Department of Biochemistry, Faculty of Medicine, University of Yamanashi, Chuo, Japan.
Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.
Genes Cells. 2021 Dec;26(12):987-998. doi: 10.1111/gtc.12899. Epub 2021 Oct 23.
Van Gogh-like 2 (Vangl2) is a mammalian homolog of Drosophila core planar cell polarity (PCP) protein Vang/Strabismus, which organizes asymmetric cell axes for developmental proliferation, fate determination, and polarized movements in multiple tissues, including neurons. Although the PCP pathway has an essential role for dendrite and dendritic spine formation, the molecular mechanism remains to be clarified. To investigate the mechanism of Vangl2-related neuronal development, we screened for proteins that interact with the Vangl2 cytosolic N-terminus from postnatal day 9 mouse brains using a yeast two-hybrid system. From 61 genes, we identified adaptor-related protein complex 2, mu 1 subunit (Ap2m1) as the Vangl2 N-terminal binding protein. Intriguingly, however, the pull-down assay demonstrated that Vangl2 interacted with Ap2m1 not only at its N-terminus but also at the C-terminal Prickle binding domain. Furthermore, we verified that the downregulation of Ap2m1 in the developing cortical neurons reduced the dendritic branching similar to what occurs in a knockdown of Vangl2. From these results, we suggest that the membrane internalization regulated by the PCP pathway is required for the developmental morphological change in neurons.
梵高样蛋白 2（Vangl2）是果蝇核心平面细胞极性（PCP）蛋白 Vang/斜视的哺乳动物同源物，它组织不对称细胞轴，用于发育增殖、命运决定和包括神经元在内的多种组织中的极化运动。尽管 PCP 途径对树突和树突棘形成具有重要作用，但分子机制仍有待阐明。为了研究与 Vangl2 相关的神经元发育机制，我们使用酵母双杂交系统从出生后 9 天的小鼠脑中筛选与 Vangl2 胞质 N 端相互作用的蛋白质。从 61 个基因中，我们鉴定出衔接蛋白相关复合物 2，μ1 亚基（Ap2m1）为 Vangl2 N 端结合蛋白。然而，有趣的是，下拉实验表明 Vangl2 不仅与 Ap2m1 的 N 端，而且与 Prickle 结合域的 C 端相互作用。此外，我们验证了在发育中的皮质神经元中下调 Ap2m1 会减少类似于 Vangl2 敲低时发生的树突分支。从这些结果中，我们认为 PCP 途径调节的膜内化对于神经元的发育形态变化是必需的。
