Fig. 6. Triglucosylated TYR(C89R) is degraded by the proteasome at a rate similar to the control. (A) TYR(C89R) was translated in the presence of SP-melanocytes with or without DNJ and/or ß-lac for 1 hour. Isolated membranes were resuspended in URL and chased at 37°C. Samples were removed at the indicated chase times, split and either separated on SDS-PAGE as described previously, or precipitated with TCA. The resulting supernatants were quantified using a scintillation counter. (B) Tyr(C85S) melanocytes were incubated with DNJ in the presence or absence of LCT, and chased with the protein synthesis inhibitor cycloheximide for 8 hours. Melanocytes were then fixed, permeabilized, and labeled with anti-tyrosinase or anti-BiP antibodies.