Shh protein is secreted by Purkinje cells in the cerebellum with both autocrine and paracrine functions. The Shh signaling is mediated by the interaction of Shh with transmembrane proteins, Patched and Smoothened. The Shh pathway cross-talks Notch and Wnt pathways and acts via downstream targets such as cyclins, gamma catenin, myc and other transcription factors. The Hh family members have multiple roles as morphogens, cell survival factors, setting anterior-posterior axis and digit formation during development of limb and axon guidance factors during the development of brain and nervous system.
