Structural basis for R-spondin recognition by LGR4/5/6 receptors.

ABSTRACT: The R-spondin (RSPO) family of secreted proteins (RSPO1-RSPO4) has pleiotropic functions in development and stem cell growth by strongly enhancing Wnt pathway activation. Recently, leucine-rich repeat-containing G-protein-coupled receptor 4 (LGR4), LGR5, and LGR6 have been identified as receptors for RSPOs. Here we report the complex structure of the LGR4 extracellular domain (ECD) with the RSPO1 N-terminal fragment (RSPO1-2F) containing two adjacent furin-like cysteine-rich domains (FU-CRDs). The LGR4-ECD adopts the anticipated TLR horseshoe structure and uses its concave surface close to the N termini to bind RSPO1-2F. Both the FU-CRD1 and FU-CRD2 domains of RSPO1 contribute to LGR4 interaction, and binding and cellular assays identified critical RSPO1 residues for its biological activit

SUBMITTER: Wang D 

PROVIDER: S-EPMC3701189 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature