A, Schematic representation of the various Slit2 constructs. Slit2-full represents the native full-length Slit2. The nine EGF repeats and the ALPS domain are represented, and the nine amino acids sequence deleted to generate Slit2-U is indicated (arrowhead). All proteins except Slit2-N are also myc tagged at their C termini, and Slit2-N and Slit2-C are tagged by the alkaline phosphatase at their N termini.B–D, Western blots using anti-alkaline phosphatase (B), 9E10 anti-myc (C), and anti-hSlit2 (D) antibodies. All Slit2 fragments can be detected in conditioned medium (sup) and after extraction in 1 m NaCl (salt). Slit2-NAP is recognized by anti-hSlit2 and anti-alkaline phosphatase (B, D), whereas Slit2-U is detected by anti-myc and anti-hSlit2 (C,D). Slit2-C can be detected by the anti-alkaline phosphatase and the anti-myc antibodies (B,C). All protein fragments migrate at the expected molecular weight, and Slit2-U migrates as a single band and therefore is not cleaved.