Figure 5.

Requirement for furin in proreceptor proteolytic processing. Immunoblot analysis of receptors transfected into furin-null RPE40 cells and the isogenic control cells (furin+). The presence of carbohydrate added in the trans-Golgi is indicated (added carbohydrate, +CHO; without added carbohydrate, −CHO). Exposure times of the ECL film for wild-type (WT) and Pro⁶² samples were optimized separately. (B) Immunoblot analysis of receptors transfected into HEK293 cells. The transfected cDNA is indicated at the top (lane 1, WT; lane 2, WT and furin; lane 3, Pro⁶² (P⁶²); lane 4, Pro⁶² and furin; lane 5, [P⁶²A⁷³²]; lane 6, [P⁶²A⁷³²] and furin).