Regulation of Protein Phosphatase Inhibitor-1 by Cdk5

描述(申请人提供)：尽管学习和记忆几个世纪以来一直困扰着人们，但科学家们一直未能找到这些过程的细胞模型，直到20世纪70年代LTP和LTD被发现。三十年后，一个涉及钙/钙调蛋白依赖的激酶II(CaMKII)、蛋白磷酸酶1(PP-1)和抑制物-1的一般生化级联反应已经得到了广泛的接受，尽管许多细节仍然不清楚。这项建议将使用生化和神经药理学技术来表征细胞周期蛋白依赖性激酶5(CDK5)对抑制物-1的一种新的磷酸化事件及其对突触可塑性的影响。将评估这种磷酸化反应的动力学及其对抑制物-1的激活、失活和对PP-1的抑制活性的影响。然后将使用海马片在体内表征这一事件，根据基础水平的磷酸化，以及不同信号通路的调制和对下游PP-1靶点的可能影响。最后，负责该位点去磷酸化的磷酸酶(S)将通过体外和体内方法进行测定。

DESCRIPTION (provided by applicant): While learning and memory have mystified people for centuries, a cellular model for these processes eluded scientists until the discovery of LTP and LTD in the 1970s. Three decades later a general biochemical cascade involving calcium/calmodulin-dependent kinase II (CaMKII), protein phosphatase 1 (PP-1), and inhibitor-1 has gained widespread acceptance, although many details remain obscure. This proposal will employ biochemical and neuropharmacological techniques to characterize a novel phosphorylation event on inhibitor-1 by cyclin-dependent kinase 5 (Cdk5) and its implications for synaptic plasticity. The kinetics of this phosphorylation reaction and its effect upon inhibitor-1 activation, deactivation, and inhibitory activity against PP-1 will be assessed. Hippocampal slices will then be used to characterize this event in vivo, in terms of basal levels of phosphorylation, as well as modulation by different signaling pathways and possible effects on downstream PP-1 targets. Finally, the phosphatase(s) responsible for dephosphorylation of this site will be determined by both in vitro and in vivo methods.