Specificity
SI-CLP (stabilin-1 interacting chitinase-like), also known as CHID1 (chitinase domain-containing protein 1), is a 393 amino acid secreted protein that belongs to the glycosyl hydrolase 18 family. SI-CLP interacts with STAB1 and localizes to lysosome in cells of monocytic, T, B and epithelial origin. SI-CLP is a saccharide- and LPS-binding protein with possible roles in pathogen sensing and endotoxin neutralization. Ligand-binding specificity relates to the length of the oligosaccharides, with preference for chitotetraose (in vitro). The SI-CLP protein is up-regulated by IL4/interleukin-4 and dexamethasone in the macrophages, and is also up-regulated by glucocorticoid. Existing as three alternatively spliced isoforms, the SI-CLP gene is conserved in chimpanzee, canine, bovine, mouse, rat, chicken, zebrafish, fruit fly, mosquito, A. thaliana and rice, and maps to human chromosome 11p15.5.
