Interleukin 1 Epsilon (IL1e)

The cytokine interleukin-1 (IL1) elicits a wide array of biologic activities that initiate and promote the host response to injury or infection by activating a set of transcription factors, including NFKB and AP1, which in turn induce production of effectors of the inflammatory response. By searching an EST database for sequences resembling IL1 and probing a human genomic library, Smith et al. (2000) identified a cDNA encoding IL1F6, which they designated FIL1-epsilon. The deduced 158-amino acid protein, like FIL1-delta, contains neither a signal peptide nor a prodomain. It shares 48% sequence identity with FIL1-eta. PCR analyses detected expression in immune system and fetal brain, but not in other tissues tested or in multiple hematopoietic cell lines. Modeling indicated that FIL1-epsilon has a conserved 12-stranded beta-trefoil structure.