Co-localization of Patched and activated Sonic hedgehog to lysosomes in neurons

We demonstrate co-localization of the Patched I (Ptcl) receptor and its ligand sonic hedgehog (Shh) in lysosomes suggests an intracellular sorting mechanism for this receptor and its ligand. Treatment of murine brain primary cultures and a human teratoma cell line with the N-terminal activated form of Shh (ShhNT), a Ptcl-Shh complex was observed in lysosomes. Consistent with this interaction, Western immunoblot analysis revealed intracellular localization of native Ptcl and ShhNT. Examination of the topological model of the Ptc I receptor revealed a number of Yxx phi, lysosomal targeting sequences consistent with our observations for Ptcl sorting. NeuroReport 11:581-585 (C) 2000 Lippincott Williams & Wilkins.