Jiang Zhi-Yan, Wu Yu-Ke, Deng Zuo-Qi, Chen Lu, Zhu Yi-Min, Yu Yuan-Song, Wu Hong-Bo, Fan Heng-Yu
Zhejiang Key Laboratory of Precise Protection and Promotion of Fertility, Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, China.
MOE Key Laboratory for Biosystems Homeostasis and Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
Adv Sci (Weinh). 2024 Dec;11(47):e2400133. doi: 10.1002/advs.202400133. Epub 2024 Nov 18.
Massive numbers of modified bases in mRNAs sculpt the epitranscriptome and play vital roles in RNA metabolism. The only known acetylated RNA modification, N-4-acetylcytidine (acC), is highly conserved across cell types and among species. Although the GCN5-related acetyltransferase 10 (NAT10) functions as an acC writer, the mechanism underlying the acetylation process is largely unknown. In this study, the NAT10/PCBP/TDP43 complex mediated mRNA acC formation in mammalian cells is identified. RNA-binding proteins (RBPs) are identified, affiliated with two different families, poly(rC)-binding protein 1/2 (PCBP1/2) and TAR DNA binding protein 43 (TDP43), as NAT10 adaptors for mRNA tethering and substrate selection. Knockdown of the adaptors resulted in decreased mRNA acetylation abundance in HEK293T cells and ablated cytidine-rich acC motifs. The adaptors also affect the acC sites by recruiting NAT10 to their binding sequences. The presence of the NAT10/PCBP/TDP43 complex in mouse testes highlights its potential physiological functions in vivo. These findings reveal the composition of the mRNA acC writer complex in mammalian cells and expand the knowledge of mRNA acetylation and acC site preferences.
信使核糖核酸（mRNA）中大量经过修饰的碱基塑造了表转录组，并在RNA代谢中发挥着至关重要的作用。唯一已知的乙酰化RNA修饰，即N4-乙酰胞苷（acC），在不同细胞类型和物种之间高度保守。尽管GCN5相关的乙酰转移酶10（NAT10）作为acC的写入酶发挥作用，但乙酰化过程背后的机制在很大程度上尚不清楚。在这项研究中，鉴定了哺乳动物细胞中由NAT10/PCBP/TDP43复合物介导的mRNA的acC形成。鉴定出了与两个不同家族相关的RNA结合蛋白（RBP），即聚（rC）结合蛋白1/2（PCBP1/2）和TAR DNA结合蛋白43（TDP43），作为用于mRNA系留和底物选择的NAT10衔接子。敲低这些衔接子导致HEK293T细胞中mRNA乙酰化丰度降低，并消除了富含胞苷的acC基序。这些衔接子还通过将NAT10招募到其结合序列来影响acC位点。NAT10/PCBP/TDP43复合物在小鼠睾丸中的存在突出了其在体内的潜在生理功能。这些发现揭示了哺乳动物细胞中mRNA的acC写入酶复合物的组成，并扩展了对mRNA乙酰化和acC位点偏好的认识。
