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Repressive regulation of the aquaporin-2 gene
- Source :
- The American journal of physiology. 271(4 Pt 2)
- Publication Year :
- 1996
-
Abstract
- Expression of aquaporin-2 (AQP2) is exclusively limited to kidney collecting duct cells, and this strictly limited expression could be mediated by transcription of the gene. We first examined AQP2 mRNA expression in many cultured epithelial cells derived from kidney. Northern blot using OK, LLC-PK1, Madin-Darby canine kidney, and outer medullary collecting duct (OMCD) cells and primary culture of inner medullary collecting duct (IMCD) cells did not reveal any significant signal. A more sensitive method, ribonuclease protection assay, could detect a faint signal in OMCD cells when they were bathed in a hypertonic medium. Reverse-transcribed polymerase chain reaction applied to primary culture of IMCD cells showed a rapid dissipation of AQP2 mRNA within 4 days after culture. A reporter gene assay performed in the 1st day of primary culture of IMCD cells showed that the 5' region up to -2.9 kb worked as a promoter. Deletion experiments showed that at least two regions, from -434 to -364 and from -153 to -84, contain negatively acting cis-elements. When connected to a heterologous promoter, these regions repressed the activity in an orientation-dependent manner. These results suggest that transcription of AQP2 gene is strictly regulated and its ability is rapidly depressed in culture condition. This cell differentiation-specific expression of the gene may be, at least in part, mediated by the repressors present in its 5'-flanking region.
- Subjects :
- Transcription, Genetic
Physiology
Swine
Biology
Aquaporins
Kidney
Ion Channels
Cell Line
Mice
Dogs
Transcription (biology)
Gene expression
Animals
Northern blot
RNA, Messenger
Promoter Regions, Genetic
Genetics
Regulation of gene expression
Reporter gene
Messenger RNA
Aquaporin 2
urogenital system
Opossums
Molecular biology
Aquaporin 6
Gene Expression Regulation
Cell culture
Subjects
Details
- ISSN :
- 00029513
- Volume :
- 271
- Issue :
- 4 Pt 2
- Database :
- OpenAIRE
- Journal :
- The American journal of physiology
- Accession number :
- edsair.doi.dedup.....f181d8914378485e289a6d63608b38f7