Molecular cloning of interleukin 1 beta from rainbow trout Oncorhynchus mykiss reveals no evidence of an ice cut site

The complete coding sequence of rainbow trout IL-1 beta has been obtained. The gene contains a short 5' UTR (97 bp), a 780 bp open reading frame and a 466 6p 3' UTR, which includes a polyadenylation signal, 7 ATTTA motifs and an 18 bp poly ii tail. The predicted amino acid sequence (260 amino acids) contains 3 potential glycosylation sites, with a predicted molecular weigh t of 29 kDa, and show's between 49 and 56% amino acid similarity to mammali an IL-1 beta s and 57% similarity to carp IL-1 beta, Greatest homology was apparent within the secondary structure of the gene, with few of the amino acids known to bind to the IL-1 receptor being conserved. No ICE cut site w as apparent but multiple alignment with mammalian sequences allowed a putat ive mature peptide of 166 amino acids to be identified, in which Ala(95) wo uld be the amino terminus. Northern blot analysis showed that whilst no IL- 1 beta expression was detectable in head kidney leukocytes immediately afte r isolation, expression could be induced by stimulation with LPS for 4 h in culture. Similarly, with isolated head kidney macrophages expression was s ignificantly increased following stimulation with LPS. (C) 1999 Academic Pr ess.