Cloning and characterization of cDNA encoding a novel human leukotriene B-4 receptor

By homology screening using BLAST searches of expressed sequence tags (ESTs ), we have found a previously unidentified cDNA encoding a putative seven-t ransmembrane receptor with highest similarity to the leukotriene B-4 recept or, BLTR, Analysis of calcium flow in transfected cells, along with sequenc e analysis, revealed that the EST encoded a functionally inactive protein, lacking the segment corresponding to the C-terminal part of the putative re ceptor protein. The missing segment was obtained by PCR amplification of a human leukocyte cDNA library and ligated to the truncated EST cDNA, The nov el cDNA encodes a full-length receptor with 39% identity to the previously cloned BLTR, Studies of intracellular calcium how of transfected HeLa cells exposed to various leukotrienes showed that also the novel BLTR-like recep tor can be activated by leukotriene B-4, and it is therefore tentatively na med BLTR2, (C) 2000 Academic Press.