A highly conserved amino-terminal region of Sonic Hedgehog is required for the formation of its freely diffusible multimeric form

John A. Goetz, Samer Singh, Liza M. Suber, F. Jon Kull, David J Robbins

Research output: Contribution to journalArticle

102 Scopus citations

Abstract

Although members of the Hedgehog (Hh) family were initially described as morphogens, many of these early conclusions were based on experiments that used non-physiologically relevant forms of Hh. Native Hh is modified by cholesterol (HhNp) and palmitate. These hydrophobic modifications are responsible for the ability of Hh to associate with cellular membranes, a property that initially appeared inconsistent with its ability to act far from its site of synthesis. Although it is now clear that Hh family members are capable of acting directly in long-range signaling, the form of Hh capable of this activity remains controversial. We have previously provided evidence for a freely diffusible multimeric form of Sonic Hedgehog (Shh) termed s-ShhNp, which is capable of accumulating in a gradient fashion through a morphogenic field. Here, we provide further evidence that s-ShhNp is the physiologically relevant form of Shh. We show that the biological activity of freely diffusible ShhNp resides in its multimeric form and that this multimeric form is exceedingly stable, even to high concentrations of salt and detergent. Furthermore, we now validate the Shh-Shh interactions previously observed in the crystal structure of human Shh, showing that a highly conserved amino-terminal domain of Shh is important for the formation of s-ShhNp. We also conclusively show that palmitoylation is required for s-ShhNp formation. Thus, our results identify both protein-protein and protein-lipid interactions that are required for s-ShhNp formation, and provide the first structural analyses supporting the existence of Shh multimers.

Original languageEnglish
Pages (from-to)4087-4093
Number of pages7
JournalJournal of Biological Chemistry
Volume281
Issue number7
DOIs
StatePublished - Feb 17 2006
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Biochemistry

Cite this