Targeting of LRRC59 to the Endoplasmic Reticulum and the Inner Nuclear Membrane
Targeting of LRRC59 to the Endoplasmic Reticulum and the Inner Nuclear Membrane
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DOI：
10.3390/ijms20020334
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发表时间：
2019-01-02
影响因子：
5.6
通讯作者：
Kehlenbach, Ralph H.
中科院分区：
文献类型：
--
作者：
Blenski, Marina;Kehlenbach, Ralph H.
LRRC 59（富含亮氨酸重复序列的蛋白质59）是一种尾部锚定蛋白，在其C-末端附近具有一个单一的跨膜结构域，定位于内质网（ER）和核膜。在这里，我们研究了LRRC 59的膜整合及其靶向内核膜（INM）的机制。使用纯化的微粒体，我们表明，LRRC 59可以post-acetylationally插入到ER衍生膜。TRC途径是翻译后膜插入的主要途径，但LRRC 59不需要TRC途径。与另一种尾锚定蛋白emerin一样，LRRC 59到达INM，如雷帕霉素依赖性二聚化测定所示。使用不同的方法来抑制importin α/β依赖的可溶性蛋白质的核输入，我们表明，经典的核转运机制在INM靶向LRRC 59中不起主要作用。相反，LRRC 59的胞质结构域的大小是一个重要的特征，表明靶向是由被动扩散控制的。
LRRC59 (leucine-rich repeat-containing protein 59) is a tail-anchored protein with a single transmembrane domain close to its C-terminal end that localizes to the endoplasmic reticulum (ER) and the nuclear envelope. Here, we investigate the mechanisms of membrane integration of LRRC59 and its targeting to the inner nuclear membrane (INM). Using purified microsomes, we show that LRRC59 can be post-translationally inserted into ER-derived membranes. The TRC-pathway, a major route for post-translational membrane insertion, is not required for LRRC59. Like emerin, another tail-anchored protein, LRRC59 reaches the INM, as demonstrated by rapamycin-dependent dimerization assays. Using different approaches to inhibit importin alpha/beta-dependent nuclear import of soluble proteins, we show that the classic nuclear transport machinery does not play a major role in INM-targeting of LRRC59. Instead, the size of the cytoplasmic domain of LRRC59 is an important feature, suggesting that targeting is governed by passive diffusion.