TY - JOUR T1 - Repellent Signaling by Slit Requires the Leucine-Rich Repeats JF - The Journal of Neuroscience JO - J. Neurosci. SP - 4290 LP - 4298 DO - 10.1523/JNEUROSCI.21-12-04290.2001 VL - 21 IS - 12 AU - Robin Battye AU - Adrienne Stevens AU - Robert L. Perry AU - J. Roger Jacobs Y1 - 2001/06/15 UR - http://www.jneurosci.org/content/21/12/4290.abstract N2 - Slit is a repellent axon guidance cue produced by the midline glia in Drosophila that is required to regulate the formation of contralateral projections and the lateral position of longitudinal tracts. Four sequence motifs comprise the structure of Slit: a leucine-rich repeat (LRR), epidermal growth factor-like (EGF) repeats, a laminin-like globular (G)-domain, and a cysteine domain. Here we demonstrate that the LRR is required for repellent signaling and in vitro binding to Robo. Repellent signaling byslit is reduced by point mutations that encode single amino acid changes in the LRR domain. By contrast to the EGF or G-domains, the LRR domain is required in transgenes to affect axon guidance. Finally, we show that the midline repellent receptor, Robo, binds Slit proteins with internal deletions that also retain repellent activity. However, Robo does not bind Slit protein missing the LRR. Taken together, our data demonstrate that Robo binding and repellent signaling by Slit require the LRR region. ER -