G alpha (q) inhibits PI3K alpha

Phospholipase C activation is the classical signalling route for G alpha (q) but an additional mechanism is an inhibitory interaction between G alpha (q) and phosphatidylinositol 3-kinase alpha (PI3K alpha). There are several PI3K subtypes but only the p85 alpha/p110 alpha subtype (PI3K alpha) is a G alpha (q) effector (PMID: 18515384). Activated G alpha (q) inhibits PI3K alpha directly, in a GTP-dependent manner. G alpha(q) binding of PI3K competes with Ras, a PI3K activator (PMID: 16268778).

磷脂酰胆碱酶C的激活是G alpha (q) 的经典信号传导途径，但除此之外，还存在一种额外的机制，即G alpha (q) 与磷脂酰肌醇3激酶α (PI3K alpha) 之间的抑制性相互作用。PI3K存在多种亚型，但仅有p85 alpha/p110 alpha亚型（PI3K alpha）是G alpha (q) 的效应器（PMID: 18515384）。激活的G alpha (q) 以GTP依赖性方式直接抑制PI3K alpha。PI3K与G alpha(q) 的结合与PI3K的激活剂Ras竞争（PMID: 16268778）。