FIGURE 2.

[³⁵S]Met/Cys pulse-chase analysis of WT and mutant UCEs. Stably transfected TREx-HeLa cell lines were metabolically labeled with [³⁵S]Met/Cys for 1 h, followed by chase periods of 3–24 h. Lysates were incubated with polyclonal anti-HA Ab to immunoprecipitate the UCEs, followed by SDS-PAGE and visualization by autoradiography as described under “Experimental Procedures.” The t½ values for the non-brain form of UCE (A and B) were as follows: WT, 14 h; R328C, 7 h; H84Q, 6 h; F513SfsX113, <30 min. The values for the brain forms (C and D) were as follows: WT, 18 h; R328C, 6 h; H84Q, 14 h. ●—●, WT; ■—■, R328C; △—△, H84Q; ♢—♢, F513SfsX113. *, nonspecific band.