The adventures of sonic hedgehog in development and repair. III. Hedgehog processing and biological activity.
The Hedgehog (Hh) family of secreted proteins is necessary for aspects of the development and maintenance of the gastrointestinal tract. Hh is thought to function as a morphogen, a mitogen, a cell survival factor, and an axon guidance factor. Given its wide role in development, as well as in a variety of disease states, understanding the regulation of Hh function and activity is critically important. However, the study of Hh signaling has been impeded by its unusual biology. Hh is unique in that it is the only protein covalently modified by cholesterol, which in turn affects numerous aspects of its localization, release, movement, and activity. All are important factors when considering Hh's physiological role, and animals have developed an intricate system of regulators responsible for both promoting and inhibiting the activity of Hh. This review is intended to give a broad overview of how the biosynthesis and movement of Hh contributes to its biological activity.
Farzan
Shohreh F
SF
Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, NH 03755, USA.
Singh
Samer
S
Schilling
Neal S
NS
Robbins
David J
DJ
D000818:Animals; D019521:Body Patterning; D002465:Cell Movement; D002784:Cholesterol / Q000378:metabolism; D047108:Embryonic Development / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D053823:Hedgehog Proteins / Q000096:biosynthesis / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D012038:Regeneration / Q000502:physiology*; D015398:Signal Transduction
D016326:Extracellular Matrix Proteins; D053823:Hedgehog Proteins; D008565:Membrane Proteins; D019308:Palmitic Acid; D002784:Cholesterol