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

We demonstrate co-localization of the Patched I (Ptcl) receptor and its lig and sonic hedgehog (Shh) in lysosomes suggests an intracellular sorting mec hanism 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 wi th this interaction, Western immunoblot analysis revealed intracellular loc alization of native Ptcl and ShhNT. Examination of the topological model of the Ptc I receptor revealed a number of Yxx phi, lysosomal targeting seque nces consistent with our observations for Ptcl sorting. NeuroReport 11:581- 585 (C) 2000 Lippincott Williams & Wilkins.