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Identification of a Functional Bradykinin B 2 Receptor Expressed in HEK293 Cells.
Author(s) -
Kramarenko Inga,
Bunni Marlene,
Raymond John R,
Garnovskaya Maria N
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.305
Subject(s) - hek 293 cells , receptor , microbiology and biotechnology , phosphorylation , bradykinin receptor , transfection , chemistry , extracellular , blot , biology , bradykinin , biochemistry , gene
Human Embryonic Kidney (HEK) 293 cells are widely used in cell biology research. Although HEK293 cells have been meticulously studied, our knowledge about endogenous seven‐transmembrane receptors in these cells is incomplete. While studying the effects of bradykinin (BK), a potent growth factor for renal cells, we have unexpectedly discovered BK‐dependent activation of extracellular signal‐regulated protein kinase 1 and 2 (ERK1/2) in HEK293 cells. Exposure of HEK293 cells to BK resulted in an increase in tyrosine phosphorylation of ERK1/2. Thus, we hypothesized that HEK293 cells have endogenous BK receptors. RT‐PCR demonstrated the presence of mRNAs for BK B 1 and BK B 2 receptors in HEK293 cells. We confirmed this result on the protein level by Western blotting with a BK B 2 receptor antibody. To study signaling linkages of the BK receptor, we measured changes in extracellular acidification rate (ECAR) with a Cytosensor™ microphysiometer, and ERK1/2 phosphorylation by Western blotting with a phosphospecific ERK1/2 antibody. Exposure of HEK293 cells to BK 10 − 7 M for 5 min resulted in an increase in tyrosine phosphorylation of ERK1/2 (two times over basal) and in an ∼10% increase in ECAR. Both effects were blocked by HOE140 (B 2 receptor antagonist) but not by des‐Arg 10 ‐HOE140 (B 1 receptor antagonist). We conclude that HEK293 cells express endogenous functional BK B 2 receptors.