GPCRs expressed ubiquitously along the GI tract. Each panel refers to one GPCR showing three pieces of information: group of belonging, N terminal moieties 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. The phylogenetic grouping is based on the 7TM regions; the schematic representation of the domains in the N-termini as determined by RT-BLAST at NCBI is adapted from our previous work . Abbreviations for N-termini moieties: GPS, GPCR proteolytic site; HBD, hormone-binding domain; EGF, epidermal growth factor; OLF, olfactomedin; GBL, galactose-binding lectin domain; LRR, leucine rich repeats; Ig, immunoglobulin; SEA, sperm protein, enterokinase, and agrin; glycosylation sites (NXS or NXT tripeptide sequences that conform to the consensus sequence for N-linked glycosylation) – 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