Akt1-associated actomyosin remodelling is required for nuclear lamina dispersal and nuclear shrinkage in epidermal terminal differentiation.
Akt1-associated actomyosin remodelling is required for nuclear lamina dispersal and nuclear shrinkage in epidermal terminal differentiation.
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DOI：
10.1038/s41418-020-00712-9
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发表时间：
2021-06
影响因子：
12.4
通讯作者：
O'Shaughnessy RFL
中科院分区：
文献类型：
--
作者：
Rogerson C;Wotherspoon DJ;Tommasi C;Button RW;O'Shaughnessy RFL
角质形成细胞角化和表皮屏障形成是严格控制的过程，其需要细胞内细胞器的完全降解，包括角质形成细胞核的去除。角质形成细胞核的破坏需要Akt 1依赖性的磷酸化和核纤层蛋白，核纤层蛋白A/C，对核完整性必不可少的降解。然而，导致完全核去除的分子机制及其调节尚未明确。大鼠表皮角质形成细胞（REKs）的融合后培养物进行自发和完全分化，允许可视化和扰动的体外分化过程。我们证明，在分化的角质形成细胞中，磷酸化核纤层蛋白A/C分散到整个细胞质的结构中。我们表明磷酸化核纤层蛋白A/C的分散是Akt 1依赖性的，并且这些结构对于从核纤层中去除核纤层蛋白A/C是特异性的;核内容物和核纤层蛋白B不存在于这些结构中。免疫沉淀鉴定了一组功能相关的Akt 1靶蛋白参与核纤层蛋白A/C的分散，包括肌动蛋白，它形成细胞骨架微丝，Arp 3，所需的肌动蛋白丝成核，和Myh 9，肌球蛋白IIa，分子马达，可以沿着肌动蛋白丝易位的一个组成部分。破坏肌动蛋白丝聚合，成核或肌球蛋白IIa活性防止细胞质核纤层蛋白A/C结构的形成和分散。表达荧光标记核蛋白的角质形成细胞的实时成像显示，在最终核破坏之前，核体积减少步骤需要不到40分钟。阻止Akt 1依赖性核纤层蛋白A/C磷酸化和破坏细胞骨架Akt 1相关蛋白阻止核体积减小。我们建议角质形成细胞核的破坏和分化需要肌球蛋白II活性和肌动蛋白细胞骨架的两个中间过程：核纤层蛋白A/C分散和快速核体积减少。
Keratinocyte cornification and epidermal barrier formation are tightly controlled processes, which require complete degradation of intracellular organelles, including removal of keratinocyte nuclei. Keratinocyte nuclear destruction requires Akt1-dependent phosphorylation and degradation of the nuclear lamina protein, Lamin A/C, essential for nuclear integrity. However, the molecular mechanisms that result in complete nuclear removal and their regulation are not well defined. Post-confluent cultures of rat epidermal keratinocytes (REKs) undergo spontaneous and complete differentiation, allowing visualisation and perturbation of the differentiation process in vitro. We demonstrate that there is dispersal of phosphorylated Lamin A/C to structures throughout the cytoplasm in differentiating keratinocytes. We show that the dispersal of phosphorylated Lamin A/C is Akt1-dependent and these structures are specific for the removal of Lamin A/C from the nuclear lamina; nuclear contents and Lamin B were not present in these structures. Immunoprecipitation identified a group of functionally related Akt1 target proteins involved in Lamin A/C dispersal, including actin, which forms cytoskeletal microfilaments, Arp3, required for actin filament nucleation, and Myh9, a component of myosin IIa, a molecular motor that can translocate along actin filaments. Disruption of actin filament polymerisation, nucleation or myosin IIa activity prevented formation and dispersal of cytoplasmic Lamin A/C structures. Live imaging of keratinocytes expressing fluorescently tagged nuclear proteins showed a nuclear volume reduction step taking less than 40 min precedes final nuclear destruction. Preventing Akt1-dependent Lamin A/C phosphorylation and disrupting cytoskeletal Akt1-associated proteins prevented nuclear volume reduction. We propose keratinocyte nuclear destruction and differentiation requires myosin II activity and the actin cytoskeleton for two intermediate processes: Lamin A/C dispersal and rapid nuclear volume reduction.
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影响因子：
3.3
作者：
Chan FY;Silva AM;Saramago J;Pereira-Sousa J;Brighton HE;Pereira M;Oegema K;Gassmann R;Carvalho AX
通讯作者：
Carvalho AX
影响因子：
64.8
作者：
Guelen, Lars;Pagie, Ludo;van Steensel, Bas
通讯作者：
van Steensel, Bas
影响因子：
7.8
作者：
Wunderlich, F;Herlan, G
通讯作者：
Herlan, G
影响因子：
7.8
作者：
Mabuchi, I;Okuno, M
通讯作者：
Okuno, M
影响因子：
6
作者：
Lu X;Djabali K
通讯作者：
Djabali K