Characterization of the Core Promoter of the Na+/K+‐ATPase α1 Subunit Gene
Tóm tắt
We have analyzed the core promoter element of the Na+/K+‐ATPase α1 subunit gene by means of an
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
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Smith T. J., 1979, The role of sodium transport in thyroid thermogenesis, Fed. Proc., 38, 2150
Lingrel J. B., 1992, Na+/K+‐ATPase: isoform structure, function, and expression, J. Bioenerg. Biomembr., 24, 263, 10.1007/BF00768847
Orlowski J., 1988, Tissue‐specific and developmental regulation of rat Na, K‐ATPase catalytic α isoform and β subunit mRNAs, J. Biol. Chem., 263, 10436, 10.1016/S0021-9258(19)81535-1
Kawakami K., 1993, Different factors bind to the regulatory region of the Na+ K+‐ATPase α1‐subunit gene during the cell cycle, FEBS Lett., 535, 251, 10.1016/0014-5793(93)80740-L
Kawakami K., 1994, The sodium pump: structure, mechanism, hormonal control and its role in disease, 1
Smale S. T., 1994, Transcription; mechanisms and regulation, 63
Steinberg T. H., 1990, Tagetoxin: a new inhibitor of eukaryotic transcription by RNA polymerase III, J. Biol. Chem., 265, 499, 10.1016/S0021-9258(19)40259-7
Steinberg T. H., 1992, Tagetoxin inhibition of RNA polymerase III transcription results from enhanced pausing at discrete sites and is template‐dependent, J. Biol. Chem., 267, 20204, 10.1016/S0021-9258(19)88687-8
Kassavetis G. A., 1994, Transcription; mechanisms and regulation, 107
Goomer R. S., 1992, 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 box, Nucleic Acids Res., 18, 4903, 10.1093/nar/20.18.4903
Pruzan R., 1992, Specific transcription from the adenovirus E2E promoter by RNA polymerase III requires a subpopulation of TFIID, Nucleic Acids Res., 20, 5705, 10.1093/nar/20.21.5705
Mitchell M. T., 1992, TATA box‐mediated polymerase III transcription in vitro, J. Biol. Chem., 267, 1995, 10.1016/S0021-9258(18)46045-0
Segall J., 1980, Multiple factors are required for the accurate transcription of purified genes by RNA polymerase III, J. Biol. Chem., 255, 11986, 10.1016/S0021-9258(19)70231-2