TMK4-mediated FIP37 phosphorylation regulates auxin-triggered N-methyladenosine modification of auxin biosynthetic genes in Arabidopsis
Bin Li, Qiting Zhou, Linjun Cai, Lan Li, Chong Xie, Donghao Li, Fan Zhu, Xiushan Li, Xiaoying Zhao, Xuanming Liu, Lisha Shen, Tongda Xu, Chongsheng He
Abstract
The dynamics of N 6 -methyladenosine (m 6 A) mRNA modification are tightly controlled by the m 6 A methyltransferase complex and demethylases. Here, we find that auxin treatment alters m 6 A modification on auxin-responsive genes. Mechanically, TRANSMEMBRANE KINASE 4 (TMK4), a component of the auxin signaling pathway, interacts with and phosphorylates FKBP12-INTERACTING PROTEIN 37 (FIP37), a core component of the m 6 A methyltransferase complex, in an auxin-dependent manner. Phosphorylation of FIP37 enhances its interaction with RNA, thereby increasing m 6 A modification on its target genes, such as NITRILASE 1 ( NIT1 ), a gene involved in indole-3-acetic acid (IAA) biosynthesis. 1-Naphthalacetic acid (NAA) treatment accelerates the mRNA decay of NIT1 , in a TMK4- and FIP37-dependent manner, which leads to inhibition of auxin biosynthesis. Our findings identify a regulatory mechanism by which auxin modulates m 6 A modification through the phosphorylation of FIP37, ultimately affecting mRNA stability and auxin biosynthesis in plants.