Conserved SUN-KASH Interfaces Mediate LINC Complex-Dependent Nuclear Movement and Positioning.
Conserved SUN-KASH Interfaces Mediate LINC Complex-Dependent Nuclear Movement and Positioning.
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DOI：
10.1016/j.cub.2018.08.001
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发表时间：
2018-10-08
期刊：
影响因子：
--
通讯作者：
Starr DA
中科院分区：
文献类型：
--
作者：
Cain NE;Jahed Z;Schoenhofen A;Valdez VA;Elkin B;Hao H;Harris NJ;Herrera LA;Woolums BM;Mofrad MRK;Luxton GWG;Starr DA
许多核定位事件涉及核骨架和细胞骨架（LINC）复合物的连接体，其将细胞骨架产生的力传递穿过核膜。LINC复合物是由内核膜SUN蛋白和外核膜KASH蛋白之间的跨腔相互作用形成的，但这些相互作用如何调节尚不清楚。我们联合收割机体内C。elegans遗传学，体外受伤的成纤维细胞极化，以及计算机分子动力学模拟，以阐明LINC复合物的机制。通过一个丙氨酸残基的KASH结构域的延伸或保守的酪氨酸-7位的突变完全阻断了C的核迁移功能。83. how much do you want？小鼠nesprin-2 −7位的类似突变破坏了NIH 3 T3细胞核的向后运动，但没有破坏核锚定中的ANC-1。此外，保守的半胱氨酸预测形成SUN和KASH蛋白之间的二硫键是重要的某些LINC复合物的功能，并可能促进核迁移和核锚定之间的发育开关。SUN或KASH中保守的半胱氨酸突变破坏了C. elegans和Nesprin-2G依赖的极化成纤维细胞核运动。然而，SUN半胱氨酸突变并没有破坏核迁移。此外，分子动力学模拟表明，二硫键是必要的最大传输的细胞因子产生的力的LINC复合物在计算机上。因此，我们已经证明了SUN-KASH结合界面的功能，包括预测的分子间二硫键，作为核定位的机械决定因素，并可能代表调控的靶点。Cain等人测试了突变的SUN和KASH蛋白在C. elegans核定位，NIH 3 T3成纤维细胞极化，以及机械应变下LINC复合物的模拟，以获得对SUN-KASH相互作用如何调节以将力从细胞骨架转移到细胞核的机理见解。
Many nuclear positioning events involve linker of nucleoskeleton and cytoskeleton (LINC) complexes, which transmit forces generated by the cytoskeleton across the nuclear envelope. LINC complexes are formed by trans-luminal interactions between inner nuclear membrane SUN proteins and outer nuclear membrane KASH proteins, but how these interactions are regulated is poorly understood. We combine in vivo C. elegans genetics, in vitro wounded fibroblast polarization, and in silico molecular dynamic simulations to elucidate mechanisms of LINC complexes. The extension of the KASH domain by a single alanine residue or the mutation of the conserved tyrosine at −7 completely blocked the nuclear migration function of C. elegans UNC-83. Analogous mutations at −7 of mouse nesprin-2 disrupted rearward nuclear movements in NIH3T3 cells, but did not disrupt ANC-1 in nuclear anchorage. Furthermore, conserved cysteines predicted to form a disulfide bond between SUN and KASH proteins are important for the function of certain LINC complexes and might promote a developmental switch between nuclear migration and nuclear anchorage. Mutations of conserved cysteines in SUN or KASH disrupted ANC-1 dependent nuclear anchorage in C. elegans and Nesprin-2G dependent nuclear movements in polarizing fibroblasts. However, the SUN cysteine mutation did not disrupt nuclear migration. Moreover, molecular dynamic simulations showed that a disulfide bond is necessary for the maximal transmission of cytoskeleton-generated forces by LINC complexes in silico. Thus, we have demonstrated functions for SUN-KASH binding interfaces, including a predicted intermolecular disulfide bond, as mechanistic determinants of nuclear positioning and may represent targets for regulation. Cain et al. test the function of mutant SUN and KASH proteins in C. elegans nuclear positioning, NIH3T3 fibroblast polarization, and simulations of LINC complexes under mechanical strain to gain mechanistic insights into how SUN-KASH interactions might be regulated to transfer forces from the cytoskeleton to the nucleus.
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DOI：
10.1083/jcb.201004118
发表时间：
2010-10-04
期刊：
The Journal of cell biology
影响因子：
--
作者：
Fridolfsson HN;Starr DA
通讯作者：
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影响因子：
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作者：
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影响因子：
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10.1083/jcb.201604112
发表时间：
2016-12-19
期刊：
The Journal of cell biology
影响因子：
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作者：
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通讯作者：
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DOI：
10.1073/pnas.1000824108
发表时间：
2011-01-04
影响因子：
11.1
作者：
Folker, Eric S.;Oestlund, Cecilia;Gundersen, Gregg G.
通讯作者：
Gundersen, Gregg G.