Munc18c is required for apical localization of syntaxin 4-L25A,V26A. A, localization of syntaxin 4-WT-EGFP in control and munc18cKD2 c20 cells. B, localization of syntaxin 4-L25A,V26A-EGFP in control and munc18cKD2 c20 cells. Apical, basolateral, and z-sections are shown. C, localization of syntaxin 4-L25A,V26A in control (+dox) and FLAG-munc18c expressing cells (−dox). D, localization of syntaxin 4-L8K,L25A,V26A in control (+dox) and FLAG-munc18c expressing cells (−dox). E, localization of syntaxin 4-Δ30 in control (+dox) and FLAG-munc18c expressing cells (−dox). Top panels and z-section shows EGFP and the bottom panels show FLAG staining. Scale bars, 20 μm.