[Function, molecular structure and gene expression of interleukin-1]

Abstract

Recent cloning of human and murine IL-1 receptor (IL-1R) has revealed that there are at least two type of IL-1R: type I IL-1R is detected on T cells and fibroblasts and consists of 552 AAs with a cytoplasmic domain of 213 AAs, while type II is detected on B cells and monocytic cell lines and consists of 398 AAs with a short stretch intracytoplasmic domain of 29 AAs. Extracytoplasmic portion of IL-1R has some homology with vaccinia virus B15 Ag or fibroblast protein ST-2, while cytoplasmic portion has considerable similarity with Drosophila toll gene. By transfecting murine type I IL-1R cDNA into a human Jurkat cell line, structural and functional potion required for the IL-1 signal transduction is determined. At least broad portion of cytoplasmic domain including 364-474 AAs from N-terminus are found to be essential, while PKC acceptor site (Ser-431 and Ser-509), and PKA acceptor site (Ser-528) are not essential for the IL-8 gene expression.