1. Synaptic Targeting and Function of SAPAPs Mediated by Phosphorylation-Dependent Binding to PSD-95 MAGUKs
- Author
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Jinwei Zhu, Qingqing Zhou, Yuan Shang, Hao Li, Mengjuan Peng, Xiao Ke, Zhuangfeng Weng, Rongguang Zhang, Xuhui Huang, Shawn S.C. Li, Guoping Feng, Youming Lu, and Mingjie Zhang
- Subjects
GK domain ,PSD-95 ,SAPAP ,MAGUK ,postsynaptic density ,synaptic scaffold proteins ,synaptogenesis ,synaptic plasticity ,Biology (General) ,QH301-705.5 - Abstract
The PSD-95/SAPAP/Shank complex functions as the major scaffold in orchestrating the formation and plasticity of the post-synaptic densities (PSDs). We previously demonstrated that the exquisitely specific SAPAP/Shank interaction is critical for Shank synaptic targeting and Shank-mediated synaptogenesis. Here, we show that the PSD-95/SAPAP interaction, SAPAP synaptic targeting, and SAPAP-mediated synaptogenesis require phosphorylation of the N-terminal repeat sequences of SAPAPs. The atomic structure of the PSD-95 guanylate kinase (GK) in complex with a phosphor-SAPAP repeat peptide, together with biochemical studies, reveals the molecular mechanism underlying the phosphorylation-dependent PSD-95/SAPAP interaction, and it also provides an explanation of a PSD-95 mutation found in patients with intellectual disabilities. Guided by the structural data, we developed potent non-phosphorylated GK inhibitory peptides capable of blocking the PSD-95/SAPAP interaction and interfering with PSD-95/SAPAP-mediated synaptic maturation and strength. These peptides are genetically encodable for investigating the functions of the PSD-95/SAPAP interaction in vivo.
- Published
- 2017
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