An SMU Splicing Factor Complex Within Nuclear Speckles Contributes to Magnesium Homeostasis in Arabidopsis
| Autor: | Baohai Li, Shuji Shigenobu, Katsushi Yamaguchi, Zhihang Feng, Toru Fujiwara, Takehiro Kamiya, Yusuke Shikanai, Naoyuki Sotta, Hiroshi Nagao |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Physiology RNA Splicing Mutant Arabidopsis Plant Science Plant Roots 01 natural sciences Splicing factor Gene Expression Regulation Plant Genetics Homeostasis Arabidopsis thaliana Magnesium Cation Transport Proteins News and Views Research Articles biology Arabidopsis Proteins Chemistry Membrane Transport Proteins Transporter Nutrients biology.organism_classification Phenotype Cell biology Alternative Splicing RNA splicing 010606 plant biology & botany |
| Zdroj: | Plant Physiol |
| ISSN: | 1532-2548 0032-0889 |
| DOI: | 10.1104/pp.20.00109 |
| Popis: | Mg(2+) is among the most abundant divalent cations in living cells. In plants, investigations on magnesium (Mg) homeostasis are restricted to the functional characterization of Mg(2+) transporters. Here, we demonstrate that the splicing factors SUPPRESSORS OF MEC-8 AND UNC-52 1 (SMU1) and SMU2 mediate Mg homeostasis in Arabidopsis (Arabidopsis thaliana). A low-Mg sensitive Arabidopsis mutant was isolated, and the causal gene was identified as SMU1. Disruption of SMU2, a protein that can form a complex with SMU1, resulted in a similar low-Mg sensitive phenotype. In both mutants, an Mg(2+) transporter gene, Mitochondrial RNA Splicing 2 (MRS2-7), showed altered splicing patterns. Genetic evidence indicated that MRS2-7 functions in the same pathway as SMU1 and SMU2 for low-Mg adaptation. In contrast with previous results showing that the SMU1-SMU2 complex is the active form in RNA splicing, MRS2-7 splicing was promoted in the smu2 mutant overexpressing SMU1, indicating that complex formation is not a prerequisite for the splicing. We found here that formation of the SMU1-SMU2 complex is an essential step for their compartmentation in the nuclear speckles, a type of nuclear body enriched with proteins that participate in various aspects of RNA metabolism. Taken together, our study reveals the involvement of the SMU splicing factors in plant Mg homeostasis and provides evidence that complex formation is required for their intranuclear compartmentation. |
| Databáze: | OpenAIRE |
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