An expressed sequence tag (EST) data mining strategy succeeding in the discovery of new G-protein coupled receptors

We have developed a comprehensive expressed sequence tag database search me thod and used it for the identification of new members of the G-protein cou pled receptor superfamily. Our approach proved to be especially useful for the detection of expressed sequence tag sequences that do not encode conser ved parts of a protein, making it an ideal tool for the identification of m embers of divergent protein families or of protein parts without conserved domain structures in the expressed sequence tag database. At least 14 of th e expressed sequence tags found with this strategy are promising candidates for new putative G-protein coupled receptors. Here, we describe the sequen ce and expression analysis of five new members of this receptor superfamily , namely GPR84, GPR86, GPR87, GPR90 and GPR91. We also studied the genomic structure and chromosomal localization of the respective genes applying in silico methods. A cluster of six closely related C-protein coupled receptor s was found on the human chromosome 3q24-3q25, Tt consists of four orphan r eceptors (GPR86, GPR87, GPR91, and H963), the purinergic receptor P2Y1, and the uridine 5'-diphosphoglucose receptor KIAA0001. it seems likely that th ese receptors evolved from a common ancestor and therefore might have relat ed ligands. In conclusion, we describe a data mining procedure that proved to be useful for the identification and first characterization of new genes and is well applicable for other gene Families. (C) 2001 Academic Press.