Regulation of Protein Phosphatase Inhibitor-1 by Cdk5

描述（由申请人提供）：几个世纪以来，学习和记忆一直困扰着人们，直到20世纪70年代发现LTP和LTD，科学家们才发现了这些过程的细胞模型。三十年后，涉及钙/钙调蛋白依赖性激酶II（CaMKII），蛋白磷酸酶1（PP-1）和抑制剂-1的一般生化级联反应已获得广泛接受，尽管许多细节仍然模糊。该提案将采用生物化学和神经药理学技术来表征细胞周期蛋白依赖性激酶5（Cdk 5）对抑制剂-1的新型磷酸化事件及其对突触可塑性的影响。将评估该磷酸化反应的动力学及其对抑制剂-1活化、失活和对PP-1的抑制活性的影响。然后，海马切片将用于在体内表征这一事件，包括磷酸化的基础水平，以及不同信号传导途径的调节和对下游PP-1靶点的可能影响。最后，将通过体外和体内方法测定负责该位点去磷酸化的磷酸酶。

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.