Slit1, aa1-915, Recombinant, Human (Slit Homolog 1, Slit Homolog 1 Protein, Slit-1, KIAA0813, Multip

Slit1 is a member of the Slit family of large secreted axon guidance molecules that are ligands for Robo receptors (1, 2). Like other mammalian family members, the 1534aa, ~200kD human Slit1 contains a 33aa signal sequence followed by 23 leucine-rich repeats (LRR, aa34-900) and 9 EGF-like sequences (aa930-1454) (2). Mammalian Slits also contain a laminin-G domain between EGF6 and EGF7 (aa1166-1339), and a C-terminal cysteine-rich domain (cysteine knot, aa1459-1534) (2). Heparin sulfates are required for interaction of Robo with Slit LRR domains (2, 3). Within the LRR domains, human Slit1 shares 96% aa identity with mouse, rat, and bovine, 98% with equine and 91% with canine Slit1. Human Slits 1, 2 and 3 share 68-74% aa identity within the LRR domains. One potential isoform of 1641aa has 10aa inserted after aa338 within LRR9 and lacks aa793-816 within LRR20-21 (4). Two more potential isoforms of 1520 and 1461aa diverge at the C-terminus (aa1453 and 1411, respectively), these isoforms lack the cysteine knot, which may mediate interaction with other proteins (5). Slit1 has been found mainly, but not exclusively, in the fetal and adult brain (2). Slit1 and Slit2 (or in some cases Slit3) are expressed in complementary locations during development of the optic and olfactory tracts and the forebrain, and appear to work together to mediate Robo guidance of retinal, olfactory, hippocampal and motor axons (1, 6-11). Deletion of either Slit1 or Slit2 has less effect than deletion of both, which allows axons to wander from tracts and inappropriately cross or recross the midline (6, 7, 9-11). Expression of Slit1 by new neurons influences astrocytes to form and maintain tunnels that guide neuronal migration (12). In the injured spinal cord, presence of Slit1 along with Slit3 and Netrin-1 may be responsible for failure of axons to regenerate in the adult CNS (13). Slit1 also promotes dendrite growth and branching of cortical neurons indicating it may exert important influence on the final morphology of cortical neurons (14). Source: Recombinant corresponding to aa21-915 from human Slit1, fused with 6-His tag at C-terminal, expressed in CHO cells. Molecular Weight: ~98.8kD, Endotoxin Level: <1EU/1ug (LAL), Biological Activity: Measured by its ability to enhance neurite outgrowth of E16-E18 rat embryonic cortical neurons. Optimal neurite outgrowth was observed when neurons were plated on 96-well plates that had been pre-coated with 50ul/well of recombinant human Slit1 at 2.5-10ug/ml. Storage and Stability: Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.