Intracellular localization of proSP-CWT and proSP-CI73T 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-CWT (green) forms and partial localization of proSP-CI73T (green) inside of lamellar body like organelles, and no colocalization of WT or mutant forms with calnexin indicating no ER retention. While proSP-CWT localized with (C) syntaxin 2, a protein found within lamellar bodies as surfactant secretory vesicles, and proSP-CI73T only partially, (D) proSP-CI73T was detectable in a significant amount in EEA1-positive early endosomes. Nuclei are stained with DAPI (blue). Scale bars - 10 μm.
Woischnik et al. BMC Cell Biology 2010 11:88 doi:10.1186/1471-2121-11-88