Semaphorin 4A (SEMA4A) (SEMA4A)

Semaphorin 4A (SEMA4A) is a transmembrane glycoprotein belonging to the class IV semaphorin family, primarily known for its role in immune regulation and neural development (UniProt Q9H3S1). The extracellular domain of SEMA4A contains a characteristic Sema domain that facilitates binding to its primary receptors, including Plexin-B1, Plexin-B2, Plexin-D1, and Neuropilin-1 (PubMed: 21844396). In the immune system, SEMA4A acts as a costimulatory molecule that enhances T-cell activation and promotes the differentiation of Th1 cells, making it a key player in inflammatory responses (PubMed: 11069997). It also plays a significant role in the visual system, where it is essential for the maintenance of retinal homeostasis; consequently, mutations in SEMA4A are associated with retinal degenerative diseases like retinitis pigmentosa (PubMed: 15618541). In oncology, SEMA4A expression is often dysregulated and can influence tumor angiogenesis and the infiltration of immune cells into the tumor microenvironment (PubMed: 25065635). Therapeutic targeting of the SEMA4A extracellular domain using monoclonal antibodies is currently being explored as a strategy to treat autoimmune diseases and certain types of cancer by modulating these signaling pathways (PubMed: 30305474).

Other names

SEMBSEM4ASemaphorin-BSemaphorin-4A

Modulation of Plexin (B1, B2, D1) and Neuropilin-1 receptor signaling to regulate immune cell costimulation and vascular growth (PubMed: 21844396, PubMed: 30305474).