Analysis of endogenous S1P and LPA receptor expression in CHO-K1 cells.

The CHO-K1 cell line is commonly used for studies of recombinantly expressed proteins, including proteins of the G protein-coupled receptor (GPCR) family. This laboratory has used CHO-K1 cells for the functional characterization of Edg family GPCRs. However, parental CHO-K1 cells respond to lysophospholipids in in-vitro functional assays, which suggests expression of endogenous Edg family GPCRs. To determine the repertoire of Edg family receptor expression in this cell line, alignments of human and rodent sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) receptor sequences were used to design semi-redundant oligonucleotide pairs. A portion of each receptor gene coding sequence was amplified from Chinese hamster genomic DNA and the resultant gene fragments sequenced. Species-specific oligonucleotide pairs were designed using this novel sequence information and used to detect expression of S1P(1,2,4) and LPA(1) transcripts in CHO-K1 cells by RT-PCR.