Fig. 3.

GPCR signaling is functional to almost any aspect of cell physiology including the organization of the stem cells niche. Gs coupled receptors like LGR and PTHR cooperate with FZD producing very articulated downstream signalling that is also modulated by single transmembrane domain co-receptors. Here a highly simplified scheme representing signalling intermediates described in the text. Multiple arrows indicate indirect activation. In the callout, congenital diseases associated to mutations upregulating the downstream pathway