pubmed-article:3491144 | pubmed:abstractText | A human interleukin 1 beta (IL 1 beta) cDNA probe was utilized to identify a homologous murine cDNA clone. The murine cDNA encodes a 269-residue protein which is 67% homologous to human IL 1 beta. The murine sequence was engineered for expression in mammalian cells and directs the synthesis of biologically active IL 1. This protein, termed murine IL 1 beta, is only 22% homologous with the previously described murine IL 1 sequence. Both IL 1 alpha and IL 1 beta are encoded by single genes, but IL 1 beta mRNA is about fivefold more abundant in a stimulated macrophage cell line. | lld:pubmed |