Members of the Gq alpha subunit gene family activate phospholipase C beta isozymes.
Members of the Gq alpha subunit gene family activate phospholipase C beta isozymes.
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DOI：
10.1016/s0021-9258(18)41962-x
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发表时间：
1992-08
期刊：
影响因子：
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通讯作者：
C. Lee;D. Park;Dianqing Wu;S. Rhee;Melvin I. Simon
中科院分区：
文献类型：
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作者：
C. Lee;D. Park;Dianqing Wu;S. Rhee;Melvin I. Simon
测试了 GTP 结合蛋白 G α q 家族成员激活不同磷酸肌醇特异性磷脂酶 C (PI-PLC) β 同工酶的能力的相对特异性。用对应于 G α q、G α 11、G α 14 和 G α 16 的 cDNA 转染 Cos-7 细胞。大多数重组蛋白与细胞膜结合，洗涤这些膜以洗脱内源 PI-PLC 活性。用纯化的 PI-PLC β 同工酶制剂重构膜制剂，并测量鸟苷 5'-O-硫代三磷酸 (GTP γ S) 刺激的酶活性。研究发现 G α q 家族的所有四种蛋白质都能刺激 PI-PLC beta 1，其中 G α q 和 G α 11 最为有效。另一方面，发现 G α 16 最有效地激活 PI-PLC beta 2，而 G α q、G α 11 和 G α 14 显示出较少的刺激。特异性抗 G α 16 抗体阻断富集膜组分中 PI-PLC β 1 和 PI-PLC β 2 的刺激。我们得出的结论是，Gq 家族不同成员与不同 PI-PLC β 效应子的相互作用存在特异性。这种特异性对于体内产生组织或受体特异性反应可能很重要。
The relative specificities of members of the G alpha q family of GTP-binding proteins were tested for their ability to activate different phosphoinositide-specific phospholipase C (PI-PLC) beta isozymes. Cos-7 cells were transfected with cDNA corresponding to G alpha q, G alpha 11, G alpha 14, and G alpha 16. Most of the recombinant protein was bound to the cell membrane and these membranes were washed to elute endogenous PI-PLC activity. The membrane preparation was reconstituted with purified preparations of the PI-PLC beta isozymes and guanosine 5'-O-thiotriphosphate (GTP gamma S)-stimulated enzyme activity was measured. All four proteins of the G alpha q family were found to stimulate PI-PLC beta 1, with G alpha q and G alpha 11 being most efficient. On the other hand, G alpha 16 was found to most effectively activate PI-PLC beta 2, while G alpha q, G alpha 11, and G alpha 14 showed less stimulation. Specific anti- G alpha 16 antibody blocked the stimulation of both PI-PLC beta 1 and PI-PLC beta 2 in the enriched membrane fraction. We conclude that there is specificity in the interaction of different members of the Gq family with different PI-PLC beta effectors. This specificity may be important in generating tissue- or receptor-specific responses in vivo.