In:
Biochemical Journal, Portland Press Ltd., Vol. 327, No. 3 ( 1997-11-01), p. 803-809
Abstract:
The gene coding for the G-protein αq subunit was interrupted by homologous recombination in murine embryonic stem cells (αq-null ES cells) as detected by Southern analysis and reverse-transcriptase PCR. The bradykinin (BK) B2 receptor was stably transfected into wild-type (WT) αi-2-null and αq-null ES cells. The B2 receptor bound BK with high affinity and mobilized Ca2+. BK also activated phospholipase C (PLC), as determined by total inositol phosphate (IP) accumulation in a Bordetella pertussis toxin- and genistein-insensitive manner. In WT and αi-2-null ES cells, BK increased IP levels approx. 4-fold above baseline. Most interestingly, in αq-null ES cells, BK increased IP accumulation approx. 9-fold above baseline. Re-expression of αq in αq-null ES cells resulted in normalization of the BK-stimulated IP accumulation (4-fold above baseline). These results suggest that the B2 receptor activates PLC through more than one member of the Gq family. Additionally, the absence of αq alters the kinetics of IP generation, which may reflect intrinsic characteristics of individual members of the Gq family or a decreased susceptibility to heterologous regulation in the αq-null ES cells, thus allowing for a more sustained generation of IP.
Type of Medium:
Online Resource
ISSN:
0264-6021
,
1470-8728
Language:
English
Publisher:
Portland Press Ltd.
Publication Date:
1997
detail.hit.zdb_id:
1473095-9
SSG:
12
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