Nerve growth factor mRNA stability is controlled by a cis-acting instability determinant in the 3'-untranslated region.
Nerve growth factor (NGF) mRNA is rapidly degraded in many non-neuronal cell types with a half-life of between 30 and 60 min. Similar to other short-lived mRNAs the 3'-untranslated region (3'-UTR) of the NGF mRNA contains a short AU nucleotide-rich sequence. To implicate this region as a cis-acting determinant of NGF mRNA instability, expression vectors containing NGF cDNA with and without the 3'-UTR, and vectors containing only the 3'-UTR were constructed and used in cell transfection experiments. Transfection of HEK293 or NIH3T3 cells with these expression vectors followed by measurement of NGF mRNA half-life indicated that NGF mRNA without the AU-rich 3'-UTR was approximately 3-fold more stable than NGF mRNA containing the 3'-UTR. Similar results were seen in a polysome-based cell-free RNA decay assay using NGF mRNA with and without the 3'-UTR prepared from transfected cells. Addition of a short RNA containing the AU-rich 3'-UTR to the cell-free RNA decay system prolonged the half-life of the full-length NGF mRNA, suggesting competition between these two RNA species for polysome-associated factors which degrade the NGF mRNA. Moreover, transfection of HEK293 or astroglial cells with vectors designed to express only the AU-rich region of the 3'-UTR resulted in enhanced expression of NGF mRNA. The results indicate that the 3'-UTR of the NGF mRNA contains a cis-acting instability determinant which, perhaps by interacting with trans-acting RNA-binding proteins, controls the rate of NGF mRNA turnover.
Tang
B
B
Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20007, USA.
Wang
M
M
Wise
B C
BC
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002478:Cells, Cultured / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D007668:Kidney / Q000166:cytology; D009414:Nerve Growth Factors / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D014162:Transfection
D009414:Nerve Growth Factors; D012333:RNA, Messenger