Figure 2

Intracellular localization of proSP-C^WT and proSP-C^I73T forms in stabile MLE-12 cells. Immunofluorescent analysis with an antibody against (A) lamellar body/lysosomal protein LAMP3 (red) and (B) ER protein calnexin (red) show complete localization of proSP-C^WT (green) forms and partial localization of proSP-C^I73T (green) inside of lamellar body like organelles, and no colocalization of WT or mutant forms with calnexin indicating no ER retention. While proSP-C^WT localized with (C) syntaxin 2, a protein found within lamellar bodies as surfactant secretory vesicles, and proSP-C^I73T only partially, (D) proSP-C^I73T was detectable in a significant amount in EEA1-positive early endosomes. Nuclei are stained with DAPI (blue). Scale bars - 10 μm.