Enhanced bradykinin-stimulated phospholipase C activity in murine embryonic stem cells lacking the G-protein alphaq-subunit.
Enhanced bradykinin-stimulated phospholipase C activity in murine embryonic stem cells lacking the G-protein alphaq-subunit.
复制标题
在缺乏 G 蛋白 alphaq 亚基的小鼠胚胎干细胞中，缓激肽刺激的磷脂酶 C 活性增强。
DOI：
10.1042/bj3270803
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Mortensen,RM
中科院分区：
文献类型：
--
作者：
Ricupero,DA;Polgar,P;Taylor,L;Sowell,MO;Gao,Y;Bradwin,G;Mortensen,RM
The gene coding for the G-protein αqsubunit 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 aBordetella pertussistoxin- 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 αqin 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 Gqfamily. Additionally, the absence of αqalters the kinetics of IP generation, which may reflect intrinsic characteristics of individual members of the Gqfamily or a decreased susceptibility to heterologous regulation in the αq-null ES cells, thus allowing for a more sustained generation of IP.
