GPCRs with limited expression along the GI tract. Each panel refers to one GPCR showing three pieces of information: group of belonging, N terminal region and relative expression in twelve segments of the GI tract. Expression levels are relative for each gene (maximal level of expression set to 1). Values are plotted as the mean ± SD; n = 3. GPR111, GPR113, GPR115 were only expressed in one sub-segment: the expression value was arbitrarily set to 1 to indicate the presence of expression. Abbreviations for N-termini moieties: GPS, GPCR proteolytic site; HBD, hormone-binding domain; TSP1, thrombospondin; PTX, pentraxin domain. Glycosylation sites (NXS or NXT tripeptide sequences that conform to the consensus sequence for N-linked glycosylation) are shown as small circles attached to the N-termini stretches; E, esophagus; F, corpus of the stomach; A, antrum of the stomach; D1 and D2, proximal and distal parts of the duodenum; J1 and J2, proximal and distal parts of the jejunum; I1 and I2, proximal and distal parts of the ileum; C, cecum; K1 and K2, proximal and distal parts of the colon.
Badiali et al. BMC Gastroenterology 2012 12:134 doi:10.1186/1471-230X-12-134