Tonicity Responsive Enhancer Binding Protein
| Nuclear factor of activated T-cells 5, tonicity-responsive | ||
|---|---|---|
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| Structure of NFAT5 according to PDB 1imh | ||
| Properties of human protein | ||
| Mass / length primary structure | 1531 aa; 165.7 kDa | |
| Identifier | ||
| Gene names | NFAT5 ; KIAA0827; NF-AT5; NFATL1; NFATZ; OREBP; TONEBP | |
| External IDs | ||
| Occurrence | ||
| Parent taxon | Euteleostomi | |
| Orthologue | ||
| human | mouse | |
| Entrez | 10725 | 54446 |
| Ensemble | ENSG00000102908 | ENSMUSG00000003847 |
| UniProt | O94916 | Q3UW17 |
| Refseq (mRNA) | NM_006599 | NM_018823 |
| Refseq (protein) | NP_006590 | NP_061293 |
| Gene locus | Chr 16: 68.16 - 68.3 Mb | Chr 8: 110.18 - 110.27 Mb |
| PubMed search | 10725 |
54446
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Tonicity-Responsive Enhancer Binding Protein (TonEBP or NFAT5 / OREBP) is a transcription factor that belongs to the Rel family of transcription factors. TonEBP protects the cell from hypertonic stress. If the osmolar pressure in the cell is normal (isoosmolar situation), TonEBP is only partially (partially) active. If the osmolar pressure in the cell increases, the TonEBP mRNA is stabilized and the TonEBP protein is thus transcribed more intensely . TonEBP promotes the transcription of the genes of various proteins, such as aldose reductase , sodium myo-inositol cotransporters , sodium chloride betaine cotransporters , and taurine transporters . This leads to an increase in the concentration of the molecules sorbitol , betaine , myo- inositol and taurine in the cell. These molecules are osmotically active ( osmolytes ) and electrically neutral; an increase in their concentration therefore reduces the osmotic pressure on the cell wall and the ionic strength in the cell. In addition, TonEBP stimulates the transcription of the genes of ADH -regulated urea transporters and heat shock proteins . These proteins protect the cell from the harmful effects of excessively high urea concentrations. In the kidney, TonEBP promotes transcription of the aquaporin or water channel AQP2. As a result, the excretion of water decreases, the concentration of the urine increases and the osmolarity of the extracellular fluid decreases.
References
- ↑ Udo Hasler et al .: Tonicity-Responsive Enhancer Binding Protein Is an Essential Regulator of Aquaporin-2 Expression in Renal Collecting Duct Principal Cells . In: J Am Soc Nephrol 2006 17: 1521-1531