Fig. 2. Levels of expression of syntaxins and munc-18 proteins in transfected epithelial cells. Total rat brain extract (lane 4, 15 µg of protein), and total cell extracts (40 µg of protein) prepared from MDCK cells non-transfected (lanes 1 and 6) or transfected with either syn3 (Syn3, lane 2), syn1A (Syn1A, lane 3), syn1A and munc-18-1 (Syn1A, M-18-1, lane 5), or syn1A and munc-18-2 (Syn1A, M-18-2, lane 7), were analyzed by western blotting using antibodies against syn3 (Syn3, lanes 1, 2), syn1 (Syn1, lanes 3,4-7), munc-18-1 (M-18-1, lanes 4 and 5) or munc-18-2 (M-18-2, lanes 6 and 7). After cDNA transfections, syn1A (lane 3) or syn1A and munc-18-1 (lane 5) are immunodetected in MDCK cells. Note the increased levels of syn3 after transfection (compare lanes 1 and 2). Similarly, after cotransfection of munc-18-2 with syn1A (lane 7) the levels of munc-18-2 are also largely increased compared to untransfected MDCK cells (compare lanes 6 and 7).
