Pseudophosphatase MK-STYX Alters Histone Deacetylase 6 Cytoplasmic Localization, Decreases Its Phosphorylation, and Increases Detyrosination of Tubulin
Pseudophosphatase MK-STYX Alters Histone Deacetylase 6 Cytoplasmic Localization, Decreases Its Phosphorylation, and Increases Detyrosination of Tubulin
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DOI：
10.3390/ijms20061455
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发表时间：
2019-03-21
影响因子：
5.6
通讯作者：
Hinton, Shanta D.
中科院分区：
文献类型：
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作者：
Cao, Yuming;Banks, Dallas A.;Hinton, Shanta D.
催化失活的丝裂原激活蛋白 (MAP) 激酶磷酸酶 MK-STYX（MAPK（丝裂原激活蛋白激酶）磷酸丝氨酸/苏氨酸/酪氨酸结合蛋白）与应激颗粒成核剂 G3BP-1（Ras-GAP（GTP 酶激活蛋白）SH3（Src 同源性 3）结构域结合蛋白-1）相互作用，并减少应激颗粒（停滞的 mRNA）形成。组蛋白脱乙酰酶亚型 6 (HDAC6) 也结合 G3BP-1，并作为应激颗粒的主要成分。 MK-STYX 和 HDAC6 均与 G3BP-1 相互作用的发现促使我们研究 MK-STYX 对 HDAC6 动力学的影响。在对照 HEK/293 细胞中，HDAC6 正如预期的那样位于胞质中，并在应激条件下形成聚集体。相反，在过表达 MK-STYX 的细胞中，HDAC6 既存在于细胞核又存在于细胞质中，并且应激诱导的聚集体数量显着减少。免疫印迹显示 MK-STYX 降低 HDAC6 丝氨酸磷酸化、蛋白质酪氨酸磷酸化和赖氨酸乙酰化。已知 HDAC6 可以调节微管动力学以形成聚集体。 MK-STYX 不影响微管的组织，但确实影响其翻译后修饰。 MK-STYX 存在时微管蛋白乙酰化增加。此外，在 MK-STYX 存在下，微管蛋白的去酪氨酸作用显着增加。这些发现表明，MK-STYX 减少了含有 HDAC6 的聚集体的数量并改变其定位，维持微管乙酰化，并增加微管的去酪氨酸化，表明 MK-STYX 作为 HDAC6 活性中的信号分子。
The catalytically inactive mitogen-activated protein (MAP) kinase phosphatase, MK-STYX (MAPK (mitogen-activated protein kinase) phosphoserine/threonine/tyrosine-binding protein) interacts with the stress granule nucleator G3BP-1 (Ras-GAP (GTPase-activating protein) SH3 (Src homology 3) domain-binding protein-1), and decreases stress granule (stalled mRNA) formation. Histone deacetylase isoform 6 (HDAC6) also binds G3BP-1 and serves as a major component of stress granules. The discovery that MK-STYX and HDAC6 both interact with G3BP-1 led us to investigate the effects of MK-STYX on HDAC6 dynamics. In control HEK/293 cells, HDAC6 was cytosolic, as expected, and formed aggregates under conditions of stress. In contrast, in cells overexpressing MK-STYX, HDAC6 was both nuclear and cytosolic and the number of stress-induced aggregates significantly decreased. Immunoblots showed that MK-STYX decreases HDAC6 serine phosphorylation, protein tyrosine phosphorylation, and lysine acetylation. HDAC6 is known to regulate microtubule dynamics to form aggregates. MK-STYX did not affect the organization of microtubules, but did affect their post-translational modification. Tubulin acetylation was increased in the presence of MK-STYX. In addition, the detyrosination of tubulin was significantly increased in the presence of MK-STYX. These findings show that MK-STYX decreases the number of HDAC6-containing aggregates and alters their localization, sustains microtubule acetylation, and increases detyrosination of microtubules, implicating MK-STYX as a signaling molecule in HDAC6 activity.