Wilkinson Kevin A, Konopacki Filip, Henley Jeremy M
MRC Centre for Synaptic Plasticity; School of Biochemistry; Medical Sciences Building; University of Bristol; Bristol, UK.
Commun Integr Biol. 2012 Mar 1;5(2):223-6. doi: 10.4161/cib.19195.
Kainate receptors (KARs) are tetrameric glutamate-gated ion channels composed of combinations of the subunits GluK1-5. Depending on their precise localization and subunit composition, KARs can regulate neurotransmitter release, synaptic function and neuronal excitability. Because of these diverse roles, the regulated and precisely targeted trafficking of KARs is of crucial importance to neuronal function. We previously reported that the KAR subunit GluK2 is post-translationally modified by attachment of Small Ubiquitin-like Modifier 1 (SUMO-1) and that SUMOylation is required for agonist-dependent endocytosis of GluK2. We recently extended these findings to demonstrate that agonist activation leads to PKC-mediated phosphorylation of GluK2 at serine 868, which directly enhances GluK2 SUMOylation and, in turn, leads to endocytosis of the receptor. These new data demonstrate the importance of interplay between two post-translational modifications in orchestrating the temporal and spatial regulation of kainate receptor trafficking.
海人酸受体（KARs）是由亚基GluK1 - 5组合而成的四聚体谷氨酸门控离子通道。根据其精确的定位和亚基组成，KARs可以调节神经递质释放、突触功能和神经元兴奋性。由于这些多样的作用，KARs的受调控且精确靶向的运输对神经元功能至关重要。我们之前报道过海人酸受体亚基GluK2在翻译后通过附着小泛素样修饰物1（SUMO - 1）进行修饰，并且SUMO化是GluK2激动剂依赖性内吞作用所必需的。我们最近扩展了这些发现以证明激动剂激活导致PKC介导的GluK2在丝氨酸868处磷酸化，这直接增强了GluK2的SUMO化，进而导致受体的内吞作用。这些新数据证明了两种翻译后修饰之间的相互作用在协调海人酸受体运输的时空调节中的重要性。
