Department of Biochemistry, Kochi University Medical School, Nankoku, Kochi, Japan.
Department of Biochemistry, Kochi University Medical School, Nankoku, Kochi, Japan.
J Lipid Res. 2020 Dec;61(12):1747-1763. doi: 10.1194/jlr.RA120001087. Epub 2020 Sep 22.
The plasma membrane of neurons consists of distinct domains, each of which carries specialized functions and a characteristic set of membrane proteins. While this compartmentalized membrane organization is essential for neuronal functions, it remains controversial how neurons establish these domains on the laterally fluid membrane. Here, using immunostaining, lipid-MS analysis and gene ablation with the CRISPR/Cas9 system, we report that the pancreatic lipase-related protein 2 (PLRP2), a phospholipase A1 (PLA1), is a key organizer of membrane protein localization at the neurite tips of PC12 cells. PLRP2 produced local distribution of 1-oleoyl-2-palmitoyl-PC at these sites through acyl-chain remodeling of membrane phospholipids. The resulting lipid domain assembled the syntaxin 4 (Stx4) protein within itself by selectively interacting with the transmembrane domain of Stx4. The localized Stx4, in turn, facilitated the fusion of transport vesicles that contained the dopamine transporter with the domain of the plasma membrane, which led to the localized distribution of the transporter to that domain. These results revealed the pivotal roles of PLA1, specifically PLRP2, in the formation of functional domains in the plasma membrane of neurons. In addition, our results suggest a mode of membrane organization in which the local acyl-chain remodeling of membrane phospholipids controls the selective localization of membrane proteins by regulating both lipid-protein interactions and the fusion of transport vesicles to the lipid domain.
神经元的质膜由不同的域组成,每个域都具有专门的功能和一组特征性的膜蛋白。虽然这种分隔的膜组织对于神经元功能至关重要,但神经元如何在横向流动的膜上建立这些域仍然存在争议。在这里,我们使用免疫染色、脂质-MS 分析和 CRISPR/Cas9 系统的基因敲除,报告了胰腺脂酶相关蛋白 2(PLRP2),一种磷脂酶 A1(PLA1),是 PC12 细胞的神经突尖端膜蛋白定位的关键组织者。PLRP2 通过膜磷脂的酰基链重塑在这些部位产生 1-油酰基-2-棕榈酰-PC 的局部分布。由此产生的脂质域通过与 Stx4 跨膜结构域的选择性相互作用将 Stx4 蛋白组装在自身内。局部化的 Stx4 反过来促进了含有多巴胺转运体的运输小泡与质膜域的融合,从而导致转运体局部分布到该域。这些结果揭示了 PLA1,特别是 PLRP2,在神经元质膜中功能性域形成中的关键作用。此外,我们的结果表明了一种膜组织的模式,其中膜磷脂的局部酰基链重塑通过调节脂质-蛋白相互作用和运输小泡与脂质域的融合来控制膜蛋白的选择性定位。