Arabidopsis MOS4-associated complex promotes microRNA biogenesis and pre-mRNA splicing
Ontology highlight
ABSTRACT:
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE103423 | GEO | 2017/12/06
SECONDARY ACCESSION(S): PRJNA401314
REPOSITORIES: GEO
Similar Datasets
Project description:The evolutionarily conserved, putative RNA helicase MAC7 exists in both animals and plants. The human MAC7 homolog, Aquarius, is part of the spliceosome and plays a role in pre-mRNA splicing in vitro. In Arabidopsis, MAC7 was shown to be part of the MOS4-associated complex (MAC), which is required for plant defense and development. Here through RNA-seq analysis we discover that down-regulated genes in MAC subunit mutants are mostly involved in plant defense and stimulus response, confirming a role of MAC in the regulation of biotic and abiotic stress responses. We also discover global intron retention defects in mutants in three members of MAC, thus linking the functions of MAC to splicing in Arabidopsis. In addition, we show that mac7-1, a partial loss-of-function mutant in MAC7, and two other MAC subunit mutants, mac3a mac3b and prl1 prl2, exhibit reduced microRNA levels in general, indicating that MAC promotes microRNA biogenesis. The mac7-1 mutant shows reduced primary miRNA (pri-miRNA) levels without affecting MIR promoter activity or the degradation of pri-miRNA transcripts, implicating functions of MAC7 during transcription elongation or maturation of pri-miRNAs. As a nuclear protein, MAC7 is not localized in dicing bodies, but it affects the localization of HYL1 to dicing bodies. We propose that MAC acts to link MIR transcription to pri-miRNA processing.
2017-12-08 | GSE103422 | GEO
Project description:The evolutionarily conserved, putative RNA helicase MAC7 exists in both animals and plants. The human MAC7 homolog, Aquarius, is part of the spliceosome and plays a role in pre-mRNA splicing in vitro. In Arabidopsis, MAC7 was shown to be part of the MOS4-associated complex (MAC), which is required for plant defense and development. Here through RNA-seq analysis we discover that down-regulated genes in MAC subunit mutants are mostly involved in plant defense and stimulus response, confirming a role of MAC in the regulation of biotic and abiotic stress responses. We also discover global intron retention defects in mutants in three members of MAC, thus linking the functions of MAC to splicing in Arabidopsis. In addition, we show that mac7-1, a partial loss-of-function mutant in MAC7, and two other MAC subunit mutants, mac3a mac3b and prl1 prl2, exhibit reduced microRNA levels in general, indicating that MAC promotes microRNA biogenesis. The mac7-1 mutant shows reduced primary miRNA (pri-miRNA) levels without affecting MIR promoter activity or the degradation of pri-miRNA transcripts, implicating functions of MAC7 during transcription elongation or maturation of pri-miRNAs. As a nuclear protein, MAC7 is not localized in dicing bodies, but it affects the localization of HYL1 to dicing bodies. We propose that MAC acts to link MIR transcription to pri-miRNA processing.
2017-12-08 | GSE98035 | GEO
Project description:Arabidopsis MOS4-associated complex promotes microRNA biogenesis and pre-mRNA splicing
| PRJNA401314 | ENA
Project description:MicroRNAs (miRNAs) are central regulators of gene expression, and a large fraction of them are encoded in introns of RNA polymerase II transcripts. Thus, the biogenesis of intronic miRNAs by the microprocessor and the splicing of their host introns by the spliceosome require coordination between these processing events. This cross-talk is addressed here. We show that key microprocessor proteins Drosha and DGCR8 as well as pre-miRNAs cosediment with supraspliceosomes, where nuclear posttranscriptional processing is executed. We further show that inhibition of splicing increases miRNAs expression, whereas knock-down of Drosha increases splicing. We identified a novel splicing event in intron 13 of MCM7, where the miR-106b-25 cluster is located. The unique splice isoform includes a hosted pre-miRNA in the extended exon and excludes its processing. This indicates a possible mechanism of altering the levels of different miRNAs originating from the same transcript. Altogether, our study indicates interplay between the splicing and microprocessor machineries within a supraspliceosome context.
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Project description:Light signals perceived by a group of photoreceptors have profound effects on the physiology, growth, and development of plants. The red/far-red light-absorbing phytochromes (phys) modulate these aspects by intricately regulating gene expression at multiple levels. Here, we report the identification and functional characterization of an RNA-binding splicing factor, SWAP1 (SUPPRESSOR-OF-WHITE-APRICOT/SURP RNA-BINDING DOMAIN-CONTAINING PROTEIN1). Loss-of-function swap1-1 mutant is hyposensitive to red light and exhibits a day length-independent early flowering phenotype. SWAP1 physically interacts with two other splicing factors, (SFPS) SPLICING FACTOR FOR PHYTOCHROME SIGNALING and (RRC1) REDUCED RED LIGHT RESPONSES IN CRY1CRY2 BACKGROUND 1 in a light-independent manner and forms a ternary complex. In addition, SWAP1 physically interacts with photoactivated phyB and colocalizes with nuclear phyB photobodies. Phenotypic analyses show that the swap1sfps, swap1rrc1, and sfpsrrc1 double mutants display hypocotyl lengths similar to that of the respective single mutants under red light, suggesting that they function in the same genetic pathway. The swap1sfps double and swap1sfpsrrc1 triple mutants display pleiotropic phenotypes, including sterility at the adult stage. Deep RNA sequencing (RNA-seq) analyses show that SWAP1 regulates the gene expression and pre-messenger RNA (mRNA) alternative splicing of a large number of genes, including those involved in plant responses to light signaling. A comparative analysis of alternative splicing among single, double, and triple mutants showed that all three splicing factors coordinately regulate the alternative splicing of a subset of genes. Our study uncovered the function of a splicing factor that modulates light-regulated alternative splicing by interacting with photoactivated phyB and other splicing factors.
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Project description:MicroRNAs (miRNAs) are essential regulators of gene expression in metazoans and plants. In plants, most miRNAs are generated from primary miRNA transcripts (pri-miRNAs), which are processed by the Dicer-like 1 (DCL1) complex along with accessory proteins. Serrate-Associated Protein 1 (SEAP1), a conserved splicing-related protein, has been studied in human and yeast. However, the functions of SEAP1 in plants remain elusive. Lack of SEAP1 results in embryo lethality and knockdown of SEAP1 by an artificial miRNA (amiRSEAP1 ) causes pleiotropic developmental defects and reduction in miRNA accumulation. SEAP1 associates with the DCL1 complex, and may promote the interaction of the DCL1 complexes with pri-miRNAs. SEAP1 also enhances pri-miRNA accumulation, but does not affect pri-miRNA transcription, suggesting it may indirectly or directly stabilize pri-miRNAs. In addition, SEAP1 affects the splicing of some pri-miRNAs and intron retention of messenger RNAs at global levels. Our findings uncover both conserved and novel functions of SEAP1 in plants. Besides the role as a splicing factor, SEPA1 may promote miRNA biogenesis by positively modulating pri-miRNA splicing, processing and/or stability.
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Project description:Light signals regulate plant growth and development by controlling a plethora of gene expression changes. Posttranscriptional regulation, especially pre-mRNA processing, is a key modulator of gene expression; however, the molecular mechanisms linking pre-mRNA processing and light signaling are not well understood. Here we report a protein related to the human splicing factor 45 (SPF45) named splicing factor for phytochrome signaling (SFPS), which directly interacts with the photoreceptor phytochrome B (phyB). In response to light, SFPS-RFP (red fluorescent protein) colocalizes with phyB-GFP in photobodies. sfps loss-of-function plants are hyposensitive to red, far-red, and blue light, and flower precociously. SFPS colocalizes with U2 small nuclear ribonucleoprotein-associated factors including U2AF65B, U2A', and U2AF35A in nuclear speckles, suggesting SFPS might be involved in the 3' splice site determination. SFPS regulates pre-mRNA splicing of a large number of genes, of which many are involved in regulating light signaling, photosynthesis, and the circadian clock under both dark and light conditions. In vivo RNA immunoprecipitation (RIP) assays revealed that SFPS associates with EARLY FLOWERING 3 (ELF3) mRNA, a critical link between light signaling and the circadian clock. Moreover, PHYTOCHROME INTERACTING FACTORS (PIFs) transcription factor genes act downstream of SFPS, as the quadruple pif mutant pifq suppresses defects of sfps mutants. Taken together, these data strongly suggest SFPS modulates light-regulated developmental processes by controlling pre-mRNA splicing of light signaling and circadian clock genes.
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