Characterization of cis-acting element in renal NaPi-2 cotransporter mRNA that determines mRNA stability.
Hypophosphatemia leads to an increase in Na(+)-P(i) cotransporter (NaPi-2) mRNA levels. This increase is posttranscriptional and correlates with a more stable transcript mediated by the terminal 698 nt of the NaPi-2 mRNA. A 71-nt binding element was identified with renal proteins from rats fed control and low-P(i) (-P(i)) diet. The binding of -P(i) renal proteins to this transcript was increased compared with control proteins. The functionality of the cis element was demonstrated by an in vitro degradation assay. -P(i) renal proteins stabilized transcripts that included the cis element compared with control renal extracts. The full-length NaPi-2 transcript, but not control transcripts, was stabilized by -P(i) extracts. Insertion of the binding element into green fluorescent protein (GFP) as a reporter gene decreased chimeric GFP mRNA levels in transfection experiments. Our results suggest that the protein-binding region of the NaPi-2 mRNA functions as a cis-acting instability element. In hypophosphatemia there is increased binding to the cis-acting element and subsequent stabilization of NaPi-2 mRNA.
Moz
Yulia
Y
Minerva Center for Calcium and Bone Metabolism, Nephrology Services, Hadassah University Hospital, Jerusalem, Israel 91120.
Silver
Justin
J
Naveh-Many
Tally
T
D000818:Animals; D002474:Cell-Free System; D024202:Electrophoretic Mobility Shift Assay; D017930:Genes, Reporter; D007668:Kidney / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D016226:Phosphorus, Dietary; D011485:Protein Binding / Q000502:physiology; D020871:RNA Stability / Q000502:physiology*; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D020218:Response Elements / Q000502:physiology*; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters / Q000235:genetics*; D014162:Transfection
D016226:Phosphorus, Dietary; D012333:RNA, Messenger; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters