BD Pharmingen™ Purified Rat Anti-Mouse Syndecan-4

The KY/8.2 mAb reacts with mouse syndecan-4, a cell-surface heparan sulfate proteoglycan. Although the ligand(s) for this molecule is unknown, syndecans are known to interact with the heparin-binding domain of growth factors, chemokines, and extracellular matrix components. Accordingly, heparin inhibits the binding of syndecan-4 to the pre-B cell line BC7.12. Syndecan-4 is localized to focal adhesions and binds protein-kinase Cα. Thus, it is involved in cytoskeletal organization and signaling. Syndecan-4 is expressed on stromal cells and B-lymphocyte precursors in bone marrow, in addition to most splenic B cells and a small population of T lymphocytes. It is highly expressed on activated B lymphocytes, but is downregulated in isotype-switched memory B cells. The ectodomain of syndecan-4 is shed from cell surfaces constitutively and in response to specific physiological signals, and the resulting soluble fragments are functional. Immobilized KY/8.2 mAb induced the formation of dendritic  processes on syndecan-4-transfected cells and on anti-CD40-activated splenic B cells. Other methods of activating B cells have not produced the same effect. This antibody recognizes an epitope in the N-terminus of syndecan-4, regardless of post-translational modifications.