FIG. 2.
Mutation of a polyadenylation site in the HSA cDNA alters the size of HSA mRNA but does not significantly affect the level of HSA expression. The polyadenylation signal (AATAAA) at nt 993 to 998 in HSA cDNA was changed to AgcAAA in HSA-pA-M. COS cells were transfected with either HSA-Full or HSA-pA-M. (a) Analyses of HSA mRNA by Northern blotting with an HSA DNA fragment from nt 38 to 440 as a probe. Note the essential elimination of the 1.1-kb band in the pA-M transfectants. (b) Analysis of cell surface HSA expression by flow cytometry. Histograms of HSA expression determined by staining with anti-HSA MAb M1/69 are shown. The mean fluorescence values are indicated in each panel.