Cell Surface Expression of CEACAM1-4S.

<p>253T-NT cultures stably transfected with wild type or mutated forms of CEACAM1-4S were labeled by indirect immunofluorescence with MAb 9.2, a monoclonal antibody specific for CEACAM1. Cell nuclei were stained with propidium iodide. Confocal digital images constructed from 7–15 optical sections for each labeled subline are shown in panels A–L. (<b>A</b>) wild type CEACAM1-4S; (<b>B</b>) G424L mutant; (<b>C</b>) G432L mutant; (<b>D</b>) G424L and G432L double mutant; (<b>E</b>) Empty vector; (<b>F</b>) Y445V mutant; (<b>G</b>) Y448V mutant; (<b>H</b>) Y445V and Y448V double mutant; (<b>I</b>) G424L, G432L, Y445V, Y448V quadruple mutant; (<b>J</b>) untransfected 253T-NT cells; (<b>K</b>) G424L, G432L and Y445V triple mutant; (<b>L</b>) G424L, G432L and Y448V triple mutant. Scale bar represents 20 mm.