Hedgehog Signaling Pathway (Hh)

The Hedgehog (Hh) signaling pathway is a highly conserved cell–cell communication system that plays a critical role in embryonic development, tissue patterning, and stem cell maintenance. It regulates processes such as cell differentiation, proliferation, and organogenesis. In adults, Hh signaling contributes to tissue repair and regeneration but can also be implicated in disease when dysregulated. Key components include Hh ligands (Shh, Ihh, Dhh), receptors (PTCH), signal transducer (SMO), and transcription factors (GLI1/2/3).

Other names

Hedgehog pathwayHh pathway

Hedgehog ligands bind to PTCH, relieving its inhibition of SMO. Activated SMO triggers a cascade resulting in activation of GLI transcription factors, which then translocate to the nucleus and promote transcription of target genes involved in growth and development.