Calcium-regulated membrane-binding protein whose affinity for calcium is greatly enhanced by anionic phospholipids. It binds two calcium ions with high affinity. May be involved in heat-stress response. Inhibits PCSK9-enhanced LDLR degradation, probably reduces PCSK9 protein levels via a translational mechanism but also competes with LDLR for binding with PCSK9. Heterotetramer containing 2 light chains of S100A10/p11 and 2 heavy chains of ANXA2/p36 (PubMed:17446234). 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). Interacts with APPL2 and APPL1; targets APPL2 to endosomes and acting in parallel to RAB5A (By similarity). Interacts with S100A4 (By similarity). In the lamina beneath the plasma membrane. Detected in myometrium. Up-regulated in myometrium upon progesterone treatment. A pair of annexin repeats may form one binding site for calcium and phospholipid. ISGylated. It may cross-link plasma membrane phospholipids with actin and the cytoskeleton and be involved with exocytosis. Belongs to the annexin family. Red velvet - Issue 86 of September 2007