Derkinderen P, Siciliano J, Toutant M, Girault J A
INSERM U 114, Chaire de Neuropharmacologie, Paris, France.
Eur J Neurosci. 1998 May;10(5):1667-75. doi: 10.1046/j.1460-9568.1998.00174.x.
FAK+, an isoform of focal adhesion kinase preferentially expressed in brain and PYK2/Cakbeta (proline-rich tyrosine kinase 2/cell adhesion kinasebeta) are two related cytoplasmic tyrosine kinases. They are candidates for coupling electrical activity and stimulation of neurotransmitter receptors to short and long-term changes in synaptic properties, cytoskeletal organization and gene expression in neurons. As the same set of stimuli appear capable of stimulating FAK and/or PYK2 in non-neuronal cells and in cell lines with neuronal characteristics, we investigated the selectivity of regulation of these two kinases in mature nervous tissue. Using rat hippocampal slices, we compared the regulation of FAK+ and PYK2 by stimuli known to be active on one or the other of these two kinases in other cell types: lysophosphatidic acid (LPA), carbachol, depolarization, and hyperosmolarity. Phosphorylation of FAK+ was markedly increased by carbachol and LPA. Carbachol effects occurred via activation of M1 muscarinic receptors and nicotinic receptors. The effects of carbachol and LPA were prevented by protein kinase C inhibitors, whereas 8-Br-cAMP attenuated the effects of carbachol but not of LPA. Tyrosine phosphorylation of PYK2 but not of FAK+ was very strongly enhanced by depolarization and hyperosmolarity. This study and our previous results show that FAK+ and PYK2 are regulated differentially in hippocampal slices: FAK+ is phosphorylated on tyrosine in response to stimulation of G protein-coupled receptors, whereas PYK2 is mainly sensitive to depolarization and hyperosmolarity. Thus, FAK+ and PYK2 may provide specific and separate links between activation of neurotransmitters receptors, depolarization and tyrosine phosphorylation in mature hippocampus.
粘着斑激酶的一种异构体FAK+在大脑中优先表达，而富含脯氨酸的酪氨酸激酶2/细胞粘着激酶β（PYK2/Cakbeta）是两种相关的细胞质酪氨酸激酶。它们是将电活动和神经递质受体刺激与神经元突触特性、细胞骨架组织和基因表达的短期和长期变化相偶联的候选分子。由于同一组刺激似乎能够在非神经元细胞和具有神经元特征的细胞系中刺激FAK和/或PYK2，我们研究了这两种激酶在成熟神经组织中的调节选择性。使用大鼠海马切片，我们比较了已知在其他细胞类型中对这两种激酶中的一种或另一种有活性的刺激对FAK+和PYK2的调节：溶血磷脂酸（LPA）、卡巴胆碱、去极化和高渗。卡巴胆碱和LPA显著增加了FAK+的磷酸化。卡巴胆碱的作用通过M1毒蕈碱受体和烟碱受体的激活而发生。蛋白激酶C抑制剂可阻止卡巴胆碱和LPA的作用，而8-溴-cAMP减弱了卡巴胆碱的作用，但不影响LPA的作用。去极化和高渗非常强烈地增强了PYK2的酪氨酸磷酸化，但未增强FAK+的酪氨酸磷酸化。这项研究和我们之前的结果表明，FAK+和PYK2在海马切片中的调节存在差异：FAK+在酪氨酸上的磷酸化是对G蛋白偶联受体刺激的反应，而PYK2主要对去极化和高渗敏感。因此，FAK+和PYK2可能在成熟海马体中神经递质受体激活、去极化和酪氨酸磷酸化之间提供特定且独立的联系。
