Description
Slit1 is a member of the Slit family of large secreted axon guidance molecules that are ligands for Robo receptors. Like other mammalian family members, the 1531 amino acid (aa), ~200 kDa Slit1 contains a 33 aa signal sequence followed by 23 leucine rich repeats (LRR, aa 34 900) and 9 EGF like sequences (aa 930 1451). Mammalian Slits also contain a laminin G domain between EGF6 and EGF7 (aa 1163 1336), and a C-terminal cysteine rich domain (cysteine knot? aa 1456 1531). Heparin sulfates are required for interaction of Robo with Slit LRR domains. Mouse Slit1 shares 99, 96, 89, 87 and 80% aa identity with rat, human, canine, Xenopus and zebrafish Slit1, respectively, within the LRR domains. Mouse Slits 1, 2 and 3 share 68 74% aa identity within the LRR domains. Slit1 and Slit2 (or in some cases Slit3) are expressed in complementary l centigradeations during development of the optic and olfactory tracts and the forebrain, and appear to work together to mediate Robo guidance of retinal, olfactory, hipp centigradeampal and motor axons