Molecular cloning, structural characterization, and chromosomal mapping of the human LECT2 gene

We originally isolated LECT2 (leukocyte cell-derived chemotaxin 2) as a 16-kDa secreted protein having a human neutrophil chemotactic activity, then cloned human and bovine LECT2 cDNAs and demonstrated the liver-specific expression of the protein. LECT2 is thought to be a multifunctional protein, because it was recently found to be identical to chondromodulin-II a growth stimulator of chondrocyte cells. We report here the cloning and the structural analysis of the human LECT2 gene. The gene spans approximately 8 kb and consists of four exons and three introns. Primer extension analysis revealed that several transcription initiation sites occur within 70-230 nucleotides upstream of the translation initiation codon. Several transcriptional control sequences relevant to the liver-specific expression have been identified at the 5' untranslated region of the human LECT2 gene. The human LECT2 gene was mapped to chromosome 5q31.1-q32 by fluorescence in situ hybridization. This region contains a cluster of cytokine genes including IL-4, IL-5, and IL-9.