ABSTRACT The double membrane nuclear envelope (NE), which is contiguous with the ER, contains nuclear pore complexes (NPCs) – the channels for nucleocytoplasmic transport, and the nuclear lamina (NL) – a scaffold for NE and chromatin organization. Since numerous human diseases linked to NE proteins occur in mesenchyme-derived cells, we used proteomics to characterize NE and other subcellular fractions isolated from mesenchymal stem cells and from adipocytes and myocytes. Based on spectral abundance, we calculated enrichment scores for proteins in the NE fractions. We demonstrated by quantitative immunofluorescence microscopy that five little-characterized proteins with high enrichment scores are substantially concentrated at the NE, with Itprip exposed at the outer nuclear membrane, Smpd4 enriched at the NPC, and Mfsd10, Tmx4, and Arl6ip6 likely residing in the inner nuclear membrane. These proteins provide new focal points for studying the functions of the NE. Moreover, our datasets provide a resource for evaluating additional potential NE proteins.

中文翻译：

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使用间充质细胞的细胞器蛋白质组学鉴定浓缩在核膜上的新跨膜蛋白

摘要 与 ER 相邻的双膜核被膜 (NE) 包含核孔复合物 (NPC) - 核细胞质运输的通道，以及核层 (NL) - NE 和染色质组织的支架。由于许多与 NE 蛋白相关的人类疾病发生在间充质衍生细胞中，我们使用蛋白质组学来表征从间充质干细胞、脂肪细胞和肌细胞中分离出的 NE 和其他亚细胞组分。基于光谱丰度，我们计算了 NE 级分中蛋白质的富集分数。我们通过定量免疫荧光显微镜证明，五种具有高富集分数的鲜为人知的蛋白质基本上集中在 NE，Itprip 暴露在外核膜处，Smpd4 在 NPC 处富集，Mfsd10、Tmx4、和 Arl6ip6 可能存在于内核膜中。这些蛋白质为研究 NE 的功能提供了新的焦点。此外，我们的数据集提供了评估其他潜在 NE 蛋白质的资源。