Fig. 9. The effect of Rab22a expression on Golgi apparatus morphology in HeLa cells. Rab22a or its mutant forms were expressed with the Vaccinia T7 system, and the cells were processed for immunofluorescence microscopy; triple stainings with antibodies against GM130, EEA1 and the expressed Rab were carried out. A-E: cells expressing wt Rab22a; F-J: cells expressing the Q64L mutant; K-O, cells expressing the S19N mutant. A,F,K, GM130 staining; B,G,L, EEA1 staining; C,H,M, Rab22a staining. Overlays are shown in D,E,I,J,N and O. The wt Rab22a and the Q64L mutant cause a complete fragmentation of the Golgi apparatus and colocalize significantly with both GM130 and EEA1. No significant mixing of the Golgi and early endosome markers is detected. An untransfected cell with a compact Golgi is seen, for example, in the upper right-hand corner of panel A. The S19N mutant shows colocalization with GM130 but does not induce any redistribution of the Golgi apparatus. Bar=10 µm.