title: AtLa1 protein initiates IRES-dependent translation of WUSCHEL mRNA and regulates the stem cell homeostasis of Arabidopsis in response to environmental hazards.
abstract: Plant stem cells are hypersensitive to environmental hazards throughout their life cycle, but the mechanism by which plants safeguard stem cell homeostasis in response to environmental hazards is largely unknown. The homeodomain transcription factor WUSCHEL (WUS) protein maintains the stem cell pool in the shoot apical meristem of Arabidopsis. Here, we demonstrate that the translation of WUS mRNA is directed by an internal ribosomal entry site (IRES) located in the 5'-untranslated region. The AtLa1 protein, an RNA-binding factor, binds to the 5'-untranslated region and initiates the IRES-dependent translation of WUS mRNA. Knockdown of AtLa1 expression represses the WUS IRES-dependent translation and leads to the arrest of growth and development. The AtLa1 protein is mainly located in the nucleoplasm. However, environmental hazards promote the nuclear-to-cytoplasmic translocation of the AtLa1 protein, which further enhances the IRES-dependent translation of WUS mRNA. Genetic evidence indicates that the WUS protein increases the tolerance of the shoot apical meristem to environmental hazards. Based on these results, we conclude that the stem cell niche in Arabidopsis copes with environmental hazards by enhancing the IRES-dependent translation of WUS mRNA under the control of the AtLa1 protein.
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Yuchao
authors.initials: Y
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Shaofei
authors.initials: S
authors.lastname: Rao
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Kaidian
authors.initials: K
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Xueliang
authors.initials: X
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Xueyi
authors.initials: X
authors.lastname: Zhu
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Wu
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Tian
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Guangdong Key Laboratory of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou, 510631, China.
authors.forename: Chengwei
authors.initials: C
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, 361102, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Huang
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004777:Environment; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006706:Homeostasis; D000067556:Internal Ribosome Entry Sites / Q000235:genetics*; D018519:Meristem / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D018520:Plant Shoots / Q000235:genetics / Q000502:physiology; D018547:Plant Stems / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D055153:Stem Cell Niche
chemical_list: D020121:5' Untranslated Regions; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D000067556:Internal Ribosome Entry Sites; C520619:La1 protein, Arabidopsis; D012333:RNA, Messenger; D018749:RNA, Plant; D016601:RNA-Binding Proteins; C116421:WUSCHEL protein, Arabidopsis
keywords: WUS mRNA; translation control