Shen K, Meyer T
Department of Cell Biology and Department of Pharmacology and Cancer Biology, Box 3709, Duke University Medical Center, Durham, NC 27710, USA.
Science. 1999 Apr 2;284(5411):162-6. doi: 10.1126/science.284.5411.162.
Calcium-calmodulin-dependent protein kinase II (CaMKII) is thought to increase synaptic strength by phosphorylating postsynaptic density (PSD) ion channels and signaling proteins. It is shown that N-methyl-D-aspartate (NMDA) receptor stimulation reversibly translocates green fluorescent protein-tagged CaMKII from an F-actin-bound to a PSD-bound state. The translocation time was controlled by the ratio of expressed beta-CaMKII to alpha-CaMKII isoforms. Although F-actin dissociation into the cytosol required autophosphorylation of or calcium-calmodulin binding to beta-CaMKII, PSD translocation required binding of calcium-calmodulin to either the alpha- or beta-CaMKII subunits. Autophosphorylation of CaMKII indirectly prolongs its PSD localization by increasing the calmodulin-binding affinity.
钙调蛋白依赖性蛋白激酶II（CaMKII）被认为通过使突触后致密区（PSD）离子通道和信号蛋白磷酸化来增强突触强度。研究表明，N-甲基-D-天冬氨酸（NMDA）受体刺激可使绿色荧光蛋白标记的CaMKII从与F-肌动蛋白结合的状态可逆地转位至与PSD结合的状态。转位时间由表达的β-CaMKII与α-CaMKII亚型的比例控制。虽然F-肌动蛋白解离进入细胞质需要β-CaMKII的自磷酸化或钙调蛋白结合，但PSD转位需要钙调蛋白与α-或β-CaMKII亚基结合。CaMKII的自磷酸化通过增加钙调蛋白结合亲和力间接延长其在PSD的定位。
