General Description
Vasodilator stimulated phosphoprotein (VASP) is encoded by the gene mapped to human chromosome 19q13.32. The encoded protein belongs to the Ena/VASP protein family. VASP is characterized with an N-terminal EVH1 domain, C-terminal EVH2 domain and proline-rich region.
Biochem/physiol Actions
Vasodilator stimulated phosphoprotein (VASP) acts as an actin-polymerization regulator and plays a vital role in regulation of cell migration by interacting with Migfilin, a cell-extracellular matrix (ECM) adhesion protein. Elevated expression of VASP contributes to the development of breast cancer (BC). Hence, this protein can be used as a potential biomarker for BC metastasis. Phosphorylation of VASP by protein kinase A (PKA) at phosphorylation site S157 aids in localization of cell periphery into focal adhesions, but phosphorylation of VASP at S239 and T278 aids in regulation of F-actin assembly.
Background
Vasodilator-stimulated phosphoprotein was originally characterized as a substrate of both cGMP- and cAMP-dependent kinases. It is now believed that VASP belongs to the Ena/VASP family of adaptor proteins linking the cytoskeletal system to the signal transduction pathways and that it functions in cytoskeletal organization, fibroblast migration, platelet activation, and axon guidance. Three phosphorylation sites, Ser157, Ser239, and Thr278, have been identified. Ser239 is the major PKG phosphorylation site, while Ser157 is the major PKA phosphorylation site. Evidence suggests that VASP phosphorylation reduces its association with actin and has a negative effect on actin polymerization. Phosphorylation at Ser239 of VASP is a useful marker for monitoring PKG activation and signaling.
References
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