Department of Bioscience and Biotechnology, Sejong University, Seoul, 05006, Republic of Korea.
Macrogen Inc., 254, Beotkkot-ro, Geumcheon-gu, Seoul, 08511, Republic of Korea.
Sci Rep. 2019 May 2;9(1):6849. doi: 10.1038/s41598-019-43235-1.
Thymosinβ-4(Tβ4) is an actin-sequestering protein involved in tumor malignancy. Primary cilia, microtubule-based organelles, are present in most eukaryotic cells, which might be related to tumor cell transformation. Here, we investigated whether ciliogenesis is affected by Tβ4 in HeLa human cervical cancer cells. The inhibition of Tβ4 attenuated primary cilia formation. The frequency of cilia was increased by Tβ4 overexpression. When yeast two-hybrid assay was performed by using Tβ4 as a bait, we rescued nephronophthisis 3(NPHP3), one of the components of primary cilia. Interaction of Tβ4 with NPHP3 in mammalian cells was confirmed by GST-pulldown assay. Their intracellular co-localization was observed by immunofluorescence staining at peripheral surface of cells. In addition, the number of ciliated cells was reduced by the inhibition of NPHP3. Moreover, NPHP3 expression was decreased by the inhibition of Tβ4 but it was increased by Tβ4 overexpression. Taken together, the results demonstrate that primary cilia formation could be regulated by Tβ4 through its interaction with NPHP3 and/or the control of NPHP3 expression. It suggests that Tβ4 is a novel regulator for primary cilia formation by NPHP3. It also suggests that tumorigenesis could be associated with inappropriate regulation of Tβ4 and/or NPHP3 expression to maintain primary cilia formation normally.
β-胸腺素 4（Tβ4）是一种肌动蛋白结合蛋白，参与肿瘤恶性转化。初级纤毛是一种微管为基础的细胞器，存在于大多数真核细胞中，这可能与肿瘤细胞转化有关。在这里，我们研究了 Tβ4 是否会影响 HeLa 人宫颈癌细胞中的纤毛发生。Tβ4 的抑制减弱了初级纤毛的形成。Tβ4 的过表达增加了纤毛的频率。当使用 Tβ4 作为诱饵进行酵母双杂交测定时，我们挽救了纤毛病 3（NPHP3），它是初级纤毛的组成部分之一。通过 GST 下拉测定证实了 Tβ4 与哺乳动物细胞中 NPHP3 的相互作用。通过免疫荧光染色在细胞外周表面观察到它们的细胞内共定位。此外，NPHP3 抑制减少了有纤毛的细胞数量。此外，Tβ4 的抑制降低了 NPHP3 的表达，但 Tβ4 的过表达增加了 NPHP3 的表达。总之，这些结果表明，初级纤毛的形成可以通过 Tβ4 与其与 NPHP3 的相互作用和/或 NPHP3 表达的控制来调节。这表明 Tβ4 是通过 NPHP3 调节初级纤毛形成的一种新型调节剂。这也表明，肿瘤发生可能与 Tβ4 和/或 NPHP3 表达的不当调节有关，以维持初级纤毛的正常形成。
