Cloning and expression of a human tumor necrosis factor receptor gene.

A human tumor necrosis factor (TNF) from the serum of cancer patients in the binding protein was purified to homogeneity and partial sequencing. TNF receptor used to isolate cDNA clones encoding the amino acid sequence information on the basis of the synthesis of DNA probes. Tumor necrosis factor receptor (TNF-R) is a 415 amino acid polypeptide with a single transmembrane region. The cysteine-rich structure of the TNF-R extracellular domain homology to the nerve growth factor receptor, and B cell activation protein BP50. Human embryonic kidney cells transfected with the TNF-R expression vector specifically binds to tumor necrosis factor-α of the two 125I-labeled and biotin. Unlabelled TNF-α and TNF-β to replace the combination of labeled tumor necrosis factor-α, TNF-R expressing cells are equally effective. Northern analysis showed that TNF-R mRNA expression in a variety of cell types in a single species. Thus, the soluble TNF binding protein may be found in human serum, is a protein hydrolyzate from the TNF-R