7PGN

HHP-C in complex with glycosaminoglycan mimic SOS

Summary for 7PGN

• Entry DOI: 10.2210/pdb7pgn/pdb
• Related PRD ID: PRD_900013
• Descriptor: Hedgehog-interacting protein, 1,3,4,6-tetra-O-sulfo-beta-D-fructofuranose-(2-1)-2,3,4,6-tetra-O-sulfonato-alpha-D-glucopyranose, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: hhip, hedgehog, morphogen, signalling, glycosaminoglycan, cholesterol, palmitate, secreted, signaling protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 109112.46

Authors

Griffiths, S.C.,Schwab, R.A.,El Omari, K.,Bishop, B.,Iverson, E.J.,Malinuskas, T.,Dubey, R.,Qian, M.,Covey, D.F.,Gilbert, R.J.C.,Rohatgi, R.,Siebold, C. (deposition date: 2021-08-14, release date: 2021-12-15, Last modification date: 2024-01-31)

Primary citation

Griffiths, S.C.,Schwab, R.A.,El Omari, K.,Bishop, B.,Iverson, E.J.,Malinauskas, T.,Dubey, R.,Qian, M.,Covey, D.F.,Gilbert, R.J.C.,Rohatgi, R.,Siebold, C.
Hedgehog-Interacting Protein is a multimodal antagonist of Hedgehog signalling.
Nat Commun, 12:7171-7171, 2021

PubMed Abstract: Hedgehog (HH) morphogen signalling, crucial for cell growth and tissue patterning in animals, is initiated by the binding of dually lipidated HH ligands to cell surface receptors. Hedgehog-Interacting Protein (HHIP), the only reported secreted inhibitor of Sonic Hedgehog (SHH) signalling, binds directly to SHH with high nanomolar affinity, sequestering SHH. Here, we report the structure of the HHIP N-terminal domain (HHIP-N) in complex with a glycosaminoglycan (GAG). HHIP-N displays a unique bipartite fold with a GAG-binding domain alongside a Cysteine Rich Domain (CRD). We show that HHIP-N is required to convey full HHIP inhibitory function, likely by interacting with the cholesterol moiety covalently linked to HH ligands, thereby preventing this SHH-attached cholesterol from binding to the HH receptor Patched (PTCH1). We also present the structure of the HHIP C-terminal domain in complex with the GAG heparin. Heparin can bind to both HHIP-N and HHIP-C, thereby inducing clustering at the cell surface and generating a high-avidity platform for SHH sequestration and inhibition. Our data suggest a multimodal mechanism, in which HHIP can bind two specific sites on the SHH morphogen, alongside multiple GAG interactions, to inhibit SHH signalling.

PubMed: 34887403
DOI: 10.1038/s41467-021-27475-2

Experimental method

X-RAY DIFFRACTION (2.4 Å)