Protein-RNA Interactions Determine the Stability of the Renal NaPi-2 Cotransporter mRNA and Its Translation in Hypophosphatemic Rats
| Autor: | Tally Naveh-Many, Justin Silver, Yulia Moz |
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| Rok vydání: | 1999 |
| Předmět: |
Male
Untranslated region Hypophosphatemia Biology Kidney Biochemistry Sodium-Phosphate Cotransporter Proteins Type II Gene expression medicine Protein biosynthesis Animals RNA Messenger 3' Untranslated Regions Molecular Biology Messenger RNA Symporters Three prime untranslated region Sodium-Phosphate Cotransporter Proteins Cell Biology medicine.disease Molecular biology Rats medicine.anatomical_structure Protein Biosynthesis 5' Untranslated Regions Carrier Proteins |
| Zdroj: | Journal of Biological Chemistry. 274:25266-25272 |
| ISSN: | 0021-9258 |
| Popis: | Hypophosphatemia leads to an increase in type II Na(+)-dependent inorganic phosphate cotransporter (NaPi-2) mRNA and protein levels in the kidney and increases renal phosphate reabsorption. Nuclear transcript run-on experiments showed that the effect of a low phosphate diet was post-transcriptional. In an in vitro degradation assay, renal proteins from hypophosphatemic rats stabilized the NaPi-2 transcript 6-fold compared with control rats and this was dependent upon an intact NaPi-2 3'-untranslated region (UTR). To determine an effect of hypophosphatemia upon NaPi-2 protein synthesis, the incorporation of injected [(35)S]methionine into renal proteins was studied in vivo. Hypophosphatemia led to increased [(35)S]methionine incorporation only into NaPi-2 protein. The effect of hypophosphatemia on translation was studied in an in vitro translation assay, where hypophosphatemic renal proteins led to increased translation of NaPi-2 and other transcripts. NaPi-2 RNA interaction with cytosolic proteins was studied by UV cross-linking and Northwestern gels. Hypophosphatemic proteins led to increased binding of renal cytosolic proteins to the 5'-UTR of NaPi-2 mRNA. Therefore, hypophosphatemia increases NaPi-2 gene expression post-transcriptionally, which correlates with a more stable transcript mediated by the 3'-UTR, and an increase in NaPi-2 translation involving protein binding to the 5'-UTR. These findings show that phosphate regulates gene expression by affecting protein-RNA interactions in vivo. |
| Databáze: | OpenAIRE |
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