Discipline of Biological Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India.
Biochemistry. 2021 Jun 15;60(23):1822-1835. doi: 10.1021/acs.biochem.1c00010. Epub 2021 May 25.
Active DNA transposases like the Drosophila P element transposase (DmTNP) undergo oligomerization as a prerequisite for transposition. Human THAP9 (hTHAP9) is a catalytically active but functionally uncharacterized homologue of DmTNP. Here we report (using co-immunoprecipitation, pull down, colocalization, and proximity ligation assays) that both full length and truncated hTHAP9 (corresponding to amino-terminal DNA binding and predicted coiled coil domains) undergo homo-oligomerization, predominantly in the nuclei of HEK293T cells. Interestingly, the oligomerization is shown to be partially mediated by DNA. However, mutating the leucines (either individually or together) or deleting the predicted coiled coil region did not significantly affect oligomerization. Thus, we highlight the importance of DNA and the amino-terminal regions of hTHAP9 for their ability to form higher-order oligomeric states. We also report that Hcf-1, THAP1, THAP10, and THAP11 are possible protein interaction partners of hTHAP9. Elucidating the functional relevance of the different putative oligomeric state(s) of hTHAP9 would help answer questions about its interaction partners as well as its unknown physiological roles.
活性 DNA 转座酶，如果蝇 P 元件转座酶（DmTNP），在转座之前需要进行寡聚化。人类 THAP9（hTHAP9）是 DmTNP 的一种具有催化活性但功能尚未确定的同源物。在这里，我们报告（使用共免疫沉淀、下拉、共定位和邻近连接测定）全长和截短的 hTHAP9（分别对应于氨基末端 DNA 结合和预测的卷曲螺旋结构域）均发生同源寡聚化，主要发生在 HEK293T 细胞的细胞核中。有趣的是，寡聚化部分由 DNA 介导。然而，突变亮氨酸（单独或一起）或删除预测的卷曲螺旋区并没有显著影响寡聚化。因此，我们强调了 DNA 和 hTHAP9 的氨基末端区域对于其形成更高阶寡聚状态的重要性。我们还报告 Hcf-1、THAP1、THAP10 和 THAP11 可能是 hTHAP9 的蛋白质相互作用伙伴。阐明 hTHAP9 不同假定的寡聚状态的功能相关性将有助于回答关于其相互作用伙伴以及其未知生理作用的问题。
