The Dicer complex of plants is regulated by phosphatase PP4/SMEK1-mediated dephosphotification.

MicroRNA (miRNA) is a class of non-coding RNA molecules encoded by endogenous genes with a length of approximately 21-24 nucleotides that regulate gene expression to participate in numerous growth and development and disease occurrence in plants and animals.
production of miRNA is very conservative in plants and animals, and it is known that miRNA is produced by the cutting of primary transcripts with neck ring structures by theDicer complex.
In recent years, the research on the identification of Dicer complex components and the molecular mechanism of identifying stem ring structure substrates has made rapid progress, but it is still unclear how the regulation ofdicer complex itself and how to integrate environmental signals to coordinate the fine regulation mechanisms produced by miRNA.
Recently, Zheng Pinglian, a researcher at Fudan University's School of Life Sciences, found that the Dicer complex of plants was regulated by phosphatase PP4/SMEK1-mediated dephosphate, and that this regulation was related to the stress of drought-like plants.
the study was published in the journal Developmental Cell, a comprehensive biology journal. in
animals found that the function of TRBP, the main member of theDicer complex, requires phosphorylation mediated by the MAPK path, while the function of HYL1, a tongon protein of TRBP, the main member of the Dicer complex in plants, requires the dephosphatization of CPL1/2 mediated.
both have been shown to be susceptible to degradation in the body.
, is there conservatism in kinases and phosphatases regulated by phosphate of the Dicer complex components of animal and plant intermediaries? The researchers identified the phosphatase complex PP4/SMEK1 through genetics, biochemistry, and cell biology, which mediated the dephosphatification of HYL1 through kinase activity of antagonist MAPK, which ultimately ensured normal miRNA production in plants.
team first found a significant decrease in miRNA content throughout the genome of the smek1 mutant, and further studies have shown that SMEK1 promotes miRNA production by stabilizing the HYL1 protein.
in vivo, SMEK1 is assembled into an active phosphatase PP4 complex as a regulatory sub-base together with catalytic sub-base PPX1/PPX2, and ITL1 is proved to be the substrate of PP4/SMEK1.
meanwhile, SMEK1 itself acts as an inhibitor of the MAPK path, ensuring the dephosphotification of HYL1 by a dual mechanism.
Unlike phosphatase CPL1/2, which regulates the dephosphatification of HYL1 at specific stages of development, PP4/SMEK1 is produced by integrating environmental factors to coordinate miRNA, since the SMEK1 protein itself is significantly induced by the aphrasic acid ABA produced under dry conditions.
this study established a link between kinase MAPK and phosphatase PP4/SMEK1 for the first time, providing important clues for further study of the relationship between plant miRNA production and changes in environmental factors.
, given the high conservatism of the PP4/SMEK1 complex in plants and animals, the team's research provides important clues to the phosphatase of theDicer complex in animals.
it is understood that the research by the National Fund Committee "Excellent Youth Fund" and the project on the surface of the funding.
author of the paper is Su Chuanbin, Ph.D. student at Fudan University's School of Life Sciences, and Zheng Pinglian is the communication author of the paper.
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