Tumor Necrosis Factor Alpha (TNFa)

TNFa  is synthesized as a 26 kDa, type II transmembrane protein that is 233 amino acids in length. It contains a 30 amino acid (aa) cytoplasmic domain, a 26 aa transmembrane segment, and a 177 aa extracellular region. TNFa is assembled intracellularly to form a transmembrane, non-covalently-linked homotrimeric protein. The 157 aa residue soluble form of TNFa (sTNF-αis released from the C-terminus of the transmembrane protein through the activity of TNFa-converting enzyme (TACE), a membrane -bound disintegrin metalloproteinase. Rat cells known to express TNF-αinclude B cells, colonic columnar epithelial cells, NK and CD3 CD56 hepatic natural T cells, macrophages, monocytes and monocyte-derived dendritic cells, CD4 and CD8 T cells, mast cells, neutrophils, keratinocytes, plasma cells, and adipocytes.