the H2A mutants produced in vitro were qualitatively similar and, in most cases, identical to those seen in oocyte injection experiments, but quite large quantitative differences were observed for some H2A mutant genes. Both the T-A-T-A box and far upstream sequences residing in the modulator segment E [Grosschedl, R. & Birnstiel, M. L. (1980) Proc. Natl. Acad. Sci. USA 77, 7102--7106] were found to be essential for maximal transcription in vitro. Deletion of either of these sequence elements reduced transcription to 20%. A similar reduction in the amount of H2a transcripts was found when a T-A-T-A-to-T-A-G-A point mutant was tested in vitro. Essential far upstream sequences were mapped between nucleotides -139 and -111, 5' to the initiation site of transcription. In the standard run-off transcription test using restriction fragments, the effects of these sequences could be mimicked by free DNA ends, suggesting that the function of this in vitro upstream sequence might be to provide an entry side for RNA polymerase II.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=345713Documentos Relacionados
- An intact histone 3'-processing site is required for transcription termination in a mouse histone H2a gene.
- Multiple sequence elements are required for maximal in vitro transcription of a human histone H2B gene.
- Spacer DNA sequences upstream of the T-A-T-A-A-A-T-A sequence are essential for promotion of H2A histone gene transcription in vivo.
- Sea urchin early histone H2A modulator binding factor 1 is a positive transcription factor also for the early histone H3 gene.
- Far upstream sequences are required for efficient transcription from the adenovirus-2 E1A transcription unit.