Effect of Differential Polyadenylation and Cell Growth Phase on Dihydrofolate Reductase mRNA Stability

AU: V. Noé, C.J. Ciudad, and L.A. Chasin

SO: Journal of Biological Chemistry 274, pp 27807-27814, 1999

We have constructed tetracycline responsive dhfr minigenes and obtained cells in which dhfr transcription can be repressed by tetracycline (tet-off). Using these cells, we have determined that DHFR mRNA half-life is significantly shorter than previously reported. In addition, we have observed that DHFR mRNA is less stable in serum-starved cells than in exponentially growing cells. Given that the dhfr gene contains multiple polyadenylation sites (1) we have analyzed the role of polyadenylation site usage on the stability of the resultant mRNA molecules. We have determined that DHFR mRNA half-life is longer when a strong polyadenylation site is used. Finally, we have observed that the poly(A) length of DHFR mRNA is involved in its cell growth stability.