Purified anti-human CD267 (TACI)

TACI, Transmembrane Activator CAML (calcium modulator and cyclophilin ligand) Interactor, is a 32 kD type III transmembrane protein. It belongs to TNF receptor superfamily, known as TNFRSF member 13B (TNFRSF13B) or CD267. TACI is expressed on B cells, and myeloma cells. TACI contains 2 cysteine-rich domains (CRDs). Recent studies, however, have shown that another shorter form (TACI_d2) of TACI exists wherein the N-terminal CRD is removed by alternative splicing. TACI_d2 contains full affinity for its ligands. Several proteins (BAFF/BLys, APRIL, Syndecan-2) have been identified as TACI ligands. The interaction of TACI with its ligands induces activation of the transcription factors NFAT, AP1, and NF-kappa B and plays a crucial role in humoral immunity by negative regulation of B cell proliferation and survival.