Publication Date:
2008-09-17
Description:
Hedgehog (Hh) proteins specify tissue pattern in metazoan embryos by forming gradients that emanate from discrete sites of expression and elicit concentration-dependent cellular differentiation or proliferation responses. Cellular responses to Hh and the movement of Hh through tissues are both precisely regulated, and abnormal Hh signalling has been implicated in human birth defects and cancer. Hh signalling is mediated by its amino-terminal domain (HhN), which is dually lipidated and secreted as part of a multivalent lipoprotein particle. Reception of the HhN signal is modulated by several cell-surface proteins on responding cells, including Patched (Ptc), Smoothened (Smo), Ihog (known as CDO or CDON in mammals) and the vertebrate-specific proteins Hip (also known as Hhip) and Gas1 (ref. 11). Drosophila Ihog and its vertebrate homologues CDO and BOC contain multiple immunoglobulin and fibronectin type III (FNIII) repeats, and the first FNIII repeat of Ihog binds Drosophila HhN in a heparin-dependent manner. Surprisingly, pull-down experiments suggest that a mammalian Sonic hedgehog N-terminal domain (ShhN) binds a non-orthologous FNIII repeat of CDO. Here we report biochemical, biophysical and X-ray structural studies of a complex between ShhN and the third FNIII repeat of CDO. We show that the ShhN-CDO interaction is completely unlike the HhN-Ihog interaction and requires calcium, which binds at a previously undetected site on ShhN. This site is conserved in nearly all Hh proteins and is a hotspot for mediating interactions between ShhN and CDO, Ptc, Hip and Gas1. Mutations in vertebrate Hh proteins causing holoprosencephaly and brachydactyly type A1 map to this calcium-binding site and disrupt interactions with these partners.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679680/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2679680/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McLellan, Jason S -- Zheng, Xiaoyan -- Hauk, Glenn -- Ghirlando, Rodolfo -- Beachy, Philip A -- Leahy, Daniel J -- R01 HD055545/HD/NICHD NIH HHS/ -- Z99 DK999999/Intramural NIH HHS/ -- Howard Hughes Medical Institute/ -- England -- Nature. 2008 Oct 16;455(7215):979-83. doi: 10.1038/nature07358. Epub 2008 Sep 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18794898" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Binding Sites
;
Calcium/metabolism
;
Cell Adhesion Molecules/chemistry/metabolism
;
Cell Cycle Proteins/chemistry/metabolism
;
Cell Line
;
*Conserved Sequence
;
Crystallography, X-Ray
;
Drosophila Proteins/*chemistry/*metabolism
;
Drosophila melanogaster/chemistry
;
Fibronectins/chemistry
;
GPI-Linked Proteins
;
Hedgehog Proteins/*chemistry/genetics/*metabolism
;
Humans
;
Immunoglobulin G/chemistry/metabolism
;
Membrane Glycoproteins/*chemistry/*metabolism
;
Membrane Proteins/chemistry/metabolism
;
Mice
;
Models, Molecular
;
Protein Binding/genetics
;
Protein Structure, Tertiary
;
Receptors, Cell Surface/*chemistry/*metabolism
;
*Sequence Homology, Amino Acid
;
Signal Transduction
;
Tumor Suppressor Proteins/chemistry/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
