ANNA2

ANNA2 generally refers to annexin A2, a member of the annexin family of calcium-dependent phospholipid-binding proteins. In humans the canonical gene symbol is ANXA2, and ANNA2 is an alternative name used in some databases and literature to denote the same gene product. The annexin A2 protein is about 36 kilodaltons and is broadly expressed across tissues, with roles in membrane dynamics and cytoskeletal organization.

Function and mechanism

Annexin A2 binds to phospholipid membranes in a calcium-dependent manner and participates in a range of cellular processes including vesicle trafficking, membrane organization, endocytosis, and exocytosis. It forms a functional heterotetrameric complex with S100A10 (p11), known as the A2t complex, which promotes plasminogen activation on the cell surface. Through these interactions, annexin A2 participates in regulating fibrinolysis, cell surface receptor activity, and extracellular matrix remodeling. The protein also associates with actin and other cytoskeletal elements, influencing cell migration and adhesion. Phosphorylation, notably by Src-family kinases at specific tyrosine residues, modulates its localization and activity, including translocation to the cell surface.

Clinical and biological significance

Annexin A2 has been studied in various physiological and pathological contexts. It is implicated in inflammatory responses, wound healing, and angiogenesis. In oncology, altered ANXA2 expression is linked with tumor progression and metastasis in several cancers, and the A2t complex can affect cancer cell invasiveness. Autoimmune conditions may feature autoantibodies against annexin A2, reflecting a role in immune-related processes. due to its surface localization and involvement in plasmin generation, annexin A2 is also explored as a potential biomarker and therapeutic target in certain diseases.

Notes

While ANXA2 is the standard gene symbol, ANNA2 may appear in some sources; readers should verify with current gene and protein databases for precise nomenclature and isoforms.