BST1


Bst1 is an enzyme that in humans is encoded by the BST1 gene. CD157 is a paralog of CD38, both of which are located on chromosome 4 in humans.
Bst1 is a stromal cell line-derived glycosylphosphatidylinositol-anchored molecule that 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.
CD157 and CD38 are both members of the ADP-ribosyl cyclase family of enzymes that catalyze the formation of cyclic ADP-ribose from NAD+, although CD157 is a much weaker catalyst than CD38. cADPR is required for regulation of Ca22+ in cells.
CD157 has an important role in controlling the migration of leukocytes, the adhesion of leukocytes to blood vessel walls, and the passage of leukocytes through blood vessel walls.
CD157 is highly expressed in acute myeloid leukemia, and is being evaluated as a diagnostic sign, as a treatment target, and as a means of monitoring treatment progress.