The 13 first N-terminal amino acids of At GCSI contain ER targeting information. CLSM analysis of transgenic tobacco BY-2 cells showing cortical views (A, C) or cross sections (B, D). (A, B) GCS90 accumulates in the ER in BY-2 suspension-cultured cells. (C, D) Δ13GCS90 accumulates into the Golgi apparatus. Bars = 8 μm.