Annexin II (p36), originally discovered as a substrate for the src oncogene, is one of the most studied members of the annexin family of calcium-dependent phospholipid-binding proteins. It exists in cells as either a monomer or a heterotetramer complexed with p11, an S100-related protein. In vitro, it has been found that unphosphorylated annexin II is capable of causing aggregation of chromaffin granules, and, upon phosphorylation, induces fusion of the granules' membranes. A similiar phenomenon may occur in the final steps of exocytosis after cytoplasmic annexin translocates to the subplasmalemmal region and is phosphorylated by protein kinase C. However, other studies refute annexin II's involvement in exocytosis, and a conclusive role for annexin II in membrane trafficking remains debated.
This antibody is routinely tested by immunofluorescence microscopy. Other applications were tested at BD Biosciences Pharmingen during antibody development only or reported in the literature.