One member of a small subfamily of thrombospondin type 1 (TSR) class molecules, defined by two domains of homology, the FS1/FS2 and TSR domains. Spondin-1 (F-spondin, vascular smooth muscle cell growth-promoting factor, VSGP, 807 aa) is expressed in the midline of the developing embryo, primarily in the floor plate of the neural tube where it attaches to the extracellular matrix and provides neuronal guidance cues. It also binds to amyloid precursor protein (APP) and inhibits cleavage by β-secretase. The other subfamily member, spondin-2 (331 aa), is also known as mindin. See also R-spondin.
Subjects: Medicine and Health.