Gene Summary: The protein encoded by TNFSF13B gene is a cytokine that belongs to the tumor necrosis factor (TNF) ligand family. This cytokine is a ligand for receptors TNFRSF13B/TACI, TNFRSF17/BCMA, and TNFRSF13C/BAFFR. This cytokine is expressed in B cell lineage cells, and acts as a potent B cell activator. It has been also shown to play an important role in the proliferation and differentiation of B cells. Alternatively spliced transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Mar 2011]General information above from NCBI
Subunit structure: Homotrimer. Isoform 2 heteromultimerizes with isoform 1, probably limiting the amount of functional isoform 1 on the cell surface. Isoform 3 is unlikely form trimers or bind to BAFF receptors.
Subcellular location: Cell membrane; Single-pass type II membrane protein.
Tumor necrosis factor ligand superfamily member 13b, soluble form: Secreted.
Tissue specificity: Abundantly expressed in peripheral blood Leukocytes and is specifically expressed in monocytes and macrophages. Also found in the spleen, lymph node, bone marrow, T- cells and dendritic cells. A lower expression seen in placenta, heart, lung, fetal liver, thymus, and pancreas. Isoform 2 is expressed in many myeloid cell lines.
Induction: Up-regulated by exposure to IFNG/IFN-gamma. Down- regulated by phorbol myristate acetate/ionomycin treatment.
Post-translational: The soluble form derives from the membrane form by proteolytic processing.
Isoform 2 is not efficiently shed from the membrane unlike isoform 1 (By similarity).
Sequence similarity: Belongs to the tumor necrosis factor family.
General information above from UniProt