Background information
Bone marrow stromal cell antigen 1 (BST1) is a pleiotropic ectoenzyme which belongs to the CD38 family and to the growing number of leukocyte surface molecules known to act independently as both receptors and enzymes. The BST1 molecule displays two distinct domains in its extracellular component. The first is implicated in the enzymic activities of the molecule (it synthesizes cyclic ADP-ribose, a second messenger that elicits calcium release from intracellular stores) and the second domain has adhesion/signalling properties.Bone marrow stromal cell antigen 1 facilitates pre-B-cell growth. The deduced amino acid sequence exhibits 33% similarity with CD38. BST1 expression is enhanced in bone marrow stromal cell lines derived from patients with rheumatoid arthritis. The polyclonal B-cell abnormalities in rheumatoid arthritis may be, at least in part, attributed to BST1 overexpression in the stromal cell population.
