Characterization of the Core Promoter of the Na+/K+‐ATPase α1 Subunit Gene
Open Access
- 1 April 1996
- journal article
- Published by Wiley in European Journal of Biochemistry
- Vol. 237 (2) , 440-446
- https://doi.org/10.1111/j.1432-1033.1996.0440k.x
Abstract
We have analyzed the core promoter element of the Na+/K+‐ATPase α1 subunit gene by means of an in vitro transcription system composed of a HeLa nuclear extract. 5′‐deletion and 3′‐deletion analyses revealed that this gene is specifically transcribed by RNA polymerase II in a manner that is dependent on the upstream regulatory region of the gene (−102 to −61), and that the 3′ boundary of the minimal promoter element does not extend beyond +5. Analysis of linker‐substitution mutations and point mutations revealed that the TATA‐like sequence (−33 to −26) is required for upstream‐sequence‐dependent transcription whereas linker‐substitution mutations and point mutations near +1 did not abolish transcription.The gene was found to be transcribed by RNA polymerase III when phosphocellulose column fractions were assayed. Deletion analysis mapped the minimal RNA‐polymerase‐III–specific promoter element from −49 to +17. The phosphocellulose 0.3‐M‐KCl fraction is absolutely required for transcription by RNA polymerase III, while the 0.85‐M‐KCl fraction represses aberrant transcription from incorrect initiation sites. Analysis of linker‐substitution mutations indicated that the TATA‐like sequence is required for RNA‐polymerase‐III–specific transcription. Although point mutations in the 5′ half of the TATA‐like sequence did not affect transcription, those in the 3′ half shifted the transcription initiation site 3 bp upstream. The results suggest that the Na+/K+‐ATPase α1 subunit gene promoter contains a TATA‐like sequence which can direct transcription by RNA polymerase III in vitro. The mechanism of alternative regulation of RNA polymerase II and RNA polymerase III is discussed.Keywords
This publication has 19 references indexed in Scilit:
- ATF-CREB heterodimer is involved in constitutive expression of the housekeeping Na,-ATPase α subunit geneNucleic Acids Research, 1995
- Different factors bind to the regulatory region of the Na+,K+‐ATPase α1‐subunit gene during the cell cycleFEBS Letters, 1993
- The transcriptional start site for a human U6 small nuclear RNA gene is dictated by a compound promoter element consisting of the PSE and the TATA boxNucleic Acids Research, 1992
- Specific transcription from the adenovirus E2E promoter by RNA polymerase III requires a subpopulation of TFIIDNucleic Acids Research, 1992
- The cloned RNA polymerase II transcription factor IID selects RNA polymerase III to transcribe the human U6 gene in vitro.Genes & Development, 1991
- Purified octamer binding transcription factors stimulate RNA polymerase III-mediated transcription of the 7SK RNA geneCell, 1989
- Accurate, TATA box-dependent polymerase III transcription from promoters of the c-myc gene in injected Xenopus oocytes.Genes & Development, 1989
- A 7 bp mutation converts a human RNA polymerase II snRNA promoter into an RNA polymerase III promoterCell, 1989
- The in vitro transcription of the 7SK RNA gene by RNA polymerase III is dependent only on the presence of an upstream promoterCell, 1987
- Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nucleiNucleic Acids Research, 1983