华中农业大学作物遗传改良国家重点实验室David Jackson团队在研究中取得进展。他们发现RNA外泌体亚基通过胞间连丝介导同源框信使 RNA (mRNA)的细胞间运输。相关论文于2022年1月14日发表于国际顶尖学术期刊《科学》杂志上。

他们表明KNOTTED1 (KN1) mRNA 的细胞间运动需要核糖体 RNA 加工蛋白 44A (AtRRP44A)，这是一种 RNA 外泌体的亚基，可加工或降解真核生物中的多种 RNA。AtRRP44A 可以与胞间连丝相互作用并介导 KN1 mRNA 的细胞间运输，遗传分析表明 AtRRP44A 是拟南芥 KN1 同源物 SHOOT MERISTEMLESS 的发育功能所必需的。他们的研究结果表明，AtRRP44A 通过胞间连丝促进 mRNA 运输，以控制植物中干细胞依赖性过程。

研究人员表示，mRNA在多细胞生物体中充当细胞间通信的移动信号。KN1同源域家族转录因子通过胞间连丝蛋白和 mRNA 的细胞间运动，自主地在非细胞内发挥作用，以控制植物干细胞的维持；然而，mRNA运动的机制在很大程度上是未知的。

附：英文原文

Title: An RNA exosome subunit mediates cell-to-cell trafficking of a homeobox mRNA via plasmodesmata

Author: Munenori Kitagawa, Peipei Wu, Rachappa Balkunde, Patrick Cunniff, David Jackson

Issue&Volume: 2022-01-14

Abstract: Messenger RNAs (mRNAs) function as mobile signals for cell-to-cell communication in multicellular organisms. The KNOTTED1 (KN1) homeodomain family transcription factors act non–cell autonomously to control stem cell maintenance in plants through cell-to-cell movement of their proteins and mRNAs through plasmodesmata; however, the mechanism of mRNA movement is largely unknown. We show that cell-to-cell movement of a KN1 mRNA requires ribosomal RNA–processing protein 44A (AtRRP44A), a subunit of the RNA exosome that processes or degrades diverse RNAs in eukaryotes. AtRRP44A can interact with plasmodesmata and mediates the cell-to-cell trafficking of KN1 mRNA, and genetic analysis indicates that AtRRP44A is required for the developmental functions of SHOOT MERISTEMLESS, an Arabidopsis KN1 homolog. Our findings suggest that AtRRP44A promotes mRNA trafficking through plasmodesmata to control stem cell–dependent processes in plants.

DOI: abm0840

Source: https://www.science.org/doi/10.1126/science.abm0840