LGR5 notes

Deep research (falcon / perplexity-lite) failed; notes from cached publications and UniProt O75473.

• LRR 7TM glycoprotein-hormone-receptor-like protein; ectodomain binds R-spondins PMID:22815884.
• Potentiates canonical Wnt via LRP6 phosphorylation PMID:21693646.
• NOT G-protein/beta-arrestin coupled PMID:21693646 -> GPCR activity and GPCR signaling REMOVED.
• Crystal structure RSPO1-LGR5 ecto 2:2 PMID:23809763.
• Facultative Wnt receptor component PMID:21727895.
• Constitutively internalized, steady-state in TGN via retromer PMID:23439653; poorly expressed at PM.

Localization conclusion: plasma membrane multipass receptor (ectodomain exposed for R-spondin binding), but
constitutively endocytosed so predominantly intracellular (trans-Golgi network) at steady state.