Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner. Half-maximal membrane binding requires about 60 uM calcium. Does not bind to membranes that lack phospholipids with an acidic headgroup. Binds to membranes enriched in phosphatidylserine or phosphatidylglycerol in a calcium-dependent manner, but requires higher calcium levels for membrane binding than isoform A. Half-maximal membrane binding requires about 320 uM calcium (By similarity). May play a role in vesicular traffic to the apical plasma membrane (Probable). Monomer and homodimer. Myristoylation anchors the protein to the membrane, but the protein also displays calcium-dependent, reversible binding to lipid membranes. Enriched in apical vesicles. Detected in intestine, and at much lower levels also in kidney (at protein level). A pair of annexin repeats may form one binding site for calcium and phospholipid. Belongs to the annexin family.