852430.fig.002
Figure 2: Recruitment of AnxA2 to several sites in the endocytic pathway. AnxA2 is shown as little green structures, filamentous actin as wavy lines, and Src is represented as orange diamonds. EPEC: Association with the actin-rich pedestals of noninvasive enteropathogenic E.coli. Phagosome: AnxA2 is recruited to actin-rich phagosomes during pigmented retinal epithelial cell phagocytosis of rod outer segments. Macropinosome: AnxA2 is recruited to PI(4,5)P2-rich (purple shading) macropinosomes and is absolutely required for their actin-based rocketing (Comet). Macropinosomes or other early endosomes may mature into APPL2/OCRL1-positive early endosomes. These in turn mature into EEA1-positive endosomes. Endocytic trafficking appears to be involved in formation and reformation of the adherens junction (AJ) and extracellular AnxA2/S110A10 complex, which may be released in exosomes when multivesicular late endosomes (MVBs) fuse with the plasma membrane that may contribute to tight junction stability by cross-linking adjacent membranes. The role of AnxA2 in formation of the apical domain is more speculative but may involve formation of a preformed vacuolar apical compartment (VAC), which then may fuse with the apical surface.