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Mangilet AF, Weber J, Schüler S, Adler M, Mjema EY, Heilmann P, Herold A, Renneberg M, Nagel L, Droste-Borel I, Streicher S, Schmutzer T, Rot G, Macek B, Schmidtke C, Laubinger S. The Arabidopsis U1 snRNP regulates mRNA 3'-end processing. NATURE PLANTS 2024:10.1038/s41477-024-01796-8. [PMID: 39313562 DOI: 10.1038/s41477-024-01796-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 08/27/2024] [Indexed: 09/25/2024]
Abstract
The removal of introns by the spliceosome is a key gene regulatory mechanism in eukaryotes, with the U1 snRNP subunit playing a crucial role in the early stages of splicing. Studies in metazoans show that the U1 snRNP also conducts splicing-independent functions, but the lack of genetic tools and knowledge about U1 snRNP-associated proteins have limited the study of such splicing-independent functions in plants. Here we describe an RNA-centric approach that identified more than 200 proteins associated with the Arabidopsis U1 snRNP and revealed a tight link to mRNA cleavage and polyadenylation factors. Interestingly, we found that the U1 snRNP protects mRNAs against premature cleavage and polyadenylation within introns-a mechanism known as telescripting in metazoans-while also influencing alternative polyadenylation site selection in 3'-UTRs. Overall, our work provides a comprehensive view of U1 snRNP interactors and reveals novel functions in regulating mRNA 3'-end processing in Arabidopsis, laying the groundwork for understanding non-canonical functions of plant U1 snRNPs.
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Affiliation(s)
- Anchilie F Mangilet
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
- Max Planck Institute for Plant Breeding Research (MPIPZ), Cologne, Germany
| | - Joachim Weber
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Sandra Schüler
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Manon Adler
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Eneza Yoeli Mjema
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Paula Heilmann
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Angie Herold
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Monique Renneberg
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Luise Nagel
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | | | - Samuel Streicher
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Thomas Schmutzer
- Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Gregor Rot
- Institute of Molecular Life Sciences of the University of Zurich and Swiss Institute of Bioinformatics, Zurich, Switzerland
| | - Boris Macek
- Proteome Center, University of Tuebingen, Tuebingen, Germany
| | - Cornelius Schmidtke
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Sascha Laubinger
- Institute of Biology and Environmental Sciences, University of Oldenburg, Oldenburg, Germany.
- Institute of Biology, Department of Genetics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
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Hao S, Zhang L, Zhao D, Zhou J, Ye C, Qu H, Li QQ. Inhibitor AN3661 reveals biological functions of Arabidopsis CLEAVAGE and POLYADENYLATION SPECIFICITY FACTOR 73. PLANT PHYSIOLOGY 2023; 193:537-554. [PMID: 37335917 DOI: 10.1093/plphys/kiad352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 05/09/2023] [Accepted: 05/21/2023] [Indexed: 06/21/2023]
Abstract
Cleavage and polyadenylation specificity factor (CPSF) is a protein complex that plays an essential biochemical role in mRNA 3'-end formation, including poly(A) signal recognition and cleavage at the poly(A) site. However, its biological functions at the organismal level are mostly unknown in multicellular eukaryotes. The study of plant CPSF73 has been hampered by the lethality of Arabidopsis (Arabidopsis thaliana) homozygous mutants of AtCPSF73-I and AtCPSF73-II. Here, we used poly(A) tag sequencing to investigate the roles of AtCPSF73-I and AtCPSF73-II in Arabidopsis treated with AN3661, an antimalarial drug with specificity for parasite CPSF73 that is homologous to plant CPSF73. Direct seed germination on an AN3661-containing medium was lethal; however, 7-d-old seedlings treated with AN3661 survived. AN3661 targeted AtCPSF73-I and AtCPSF73-II, inhibiting growth through coordinating gene expression and poly(A) site choice. Functional enrichment analysis revealed that the accumulation of ethylene and auxin jointly inhibited primary root growth. AN3661 affected poly(A) signal recognition, resulted in lower U-rich signal usage, caused transcriptional readthrough, and increased the distal poly(A) site usage. Many microRNA targets were found in the 3' untranslated region lengthened transcripts; these miRNAs may indirectly regulate the expression of these targets. Overall, this work demonstrates that AtCPSF73 plays important part in co-transcriptional regulation, affecting growth, and development in Arabidopsis.
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Affiliation(s)
- Saiqi Hao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Lidan Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Danhui Zhao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Jiawen Zhou
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Congting Ye
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Haidong Qu
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
| | - Qingshun Q Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian 361102, China
- Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA 91766, USA
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Ma H, Lin J, Mei F, Mao H, Li QQ. Differential alternative polyadenylation of homoeologous genes of allohexaploid wheat ABD subgenomes during drought stress response. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:499-518. [PMID: 36786697 DOI: 10.1111/tpj.16150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 05/10/2023]
Abstract
Because allohexaploid wheat genome contains ABD subgenomes, how the expression of homoeologous genes is coordinated remains largely unknown, particularly at the co-transcriptional level. Alternative polyadenylation (APA) is an important part of co-transcriptional regulation, which is crucial in developmental processes and stress responses. Drought stress is a major threat to the stable yield of wheat. Focusing on APA, we used poly(A) tag sequencing to track poly(A) site dynamics in wheat under drought stress. The results showed that drought stress led to extensive APA involving 37-47% of differentially expressed genes in wheat. Significant poly(A) site switching was found in stress-responsive genes. Interestingly, homoeologous genes exhibit unequal numbers of poly(A) sites, divergent APA patterns with tissue specificity and time-course dynamics, and distinct 3'-UTR length changes. Moreover, differentially expressed transcripts in leaves and roots used different poly(A) signals, the up- and downregulated isoforms had distinct preferences for non-canonical poly(A) sites. Genes that encode key polyadenylation factors showed differential expression patterns under drought stress. In summary, poly(A) signals and the changes in core poly(A) factors may widely affect the selection of poly(A) sites and gene expression levels during the response to drought stress, and divergent APA patterns among homoeologous genes add extensive plasticity to this responsive network. These results not only reveal the significant role of APA in drought stress response, but also provide a fresh perspective on how homoeologous genes contribute to adaptability through transcriptome diversity. In addition, this work provides information about the ends of transcripts for a better annotation of the wheat genome.
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Affiliation(s)
- Hui Ma
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
- Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Juncheng Lin
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Fangming Mei
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, Shanxi, 712100, China
| | - Hude Mao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Agronomy, Northwest A&F University, Yangling, Shanxi, 712100, China
| | - Qingshun Q Li
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
- Biomedical Sciences, College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA
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Ramazan S, Jan N, John R. Comparative protein analysis of two maize genotypes with contrasting tolerance to low temperature. BMC PLANT BIOLOGY 2023; 23:183. [PMID: 37020183 PMCID: PMC10074880 DOI: 10.1186/s12870-023-04198-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 03/28/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Low temperature (LT) stress is one of the major environmental stress factors affecting the growth and yield of maize (Zea mays L.). Hence, it is important to unravel the molecular mechanisms behind LT stress tolerance to improve molecular breeding in LT tolerant genotypes. In the present study, two maize genotypes viz. Gurez local from Kashmir Himalaya and tropical grown GM6, were dissected for their LT stress response in terms of accumulation of differentially regulated proteins (DRPs). Leaf proteome analysis at three-leaf stage of maize seedlings subjected to LT stress of 6 °C for a total of 12 h duration was performed using two dimensional gel electrophoresis (2D-PAGE) followed by subsequent identification of the proteins involved. RESULTS After MALDI-TOF (Matrix-assisted laser desorption/ionization-time of flight) and bioinformatics analysis, 19 proteins were successfully identified in Gurez local, while as 10 proteins were found to get successful identification in GM6. The interesting observations from the present investigation is the identification of three novel proteins viz. threonine dehydratase biosynthetic chloroplastic, thylakoidal processing peptidase 1 chloroplastic, and nodulin-like protein, whose role in abiotic stress tolerance, in general, and LT stress, in particular, has not been reported so far. It is important to highlight here that most of LT responsive proteins including the three novel proteins were identified from Gurez local only, owing to its exceptional LT tolerance. From the protein profiles, obtained in both genotypes immediately after LT stress perception, it was inferred that stress responsive protein accumulation and their expression fashion help the Gurez local in seedling establishment and withstand unfavorable conditions as compared to GM6. This was inferred from the findings of pathway enrichment analysis like regulation of seed growth, timing of floral transition, lipid glycosylation, and aspartate family amino acid catabolic processes, besides other key stress defense mechanisms. However, in GM6, metabolic pathways enriched were found to be involved in more general processes including cell cycle DNA replication and regulation of phenylpropanoid metabolism. Furthermore, majority of the qRT-PCR results of the selected proteins demonstrated positive correlation between protein levels and transcript abundance, thereby strengthening our findings. CONCLUSIONS In conclusion, our findings reported majority of the identified proteins in Gurez local exhibiting up-regulated pattern under LT stress as compared to GM6. Furthermore, three novel proteins induced by LT stress were found in Gurez local, requiring further functional validation. Therefore, our results offer more insights for elucidating the molecular networks mediating LT stress tolerance in maize.
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Affiliation(s)
- Salika Ramazan
- Plant Molecular Biology Lab, Department of Botany, University of Kashmir, Srinagar, Kashmir, 190 006, India
| | - Nelofer Jan
- Plant Molecular Biology Lab, Department of Botany, University of Kashmir, Srinagar, Kashmir, 190 006, India
| | - Riffat John
- Plant Molecular Biology Lab, Department of Botany, University of Kashmir, Srinagar, Kashmir, 190 006, India.
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Alternative Polyadenylation Is a Novel Strategy for the Regulation of Gene Expression in Response to Stresses in Plants. Int J Mol Sci 2023; 24:ijms24054727. [PMID: 36902157 PMCID: PMC10003127 DOI: 10.3390/ijms24054727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/13/2023] [Accepted: 02/17/2023] [Indexed: 03/05/2023] Open
Abstract
Precursor message RNA requires processing to generate mature RNA. Cleavage and polyadenylation at the 3'-end in the maturation of mRNA is one of key processing steps in eukaryotes. The polyadenylation (poly(A)) tail of mRNA is an essential feature that is required to mediate its nuclear export, stability, translation efficiency, and subcellular localization. Most genes have at least two mRNA isoforms via alternative splicing (AS) or alternative polyadenylation (APA), which increases the diversity of transcriptome and proteome. However, most previous studies have focused on the role of alternative splicing on the regulation of gene expression. In this review, we summarize the recent advances concerning APA in the regulation of gene expression and in response to stresses in plants. We also discuss the mechanisms for the regulation of APA for plants in the adaptation to stress responses, and suggest that APA is a novel strategy for the adaptation to environmental changes and response to stresses in plants.
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Architectural and functional details of CF IA proteins involved in yeast 3'-end pre-mRNA processing and its significance for eukaryotes: A concise review. Int J Biol Macromol 2021; 193:387-400. [PMID: 34699898 DOI: 10.1016/j.ijbiomac.2021.10.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/04/2021] [Accepted: 10/18/2021] [Indexed: 11/22/2022]
Abstract
In eukaryotes, maturation of pre-mRNA relies on its precise 3'-end processing. This processing involves co-transcriptional steps regulated by sequence elements and other proteins. Although, it holds tremendous importance, defect in the processing machinery will result in erroneous pre-mRNA maturation leading to defective translation. Remarkably, more than 20 proteins in humans and yeast share homology and execute this processing. The defects in this processing are associated with various diseases in humans. We shed light on the CF IA subunit of yeast Saccharomyces cerevisiae that contains four proteins (Pcf11, Clp1, Rna14 and Rna15) involved in this processing. Structural details of various domains of CF IA and their roles during 3'-end processing, like cleavage and polyadenylation at 3'-UTR of pre-mRNA and other cellular events are explained. Further, the chronological development and important discoveries associated with 3'-end processing are summarized. Moreover, the mammalian homologues of yeast CF IA proteins, along with their key roles are described. This knowledge would be helpful for better comprehension of the mechanism associated with this marvel; thus opening up vast avenues in this area.
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Yang J, Cao Y, Ma L. Co-Transcriptional RNA Processing in Plants: Exploring from the Perspective of Polyadenylation. Int J Mol Sci 2021; 22:ijms22073300. [PMID: 33804866 PMCID: PMC8037041 DOI: 10.3390/ijms22073300] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/09/2021] [Accepted: 03/19/2021] [Indexed: 12/13/2022] Open
Abstract
Most protein-coding genes in eukaryotes possess at least two poly(A) sites, and alternative polyadenylation is considered a contributing factor to transcriptomic and proteomic diversity. Following transcription, a nascent RNA usually undergoes capping, splicing, cleavage, and polyadenylation, resulting in a mature messenger RNA (mRNA); however, increasing evidence suggests that transcription and RNA processing are coupled. Plants, which must produce rapid responses to environmental changes because of their limited mobility, exhibit such coupling. In this review, we summarize recent advances in our understanding of the coupling of transcription with RNA processing in plants, and we describe the possible spatial environment and important proteins involved. Moreover, we describe how liquid–liquid phase separation, mediated by the C-terminal domain of RNA polymerase II and RNA processing factors with intrinsically disordered regions, enables efficient co-transcriptional mRNA processing in plants.
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Bernardes WS, Menossi M. Plant 3' Regulatory Regions From mRNA-Encoding Genes and Their Uses to Modulate Expression. FRONTIERS IN PLANT SCIENCE 2020; 11:1252. [PMID: 32922424 PMCID: PMC7457121 DOI: 10.3389/fpls.2020.01252] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 07/29/2020] [Indexed: 05/08/2023]
Abstract
Molecular biotechnology has made it possible to explore the potential of plants for different purposes. The 3' regulatory regions have a great diversity of cis-regulatory elements directly involved in polyadenylation, stability, transport and mRNA translation, essential to achieve the desired levels of gene expression. A complex interaction between the cleavage and polyadenylation molecular complex and cis-elements determine the polyadenylation site, which may result in the choice of non-canonical sites, resulting in alternative polyadenylation events, involved in the regulation of more than 80% of the genes expressed in plants. In addition, after transcription, a wide array of RNA-binding proteins interacts with cis-acting elements located mainly in the 3' untranslated region, determining the fate of mRNAs in eukaryotic cells. Although a small number of 3' regulatory regions have been identified and validated so far, many studies have shown that plant 3' regulatory regions have a higher potential to regulate gene expression in plants compared to widely used 3' regulatory regions, such as NOS and OCS from Agrobacterium tumefaciens and 35S from cauliflower mosaic virus. In this review, we discuss the role of 3' regulatory regions in gene expression, and the superior potential that plant 3' regulatory regions have compared to NOS, OCS and 35S 3' regulatory regions.
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Li G, Zou W, Jian L, Qian J, Deng Y, Zhao J. Non-SMC elements 1 and 3 are required for early embryo and seedling development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:1039-1054. [PMID: 28207059 PMCID: PMC5441860 DOI: 10.1093/jxb/erx016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Early embryo development from the zygote is an essential stage in the formation of the seed, while seedling development is the beginning of the formation of an individual plant. AtNSE1 and AtNSE3 are subunits of the structural maintenance of chromosomes (SMC) 5/6 complex and have been identified as non-SMC elements, but their functions in Arabidopsis growth and development remain as yet unknown. In this study, we found that loss of function of AtNSE1 and AtNSE3 led to severe defects in early embryo development. Partially complemented mutants showed that the development of mutant seedlings was inhibited, that chromosome fragments occurred during anaphase, and that the cell cycle was delayed at G2/M, which led to the occurrence of endoreduplication. Further, a large number of DNA double-strand breaks (DSBs) occurred in the nse1 and nse3 mutants, and the expression of AtNSE1 and AtNSE3 was up-regulated following treatment of the plants with DSB inducer compounds, suggesting that AtNSE1 and AtNSE3 have a role in DNA damage repair. Therefore, we conclude that AtNSE1 and AtNSE3 facilitate DSB repair and contribute to maintaining genome stability and cell division in mitotic cells. Thus, we think that AtNSE1 and AtNSE3 may be crucial factors for maintaining proper early embryonic and post-embryonic development.
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Affiliation(s)
- Gang Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Liufang Jian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Qian
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yingtian Deng
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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Teng L, Fan X, Xu D, Zhang X, Mock T, Ye N. Identification of Genes under Positive Selection Reveals Differences in Evolutionary Adaptation between Brown-Algal Species. FRONTIERS IN PLANT SCIENCE 2017; 8:1429. [PMID: 28861104 PMCID: PMC5559719 DOI: 10.3389/fpls.2017.01429] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 08/03/2017] [Indexed: 05/07/2023]
Abstract
Brown algae are an important taxonomic group in coastal ecosystems. The model brown algal species Ectocarpus siliculosus and Saccharina japonica are closely related lineages. Despite their close phylogenetic relationship, they vary greatly in morphology and physiology. To obtain further insights into the evolutionary forces driving divergence in brown algae, we analyzed 3,909 orthologs from both species to identify Genes Under Positive Selection (GUPS). About 12% of the orthologs in each species were considered to be under positive selection. Many GUPS are involved in membrane transport, regulation of homeostasis, and sexual reproduction in the small sporophyte of E. siliculosus, which is known to have a complex life cycle and to occupy a wide range of habitats. Genes involved in photosynthesis and cell division dominated the group of GUPS in the large kelp of S. japonica, which might explain why this alga has evolved the ability to grow very rapidly and to form some of the largest sporophytes. A significant number of molecular chaperones (e.g., heat-shock proteins) involved in stress responses were identified to be under positive selection in both species, potentially indicating their important roles for macroalgae to cope with the relatively variable environment of coastal ecosystems. Moreover, analysis of previously published microarray data of E. siliculosus showed that many GUPS in E. siliculosus were responsive to stress conditions, such as oxidative and hyposaline stress, whereas our RNA-seq data of S. japonica showed that GUPS in this species were most highly expressed in large sporophytes, which supports the suggestion that selection largely acts on different sets of genes in both marcoalgal species, potentially reflecting their adaptation to different ecological niches.
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Affiliation(s)
- Linhong Teng
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery SciencesQingdao, China
| | - Xiao Fan
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery SciencesQingdao, China
| | - Dong Xu
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery SciencesQingdao, China
| | - Xiaowen Zhang
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery SciencesQingdao, China
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research ParkNorwich, United Kingdom
| | - Naihao Ye
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery SciencesQingdao, China
- Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
- *Correspondence: Naihao Ye
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Tränkner C, Lemnian IM, Emrani N, Pfeiffer N, Tiwari SP, Kopisch-Obuch FJ, Vogt SH, Müller AE, Schilhabel M, Jung C, Grosse I. A Detailed Analysis of the BR1 Locus Suggests a New Mechanism for Bolting after Winter in Sugar Beet ( Beta vulgaris L.). FRONTIERS IN PLANT SCIENCE 2016; 7:1662. [PMID: 27895650 PMCID: PMC5107561 DOI: 10.3389/fpls.2016.01662] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/21/2016] [Indexed: 05/29/2023]
Abstract
Sugar beet (Beta vulgaris ssp. vulgaris) is a biennial, sucrose-storing plant, which is mainly cultivated as a spring crop and harvested in the vegetative stage before winter. For increasing beet yield, over-winter cultivation would be advantageous. However, bolting is induced after winter and drastically reduces yield. Thus, post-winter bolting control is essential for winter beet cultivation. To identify genetic factors controlling bolting after winter, a F2 population was previously developed by crossing the sugar beet accessions BETA 1773 with reduced bolting tendency and 93161P with complete bolting after winter. For a mapping-by-sequencing analysis, pools of 26 bolting-resistant and 297 bolting F2 plants were used. Thereby, a single continuous homozygous region of 103 kb was co-localized to the previously published BR1 QTL for post-winter bolting resistance (Pfeiffer et al., 2014). The BR1 locus was narrowed down to 11 candidate genes from which a homolog of the Arabidopsis CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR 73-I (CPSF73-I) was identified as the most promising candidate. A 2 bp deletion within the BETA 1773 allele of BvCPSF73-Ia results in a truncated protein. However, the null allele of BvCPSF73-Ia might partially be compensated by a second BvCPSF73-Ib gene. This gene is located 954 bp upstream of BvCPSF73-Ia and could be responsible for the incomplete penetrance of the post-winter bolting resistance allele of BETA 1773. This result is an important milestone for breeding winter beets with complete bolting resistance after winter.
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Affiliation(s)
- Conny Tränkner
- Plant Breeding Institute, University of KielKiel, Germany
| | - Ioana M. Lemnian
- Institute of Computer Science, Martin Luther University Halle-WittenbergHalle, Germany
| | - Nazgol Emrani
- Plant Breeding Institute, University of KielKiel, Germany
| | - Nina Pfeiffer
- Plant Breeding Institute, University of KielKiel, Germany
| | | | | | | | | | - Markus Schilhabel
- Institute of Clinical Molecular Biology, University of KielKiel, Germany
| | - Christian Jung
- Plant Breeding Institute, University of KielKiel, Germany
| | - Ivo Grosse
- Institute of Computer Science, Martin Luther University Halle-WittenbergHalle, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Leipzig-JenaLeipzig, Germany
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12
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Liu Y, Li S, Chen Y, Kimberlin AN, Cahoon EB, Yu B. snRNA 3' End Processing by a CPSF73-Containing Complex Essential for Development in Arabidopsis. PLoS Biol 2016; 14:e1002571. [PMID: 27780203 PMCID: PMC5079582 DOI: 10.1371/journal.pbio.1002571] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/26/2016] [Indexed: 01/26/2023] Open
Abstract
Uridine-rich small nuclear RNAs (snRNAs) are the basal components of the spliceosome and play essential roles in splicing. The biogenesis of the majority of snRNAs involves 3′ end endonucleolytic cleavage of the nascent transcript from the elongating DNA-dependent RNA ploymerase II. However, the protein factors responsible for this process remain elusive in plants. Here, we show that DEFECTIVE in snRNA PROCESSING 1 (DSP1) is an essential protein for snRNA 3′ end maturation in Arabidopsis. A hypomorphic dsp1-1 mutation causes pleiotropic developmental defects, impairs the 3′ end processing of snRNAs, increases the levels of snRNA primary transcripts (pre-snRNAs), and alters the occupancy of Pol II at snRNA loci. In addition, DSP1 binds snRNA loci and interacts with Pol-II in a DNA/RNA-dependent manner. We further show that DSP1 forms a conserved complex, which contains at least four additional proteins, to catalyze snRNA 3′ end maturation in Arabidopsis. The catalytic component of this complex is likely the cleavage and polyadenylation specificity factor 73 kDa-I (CSPF73-I), which is the nuclease cleaving the pre-mRNA 3′ end. However, the DSP1 complex does not affect pre-mRNA 3′ end cleavage, suggesting that plants may use different CPSF73-I-containing complexes to process snRNAs and pre-mRNAs. This study identifies a complex responsible for the snRNA 3′ end maturation in plants and uncovers a previously unknown function of CPSF73 in snRNA maturation. This study identifies a protein complex in plants that is responsible for the maturation of the 3′ ends of spliceosomal snRNAs and uncovers a novel function for the mRNA 3′ cleavage nuclease CPSF73. snRNAs form the RNA components of the spliceosome and are required for spliceosome formation and splicing. The generation of snRNAs involves 3′ end endonucleolytic cleavage of primary snRNA transcripts (pre-snRNAs). The factors responsible for pre-snRNA 3′ end cleavage are known in metazoans, but many of these components are missing in plants. Therefore, the proteins that catalyze pre-snRNA cleavage in plants and the mechanism leading to plant snRNA 3′ maturation are unknown. Here, we show that a DSP1 complex (containing DSP1, DSP2, DSP3, DSP4, and CPFS73-I) is responsible for pre-snRNA 3′ end cleavage in Arabidopsis. We further show that CPSF73-I, which is known to cleave the pre-mRNA 3′ end, is likely the enzyme also catalyzing snRNA 3′ end maturation in plants. Interestingly, plants appear to use two different CPSF73-I-containing complexes to catalyze the maturation of mRNAs and snRNAs. The study thereby identifies an snRNA-processing complex in plants and also elucidates a new role for CPSF73-I in this process.
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Affiliation(s)
- Yunfeng Liu
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Shengjun Li
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Yuan Chen
- Plant Gene Expression Center, US Department of Agriculture-Agricultural Research Service, University of California-Berkeley, Albany, California, United States of America
| | - Athen N. Kimberlin
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Edgar B. Cahoon
- Center for Plant Science Innovation and Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Bin Yu
- Center for Plant Science Innovation and School of Biological Sciences, University of Nebraska, Lincoln, Nebraska, United States of America
- * E-mail:
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Chakrabarti M, Hunt AG. CPSF30 at the Interface of Alternative Polyadenylation and Cellular Signaling in Plants. Biomolecules 2015; 5:1151-68. [PMID: 26061761 PMCID: PMC4496715 DOI: 10.3390/biom5021151] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/26/2015] [Accepted: 05/29/2015] [Indexed: 01/05/2023] Open
Abstract
Post-transcriptional processing, involving cleavage of precursor messenger RNA (pre mRNA), and further incorporation of poly(A) tail to the 3' end is a key step in the expression of genetic information. Alternative polyadenylation (APA) serves as an important check point for the regulation of gene expression. Recent studies have shown widespread prevalence of APA in diverse systems. A considerable amount of research has been done in characterizing different subunits of so-called Cleavage and Polyadenylation Specificity Factor (CPSF). In plants, CPSF30, an ortholog of the 30 kD subunit of mammalian CPSF is a key polyadenylation factor. CPSF30 in the model plant Arabidopsis thaliana was reported to possess unique biochemical properties. It was also demonstrated that poly(A) site choice in a vast majority of genes in Arabidopsis are CPSF30 dependent, suggesting a pivotal role of this gene in APA and subsequent regulation of gene expression. There are also indications of this gene being involved in oxidative stress and defense responses and in cellular signaling, suggesting a role of CPSF30 in connecting physiological processes and APA. This review will summarize the biochemical features of CPSF30, its role in regulating APA, and possible links with cellular signaling and stress response modules.
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Affiliation(s)
- Manohar Chakrabarti
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA.
| | - Arthur G Hunt
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312, USA.
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Transcriptional profile of processing machinery of 3′ end of mRNA in Trichomonas vaginalis. Genes Genomics 2015. [DOI: 10.1007/s13258-015-0268-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Chen H, Zou W, Zhao J. Ribonuclease J is required for chloroplast and embryo development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2079-91. [PMID: 25871650 PMCID: PMC4378637 DOI: 10.1093/jxb/erv010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 05/20/2023]
Abstract
Chloroplasts perform many essential metabolic functions and their proper development is critically important in embryogenesis. However, little is known about how chloroplasts function in embryogenesis and more relevant components need to be characterized. In this study, we show that Arabidopsis Ribonuclease J (RNase J) is required for chloroplast and embryo development. Mutation of AtRNJ led to albino ovules containing aborted embryos; the morphological development of rnj embryos was disturbed after the globular stage. Observation of ultrastructures indicated that these aborted embryos may result from impaired chloroplast development. Furthermore, by analyzing the molecular markers of cell fate decisions (STM, FIL, ML1, SCR, and WOX5) in rnj embryos, we found that this impairment of chloroplast development may lead to aberrant embryo patterning along the apical-basal axis, indicating that AtRNJ is important in initiating and maintaining the organization of shoot apical meristems (SAMs), cotyledons, and hypocotyls. Moreover, the transport and response of auxin in rnj embryos was found to be disrupted, suggesting that AtRNJ may be involved in auxin-mediated pathways during embryogenesis. Therefore, we speculate that RNJ plays a vital role in embryo morphogenesis and apical-basal pattern formation by regulating chloroplast development.
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Affiliation(s)
- Hongyu Chen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Wenxuan Zou
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jie Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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Tsukaya H, Byrne ME, Horiguchi G, Sugiyama M, Van Lijsebettens M, Lenhard M. How do 'housekeeping' genes control organogenesis?--Unexpected new findings on the role of housekeeping genes in cell and organ differentiation. JOURNAL OF PLANT RESEARCH 2013; 126:3-15. [PMID: 22922868 DOI: 10.1007/s10265-012-0518-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/31/2012] [Indexed: 05/08/2023]
Abstract
In recent years, an increasing number of mutations in what would appear to be 'housekeeping genes' have been identified as having unexpectedly specific defects in multicellular organogenesis. This is also the case for organogenesis in seed plants. Although it is not surprising that loss-of-function mutations in 'housekeeping' genes result in lethality or growth retardation, it is surprising when (1) the mutant phenotype results from the loss of function of a 'housekeeping' gene and (2) the mutant phenotype is specific. In this review, by defining housekeeping genes as those encoding proteins that work in basic metabolic and cellular functions, we discuss unexpected links between housekeeping genes and specific developmental processes. In a surprising number of cases housekeeping genes coding for enzymes or proteins with functions in basic cellular processes such as transcription, post-transcriptional modification, and translation affect plant development.
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Affiliation(s)
- Hirokazu Tsukaya
- Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
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Plant polyadenylation factors: conservation and variety in the polyadenylation complex in plants. BMC Genomics 2012; 13:641. [PMID: 23167306 PMCID: PMC3538716 DOI: 10.1186/1471-2164-13-641] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 11/07/2012] [Indexed: 01/10/2023] Open
Abstract
Background Polyadenylation, an essential step in eukaryotic gene expression, requires both cis-elements and a plethora of trans-acting polyadenylation factors. The polyadenylation factors are largely conserved across mammals and fungi. The conservation seems also extended to plants based on the analyses of Arabidopsis polyadenylation factors. To extend this observation, we systemically identified the orthologs of yeast and human polyadenylation factors from 10 plant species chosen based on both the availability of their genome sequences and their positions in the evolutionary tree, which render them representatives of different plant lineages. Results The evolutionary trajectories revealed several interesting features of plant polyadenylation factors. First, the number of genes encoding plant polyadenylation factors was clearly increased from “lower” to “higher” plants. Second, the gene expansion in higher plants was biased to some polyadenylation factors, particularly those involved in RNA binding. Finally, while there are clear commonalities, the differences in the polyadenylation apparatus were obvious across different species, suggesting an ongoing process of evolutionary change. These features lead to a model in which the plant polyadenylation complex consists of a conserved core, which is rather rigid in terms of evolutionary conservation, and a panoply of peripheral subunits, which are less conserved and associated with the core in various combinations, forming a collection of somewhat distinct complex assemblies. Conclusions The multiple forms of plant polyadenylation complex, together with the diversified polyA signals may explain the intensive alternative polyadenylation (APA) and its regulatory role in biological functions of higher plants.
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Xing D, Li QQ. Alternative polyadenylation and gene expression regulation in plants. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 2:445-58. [DOI: 10.1002/wrna.59] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Dominski Z. The hunt for the 3' endonuclease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 1:325-40. [PMID: 21935893 DOI: 10.1002/wrna.33] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pre-mRNAs are typically processed at the 3(') end by cleavage/polyadenylation. This is a two-step processing reaction initiated by endonucleolytic cleavage of pre-mRNAs downstream of the AAUAAA sequence or its variant, followed by extension of the newly generated 3(') end with a poly(A) tail. In metazoans, replication-dependent histone transcripts are cleaved by a different 3(') end processing mechanism that depends on the U7 small nuclear ribonucleoprotein and the polyadenylation step is omitted. Each of the two mechanisms occurs in a macromolecular assembly that primarily functions to juxtapose the scissile bond with the 3(') endonuclease. Remarkably, despite characterizing a number of processing factors, the identity of this most critical component remained elusive until recently. For cleavage coupled to polyadenylation, much needed help was offered by bioinformatics, which pointed to CPSF-73, a known processing factor required for both cleavage and polyadenylation, as the possible 3(') endonuclease. In silico structural analysis indicated that this protein is a member of the large metallo-β-lactamase family of hydrolytic enzymes and belongs to the β-CASP subfamily that includes several RNA and DNA-specific nucleases. Subsequent experimental studies supported the notion that CPSF-73 does function as the endonuclease in the formation of polyadenylated mRNAs, but some controversy still remains as a different cleavage and polyadenylation specificity factor (CPSF) subunit, CPSF-30, displays an endonuclease activity in vitro while recombinant CPSF-73 is inactive. Unexpectedly, CPSF-73 as the 3(') endonuclease in cleavage coupled to polyadenylation found a strong ally in U7-dependent processing of histone pre-mRNAs, which was shown to utilize the same protein as the cleaving enzyme. It thus seems likely that these two processing reactions evolved from a common mechanism, with CPSF-73 as the endonuclease.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics and Program in Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Zhao H, Xing D, Li QQ. Unique features of plant cleavage and polyadenylation specificity factor revealed by proteomic studies. PLANT PHYSIOLOGY 2009; 151:1546-56. [PMID: 19748916 PMCID: PMC2773083 DOI: 10.1104/pp.109.142729] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 09/08/2009] [Indexed: 05/23/2023]
Abstract
Cleavage and polyadenylation of precursor mRNA is an essential process for mRNA maturation. Among the 15 to 20 protein factors required for this process, a subgroup of proteins is needed for both cleavage and polyadenylation in plants and animals. This subgroup of proteins is known as the cleavage and polyadenylation specificity factor (CPSF). To explore the in vivo structural features of plant CPSF, we used tandem affinity purification methods to isolate the interacting protein complexes for each component of the CPSF subunits using Arabidopsis (Arabidopsis thaliana ecotype Landsberg erecta) suspension culture cells. The proteins in these complexes were identified by mass spectrometry and western immunoblots. By compiling the in vivo interaction data from tandem affinity purification tagging as well as other available yeast two-hybrid data, we propose an in vivo plant CPSF model in which the Arabidopsis CPSF possesses AtCPSF30, AtCPSF73-I, AtCPSF73-II, AtCPSF100, AtCPSF160, AtFY, and AtFIPS5. Among them, AtCPSF100 serves as a core with which all other factors, except AtFIPS5, are associated. These results show that plant CPSF possesses distinct features, such as AtCPSF73-II and AtFY, while sharing other ortholog components with its yeast and mammalian counterparts. Interestingly, these two unique plant CPSF components have been associated with embryo development and flowering time controls, both of which involve plant-specific biological processes.
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Rao S, Dinkins RD, Hunt AG. Distinctive interactions of the Arabidopsis homolog of the 30 kD subunit of the cleavage and polyadenylation specificity factor (AtCPSF30) with other polyadenylation factor subunits. BMC Cell Biol 2009; 10:51. [PMID: 19573236 PMCID: PMC2712457 DOI: 10.1186/1471-2121-10-51] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 07/02/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Arabidopsis ortholog of the 30 kD subunit of the mammalian Cleavage and Polyadenylation Specificity Factor (AtCPSF30) is an RNA-binding endonuclease that is associated with other Arabidopsis CPSF subunits (orthologs of the 160, 100, and 73 kD subunits of CPSF). In order to further explore the functions of AtCPSF30, the subcellular distribution of the protein was examined by over-expressing fusion proteins containing fluorescent reporters linked to different CPSF subunits. RESULTS It was found that AtCPSF30 by itself localizes, not to the nucleus, but to the cytoplasm. AtCPSF30 could be found in the nucleus when co-expressed with AtCPSF160 or AtCPSF73(I), one of the two Arabidopsis orthologs of CPSF73. This re-directing of AtCPSF30 indicates that AtCPSF30 is retained in the nucleus via interactions with either or both of these other CPSF subunits. Co-expression of AtCSPF30 with AtCPSF100 altered the location, not of AtCPSF30, but rather of AtCPSF100, with these proteins residing in the cytoplasm. Deletion of plant-specific N- or C-terminal domains of AtCPSF30 abolished various of the interactions between AtCPSF30 and other CPSF subunits, suggesting that the plant CPSF complex assembles via novel protein-protein interactions. CONCLUSION These results suggest that the nuclear CPSF complex in plants is a dynamic one, and that the interactions between AtCPSF30 and other CPSF subunits are different from those existing in other eukaryotes.
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Affiliation(s)
- Suryadevara Rao
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312 USA
| | - Randy D Dinkins
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312 USA
- USDA-ARS, FAPRU, Lexington, KY 40546-0091 USA
| | - Arthur G Hunt
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546-0312 USA
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Xing D, Li QQ. Alternative polyadenylation: a mechanism maximizing transcriptome diversity in higher eukaryotes. PLANT SIGNALING & BEHAVIOR 2009; 4:440-442. [PMID: 19816115 PMCID: PMC2676760 DOI: 10.4161/psb.4.5.8345] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 03/06/2009] [Indexed: 06/03/2023]
Abstract
Based on comparative genome analyses, the increases in protein-coding gene number could not account for the increases of morphological and behavioral complexity of higher eukaryotes. Transcriptional regulations, alternative splicing and the involvement of non-coding RNA in gene expression regulations have been credited for the drastic increase of transcriptome complexity. However, an emerging theme of another mechanism that contributes to the formation of alternative mRNA 3'-ends is alternative polyadenylation (APA). First, recent studies indicated that APA is a wide spread phenomenon across the transcriptomes of higher eukaryotes and being regulated by developmental and environmental cues. Secondly, our characterization of the Arabidopsis polyadenylation factors suggested that plant polyadenylation has also evolved to regulate the expression of specific genes by means of APA and therefore the specific biological functions. Finally, Phylogenetic analyses of eukaryotic polyadenylation factors from several organisms revealed that the number of polyadenylation factors tends to increase in higher eukaryotes, which provides the potential for their functional differentiation in regulating gene expression through APA. Based on above evidence, we, thus, hypothesize that APA, serving as an additional mechanism, contributes to the complexity of higher eukaryotes.
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Affiliation(s)
- Denghui Xing
- Department of Botany, Miami University, Oxford, OH, USA
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Xing D, Zhao H, Li QQ. Arabidopsis CLP1-SIMILAR PROTEIN3, an ortholog of human polyadenylation factor CLP1, functions in gametophyte, embryo, and postembryonic development. PLANT PHYSIOLOGY 2008; 4:440-2. [PMID: 18971429 PMCID: PMC2593670 DOI: 10.1104/pp.108.129817] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2008] [Accepted: 10/23/2008] [Indexed: 05/20/2023]
Abstract
Polyadenylation factor CLP1 is essential for mRNA 3'-end processing in yeast and mammals. The Arabidopsis (Arabidopsis thaliana) CLP1-SIMILAR PROTEIN3 (CLPS3) is an ortholog of human hCLP1. CLPS3 was previously found to be a subunit in the affinity-purified PCFS4-TAP (tandem affinity purification) complex involved in the alternative polyadenylation of FCA and flowering time control in Arabidopsis. In this article, we further explored the components in the affinity-purified CLPS3-TAP complex, from which Arabidopsis cleavage and polyadenylation specificity factor (CPSF) subunits AtCPSF100 and AtCPSF160 were found. This result implies that CLPS3 may bridge CPSF to the PCFS4 complex. Characterization of the CLPS3 mutant revealed that CLPS3 was essential for embryo development and important for female gametophyte transmission. Overexpression of CLPS3-TAP fusion caused a range of postembryonic development abnormalities, including early flowering time, altered phyllotaxy, and abnormal numbers and shapes of flower organs. These phenotypes are associated with the altered gene expression levels of FCA, WUS, and CUC1. The decreased ratio of FCA-beta to FCA-gamma in the overexpression plants suggests that CLPS3 favored the usage of FCA regular poly(A) site over the alternative site. These observations indicate that Arabidopsis CLPS3 might be involved in the processing of pre-mRNAs encoded by a distinct subset of genes that are important in plant development.
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Affiliation(s)
- Denghui Xing
- Botany Department, Miami University, Oxford, Ohio 45056, USA
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Zhang J, Addepalli B, Yun KY, Hunt AG, Xu R, Rao S, Li QQ, Falcone DL. A polyadenylation factor subunit implicated in regulating oxidative signaling in Arabidopsis thaliana. PLoS One 2008; 3:e2410. [PMID: 18545667 PMCID: PMC2408970 DOI: 10.1371/journal.pone.0002410] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 05/02/2008] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Plants respond to many unfavorable environmental conditions via signaling mediated by altered levels of various reactive oxygen species (ROS). To gain additional insight into oxidative signaling responses, Arabidopsis mutants that exhibited tolerance to oxidative stress were isolated. We describe herein the isolation and characterization of one such mutant, oxt6. METHODOLOGY/PRINCIPAL FINDINGS The oxt6 mutation is due to the disruption of a complex gene (At1g30460) that encodes the Arabidopsis ortholog of the 30-kD subunit of the cleavage and polyadenylation specificity factor (CPSF30) as well as a larger, related 65-kD protein. Expression of mRNAs encoding Arabidopsis CPSF30 alone was able to restore wild-type growth and stress susceptibility to the oxt6 mutant. Transcriptional profiling and single gene expression studies show elevated constitutive expression of a subset of genes that encode proteins containing thioredoxin- and glutaredoxin-related domains in the oxt6 mutant, suggesting that stress can be ameliorated by these gene classes. Bulk poly(A) tail length was not seemingly affected in the oxt6 mutant, but poly(A) site selection was different, indicating a subtle effect on polyadenylation in the mutant. CONCLUSIONS/SIGNIFICANCE These results implicate the Arabidopsis CPSF30 protein in the posttranscriptional control of the responses of plants to stress, and in particular to the expression of a set of genes that suffices to confer tolerance to oxidative stress.
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Affiliation(s)
- Jingxian Zhang
- Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Balasubramanyam Addepalli
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
| | - Kil-Young Yun
- Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Biological Sciences, University of Massachusetts, Lowell, Massachusetts, United States of America
| | - Arthur G. Hunt
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail: (DF), (AH)
| | - Ruqiang Xu
- Department of Botany, Miami University, Oxford, Ohio, United States of America
| | - Suryadevara Rao
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
| | - Qingshun Q. Li
- Department of Botany, Miami University, Oxford, Ohio, United States of America
| | - Deane L. Falcone
- Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Biological Sciences, University of Massachusetts, Lowell, Massachusetts, United States of America
- * E-mail: (DF), (AH)
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Hunt AG, Xu R, Addepalli B, Rao S, Forbes KP, Meeks LR, Xing D, Mo M, Zhao H, Bandyopadhyay A, Dampanaboina L, Marion A, Von Lanken C, Li QQ. Arabidopsis mRNA polyadenylation machinery: comprehensive analysis of protein-protein interactions and gene expression profiling. BMC Genomics 2008; 9:220. [PMID: 18479511 PMCID: PMC2391170 DOI: 10.1186/1471-2164-9-220] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 05/14/2008] [Indexed: 01/31/2023] Open
Abstract
Background The polyadenylation of mRNA is one of the critical processing steps during expression of almost all eukaryotic genes. It is tightly integrated with transcription, particularly its termination, as well as other RNA processing events, i.e. capping and splicing. The poly(A) tail protects the mRNA from unregulated degradation, and it is required for nuclear export and translation initiation. In recent years, it has been demonstrated that the polyadenylation process is also involved in the regulation of gene expression. The polyadenylation process requires two components, the cis-elements on the mRNA and a group of protein factors that recognize the cis-elements and produce the poly(A) tail. Here we report a comprehensive pairwise protein-protein interaction mapping and gene expression profiling of the mRNA polyadenylation protein machinery in Arabidopsis. Results By protein sequence homology search using human and yeast polyadenylation factors, we identified 28 proteins that may be components of Arabidopsis polyadenylation machinery. To elucidate the protein network and their functions, we first tested their protein-protein interaction profiles. Out of 320 pair-wise protein-protein interaction assays done using the yeast two-hybrid system, 56 (~17%) showed positive interactions. 15 of these interactions were further tested, and all were confirmed by co-immunoprecipitation and/or in vitro co-purification. These interactions organize into three distinct hubs involving the Arabidopsis polyadenylation factors. These hubs are centered around AtCPSF100, AtCLPS, and AtFIPS. The first two are similar to complexes seen in mammals, while the third one stands out as unique to plants. When comparing the gene expression profiles extracted from publicly available microarray datasets, some of the polyadenylation related genes showed tissue-specific expression, suggestive of potential different polyadenylation complex configurations. Conclusion An extensive protein network was revealed for plant polyadenylation machinery, in which all predicted proteins were found to be connecting to the complex. The gene expression profiles are indicative that specialized sub-complexes may be formed to carry out targeted processing of mRNA in different developmental stages and tissue types. These results offer a roadmap for further functional characterizations of the protein factors, and for building models when testing the genetic contributions of these genes in plant growth and development.
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Affiliation(s)
- Arthur G Hunt
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA.
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Dominski Z. Nucleases of the metallo-beta-lactamase family and their role in DNA and RNA metabolism. Crit Rev Biochem Mol Biol 2007; 42:67-93. [PMID: 17453916 DOI: 10.1080/10409230701279118] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Proteins of the metallo-beta-lactamase family with either demonstrated or predicted nuclease activity have been identified in a number of organisms ranging from bacteria to humans and has been shown to be important constituents of cellular metabolism. Nucleases of this family are believed to utilize a zinc-dependent mechanism in catalysis and function as 5' to 3' exonucleases and or endonucleases in such processes as 3' end processing of RNA precursors, DNA repair, V(D)J recombination, and telomere maintenance. Examples of metallo-beta-lactamase nucleases include CPSF-73, a known component of the cleavage/polyadenylation machinery, which functions as the endonuclease in 3' end formation of both polyadenylated and histone mRNAs, and Artemis that opens DNA hairpins during V(D)J recombination. Mutations in two metallo-beta-lactamase nucleases have been implicated in human diseases: tRNase Z required for 3' processing of tRNA precursors has been linked to the familial form of prostate cancer, whereas inactivation of Artemis causes severe combined immunodeficiency (SCID). There is also a group of as yet uncharacterized proteins of this family in bacteria and archaea that based on sequence similarity to CPSF-73 are predicted to function as nucleases in RNA metabolism. This article reviews the cellular roles of nucleases of the metallo-beta-lactamase family and the recent advances in studying these proteins.
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Affiliation(s)
- Zbigniew Dominski
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
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Xu R, Zhao H, Dinkins RD, Cheng X, Carberry G, Li QQ. The 73 kD subunit of the cleavage and polyadenylation specificity factor (CPSF) complex affects reproductive development in Arabidopsis. PLANT MOLECULAR BIOLOGY 2006; 61:799-815. [PMID: 16897494 DOI: 10.1007/s11103-006-0051-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Accepted: 03/22/2006] [Indexed: 05/11/2023]
Abstract
The cleavage and polyadenylation specificity factor (CPSF) is an important multi-subunit component of the mRNA 3'-end processing apparatus in eukaryotes. The Arabidopsis genome contains five genes encoding CPSF homologues (AtCPSF160, AtCPSF100, AtCPSF73-I, AtCPSF73-II and AtCPSF30). These CPSF homologues interact with each other in a way that is analogous to the mammalian CPSF complex or their yeast counterparts, and also interact with the Arabidopsis poly(A) polymerase (PAP). There are two CPSF73 like proteins (AtCPSF73-I and AtCPSF73-II) that share homology with the 73 kD subunit of the mammalian CPSF complex. AtCPSF73-I appears to correspond to the functionally characterized mammalian CPSF73 and its yeast counterpart. AtCPSF73-II was identified as a novel protein with uncharacterized protein homologues in other multicellular organisms, but not in yeast. Both of the AtCPSF73 proteins are targeted in the nucleus and were found to interact with AtCPSF100. They are also essential since knockout or knockdown mutants are lethal. In addition, the expression level of AtCPSF73-I is critical for Arabidopsis development because overexpression of AtCPSF73-I is lethal. Interestingly, transgenic plants carrying an additional copy of the AtCPSF73-I gene, that is, the full-length cDNA under the control of its native promoter, appeared normal but were male sterile due to delayed anther dehiscence. In contrast, we previously demonstrated that a mutation in the AtCPSF73-II gene was detrimental to the genetic transmission of female gametes. Thus, two 73 kD subunits of the AtCPSF complex appear to have special functions during flower development. The important roles of mRNA 3'-end processing machinery in modulating plant development are discussed.
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Affiliation(s)
- Ruqiang Xu
- Department of Botany, Miami University, Oxford, OH 45056, USA
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Delaney KJ, Xu R, Zhang J, Li QQ, Yun KY, Falcone DL, Hunt AG. Calmodulin interacts with and regulates the RNA-binding activity of an Arabidopsis polyadenylation factor subunit. PLANT PHYSIOLOGY 2006; 140:1507-21. [PMID: 16500995 PMCID: PMC1459842 DOI: 10.1104/pp.105.070672] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The Arabidopsis (Arabidopsis thaliana) gene that encodes the probable ortholog of the 30-kD subunit of the mammalian cleavage and polyadenylation specificity factor (CPSF) is a complex one, encoding small (approximately 28 kD) and large (approximately 68 kD) polypeptides. The small polypeptide (AtCPSF30) corresponds to CPSF30 and is the focus of this study. Recombinant AtCPSF30 was purified from Escherichia coli and found to possess RNA-binding activity. Mutational analysis indicated that an evolutionarily conserved central core of AtCPSF30 is involved in RNA binding, but that RNA binding also requires a short sequence adjacent to the N terminus of the central core. AtCPSF30 was found to bind calmodulin, and calmodulin inhibited the RNA-binding activity of the protein in a calcium-dependent manner. Mutational analysis showed that a small part of the protein, again adjacent to the N terminus of the conserved core, is responsible for calmodulin binding; point mutations in this region abolished both binding to and inhibition of RNA binding by calmodulin. Interestingly, AtCPSF30 was capable of self-interactions. This property also mapped to the central conserved core of the protein. However, calmodulin had no discernible effect on the self-association. These results show that the central portion of AtCPSF30 is involved in a number of important functions, and they raise interesting possibilities for both the interplay between splicing and polyadenylation and the regulation of these processes by stimuli that act through calmodulin.
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Affiliation(s)
- Kimberly J Delaney
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, USA
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Gutierrez L, Conejero G, Castelain M, Guénin S, Verdeil JL, Thomasset B, Van Wuytswinkel O. Identification of new gene expression regulators specifically expressed during plant seed maturation. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:1919-32. [PMID: 16606634 DOI: 10.1093/jxb/erj138] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A cDNA-AFLP approach on Linum usitatissimum (flax) was used to identify genes specifically expressed during the seed maturation process. Among the 20,000 cDNA-AFLP tags produced, 486 were selected for their seed-specific expression during maturation. When compared with the publicly available databases, half of them presented some significant similarity with known plant sequences. The results obtained confirmed the accuracy of the approach as numerous genes previously described as being expressed exclusively in plant seeds were identified in this screen. The focus was on sequences similar to plant regulators involved in the control of gene expression, either at the transcriptional, post-transcriptional, or post-translational levels. Using a real-time RT-PCR approach, seed-specific expression kinetics were confirmed for 13 of these regulators that were never characterized for being expressed during seed maturation. Among these, a flax gene of the non-LEC1-like HAP3 family and a flax MYB factor were shown to be expressed in specialized tissues of flax embryo using an in situ hybridization approach. By expression kinetic comparison between these flax genes and their Arabidopsis counterparts, it was found that the new HAP3 gene should be related to a ubiquitous seed maturation mechanism, while a new MYB factor appears to be related to a more seed-specific maturation mechanism. These results demonstrate the utility of the flax database in not only identifying new genes expressed during seed maturation but also in being able to highlight the distinction between conserved and non-conserved seed maturation mechanisms.
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Affiliation(s)
- Laurent Gutierrez
- Laboratoire de Génomique Fonctionnelle des Plantes, Université de Picardie Jules Verne, Faculté des Sciences, Amiens, France
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Bonatto D, Brendel M, Henriques JAP. The eukaryotic Pso2p/Snm1p family revisited: in silico analyses of Pso2p A, B and Plasmodium groups. Comput Biol Chem 2005; 29:420-33. [PMID: 16290064 DOI: 10.1016/j.compbiolchem.2005.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Accepted: 09/24/2005] [Indexed: 11/28/2022]
Abstract
The eukaryotic family of Pso2/Snm1 exo/endonuclease proteins has important functions in repair of DNA damages induced by chemical interstrand cross-linking agents and ionizing radiation. These exo/endonucleases are also necessary for V(D)J recombination and genomic caretaking. However, despite the growing biochemical data about this family, little is known about the number of orthologous/paralogous Pso2p/Snm1p sequences in eukaryotes and how they are phylogenetically organized. In this work we have characterized new Pso2p/Snm1p sequences from the finished and unfinished eukaryotic genomes and performed an in-depth phylogenetic analysis. The results indicate that four phylogenetically related groups compose the Pso2p/Snm1p family: (i) the Artemis/Artemis-like group, (ii) the Pso2p A group, (iii) the Pso2p B group and (iv) the Pso2p Plasmodium group. Using the available biochemical and genomic information about Pso2p/Snm1p family, we concentrate our research in the study of Pso2p A, B and Plasmodium groups. The phylogenetic results showed that A and B groups can be organized in specific subgroups with different functions in DNA metabolism. Moreover, we subjected selected Pso2p A, B and Plasmodium proteins to hydrophobic cluster analysis (HCA) in order to map and to compare conserved regions within these sequences. Four conserved regions could be detected by HCA, which are distributed along the metallo-beta-lactamase and beta-CASP motifs. Interestingly, both Pso2p A and B proteins are structurally similar, while Pso2p Plasmodium proteins have a unique domain organization. The possible functions of A, B and Plasmodium groups are discussed.
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Affiliation(s)
- Diego Bonatto
- Departamento de Biofísica/Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9500, 91507-970 Porto Alegre, RS, Brazil
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Forbes KP, Addepalli B, Hunt AG. An Arabidopsis Fip1 homolog interacts with RNA and provides conceptual links with a number of other polyadenylation factor subunits. J Biol Chem 2005; 281:176-86. [PMID: 16282318 DOI: 10.1074/jbc.m510964200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein Fip1 is an important subunit of the eukaryotic polyadenylation apparatus, since it provides a bridge of sorts between poly(A) polymerase, other subunits of the polyadenylation apparatus, and the substrate RNA. In this study, a previously unreported Arabidopsis Fip1 homolog is characterized. The gene for this protein resides on chromosome V and encodes a 1196-amino acid polypeptide. Yeast two-hybrid and in vitro assays indicate that the N-terminal 137 amino acids of the Arabidopsis Fip1 protein interact with poly(A) polymerase (PAP). This domain also stimulates the activity of the PAP. Interestingly, this part of the Arabidopsis Fip1 interacts with Arabidopsis homologs of CstF77, CPSF30, CFIm-25, and PabN1. The interactions with CstF77, CPSF30, and CFIm-25 are reminiscent in various respects of similar interactions seen in yeast and mammals, although the part of the Arabidopsis Fip1 protein that participates in these interactions has no apparent counterpart in other eukaryotic Fip1 proteins. Interactions between Fip1 and PabN1 have not been reported in other systems; this may represent plant-specific associations. The C-terminal 789 amino acids of the Arabidopsis Fip1 protein were found to contain an RNA-binding domain; this domain correlated with an intact arginine-rich region and had a marked preference for poly(G) among the four homopolymers studied. These results indicate that the Arabidopsis Fip1, like its human counterpart, is an RNA-binding protein. Moreover, they provide conceptual links between PAP and several other Arabidopsis polyadenylation factor subunit homologs.
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Affiliation(s)
- Kevin P Forbes
- Plant Physiology, Biochemistry, and Molecular Biology Program, Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546-0312, USA
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Belostotsky DA, Rose AB. Plant gene expression in the age of systems biology: integrating transcriptional and post-transcriptional events. TRENDS IN PLANT SCIENCE 2005; 10:347-53. [PMID: 15951220 DOI: 10.1016/j.tplants.2005.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Revised: 04/20/2005] [Accepted: 05/26/2005] [Indexed: 05/02/2023]
Abstract
The extensive mechanistic and regulatory interconnections between the various events of mRNA biogenesis are now recognized as a fundamental principle of eukaryotic gene expression, yet the specific details of the coupling between the various steps of mRNA biogenesis do differ, and sometimes dramatically, between the different kingdoms. In this review, we emphasize examples where plants must differ in this respect from other eukaryotes, and highlight a recurring trend of recruiting the conserved, versatile functional modules, which have evolved to support the general mRNA biogenesis reactions, for plant-specific functions. We also argue that elucidating the inner workings of the plant 'mRNA factory' is essential for accomplishing the ambitious goal of building the 'virtual plant'.
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Affiliation(s)
- Dmitry A Belostotsky
- Department of Biological Sciences, State University of New York at Albany, 1400 Washington Ave, Albany, NY 12222, USA.
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Dominski Z, Yang XC, Purdy M, Wagner EJ, Marzluff WF. A CPSF-73 homologue is required for cell cycle progression but not cell growth and interacts with a protein having features of CPSF-100. Mol Cell Biol 2005; 25:1489-500. [PMID: 15684398 PMCID: PMC548002 DOI: 10.1128/mcb.25.4.1489-1500.2005] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Formation of the mature 3' ends of the vast majority of cellular mRNAs occurs through cleavage and polyadenylation and requires a cleavage and polyadenylation specificity factor (CPSF) containing, among other proteins, CPSF-73 and CPSF-100. These two proteins belong to a superfamily of zinc-dependent beta-lactamase fold proteins with catalytic specificity for a wide range of substrates including nucleic acids. CPSF-73 contains a zinc-binding histidine motif involved in catalysis in other members of the beta-lactamase superfamily, whereas CPSF-100 has substitutions within the histidine motif and thus is unlikely to be catalytically active. Here we describe two previously unknown human proteins, designated RC-68 and RC-74, which are related to CPSF-73 and CPSF-100 and which form a complex in HeLa and mouse cells. RC-68 contains the intact histidine motif, and hence it might be a functional counterpart of CPSF-73, whereas RC-74 lacks this motif, thus resembling CPSF-100. In HeLa cells RC-68 is present in both the cytoplasm and the nucleus whereas RC-74 is exclusively nuclear. RC-74 does not interact with CPSF-73, and neither RC-68 nor RC-74 is found in a complex with CPSF-160, indicating that these two proteins form a separate entity independent of the CPSF complex and are likely involved in a pre-mRNA processing event other than cleavage and polyadenylation of the vast majority of cellular pre-mRNAs. RNA interference-mediated depletion of RC-68 arrests HeLa cells early in G(1) phase, but surprisingly the arrested cells continue growing and reach the size typical of G(2) cells. RC-68 is highly conserved from plants to humans and may function in conjunction with RC-74 in the 3' end processing of a distinct subset of cellular pre-mRNAs encoding proteins required for G(1) progression and entry into S phase.
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Affiliation(s)
- Zbigniew Dominski
- Program in Molecular Biology and Biotechnology, CB #3280, University of North Carolina, Chapel Hill, NC 27599.
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Joobeur T, King JJ, Nolin SJ, Thomas CE, Dean RA. The Fusarium wilt resistance locus Fom-2 of melon contains a single resistance gene with complex features. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 39:283-97. [PMID: 15255859 DOI: 10.1111/j.1365-313x.2004.02134.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The soil-borne fungus Fusarium oxysporum f.sp. melonis causes significant losses in the cultivated melon, a key member of the economically important family, the Cucurbitaceae. Here, we report the map-based cloning and characterization of the resistance gene Fom-2 that confers resistance to race 0 and 1 of this plant pathogen. Two recombination events, 75 kb apart, were found to bracket Fom-2 after screening approximately 1324 gametes with PCR-based markers. Sequence analysis of the Fom-2 interval revealed the presence of two candidate genes. One candidate gene showed significant similarity to previously characterized resistance genes. Sequence analysis of this gene revealed clear polymorphisms between resistant and susceptible materials and was therefore designated as Fom-2. Analysis of susceptible breeding lines (BL) presenting a haplotype very similar to the resistant cultivar MR-1 indicated that a gene conversion had occurred in Fom-2, resulting in a significant rearrangement of this gene. The second candidate gene which shared high similarity to an essential gene in Arabidopsis, presented an almost identical sequence in MR-1 and BL, further supporting Fom-2 identity. The gene conversion in Fom-2 produced a truncated R gene, revealing new insights into R gene evolution. Fom-2 was predicted to encode an NBS-LRR type R protein of the non-TIR subfamily. In contrast to most members of this class a coiled-coil structure was predicted within the LRR region rather than in the N-terminal. The Fom-2 physical region contained retroelement-like sequences and truncated genes, suggesting that this locus is complex.
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Affiliation(s)
- Tarek Joobeur
- Department of Plant Pathology, Fungal Genomics Laboratory, North Carolina State University, Raleigh, NC 27965, USA
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