Fig. 1. Rab8 modulates cell shape changes. (A) A control stable cell line expressing GFP (green fluorescent protein) form semi-ordered contacts, while (B) a stable cell line expressing Rab8-Q67L (pEGFP-Rab8-Q67L) have lost contact inhibition and (C) a stable cell line expressing Rab8-T22N (pEGFP-Rab8-T22N) shows close cell-cell contacts. (D) Expression of EGFP-Rab8-T22N, EGFP-RabQ67L (GFP-Rab8) and endogenous Rab8 (Rab8) in these stable cell lines was monitored by western blotting. (E-K) Depletion of Rab8 from HT1080 fibrosarcoma cells by RNAi. HT1080 cells were transfected with control RNAi (E,G,I) or with Rab8-specific RNAi (F,H,J). Note that Rab8 depletion promotes cell-cell adhesion (F,H). Arrows indicated cells with lamellar structures (I), whereas cells containing actin stress fibers are indicated by arrowheads (J). (K) Total lysates from cells transfected with control or Rab8-specific RNAi were analyzed by western blotting by anti-actin and anti-Rab8 antibodies. Bars, 200 µM (A-C,E-H), 20 µM (I,J).