Calcium-regulated membrane-binding protein whose affinity for calcium is greatly enhanced by anionic phospholipids. It binds two calcium ions with high affinity (By similarity). Heterotetramer containing 2 light chains of S100A10/p11 and 2 heavy chains of ANXA2/p36 (By similarity). Interacts with ATP1B1 (By similarity). Interacts with DYSF (By similarity). Interacts with COCH. Interacts (via repeat Annexin 1) with PCSK9 (via the C-terminal domain); the interaction inhibits the degradation of LDLR. Interacts with CEACAM1 (via the cytoplasmic domain); this interaction is regulated by phosphorylation of CEACAM1 (By similarity). Belongs to the annexin family.