Recombinant Human TNF RII/TNFRSF1B (aa 24-206) Protein

TNF RI (also known as the p60 or p55 TNFR) and TNF RII (the p75 or p80 TNFR) are two distinct type I transmembrane glycoproteins that bind TNF with high-affinity. Both RI and RII are prototypic members of the TNF receptor superfamily and have been designated TNFRSF1A and TNFRSF1B, respectively. The extracellular domains of both receptors contain four conserved cysteine-rich domains while their intracellular domains are dissimilar, indicative of distinct signaling pathways. Human TNF RII cDNA encodes a 461 amino acid (aa) residue precursor protein with a 22 aa putative signal peptide, a 235 aa extracellular domain, a 20 aa transmembrane domain and a 174 aa cytoplasmic domain. Whereas all cell types studied express TNF RI, TNF RII expression is limited primarily to hematopoietic cells and cells of the immune system. Most of the biological functions of TNF are mediated via TNF RI. Soluble forms of both TNF RI and TNF RII, generated as a result of proteolytic cleavage of the extracellular domains, have been detected in vivo in various biological fluids. The soluble TNF receptors can bind TNF with high affinity and function as TNF antagonists (1 - 4).