دورية أكاديمية
Sp1 and Sp3 control constitutive expression of the human NHE2 promoter by interactions with the proximal promoter and the transcription initiation site
| العنوان: | Sp1 and Sp3 control constitutive expression of the human NHE2 promoter by interactions with the proximal promoter and the transcription initiation site |
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| المؤلفون: | Pearse, Ian, Zhu, Ying X., Murray, Eleanor J., Dudeja, Pradeep K., Ramaswamy, Krishnamurthy, Malakooti, Jaleh |
| المصدر: | Biochemical Journal ; volume 407, issue 1, page 101-111 ; ISSN 0264-6021 1470-8728 |
| بيانات النشر: | Portland Press Ltd. |
| سنة النشر: | 2007 |
| مصطلحات موضوعية: | Cell Biology, Molecular Biology, Biochemistry |
| الوصف: | We have previously cloned the human Na+/H+ exchanger NHE2 gene and its promoter region. In the present study, the regulatory elements responsible for the constitutive expression of NHE2 were studied. Transient transfection assays revealed that the −40/+150 promoter region contains the core promoter responsible for the optimal promoter activity. A smaller fragment, −10/+40, containing the TIS (transcription initiation site) showed minimal activity. We identified a palindrome that overlaps the TIS and binds to the transcription factors Sp1 and Sp3. Mutations in the 5′ flank of the palindrome abolished the Sp1/Sp3 interaction and reduced promoter activity by approx. 45%. In addition, a conserved GC-box centered at −25 was found to play a critical role in basal promoter activity and also interacted with Sp1 and Sp3. An internal deletion in the GC-box severely reduced the promoter activity. Sp1/Sp3 binding to these elements was established using gel-mobility shift assays, confirmed by chromatin immunoprecipitation and co-transfections in Drosophila SL2 cells. Furthermore, we identified two positive regulatory elements in the DNA region corresponding to the 5′-UTR (5′-untranslated region). The results in the present study indicate that Sp1 and Sp3 are required for constitutive NHE2 expression and that the positive regulatory elements of the 5′-UTR may co-operate with the 5′-flanking region to achieve the optimal promoter activity. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1042/bj20070364 |
| الإتاحة: | https://doi.org/10.1042/bj20070364Test https://portlandpress.com/biochemj/article-pdf/407/1/101/648010/bj4070101.pdfTest |
| رقم الانضمام: | edsbas.CA7154C3 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1042/bj20070364 |
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