Ma Ao, Liang Zhi, Zhang Hongde, Meng Zhichao, Zhu Jiehao, Chen Shu, Lin Qisheng, Jiang Tao, Tan Minghui
Department of Orthopedics, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, China.
Department of Orthopedics, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518033, China.
J Mol Neurosci. 2025 Apr 24;75(2):54. doi: 10.1007/s12031-025-02348-1.
As a key component of the cytoskeleton, microtubule dynamic provides structural support for neurite outgrowth. Spastin, a microtubule severing enzyme associated with hereditary spastic paraplegia (HSP), is crucial for the growth and branching of neuronal processes. Thus, the activity and function of spastin need to be strictly regulated. However, the mechanism by which spastin protein levels are regulated is still poorly understood. In the current study, we showed that UCHL1 interacted with spastin via mass spectrometry, GST-pulldown and immunoprecipitation assays. Overexpression of UCHL1 decreased the protein level of spastin, while the genetic knockdown of UCHL1 increased that of spastin. CHX chase assay showed that UCHL1 regulated the protein degradation of spastin. Application of proteasome inhibitor MG-132 suppressed UCHL1-mediated spastin degradation. Furthermore, overexpression or knockout of UCHL1 can inhibit or restore spastin-mediated microtubule severing, thereby regulating neuronal length and branch formation. These findings reveal the important regulatory mechanism of UCHL1 on spastin-mediated neurite outgrowth.
作为细胞骨架的关键组成部分，微管动力学为神经突生长提供结构支持。痉挛素是一种与遗传性痉挛性截瘫（HSP）相关的微管切断酶，对神经元突起的生长和分支至关重要。因此，痉挛素的活性和功能需要严格调控。然而，痉挛素蛋白水平的调控机制仍知之甚少。在本研究中，我们通过质谱、GST沉降和免疫沉淀实验表明UCHL1与痉挛素相互作用。UCHL1的过表达降低了痉挛素的蛋白水平，而UCHL1的基因敲低则增加了痉挛素的蛋白水平。CHX追踪实验表明UCHL1调节痉挛素的蛋白降解。蛋白酶体抑制剂MG-132的应用抑制了UCHL1介导的痉挛素降解。此外，UCHL1的过表达或敲除可抑制或恢复痉挛素介导的微管切断，从而调节神经元长度和分支形成。这些发现揭示了UCHL1对痉挛素介导的神经突生长的重要调控机制。
