Department of Anatomy and Neurobiology, College of Medicine, Hallym University, Chunchon, Kangwon-Do, South Korea.
Hippocampus. 2009 Nov;19(11):1078-89. doi: 10.1002/hipo.20568.
Pyridoxal-5'-phosphate (PLP)-phosphatase/chronophin (PLPP/CIN) directly dephosphorylates actin-depolymerizing factor (ADF)/cofilin as well as PLP. Although PLPP/CIN plays a role in the regulation of F-actin and vitamin B(6) metabolism, there is no direct evidence to support a correlation between PLPP/CIN and F-actin polymerization during long-term potentiation (LTP) induction. In this study, we investigated whether the expression of PLPP/CIN is altered following LTP induction, and whether Tat-PLPP/CIN transduction affects LTP induction in the rat dentate gyrus (DG). PLPP/CIN immunoreactivity was markedly decreased in dentate granule cells after the induction of LTP. Tat-PLPP/CIN transduction (20 and 200 microg/kg) decreased the efficiency of high frequency stimulus-induced potentiation of populations spike amplitude as compared to saline or Tat-protein-treated animals. The PLPP/CIN protein level showed an inverse correlation with phosphorylated ADF/cofilin levels and F-actin content. These findings suggest that PLPP/CIN-mediated actin dynamics may play an important role in the changes of morphological properties (dendritic spine reorganization) of the hippocampus in LTP.
吡哆醛-5'-磷酸（PLP）-磷酸酶/chronophin（PLPP/CIN）可直接去磷酸化肌动蛋白解聚因子（ADF）/丝切蛋白以及 PLP。尽管 PLPP/CIN 在 F-肌动蛋白和维生素 B(6)代谢的调节中发挥作用，但没有直接证据表明 PLPP/CIN 与长时程增强（LTP）诱导期间的 F-肌动蛋白聚合之间存在相关性。在这项研究中，我们研究了 LTP 诱导后 PLPP/CIN 的表达是否发生改变，以及 Tat-PLPP/CIN 转导是否会影响大鼠齿状回（DG）中的 LTP 诱导。LTP 诱导后，齿状颗粒细胞中的 PLPP/CIN 免疫反应性明显降低。与盐水或 Tat-蛋白处理的动物相比，Tat-PLPP/CIN 转导（20 和 200 μg/kg）降低了高频刺激诱导的群体锋电位幅度增强的效率。PLPP/CIN 蛋白水平与磷酸化 ADF/丝切蛋白水平和 F-肌动蛋白含量呈负相关。这些发现表明，PLPP/CIN 介导的肌动蛋白动力学可能在 LTP 中海马体形态特性（树突棘重组）的变化中发挥重要作用。
