Shin B C, Suzuki M, Inukai K, Anai M, Asano T, Takata K
Department of Cell Biology, Gunma University, Japan.
Biochem Biophys Res Commun. 1998 May 19;246(2):313-9. doi: 10.1006/bbrc.1998.8606.
Phosphatidylinositol 3-kinase (PI3-kinase) is a heterodimeric enzyme composed of a catalytic subunit of 110 kDa and an adaptor regulatory subunit. We investigated the presence and localization of five isoforms of the regulatory subunits, p55 alpha, p55 gamma, p85 alpha, p85 beta, and p50 alpha, in the rat brain. In situ hybridization histochemistry using isoform-specific cRNA probes revealed that all five isoforms were expressed in the neurons of the brain. Interestingly, most neuronal cells including Purkinje cells in the cerebellum and pyramidal cells in the cerebrum expressed all five isoforms. Immunohistochemical staining also showed the localization of p55 alpha, p55 gamma, p85 alpha, and p50 alpha in the neuronal cells in the brain. Expression of multiple isoforms in neurons suggests that they may play important roles in signal transduction in the brain.
磷脂酰肌醇3激酶（PI3激酶）是一种异二聚体酶，由一个110 kDa的催化亚基和一个衔接调节亚基组成。我们研究了调节亚基的五种异构体，即p55α、p55γ、p85α、p85β和p50α在大鼠脑中的存在情况和定位。使用异构体特异性cRNA探针进行的原位杂交组织化学显示，所有五种异构体均在脑神经元中表达。有趣的是，大多数神经元细胞，包括小脑浦肯野细胞和大脑锥体细胞，都表达了所有五种异构体。免疫组织化学染色也显示了p55α、p55γ、p85α和p50α在脑神经元细胞中的定位。神经元中多种异构体的表达表明它们可能在脑信号转导中发挥重要作用。
