MOLECULAR CHARACTERIZATION OF THE GENE FOR HUMAN CARTILAGE GP-39 (CHI3L1), A MEMBER OF THE CHITINASE PROTEIN FAMILY AND MARKER FOR LATE STAGES OF MACROPHAGE DIFFERENTIATION

We have previously reported that the expression of HC gp-39, a 39-kDa secretory glycoprotein and member of the chitinase protein family, is associated with late stages of monocyte to macrophage maturation. To a llow further investigations of its unique expression pattern and to fa cilitate studies on the regulation of this ''marker gene,'' we charact erized the genomic organization of the HC gp-39 gene (HGMW-approved sy mbol CHI3L1) and cloned its 5'-proximal promotor region. The gene is c omposed of 10 exons distributed over an 8-kb region. Two transcription al initiation sites located 82 and 126 nucleotides upstream of the ATG start codon were identified using primer extension and S1 nuclease pr otection assays. We sequenced 1.3 kb of the 5'-flanking region and ide ntified a variety of putative regulatory elements. (C) 1997 Academic P ress.