Nesprins: tissue-specific expression of epsilon and other short isoforms.
Nesprins: tissue-specific expression of epsilon and other short isoforms.
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DOI：
10.1371/journal.pone.0094380
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Holt I
中科院分区：
文献类型：
--
作者：
Duong NT;Morris GE;Lam le T;Zhang Q;Sewry CA;Shanahan CM;Holt I
Nesprin-1-giant和Nesprin-2-giant通过其C-末端KASH结构域与核膜SUN蛋白的相互作用以及其N-末端钙调蛋白同源结构域与细胞骨架肌动蛋白的相互作用来调节核定位。许多缺乏肌动蛋白结合结构域的短同种型由内部促进产生。我们已经评估了这些较短的异构体的意义，使用定量RT-PCR和蛋白质印迹与位点特异性单克隆抗体。在一个完整的地图nesprin异构体，我们描述了两个新的nesprin-2 β异构体的第一次。表雄酮异构体在大小和结构上与nesprin-1-alpha相似。nesprin亚型的表达是高度组织依赖性的。Nesprin-2-β-1存在于早期胚胎细胞中，而Nesprin-2-β-2存在于心脏和其他成人组织中，但不存在于骨骼肌中。一些细胞系缺乏较短的同种型，只表达两种nesprin基因中的一种，这表明两种巨大的nesprin基因中的任何一种都足以维持基本的细胞功能。对于第一次，本地化的内源性nesprin远离核膜显示在细胞中的KASH结构域的选择性剪接发生去除。通过在蛋白质印迹上区分降解产物和真正的同种型，发现先前描述的β和γ同种型仅以低水平或有限的组织分布表达。两种最短的α亚型，nesprin-1-α-2和nesprin-2-α-1，几乎只在心肌和骨骼肌中发现，并且在两种nesprin基因中均存在的高度保守和选择性剪接的外显子总是包含在这些组织中。这些“肌肉特异性”同种型被认为在内核膜处与Emerin和核纤层蛋白A/C形成复合物，并且所有三种蛋白质中的突变引起Emery-Dreifuss肌营养不良和/或遗传性扩张型心肌病，其中仅骨骼肌和/或心脏受到影响的病症。
Nesprin-1-giant and nesprin-2-giant regulate nuclear positioning by the interaction of their C-terminal KASH domains with nuclear membrane SUN proteins and their N-terminal calponin-homology domains with cytoskeletal actin. A number of short isoforms lacking the actin-binding domains are produced by internal promotion. We have evaluated the significance of these shorter isoforms using quantitative RT-PCR and western blotting with site-specific monoclonal antibodies. Within a complete map of nesprin isoforms, we describe two novel nesprin-2 epsilon isoforms for the first time. Epsilon isoforms are similar in size and structure to nesprin-1-alpha. Expression of nesprin isoforms was highly tissue-dependent. Nesprin-2-epsilon-1 was found in early embryonic cells, while nesprin-2-epsilon-2 was present in heart and other adult tissues, but not skeletal muscle. Some cell lines lack shorter isoforms and express only one of the two nesprin genes, suggesting that either of the giant nesprins is sufficient for basic cell functions. For the first time, localisation of endogenous nesprin away from the nuclear membrane was shown in cells where removal of the KASH domain by alternative splicing occurs. By distinguishing between degradation products and true isoforms on western blots, it was found that previously-described beta and gamma isoforms are expressed either at only low levels or with a limited tissue distribution. Two of the shortest alpha isoforms, nesprin-1-alpha-2 and nesprin-2-alpha-1, were found almost exclusively in cardiac and skeletal muscle and a highly conserved and alternatively-spliced exon, available in both nesprin genes, was always included in these tissues. These “muscle-specific” isoforms are thought to form a complex with emerin and lamin A/C at the inner nuclear membrane and mutations in all three proteins cause Emery-Dreifuss muscular dystrophy and/or inherited dilated cardiomyopathy, disorders in which only skeletal muscle and/or heart are affected.
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影响因子：
3.5
作者：
Puckelwartz, Megan J.;Kessler, Eric;McNally, Elizabeth M.
通讯作者：
McNally, Elizabeth M.
DOI：
10.1074/jbc.m109.071910
发表时间：
2010-01-29
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Haque F;Mazzeo D;Patel JT;Smallwood DT;Ellis JA;Shanahan CM;Shackleton S
通讯作者：
Shackleton S
影响因子：
6.2
作者：
Rajgor D;Shanahan CM
通讯作者：
Shanahan CM
影响因子：
4.8
作者：
Apel, ED;Lewis, RM;Sanes, JR
通讯作者：
Sanes, JR
影响因子：
3.7
作者：
Pare, GC;Easlick, JL;Kapiloff, MS
通讯作者：
Kapiloff, MS