Figure 11.

Shh protein autoprocessing in mouse embryos. Western blotting of lysates from wild-type (track 3), heterozygous (track 4) and knockout (track 5) embryos at E11.5, or COS1 cells transfected with Shh (track 1) or Shh-N (track 2) were probed with anti-Shh-N19 antibodies. 20 μ g of lysate proteins from Shh transfected COS1 cells and 75 μ g from embryos was loaded. Both unprocessed (Shh, upper arrow ~45 kDa, faint signal) and processed (Shh-Np, lowest arrow, strong signal, track 1) forms of Shh were detected from Shh transfected COS1 cells. The two slower migrating bands in Shh-N transfected COS1 cells (track 2) represented Shh-N proteins with different lipid modifications at its N terminus. A major band running at the same position as processed Shh was detected in lysates from all the embryos (tracks 3–5). Importantly, no significant amounts of unprocessed or aberrantly migrating Shh proteins were detected in lysates from knockout embryos at this stage.