Figure 2.

GPCR-GRAFS classification: GPCR alternative classification based on their phylogenetic analysis in mammalian system. In the GRAFS classification, receptors are divided into five families: glutamate-like family (G, green), rhodopsin-like (R, pink), adhesion-like family (A, blue), frizzle/taste2-like family (F, red) and secretin-like family (S, light blue). Here we list the GPCRs found in the endomembrane system and mentioned in this review, and we classify them according the GRAFS system.