Computational EST database analysis identifies a novel member of the neuropoietic cytokine family

A novel member of the neuropoietic cytokine family has been cloned and the protein expressed and characterized. In an effort to identify novel secrete d proteins, an algorithm incorporating neural network algorithms was applie d to a large EST database. A full-length clone was identified that is 1710 bp in length and has a single open reading frame of 225 amino acids. This n ew cytokine is most homologous to cardiotrophin-1, having a similarity and an identity of 46 and 29%, respectively, and therefore we have named it car diotrophin-like cytokine (CLC). Northern hybridization analysis identified a 1.4-kb messenger RNA that is highly expressed in spleen and peripheral le ukocytes. Purified recombinant CLC induced the activation of NF kappa B and SRE reporter constructs in the TF-1, U937, and M1 cell lines. Furthermore, the signal transduction pathway for CLC was characterized in the neuroblas toma cell line SK-N-MC and found to involve tyrosine phosphorylation of gp1 30 and STAT-1. (C) 1999 Academic Press.