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 (PubMed:18799458, PubMed:24808179, PubMed:22848640). 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 (PubMed:21886777). Interacts (via repeat Annexin 1) with PCSK9 (via the C-terminal domain); the interaction inhibits the degradation of LDLR (PubMed:18799458). Interacts with CEACAM1 (via the cytoplasmic domain); this interaction is regulated by phosphorylation of CEACAM1 (PubMed:14522961). Interacts with APPL2 and APPL1; targets APPL2 to endosomes and acting in parallel to RAB5A (By similarity). Interacts with S100A4 (PubMed:28669632). (Microbial infection) Interacts with human cytomegalovirus (HCMV). In the lamina beneath the plasma membrane. Identified by mass spectrometry in melanosome fractions from stage I to stage IV. Translocated from the cytoplasm to the cell surface through a Golgi-independent mechanism. A pair of annexin repeats may form one binding site for calcium and phospholipid. Phosphorylation of Tyr-24 enhances heat stress-induced translocation to the cell surface. ISGylated. It may cross-link plasma membrane phospholipids with actin and the cytoskeleton and be involved with exocytosis. Belongs to the annexin family. Extended N-terminus. Red velvet - Issue 86 of September 2007