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Thore S, Raoelijaona F, Talenton V, Fribourg S, Mackereth CD. Molecular details of the CPSF73-CPSF100 C-terminal heterodimer and interaction with Symplekin. Open Biol 2023; 13:230221. [PMID: 37989222 PMCID: PMC10688271 DOI: 10.1098/rsob.230221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/27/2023] [Indexed: 11/23/2023] Open
Abstract
Eukaryotic pre-mRNA is processed by a large multiprotein complex to accurately cleave the 3' end, and to catalyse the addition of the poly(A) tail. Within this cleavage and polyadenylation specificity factor (CPSF) machinery, the CPSF73/CPSF3 endonuclease subunit directly contacts both CPSF100/CPSF2 and the scaffold protein Symplekin to form a subcomplex known as the core cleavage complex or mammalian cleavage factor. Here we have taken advantage of a stable CPSF73-CPSF100 minimal heterodimer from Encephalitozoon cuniculi to determine the solution structure formed by the first and second C-terminal domain (CTD1 and CTD2) of both proteins. We find a large number of contacts between both proteins in the complex, and notably in the region between CTD1 and CTD2. A similarity is also observed between CTD2 and the TATA-box binding protein (TBP) domains. Separately, we have determined the structure of the terminal CTD3 domain of CPSF73, which also belongs to the TBP domain family and is connected by a flexible linker to the rest of CPSF73. Biochemical assays demonstrate a key role for the CTD3 of CPSF73 in binding Symplekin, and structural models of the trimeric complex from other species allow for comparative analysis and support an overall conserved architecture.
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Affiliation(s)
- Stéphane Thore
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Finaritra Raoelijaona
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Vincent Talenton
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, Institut Européen de Chimie et Biologie, U1212, UMR 5320, 33600 Pessac, France
| | - Sébastien Fribourg
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, U1212, UMR 5320, 33000 Bordeaux, France
| | - Cameron D. Mackereth
- Inserm, CNRS, ARNA Laboratory, Univ. Bordeaux, Institut Européen de Chimie et Biologie, U1212, UMR 5320, 33600 Pessac, France
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2
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Liu L, Yu AM, Wang X, Soles LV, Chen Y, Yoon Y, Sarkan KSK, Valdez MC, Linder J, Marazzi I, Yu Z, Qiao F, Li W, Seelig G, Shi Y. The anti-cancer compound JTE-607 reveals hidden sequence specificity of the mRNA 3' processing machinery. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.11.536453. [PMID: 37090613 PMCID: PMC10120630 DOI: 10.1101/2023.04.11.536453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
JTE-607 is a small molecule compound with anti-inflammation and anti-cancer activities. Upon entering the cell, it is hydrolyzed to Compound 2, which directly binds to and inhibits CPSF73, the endonuclease for the cleavage step in pre-mRNA 3' processing. Although CPSF73 is universally required for mRNA 3' end formation, we have unexpectedly found that Compound 2- mediated inhibition of pre-mRNA 3' processing is sequence-specific and that the sequences flanking the cleavage site (CS) are a major determinant for drug sensitivity. By using massively parallel in vitro assays, we have measured the Compound 2 sensitivities of over 260,000 sequence variants and identified key sequence features that determine drug sensitivity. A machine learning model trained on these data can predict the impact of JTE-607 on poly(A) site (PAS) selection and transcription termination genome-wide. We propose a biochemical model in which CPSF73 and other mRNA 3' processing factors bind to RNA of the CS region in a sequence-specific manner and the affinity of such interaction determines the Compound 2 sensitivity of a PAS. As the Compound 2-resistant CS sequences, characterized by U/A-rich motifs, are prevalent in PASs from yeast to human, the CS region sequence may have more fundamental functions beyond determining drug resistance. Together, our study not only characterized the mechanism of action of a compound with clinical implications, but also revealed a previously unknown and evolutionarily conserved sequence-specificity of the mRNA 3' processing machinery.
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Cao Y, Huang C, Zhao X, Yu J. Regulation of SUMOylation on RNA metabolism in cancers. Front Mol Biosci 2023; 10:1137215. [PMID: 36911524 PMCID: PMC9998694 DOI: 10.3389/fmolb.2023.1137215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 02/15/2023] [Indexed: 03/14/2023] Open
Abstract
Post-translational modifications of proteins play very important roles in regulating RNA metabolism and affect many biological pathways. Here we mainly summarize the crucial functions of small ubiquitin-like modifier (SUMO) modification in RNA metabolism including transcription, splicing, tailing, stability and modification, as well as its impact on the biogenesis and function of microRNA (miRNA) in particular. This review also highlights the current knowledge about SUMOylation regulation in RNA metabolism involved in many cellular processes such as cell proliferation and apoptosis, which is closely related to tumorigenesis and cancer progression.
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Affiliation(s)
- Yingting Cao
- Department of Biochemistry and Molecular Cell Biology and Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Caihu Huang
- Department of Biochemistry and Molecular Cell Biology and Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xian Zhao
- Department of Biochemistry and Molecular Cell Biology and Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jianxiu Yu
- Department of Biochemistry and Molecular Cell Biology and Shanghai Key Laboratory of Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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4
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Bragado L, Magalnik M, Mammi P, Romero A, Gaioli N, Pozzi B, Srebrow A. SUMO conjugation regulates the activity of the Integrator complex. Nucleic Acids Res 2022; 50:12444-12461. [PMID: 36454007 PMCID: PMC9757034 DOI: 10.1093/nar/gkac1055] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 10/13/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
RNA polymerase II (RNAPII) transcribes small nuclear RNA (snRNA) genes in close proximity to Cajal bodies, subnuclear compartments that depend on the SUMO isopeptidase USPL1 for their assembly. We show here that overexpression of USPL1 as well as of another nuclear SUMO isopeptidase, SENP6, alters snRNA 3'-end cleavage, a process carried out by the Integrator complex. Beyond its role in snRNA biogenesis, this complex is responsible for regulating the expression of different RNAPII transcripts. While several subunits of the complex are SUMO conjugation substrates, we found that the SUMOylation of the INTS11 subunit is regulated by USPL1 and SENP6. We defined Lys381, Lys462 and Lys475 as bona fide SUMO attachment sites on INTS11 and observed that SUMOylation of this protein modulates its subcellular localization and is required for Integrator activity. Moreover, while an INTS11 SUMOylation-deficient mutant is still capable of interacting with INTS4 and INTS9, its interaction with other subunits of the complex is affected. These findings point to a regulatory role for SUMO conjugation on Integrator activity and suggest the involvement of INTS11 SUMOylation in the assembly of the complex. Furthermore, this work adds Integrator-dependent RNA processing to the growing list of cellular processes regulated by SUMO conjugation.
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Affiliation(s)
- Laureano Bragado
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Melina Magalnik
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Pablo Mammi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Agustín Romero
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Nicolás Gaioli
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Berta Pozzi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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5
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Liu H, Heller-Trulli D, Moore CL. Targeting the mRNA endonuclease CPSF73 inhibits breast cancer cell migration, invasion, and self-renewal. iScience 2022; 25:104804. [PMID: 35992060 PMCID: PMC9385686 DOI: 10.1016/j.isci.2022.104804] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/26/2022] [Accepted: 07/15/2022] [Indexed: 12/02/2022] Open
Abstract
Cleavage by the endonuclease CPSF73 and polyadenylation of nascent RNA is an essential step in co-transcriptional mRNA maturation. Recent work has surprisingly identified CPSF73 as a promising drug target for inhibiting the growth of specific cancers, triggering further studies on understanding CPSF73 regulation and functions in cells. Here, we report that a HECT-like E3 ligase, UBE3D, participates in stabilizing CPFS73 protein by preventing its ubiquitin-mediated degradation by the proteasome. Depletion of UBE3D leads to CPSF73 downregulation, a pre-mRNA cleavage defect, and dysregulated gene expression in cells. UBE3D dysfunction or chemical inactivation of CPSF73 inhibited migration and invasion as well as stem cell renewal phenotypes in vitro in triple-negative breast cancer cells. In addition, genetic overexpression of CPSF73 promoted breast cancer stemness and knocking down CPSF73 inhibited stem cell renewal properties. Together, our findings indicate that targeting the pre-mRNA processing nuclease CPSF73 has potential for breast cancer therapy.
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Affiliation(s)
- Huiyun Liu
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Daniel Heller-Trulli
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Claire L. Moore
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
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6
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Ruta V, Pagliarini V, Sette C. Coordination of RNA Processing Regulation by Signal Transduction Pathways. Biomolecules 2021; 11:biom11101475. [PMID: 34680108 PMCID: PMC8533259 DOI: 10.3390/biom11101475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 02/06/2023] Open
Abstract
Signal transduction pathways transmit the information received from external and internal cues and generate a response that allows the cell to adapt to changes in the surrounding environment. Signaling pathways trigger rapid responses by changing the activity or localization of existing molecules, as well as long-term responses that require the activation of gene expression programs. All steps involved in the regulation of gene expression, from transcription to processing and utilization of new transcripts, are modulated by multiple signal transduction pathways. This review provides a broad overview of the post-translational regulation of factors involved in RNA processing events by signal transduction pathways, with particular focus on the regulation of pre-mRNA splicing, cleavage and polyadenylation. The effects of several post-translational modifications (i.e., sumoylation, ubiquitination, methylation, acetylation and phosphorylation) on the expression, subcellular localization, stability and affinity for RNA and protein partners of many RNA-binding proteins are highlighted. Moreover, examples of how some of the most common signal transduction pathways can modulate biological processes through changes in RNA processing regulation are illustrated. Lastly, we discuss challenges and opportunities of therapeutic approaches that correct RNA processing defects and target signaling molecules.
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Affiliation(s)
- Veronica Ruta
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Laboratory of Neuroembryology, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Correspondence:
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7
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Liu H, Moore CL. On the Cutting Edge: Regulation and Therapeutic Potential of the mRNA 3' End Nuclease. Trends Biochem Sci 2021; 46:772-784. [PMID: 33941430 PMCID: PMC8364479 DOI: 10.1016/j.tibs.2021.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/18/2021] [Accepted: 04/02/2021] [Indexed: 12/24/2022]
Abstract
Cleavage of nascent transcripts is a fundamental process for eukaryotic mRNA maturation and for the production of different mRNA isoforms. In eukaryotes, cleavage of mRNA precursors by the highly conserved endonuclease CPSF73 is critical for mRNA stability, export from the nucleus, and translation. As an essential enzyme in the cell, CPSF73 surprisingly shows promise as a drug target for specific cancers and for protozoan parasites. In this review, we cover our current understanding of CPSF73 in cleavage and polyadenylation, histone pre-mRNA processing, and transcription termination. We discuss the potential of CPSF73 as a target for novel therapeutics and highlight further research into the regulation of CPSF73 that will be critical to understanding its role in cancer and other diseases.
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Affiliation(s)
- Huiyun Liu
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Claire L Moore
- Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
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8
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Park HJ, Jung HM, Lee A, Jo SH, Lee HJ, Kim HS, Jung CK, Min SR, Cho HS. SUMO Modification of OsFKBP20-1b Is Integral to Proper Pre-mRNA Splicing upon Heat Stress in Rice. Int J Mol Sci 2021; 22:ijms22169049. [PMID: 34445755 PMCID: PMC8396655 DOI: 10.3390/ijms22169049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 11/18/2022] Open
Abstract
OsFKBP20-1b, a plant-specific cyclophilin protein, has been implicated to regulate pre-mRNA splicing under stress conditions in rice. Here, we demonstrated that OsFKBP20-1b is SUMOylated in a reconstituted SUMOylation system in E.coli and in planta, and that the SUMOylation-coupled regulation was associated with enhanced protein stability using a less SUMOylated OsFKBP20-1b mutant (5KR_OsFKBP20-1b). Furthermore, OsFKBP20-1b directly interacted with OsSUMO1 and OsSUMO2 in the nucleus and cytoplasm, whereas the less SUMOylated 5KR_OsFKBP20-1b mutant had an impaired interaction with OsSUMO1 and 2 in the cytoplasm but not in the nucleus. Under heat stress, the abundance of an OsFKBP20-1b-GFP fusion protein was substantially increased in the nuclear speckles and cytoplasmic foci, whereas the heat-responsiveness was remarkably diminished in the presence of the less SUMOylated 5KR_OsFKBP20-1b-GFP mutant. The accumulation of endogenous SUMOylated OsFKBP20-1b was enhanced by heat stress in planta. Moreover, 5KR_OsFKBP20-1b was not sufficiently associated with the U snRNAs in the nucleus as a spliceosome component. A protoplast transfection assay indicated that the low SUMOylation level of 5KR_OsFKBP20-1b led to inaccurate alternative splicing and transcription under heat stress. Thus, our results suggest that OsFKBP20-1b is post-translationally regulated by SUMOylation, and the modification is crucial for proper RNA processing in response to heat stress in rice.
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Affiliation(s)
- Hyun-Ji Park
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
| | - Hae-Myeong Jung
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Areum Lee
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Seung-Hee Jo
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Hyo-Jun Lee
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Department of Functional Genomics, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Hyun-Soon Kim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
| | - Choon-Kyun Jung
- Department of International Agricultural Technology and Crop Biotechnology Institute/Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Korea;
- Department of Agriculture, Forestry, and Bioresources and Integrated Major in Global Smart Farm, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Korea
| | - Sung-Ran Min
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Correspondence: (S.-R.M.); (H.-S.C.); Tel.: +82-42-860-4463 (S.-R.M.); +82-42-860-4469 (H.-S.C.)
| | - Hye-Sun Cho
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.-J.P.); (H.-M.J.); (A.L.); (S.-H.J.); (H.-J.L.); (H.-S.K.)
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, Korea University of Science and Technology, Daejeon 34113, Korea
- Correspondence: (S.-R.M.); (H.-S.C.); Tel.: +82-42-860-4463 (S.-R.M.); +82-42-860-4469 (H.-S.C.)
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So BR, Di C, Cai Z, Venters CC, Guo J, Oh JM, Arai C, Dreyfuss G. A Complex of U1 snRNP with Cleavage and Polyadenylation Factors Controls Telescripting, Regulating mRNA Transcription in Human Cells. Mol Cell 2019; 76:590-599.e4. [PMID: 31522989 DOI: 10.1016/j.molcel.2019.08.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/25/2019] [Accepted: 08/02/2019] [Indexed: 11/27/2022]
Abstract
Full-length transcription in the majority of human genes depends on U1 snRNP (U1) to co-transcriptionally suppress transcription-terminating premature 3' end cleavage and polyadenylation (PCPA) from cryptic polyadenylation signals (PASs) in introns. However, the mechanism of this U1 activity, termed telescripting, is unknown. Here, we captured a complex, comprising U1 and CPA factors (U1-CPAFs), that binds intronic PASs and suppresses PCPA. U1-CPAFs are distinct from U1-spliceosomal complexes; they include CPA's three main subunits, CFIm, CPSF, and CstF; lack essential splicing factors; and associate with transcription elongation and mRNA export complexes. Telescripting requires U1:pre-mRNA base-pairing, which can be disrupted by U1 antisense oligonucleotide (U1 AMO), triggering PCPA. U1 AMO remodels U1-CPAFs, revealing changes, including recruitment of CPA-stimulating factors, that explain U1-CPAFs' switch from repressive to activated states. Our findings outline this U1 telescripting mechanism and demonstrate U1's unique role as central regulator of pre-mRNA processing and transcription.
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Affiliation(s)
- Byung Ran So
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Chao Di
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Zhiqiang Cai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Christopher C Venters
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Jiannan Guo
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Jung-Min Oh
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Chie Arai
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Gideon Dreyfuss
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA.
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Yu J, Lu W, Ge T, Huang R, Chen B, Ye M, Bai Y, Shi G, Songyang Z, Ma W, Huang J. Interaction Between Sympk and Oct4 Promotes Mouse Embryonic Stem Cell Proliferation. Stem Cells 2019; 37:743-753. [PMID: 30801858 DOI: 10.1002/stem.2992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/20/2018] [Accepted: 01/17/2019] [Indexed: 01/23/2023]
Abstract
The scaffold protein Symplekin (Sympk) is involved in cytoplasmic RNA polyadenylation, transcriptional modulation, and the regulation of epithelial differentiation and proliferation via tight junctions. It is highly expressed in embryonic stem cells (ESCs), in which its role remains unknown. In this study, we found Sympk overexpression in mouse ESCs significantly increased colony formation, and Sympk deletion via CRISPR/Cas9 decreased colony formation. Sympk promoted ESC growth and its overexpression sustained ESC pluripotency, as assessed by teratoma and chimeric mouse formation. Genomic stability was preserved in these cells after long-term passage. The domain of unknown function 3453 (DUF3453) in Sympk was required for its interaction with the key pluripotent factor Oct4, and its depletion led to impaired colony formation. Sympk activated proliferation-related genes and suppressed differentiation-related genes. Our results indicate that Sympk interacts with Oct4 to promote self-renewal and pluripotency in ESCs and preserves genome integrity; accordingly, it has potential value for stem cell therapies. Stem Cells 2019;37:743-753.
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Affiliation(s)
- Jianping Yu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Weisi Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Tianyu Ge
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Rui Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Bohong Chen
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Miaoman Ye
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Yaofu Bai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Guang Shi
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China
| | - Zhou Songyang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China.,Key Laboratory of Reproductive Medicine of Guangdong Province, School of Life Sciences and the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Wenbin Ma
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, SunYat-sen University, Guangzhou, People's Republic of China.,State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China.,Key Laboratory of Reproductive Medicine of Guangdong Province, School of Life Sciences and the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China.,Key Laboratory of Reproductive Medicine of Guangdong Province, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China
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Pozzi B, Mammi P, Bragado L, Giono LE, Srebrow A. When SUMO met splicing. RNA Biol 2018; 15:689-695. [PMID: 29741121 PMCID: PMC6152442 DOI: 10.1080/15476286.2018.1457936] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/22/2018] [Accepted: 03/20/2018] [Indexed: 12/12/2022] Open
Abstract
Spliceosomal proteins have been revealed as SUMO conjugation targets. Moreover, we have reported that many of these are in a SUMO-conjugated form when bound to a pre-mRNA substrate during a splicing reaction. We demonstrated that SUMOylation of Prp3 (PRPF3), a component of the U4/U6 di-snRNP, is required for U4/U6•U5 tri-snRNP formation and/or recruitment to active spliceosomes. Expanding upon our previous results, we have shown that the splicing factor SRSF1 stimulates SUMO conjugation to several spliceosomal proteins. Given the relevance of the splicing process, as well as the complex and dynamic nature of its governing machinery, the spliceosome, the molecular mechanisms that modulate its function represent an attractive topic of research. We posit that SUMO conjugation could represent a way of modulating spliceosome assembly and thus, splicing efficiency. How cycles of SUMOylation/de-SUMOylation of spliceosomal proteins become integrated throughout the highly choreographed spliceosomal cycle awaits further investigation.
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Affiliation(s)
- Berta Pozzi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Pablo Mammi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Laureano Bragado
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Luciana E. Giono
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Anabella Srebrow
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
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12
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Pozzi B, Bragado L, Will CL, Mammi P, Risso G, Urlaub H, Lührmann R, Srebrow A. SUMO conjugation to spliceosomal proteins is required for efficient pre-mRNA splicing. Nucleic Acids Res 2017; 45:6729-6745. [PMID: 28379520 PMCID: PMC5499870 DOI: 10.1093/nar/gkx213] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 03/24/2017] [Indexed: 12/26/2022] Open
Abstract
Pre-mRNA splicing is catalyzed by the spliceosome, a multi-megadalton ribonucleoprotein machine. Previous work from our laboratory revealed the splicing factor SRSF1 as a regulator of the SUMO pathway, leading us to explore a connection between this pathway and the splicing machinery. We show here that addition of a recombinant SUMO-protease decreases the efficiency of pre-mRNA splicing in vitro. By mass spectrometry analysis of anti-SUMO immunoprecipitated proteins obtained from purified splicing complexes formed along the splicing reaction, we identified spliceosome-associated SUMO substrates. After corroborating SUMOylation of Prp3 in cultured cells, we defined Lys 289 and Lys 559 as bona fide SUMO attachment sites within this spliceosomal protein. We further demonstrated that a Prp3 SUMOylation-deficient mutant while still capable of interacting with U4/U6 snRNP components, is unable to co-precipitate U2 and U5 snRNA and the spliceosomal proteins U2-SF3a120 and U5-Snu114. This SUMOylation-deficient mutant fails to restore the splicing of different pre-mRNAs to the levels achieved by the wild type protein, when transfected into Prp3-depleted cultured cells. This mutant also shows a diminished recruitment to active spliceosomes, compared to the wild type protein. These findings indicate that SUMO conjugation plays a role during the splicing process and suggest the involvement of Prp3 SUMOylation in U4/U6•U5 tri-snRNP formation and/or recruitment.
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Affiliation(s)
- Berta Pozzi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Laureano Bragado
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Cindy L Will
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Pablo Mammi
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Guillermo Risso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, MPI for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, D-37075 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany
| | - Anabella Srebrow
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología, Biología Molecular y Celular, Buenos Aires, Argentina.,CONICET-Universidad de Buenos Aires, Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), Buenos Aires, Argentina
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13
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Zinc Finger-Containing Cellular Transcription Corepressor ZBTB25 Promotes Influenza Virus RNA Transcription and Is a Target for Zinc Ejector Drugs. J Virol 2017; 91:JVI.00842-17. [PMID: 28768860 DOI: 10.1128/jvi.00842-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/24/2017] [Indexed: 02/03/2023] Open
Abstract
Influenza A virus (IAV) replication relies on an intricate interaction between virus and host cells. How the cellular proteins are usurped for IAV replication remains largely obscure. The aim of this study was to search for novel and potential cellular factors that participate in IAV replication. ZBTB25, a transcription repressor of a variety of cellular genes, was identified by an RNA interference (RNAi) genomic library screen. Depletion of ZBTB25 significantly reduced IAV production. Conversely, overexpression of ZBTB25 enhanced it. ZBTB25 interacted with the viral RNA-dependent RNA polymerase (RdRp) protein and modulated its transcription activity. In addition, ZBTB25 also functioned as a viral RNA (vRNA)-binding protein, binding preferentially to the U-rich sequence within the 5' untranslated region (UTR) of vRNA. Both protein-protein and protein-RNA interactions involving ZBTB25 facilitated viral RNA transcription and replication. In addition, ZBTB25 suppressed interferon production, further enhancing viral replication. ZBTB25-associated functions required an intact zinc finger domain and posttranslational SUMO-1 modification of ZBTB25. Furthermore, treatment with disulfiram (a zinc ejector) of ZBTB25-overexpressing cells showed significantly reduced IAV production as a result of reduced RNA synthesis. Our findings indicate that IAV usurps ZBTB25 for IAV RNA synthesis and serves as a novel and potential therapeutic antiviral target.IMPORTANCE IAV-induced seasonal influenza causes severe illness and death in high-risk populations. However, IAV has developed resistance to current antiviral drugs due to its high mutation rate. Therefore, development of drugs targeting cellular factors required for IAV replication is an attractive alternative for IAV therapy. Here, we discovered a cellular protein, ZBTB25, that enhances viral RdRp activity by binding to both viral RdRp and viral RNA to stimulate viral RNA synthesis. A unique feature of ZBTB25 in the regulation of viral replication is its dual transcription functions, namely, promoting viral RNA transcription through binding to the U-rich region of vRNA and suppressing cellular interferon production. ZBTB25 contains a zinc finger domain that is required for RNA-inhibitory activity by chelating zinc ions. Disulfiram treatment disrupts the zinc finger functions, effectively repressing IAV replication. Based on our findings, we demonstrate that ZBTB25 regulates IAV RNA transcription and replication and serves as a promising antiviral target for IAV treatment.
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Richard P, Vethantham V, Manley JL. Roles of Sumoylation in mRNA Processing and Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 963:15-33. [PMID: 28197904 DOI: 10.1007/978-3-319-50044-7_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
SUMO has gained prominence as a regulator in a number of cellular processes. The roles of sumoylation in RNA metabolism, however, while considerable, remain less well understood. In this chapter we have assembled data from proteomic analyses, localization studies and key functional studies to extend SUMO's role to the area of mRNA processing and metabolism. Proteomic analyses have identified multiple putative sumoylation targets in complexes functioning in almost all aspects of mRNA metabolism, including capping, splicing and polyadenylation of mRNA precursors. Possible regulatory roles for SUMO have emerged in pre-mRNA 3' processing, where SUMO influences the functions of polyadenylation factors and activity of the entire complex. SUMO is also involved in regulating RNA editing and RNA binding by hnRNP proteins, and recent reports have suggested the involvement of the SUMO pathway in mRNA export. Together, these reports suggest that SUMO is involved in regulation of many aspects of mRNA metabolism and hold the promise for exciting future studies.
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Affiliation(s)
- Patricia Richard
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | | | - James L Manley
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
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15
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Kota V, Sommer G, Durette C, Thibault P, van Niekerk EA, Twiss JL, Heise T. SUMO-Modification of the La Protein Facilitates Binding to mRNA In Vitro and in Cells. PLoS One 2016; 11:e0156365. [PMID: 27224031 PMCID: PMC4880191 DOI: 10.1371/journal.pone.0156365] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/12/2016] [Indexed: 02/05/2023] Open
Abstract
The RNA-binding protein La is involved in several aspects of RNA metabolism including the translational regulation of mRNAs and processing of pre-tRNAs. Besides its well-described phosphorylation by Casein kinase 2, the La protein is also posttranslationally modified by the Small Ubiquitin-like MOdifier (SUMO), but the functional outcome of this modification has not been defined. The objective of this study was to test whether sumoylation changes the RNA-binding activity of La. Therefore, we established an in vitro sumoylation assay for recombinant human La and analyzed its RNA-binding activity by electrophoretic mobility shift assays. We identified two novel SUMO-acceptor sites within the La protein located between the RNA recognition motif 1 and 2 and we demonstrate for the first time that sumoylation facilitates the RNA-binding of La to small RNA oligonucleotides representing the oligopyrimidine tract (TOP) elements from the 5' untranslated regions (UTR) of mRNAs encoding ribosomal protein L22 and L37 and to a longer RNA element from the 5' UTR of cyclin D1 (CCND1) mRNA in vitro. Furthermore, we show by RNA immunoprecipitation experiments that a La mutant deficient in sumoylation has impaired RNA-binding activity in cells. These data suggest that modulating the RNA-binding activity of La by sumoylation has important consequences on its functionality.
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Affiliation(s)
- Venkatesh Kota
- Medical University of South Carolina, Department of Biochemistry & Molecular Biology, Charleston, South Carolina, United States of America
| | - Gunhild Sommer
- Medical University of South Carolina, Department of Biochemistry & Molecular Biology, Charleston, South Carolina, United States of America
| | - Chantal Durette
- Institute of Research in Immunology and Cancer University de Montreal, Station Centre-ville, Montreal, Canada
| | - Pierre Thibault
- Institute of Research in Immunology and Cancer University de Montreal, Station Centre-ville, Montreal, Canada
| | - Erna A. van Niekerk
- Department of Neurosciences-0626, University of California, San Diego, La Jolla, California, United States of America
| | - Jeffery L. Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
| | - Tilman Heise
- Medical University of South Carolina, Department of Biochemistry & Molecular Biology, Charleston, South Carolina, United States of America
- * E-mail:
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Nuro-Gyina PK, Parvin JD. Roles for SUMO in pre-mRNA processing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2015; 7:105-12. [PMID: 26563097 DOI: 10.1002/wrna.1318] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/14/2022]
Abstract
When the small ubiquitin-like modifier (SUMO)-1 protein is localized on the genome, it is found on proteins bound to the promoters of the most highly active genes and on proteins bound to the DNA-encoding exons. Inhibition of the SUMO-1 modification leads to reductions in initiation of messenger RNA (mRNA) synthesis and splicing. In this review, we discuss what is known about the SUMOylation of factors involved in transcription initiation, pre-mRNA processing, and polyadenylation. We suggest a mechanism by which SUMO modifications of factors at the promoters of high-activity genes trigger the formation of an RNA polymerase II complex that coordinates and integrates the stimulatory signals for each process to catalyze an extremely high level of gene expression. WIREs RNA 2016, 7:105-112. doi: 10.1002/wrna.1318 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Patrick K Nuro-Gyina
- Department of Biomedical Informatics and the Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
| | - Jeffrey D Parvin
- Department of Biomedical Informatics and the Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA
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17
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Sumoylation is Required for the Cytoplasmic Accumulation of a Subset of mRNAs. Genes (Basel) 2014; 5:982-1000. [PMID: 25333844 PMCID: PMC4276922 DOI: 10.3390/genes5040982] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/26/2014] [Accepted: 10/04/2014] [Indexed: 12/17/2022] Open
Abstract
In order to discover novel proteins that promote the nuclear export of newly synthesized mRNAs in mammalian cells, we carried out a limited RNAi screen for proteins required for the proper cytoplasmic distribution of a model intronless mRNA. From this screen we obtained two hits, Ubc9 (SUMO-conjugating E2 enzyme) and GANP (germinal center-associated nuclear protein). Depletion of Ubc9 inhibited the proper cytoplasmic distribution of certain overexpressed intronless mRNAs, while depletion of GANP affected all tested mRNAs. Depletion of Sae1, which is also required for sumoylation, partially inhibited the cytoplasmic distribution of our model mRNA. Interestingly, the block in cytoplasmic accumulation in Ubc9-depleted cells could be overcome if an intron was incorporated into the mRNA. Surprisingly, Ubc9-depleted cells had normal nuclear export of newly synthesized intronless mRNAs, indicating that the observed accumulation of the model mRNA in the nuclei of transfected cells was likely due to some more general perturbation. Indeed, depletion of Ubc9, coupled with the overexpression of the intronless mRNAs, caused the redistribution of the nuclear speckle protein SC35 to cytoplasmic foci. Our results suggest that sumoylation may play a role in the proper assembly of mRNPs and/or the distribution of key RNA binding proteins, and may thus contribute to general protein expression patterns.
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18
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Efficient mRNA polyadenylation requires a ubiquitin-like domain, a zinc knuckle, and a RING finger domain, all contained in the Mpe1 protein. Mol Cell Biol 2014; 34:3955-67. [PMID: 25135474 DOI: 10.1128/mcb.00077-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Almost all eukaryotic mRNAs must be polyadenylated at their 3' ends to function in protein synthesis. This modification occurs via a large nuclear complex that recognizes signal sequences surrounding a poly(A) site on mRNA precursor, cleaves at that site, and adds a poly(A) tail. While the composition of this complex is known, the functions of some subunits remain unclear. One of these is a multidomain protein called Mpe1 in the yeast Saccharomyces cerevisiae and RBBP6 in metazoans. The three conserved domains of Mpe1 are a ubiquitin-like (UBL) domain, a zinc knuckle, and a RING finger domain characteristic of some ubiquitin ligases. We show that mRNA 3'-end processing requires all three domains of Mpe1 and that more than one region of Mpe1 is involved in contact with the cleavage/polyadenylation factor in which Mpe1 resides. Surprisingly, both the zinc knuckle and the RING finger are needed for RNA-binding activity. Consistent with a role for Mpe1 in ubiquitination, mutation of Mpe1 decreases the association of ubiquitin with Pap1, the poly(A) polymerase, and suppressors of mpe1 mutants are linked to ubiquitin ligases. Furthermore, an inhibitor of ubiquitin-mediated interactions blocks cleavage, demonstrating for the first time a direct role for ubiquitination in mRNA 3'-end processing.
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19
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Largeot A, Paggetti J, Broséus J, Aucagne R, Lagrange B, Martin RZ, Berthelet J, Quéré R, Lucchi G, Ducoroy P, Bastie JN, Delva L. Symplekin, a polyadenylation factor, prevents MOZ and MLL activity on HOXA9 in hematopoietic cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:3054-3063. [DOI: 10.1016/j.bbamcr.2013.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 01/07/2023]
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20
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Liu S, Cheng C. Alternative RNA splicing and cancer. WILEY INTERDISCIPLINARY REVIEWS. RNA 2013; 4:547-66. [PMID: 23765697 PMCID: PMC4426271 DOI: 10.1002/wrna.1178] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/10/2013] [Accepted: 05/11/2013] [Indexed: 01/04/2023]
Abstract
Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells.
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Affiliation(s)
- Sali Liu
- Department of Medicine, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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21
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Merkel DJ, Wells SB, Hilburn BC, Elazzouzi F, Pérez-Alvarado GC, Lee BM. The C-Terminal Region of Cytoplasmic Polyadenylation Element Binding Protein Is a ZZ Domain with Potential for Protein–Protein Interactions. J Mol Biol 2013; 425:2015-2026. [DOI: 10.1016/j.jmb.2013.03.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 03/04/2013] [Accepted: 03/04/2013] [Indexed: 01/07/2023]
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22
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Multiple crosstalks between mRNA biogenesis and SUMO. Chromosoma 2013; 122:387-99. [PMID: 23584125 DOI: 10.1007/s00412-013-0408-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 03/10/2013] [Accepted: 03/13/2013] [Indexed: 12/26/2022]
Abstract
mRNA metabolism involves the orchestration of multiple nuclear events, including transcription, processing (e.g., capping, splicing, polyadenylation), and quality control. This leads to the accurate formation of messenger ribonucleoparticles (mRNPs) that are finally exported to the cytoplasm for translation. The production of defined sets of mRNAs in given environmental or physiological situations relies on multiple regulatory mechanisms that target the mRNA biogenesis machineries. Among other regulations, post-translational modification by the small ubiquitin-like modifier SUMO, whose prominence in several cellular processes has been largely demonstrated, also plays a key role in mRNA biogenesis. Analysis of the multiple available SUMO proteomes and functional validations of an increasing number of sumoylated targets have revealed the key contribution of SUMO-dependent regulation in nuclear mRNA metabolism. While sumoylation of transcriptional activators and repressors is so far best documented, SUMO contribution to other stages of mRNA biogenesis is also emerging. Modification of mRNA metabolism factors by SUMO determine their subnuclear targeting and biological activity, notably by regulating their molecular interactions with nucleic acids or protein partners. In particular, sumoylation of DNA-bound transcriptional regulators interfere with their association to target sequences or chromatin modifiers. In addition, the recent identification of enzymes of the SUMO pathway within specialized mRNA biogenesis machineries may provide a further level of regulation to their specificity. These multiple crosstalks between mRNA metabolism and SUMO appear therefore as important players in cellular regulatory networks.
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Pelisch F, Risso G, Srebrow A. RNA metabolism and ubiquitin/ubiquitin-like modifications collide. Brief Funct Genomics 2012. [PMID: 23178477 DOI: 10.1093/bfgp/els053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Alternative splicing and post-translational modifications are key events for the generation of proteome diversity in eukaryotes. The study of the molecular mechanisms governing these processes, and every other step of gene expression, has underscored the existing interconnectedness among them. Therefore, molecules that could concertedly regulate different stages from transcription to pre-mRNA processing, translation and even protein activity have called our attention. Serine/arginine-rich proteins, initially identified as splicing regulators, are involved in diverse aspects of gene expression. Although most of the roles exerted by members of this family are related to mRNA biogenesis and metabolism, few recently uncovered ones link these proteins to other regulatory steps along gene expression, particularly the regulation of post-translational modification by conjugation of the small ubiquitin-related modifier. This along with the established link between ubiquitin, transcription and pre-mRNA processing points to a general mechanism of interaction between different cellular machineries, such as ubiquitin/ubiquitin-like conjugation pathways, transcription apparatus and the spliceosome.
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Affiliation(s)
- Federico Pelisch
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales - Universidad de Buenos Aires. Ciudad Universitaria, Pabellón II, Buenos Aires (C1428EHA), Argentina.
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24
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Risso G, Pelisch F, Quaglino A, Pozzi B, Srebrow A. Regulating the regulators: serine/arginine-rich proteins under scrutiny. IUBMB Life 2012; 64:809-16. [PMID: 22941908 DOI: 10.1002/iub.1075] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 07/04/2012] [Indexed: 01/29/2023]
Abstract
Serine/arginine-rich (SR) proteins are among the most studied splicing regulators. They constitute a family of evolutionarily conserved proteins that, apart from their initially identified and deeply studied role in splicing regulation, have been implicated in genome stability, chromatin binding, transcription elongation, mRNA stability, mRNA export and mRNA translation. Remarkably, this list of SR protein activities seems far from complete, as unexpected functions keep being unraveled. An intriguing aspect that awaits further investigation is how the multiple tasks of SR proteins are concertedly regulated within mammalian cells. In this article, we first discuss recent findings regarding the regulation of SR protein expression, activity and accessibility. We dive into recent studies describing SR protein auto-regulatory feedback loops involving different molecular mechanisms such asunproductive splicing, microRNA-mediated regulation and translational repression. In addition, we take into account another step of regulation of SR proteins, presenting new findings about a variety of post-translational modifications by proteomics approaches and how some of these modifications can regulate SR protein sub-cellular localization or stability. Towards the end, we focus in two recently revealed functions of SR proteins beyond mRNA biogenesis and metabolism, the regulation of micro-RNA processing and the regulation of small ubiquitin-like modifier (SUMO) conjugation.
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Affiliation(s)
- Guillermo Risso
- Instituto de Fisiología, Biología Molecular y Neurociencias - Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
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25
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Liu HW, Zhang J, Heine GF, Arora M, Gulcin Ozer H, Onti-Srinivasan R, Huang K, Parvin JD. Chromatin modification by SUMO-1 stimulates the promoters of translation machinery genes. Nucleic Acids Res 2012; 40:10172-86. [PMID: 22941651 PMCID: PMC3488252 DOI: 10.1093/nar/gks819] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
SUMOylation of transcription factors and chromatin proteins is in many cases a negative mark that recruits factors that repress gene expression. In this study, we determined the occupancy of Small Ubiquitin-like MOdifier (SUMO)-1 on chromatin in HeLa cells by use of chromatin affinity purification coupled with next-generation sequencing. We found SUMO-1 localization on chromatin was dynamic throughout the cell cycle. Surprisingly, we observed that from G1 through late S phase, but not during mitosis, SUMO-1 marks the chromatin just upstream of the transcription start site on many of the most active housekeeping genes, including genes encoding translation factors and ribosomal subunit proteins. Moreover, we found that SUMO-1 distribution on promoters was correlated with H3K4me3, another general chromatin activation mark. Depletion of SUMO-1 resulted in downregulation of the genes that were marked by SUMO-1 at their promoters during interphase, supporting the concept that the marking of promoters by SUMO-1 is associated with transcriptional activation of genes involved in ribosome biosynthesis and in the protein translation process.
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Affiliation(s)
- Hui-wen Liu
- The Department of Biomedical Informatics and the Ohio State University Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
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26
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Chan S, Choi EA, Shi Y. Pre-mRNA 3'-end processing complex assembly and function. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 2:321-35. [PMID: 21957020 DOI: 10.1002/wrna.54] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The 3'-ends of almost all eukaryotic mRNAs are formed in a two-step process, an endonucleolytic cleavage followed by polyadenylation (the addition of a poly-adenosine or poly(A) tail). These reactions take place in the pre-mRNA 3' processing complex, a macromolecular machinery that consists of more than 20 proteins. A general framework for how the pre-mRNA 3' processing complex assembles and functions has emerged from extensive studies over the past several decades using biochemical, genetic, computational, and structural approaches. In this article, we review what we have learned about this important cellular machine and discuss the remaining questions and future challenges.
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Affiliation(s)
- Serena Chan
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, USA
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27
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McCrea PD, Gu D, Balda MS. Junctional music that the nucleus hears: cell-cell contact signaling and the modulation of gene activity. Cold Spring Harb Perspect Biol 2010; 1:a002923. [PMID: 20066098 DOI: 10.1101/cshperspect.a002923] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cell-cell junctions continue to capture the interest of cell and developmental biologists, with an emerging area being the molecular means by which junctional signals relate to gene activity in the nucleus. Although complexities often arise in determining the direct versus indirect nature of such signal transduction, it is clear that such pathways are essential for the function of tissues and that alterations may contribute to many pathological outcomes. This review assesses a variety of cell-cell junction-to-nuclear signaling pathways, and outlines interesting areas for further study.
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Affiliation(s)
- Pierre D McCrea
- Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Program in Genes and Development, University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030, USA.
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28
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The serine/arginine-rich protein SF2/ASF regulates protein sumoylation. Proc Natl Acad Sci U S A 2010; 107:16119-24. [PMID: 20805487 DOI: 10.1073/pnas.1004653107] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Protein modification by conjugation of small ubiquitin-related modifier (SUMO) is involved in diverse biological functions, such as transcription regulation, subcellular partitioning, stress response, DNA damage repair, and chromatin remodeling. Here, we show that the serine/arginine-rich protein SF2/ASF, a factor involved in splicing regulation and other RNA metabolism-related processes, is a regulator of the sumoylation pathway. The overexpression of this protein stimulates, but its knockdown inhibits SUMO conjugation. SF2/ASF interacts with Ubc9 and enhances sumoylation of specific substrates, sharing characteristics with already described SUMO E3 ligases. In addition, SF2/ASF interacts with the SUMO E3 ligase PIAS1 (protein inhibitor of activated STAT-1), regulating PIAS1-induced overall protein sumoylation. The RNA recognition motif 2 of SF2/ASF is necessary and sufficient for sumoylation enhancement. Moreover, SF2/ASF has a role in heat shock-induced sumoylation and promotes SUMO conjugation to RNA processing factors. These results add a component to the sumoylation pathway and a previously unexplored role for the multifunctional SR protein SF2/ASF.
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29
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Tkacz ID, Gupta SK, Volkov V, Romano M, Haham T, Tulinski P, Lebenthal I, Michaeli S. Analysis of spliceosomal proteins in Trypanosomatids reveals novel functions in mRNA processing. J Biol Chem 2010; 285:27982-99. [PMID: 20592024 DOI: 10.1074/jbc.m109.095349] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In trypanosomatids, all mRNAs are processed via trans-splicing, although cis-splicing also occurs. In trans-splicing, a common small exon, the spliced leader (SL), which is derived from a small SL RNA species, is added to all mRNAs. Sm and Lsm proteins are core proteins that bind to U snRNAs and are essential for both these splicing processes. In this study, SmD3- and Lsm3-associated complexes were purified to homogeneity from Leishmania tarentolae. The purified complexes were analyzed by mass spectrometry, and 54 and 39 proteins were purified from SmD3 and Lsm complexes, respectively. Interestingly, among the proteins purified from Lsm3, no mRNA degradation factors were detected, as in Lsm complexes from other eukaryotes. The U1A complex was purified and mass spectrometry analysis identified, in addition to U1 small nuclear ribonucleoprotein (snRNP) proteins, additional co-purified proteins, including the polyadenylation factor CPSF73. Defects observed in cells silenced for U1 snRNP proteins suggest that the U1 snRNP functions exclusively in cis-splicing, although U1A also participates in polyadenylation and affects trans-splicing. The study characterized several trypanosome-specific nuclear factors involved in snRNP biogenesis, whose function was elucidated in Trypanosoma brucei. Conserved factors, such as PRP19, which functions at the heart of every cis-spliceosome, also affect SL RNA modification; GEMIN2, a protein associated with SMN (survival of motor neurons) and implicated in selective association of U snRNA with core Sm proteins in trypanosomes, is a master regulator of snRNP assembly. This study demonstrates the existence of trypanosomatid-specific splicing factors but also that conserved snRNP proteins possess trypanosome-specific functions.
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Affiliation(s)
- Itai Dov Tkacz
- Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan 52900, Israel
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30
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Rosonina E, Duncan SM, Manley JL. SUMO functions in constitutive transcription and during activation of inducible genes in yeast. Genes Dev 2010; 24:1242-52. [PMID: 20504900 DOI: 10.1101/gad.1917910] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Transcription factors represent one of the largest groups of proteins regulated by SUMO (small ubiquitin-like modifier) modification, and their sumoylation is usually associated with transcriptional repression. To investigate whether sumoylation plays a general role in regulating transcription in yeast, we determined the occupancy of sumoylated proteins at a variety of genes by chromatin immunoprecipitation (ChIP) using an antibody that recognizes the yeast SUMO peptide. Surprisingly, we detected sumoylated proteins at all constitutively transcribed genes tested but not at repressed genes. Ubc9, the SUMO conjugation enzyme, was not present on these genes, but its inactivation reduced SUMO at the constitutive promoters and modestly decreased RNA polymerase II levels. In contrast, activation of the inducible GAL1, STL1, and ARG1 genes caused not only a striking accumulation of SUMO at all three promoter regions, but also recruitment of Ubc9, indicating that gene activation involves sumoylation of promoter-bound factors. However, Ubc9 inactivation, while reducing sumoylation at the induced promoters, paradoxically resulted in increased transcription. Providing an explanation for this, the reduced sumoylation impaired the cell's ability to appropriately shut off transcription of the induced ARG1 gene, indicating that SUMO can facilitate transcriptional silencing. Our findings thus establish unexpected roles for sumoylation in both constitutive and activated transcription, and provide a novel mechanism for regulating gene expression.
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Affiliation(s)
- Emanuel Rosonina
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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31
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Xu X, Vatsyayan J, Gao C, Bakkenist CJ, Hu J. Sumoylation of eIF4E activates mRNA translation. EMBO Rep 2010; 11:299-304. [PMID: 20224576 PMCID: PMC2854592 DOI: 10.1038/embor.2010.18] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Revised: 01/22/2010] [Accepted: 01/25/2010] [Indexed: 01/08/2023] Open
Abstract
Eukaryotic translation initiation factor 4E (eIF4E) is the cap-binding protein that binds the 5' cap structure of cellular messenger RNAs (mRNAs). Despite the obligatory role of eIF4E in cap-dependent mRNA translation, how the translation activity of eIF4E is controlled remains largely undefined. Here, we report that mammalian eIF4E is regulated by SUMO1 (small ubiquitin-related modifier 1) conjugation. eIF4E sumoylation promotes the formation of the active eIF4F translation initiation complex and induces the translation of a subset of proteins that are essential for cell proliferation and preventing apoptosis. Furthermore, disruption of eIF4E sumoylation inhibits eIF4E-dependent protein translation and abrogates the oncogenic and antiapoptotic functions associated with eIF4E. These data indicate that sumoylation is a new fundamental regulatory mechanism of protein synthesis. Our findings suggest further that eIF4E sumoylation might be important in promoting human cancers.
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Affiliation(s)
- Xiang Xu
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Suite 2.42D, Pittsburgh, Pennsylvania 15213, USA
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32
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Sánchez-Álvarez M, Montes M, Sánchez-Hernández N, Hernández-Munain C, Suñé C. Differential effects of sumoylation on transcription and alternative splicing by transcription elongation regulator 1 (TCERG1). J Biol Chem 2010; 285:15220-15233. [PMID: 20215116 DOI: 10.1074/jbc.m109.063750] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Modification of proteins by small ubiquitin-like modifier (SUMO) is emerging as an important control of transcription and RNA processing. The human factor TCERG1 (also known as CA150) participates in transcriptional elongation and alternative splicing of pre-mRNAs. Here, we report that SUMO family proteins modify TCERG1. Furthermore, TCERG1 binds to the E2 SUMO-conjugating enzyme Ubc9. Two lysines (Lys-503 and Lys-608) of TCERG1 are the major sumoylation sites. Sumoylation does not affect localization of TCERG1 to the splicing factor-rich nuclear speckles or the alternative splicing function of TCERG1. However, mutation of the SUMO acceptor lysine residues enhanced TCERG1 transcriptional activity, indicating that SUMO modification negatively regulates TCERG1 transcriptional activity. These results reveal a regulatory role for sumoylation in controlling the activity of a transcription factor that modulates RNA polymerase II elongation and mRNA alternative processing, which are discriminated differently by this post-translational modification.
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Affiliation(s)
- Miguel Sánchez-Álvarez
- Departments of Molecular Biology, Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain; Departments of Cell Biology and Immunology, Instituto de Parasitología y Biomedicina "López Neyra," Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain
| | - Marta Montes
- Departments of Molecular Biology, Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain
| | - Noemí Sánchez-Hernández
- Departments of Molecular Biology, Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain
| | - Cristina Hernández-Munain
- Departments of Cell Biology and Immunology, Instituto de Parasitología y Biomedicina "López Neyra," Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain
| | - Carlos Suñé
- Departments of Molecular Biology, Consejo Superior de Investigaciones Científicas, Armilla, 18100 Granada, Spain.
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33
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Kourmpetis YAI, van Dijk ADJ, Bink MCAM, van Ham RCHJ, ter Braak CJF. Bayesian Markov Random Field analysis for protein function prediction based on network data. PLoS One 2010; 5:e9293. [PMID: 20195360 PMCID: PMC2827541 DOI: 10.1371/journal.pone.0009293] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 01/15/2010] [Indexed: 01/02/2023] Open
Abstract
Inference of protein functions is one of the most important aims of modern
biology. To fully exploit the large volumes of genomic data typically produced
in modern-day genomic experiments, automated computational methods for protein
function prediction are urgently needed. Established methods use sequence or
structure similarity to infer functions but those types of data do not suffice
to determine the biological context in which proteins act. Current
high-throughput biological experiments produce large amounts of data on the
interactions between proteins. Such data can be used to infer interaction
networks and to predict the biological process that the protein is involved in.
Here, we develop a probabilistic approach for protein function prediction using
network data, such as protein-protein interaction measurements. We take a
Bayesian approach to an existing Markov Random Field method by performing
simultaneous estimation of the model parameters and prediction of protein
functions. We use an adaptive Markov Chain Monte Carlo algorithm that leads to
more accurate parameter estimates and consequently to improved prediction
performance compared to the standard Markov Random Fields method. We tested our
method using a high quality S.cereviciae validation network
with 1622 proteins against 90 Gene Ontology terms of different levels of
abstraction. Compared to three other protein function prediction methods, our
approach shows very good prediction performance. Our method can be directly
applied to protein-protein interaction or coexpression networks, but also can be
extended to use multiple data sources. We apply our method to physical protein
interaction data from S. cerevisiae and provide novel
predictions, using 340 Gene Ontology terms, for 1170 unannotated proteins and we
evaluate the predictions using the available literature.
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Affiliation(s)
| | - Aalt D. J. van Dijk
- Applied Bioinformatics, Plant Research International, Wageningen, The
Netherlands
| | - Marco C. A. M. Bink
- Biometris, Wageningen University and Research Centre, Wageningen, The
Netherlands
| | - Roeland C. H. J. van Ham
- Applied Bioinformatics, Plant Research International, Wageningen, The
Netherlands
- Laboratory of Bioinformatics, Wageningen University, Wageningen, The
Netherlands
| | - Cajo J. F. ter Braak
- Biometris, Wageningen University and Research Centre, Wageningen, The
Netherlands
- * E-mail:
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34
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Lin CL, Evans V, Shen S, Xing Y, Richter JD. The nuclear experience of CPEB: implications for RNA processing and translational control. RNA (NEW YORK, N.Y.) 2010; 16:338-48. [PMID: 20040591 PMCID: PMC2811663 DOI: 10.1261/rna.1779810] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 10/29/2009] [Indexed: 05/20/2023]
Abstract
CPEB is a sequence-specific RNA binding protein that promotes polyadenylation-induced translation in early development, during cell cycle progression and cellular senescence, and following neuronal synapse stimulation. It controls polyadenylation and translation through other interacting molecules, most notably the poly(A) polymerase Gld2, the deadenylating enzyme PARN, and the eIF4E-binding protein Maskin. Here, we report that CPEB shuttles between the nucleus and cytoplasm and that its export occurs via the CRM1-dependent pathway. In the nucleus of Xenopus oocytes, CPEB associates with lampbrush chromosomes and several proteins involved in nuclear RNA processing. CPEB also interacts with Maskin in the nucleus as well as with CPE-containing mRNAs. Although the CPE does not regulate mRNA export, it influences the degree to which mRNAs are translationally repressed in the cytoplasm. Moreover, CPEB directly or indirectly mediates the alternative splicing of at least one pre-mRNA in mouse embryo fibroblasts as well as certain mouse tissues. We propose that CPEB, together with Maskin, binds mRNA in the nucleus to ensure tight translational repression upon export to the cytoplasm. In addition, we propose that nuclear CPEB regulates specific pre-mRNA alternative splicing.
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Affiliation(s)
- Chien-Ling Lin
- University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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35
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Abstract
This chapter reviews the current literature to highlight the biological mechanisms mediated via the enzymatic actions of the SUMO-specific protease family. All members of this cysteine protease family express isopeptidase activity to deSUMOylate conjugated cellular protein targets. Here, we discuss how SUMO proteases discriminate amongst the SUMOylated targets based on subcellular localization and conjugated SUMO isoform. Several signal transduction pathways modulate endogenous levels of the deSUMOylating enzymes to regulate cell growth, cell cycle progression and gene transcription. The ability of specific proteases to mediate these cellular events is presented. In addition, we examine cases in which aberrant SUMO protease expression affects normal embryonic development, carcinogenesis and the onset of additional pathophysiological conditions.
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Affiliation(s)
- Tasneem Bawa-Khalfe
- Department of Cardiology, Anderson Cancer Center, 1515 Holcombe Blvd., Houston, Texas, 77030, USA
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36
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Millevoi S, Vagner S. Molecular mechanisms of eukaryotic pre-mRNA 3' end processing regulation. Nucleic Acids Res 2009; 38:2757-74. [PMID: 20044349 PMCID: PMC2874999 DOI: 10.1093/nar/gkp1176] [Citation(s) in RCA: 294] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Messenger RNA (mRNA) 3′ end formation is a nuclear process through which all eukaryotic primary transcripts are endonucleolytically cleaved and most of them acquire a poly(A) tail. This process, which consists in the recognition of defined poly(A) signals of the pre-mRNAs by a large cleavage/polyadenylation machinery, plays a critical role in gene expression. Indeed, the poly(A) tail of a mature mRNA is essential for its functions, including stability, translocation to the cytoplasm and translation. In addition, this process serves as a bridge in the network connecting the different transcription, capping, splicing and export machineries. It also participates in the quantitative and qualitative regulation of gene expression in a variety of biological processes through the selection of single or alternative poly(A) signals in transcription units. A large number of protein factors associates with this machinery to regulate the efficiency and specificity of this process and to mediate its interaction with other nuclear events. Here, we review the eukaryotic 3′ end processing machineries as well as the comprehensive set of regulatory factors and discuss the different molecular mechanisms of 3′ end processing regulation by proposing several overlapping models of regulation.
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Affiliation(s)
- Stefania Millevoi
- Institut National de la Santé et de la Recherche Médicale U563, Toulouse, F-31000, France.
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37
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Kim JH, Baek SH. Emerging roles of desumoylating enzymes. Biochim Biophys Acta Mol Basis Dis 2009; 1792:155-62. [PMID: 19162180 DOI: 10.1016/j.bbadis.2008.12.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 12/18/2008] [Accepted: 12/19/2008] [Indexed: 11/25/2022]
Abstract
Posttranslational modification by small ubiquitin-like modifier (SUMO) controls diverse cellular processes including transcriptional regulation, nuclear transport, cell-cycle progression, DNA repair, and signal transduction pathway. Sumoylation is a highly dynamic process that is reversed by a family of Sentrin/SUMO-specific proteases (SENPs). Thus, desumoylation process must be important for regulation of the fate and function of SUMO-conjugated proteins as well as SUMOylation process. SENPs catalyze the removal of SUMO from SUMO-conjugated target proteins as well as the cleavage of SUMO from its precursor proteins. Since the first report of yeast desumoylating enzymes, many studies have revealed the structural and cellular biological properties of SENP family. This review focuses on the specificity of the SENPs' catalytic activities with regard to SUMO isoforms and their emerging roles as cellular regulators.
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Affiliation(s)
- Jung Hwa Kim
- Department of Medical Sciences, Inha University, Incheon, South Korea.
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38
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A core complex of CPSF73, CPSF100, and Symplekin may form two different cleavage factors for processing of poly(A) and histone mRNAs. Mol Cell 2009; 34:322-32. [PMID: 19450530 DOI: 10.1016/j.molcel.2009.04.024] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 04/14/2009] [Accepted: 04/24/2009] [Indexed: 11/23/2022]
Abstract
Metazoan histone mRNAs are unique: their pre-mRNAs contain no introns, and the mRNAs are not polyadenylated, ending instead in a conserved stem-loop structure. In Drosophila, canonical poly(A) signals are located downstream of the normal cleavage site of each histone gene and are utilized when histone 3' end formation is inhibited. Here we define a subcomplex of poly(A) factors that are required for histone pre-mRNA processing. We demonstrate that Symplekin, CPSF73, and CPSF100 are present in a stable complex and interact with histone-specific processing factors. We use chromatin immunoprecipitation to show that Symplekin and CPSF73, but not CstF50, cotranscriptionally associate with histone genes. Depletion of SLBP recruits CstF50 to histone genes. Knockdown of CPSF160 or CstF64 downregulates Symplekin but does not affect histone pre-mRNA processing or association of Symplekin with the histone locus. These results suggest that a common core cleavage factor is required for processing of histone and polyadenylated pre-mRNAs.
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39
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The essential N terminus of the Pta1 scaffold protein is required for snoRNA transcription termination and Ssu72 function but is dispensable for pre-mRNA 3'-end processing. Mol Cell Biol 2009; 29:2296-307. [PMID: 19188448 DOI: 10.1128/mcb.01514-08] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Saccharomyces cerevisiae Pta1 is a component of the cleavage/polyadenylation factor (CPF) 3'-end processing complex and functions in pre-mRNA cleavage, poly(A) addition, and transcription termination. In this study, we investigated the role of the N-terminal region of Pta1 in transcription and processing. We report that a deletion of the first 75 amino acids (pta1-Delta75) causes thermosensitive growth, while the deletion of an additional 25 amino acids is lethal. The pta1-Delta75 mutant is defective for snoRNA termination, RNA polymerase II C-terminal domain Ser5-P dephosphorylation, and gene looping but is fully functional for mRNA 3'-end processing. Furthermore, different regions of Pta1 interact with the CPF subunits Ssu72, Pti1, and Ysh1, supporting the idea that Pta1 acts as a scaffold to organize CPF. The first 300 amino acids of Pta1 are sufficient for interactions with Ssu72, which is needed for pre-mRNA cleavage. By the degron-mediated depletion of Pta1, we show that the removal of this essential region leads to a loss of Ssu72, yet surprisingly, in vitro cleavage and polyadenylation remain efficient. In addition, a fragment containing amino acids 1 to 300 suppresses 3'-end processing in wild-type extracts. These findings suggest that the amino terminus of Pta1 has an inhibitory effect and that this effect can be neutralized through the interaction with Ssu72.
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40
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Ihara M, Stein P, Schultz RM. UBE2I (UBC9), a SUMO-conjugating enzyme, localizes to nuclear speckles and stimulates transcription in mouse oocytes. Biol Reprod 2008; 79:906-13. [PMID: 18703419 DOI: 10.1095/biolreprod.108.070474] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Sumoylation is a posttranslational modification in which SUMO (small ubiquitin-related modifier) proteins are covalently attached to their substrates. In vertebrates, developmental roles for sumoylation have been studied, but the function of sumoylation during mammalian oocyte growth and maturation is not known. As a prelude to conducting studies on the role of sumoylation during oocyte development, we analyzed the temporal and spatial pattern of expression of UBE2I, a SUMO-conjugating E2 enzyme. Immunocytochemical analysis of UBE2I revealed a punctate nuclear staining pattern, with transcriptionally quiescent, fully grown, GV-intact oocytes having larger UBE2I-containing bodies than transcriptionally active, meiotically incompetent growing oocytes. Inhibiting transcription in incompetent oocytes resulted in an increase in the size of the UBE2I-containing bodies. Overexpression of either wild-type UBE2I or catalytically inactive UBE2I resulted in an increase in the size of the UBE2I-containing bodies but also an increase in BrUTP incorporation, suggesting that transcriptional activation by UBE2I is independent of its catalytic activity. Although UBE2I-containing bodies did not completely colocalize with SUMO1 or SUMO2 and SUMO3, which were localized mainly on the nuclear membrane and in the nucleoplasm, UBE2I strikingly colocalized with SFRS2, which is a component of nuclear speckles and critical for mRNA processing. These results suggest a novel function for UBE2I and therefore sumoylation in gene expression.
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Affiliation(s)
- Motomasa Ihara
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA
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41
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Meinke G, Ezeokonkwo C, Balbo P, Stafford W, Moore C, Bohm A. Structure of yeast poly(A) polymerase in complex with a peptide from Fip1, an intrinsically disordered protein. Biochemistry 2008; 47:6859-69. [PMID: 18537269 DOI: 10.1021/bi800204k] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In yeast, the mRNA processing enzyme poly(A) polymerase is tethered to the much larger 3'-end processing complex via Fip1, a 36 kDa protein of unknown structure. We report the 2.6 A crystal structure of yeast poly(A) polymerase in complex with a peptide containing residues 80-105 of Fip1. The Fip1 peptide binds to the outside surface of the C-terminal domain of the polymerase. On the basis of this structure, we designed a mutant of the polymerase (V498Y, C485R) that is lethal to yeast. The mutant is unable to bind Fip1 but retains full polymerase activity. Fip1 is found in all eukaryotes and serves to connect poly(A) polymerase to pre-mRNA processing complexes in yeast, plants, and mammals. However, the Fip1 sequence is highly divergent, and residues on both Pap1 and Fip1 at the observed interaction surface are poorly conserved. Herein we demonstrate using analytical ultracentrifugation, circular dichroism, proteolytic studies, and other techniques that, in the absence of Pap1, Fip1 is largely, if not completely, unfolded. We speculate that flexibility may be important for Fip1's function as a molecular scaffold.
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Affiliation(s)
- Gretchen Meinke
- Department of Biochemistry, Tufts University, 136 Harrison Avenue, Boston, Massachusetts 02111, USA
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42
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Vethantham V, Rao N, Manley JL. Sumoylation regulates multiple aspects of mammalian poly(A) polymerase function. Genes Dev 2008; 22:499-511. [PMID: 18281463 DOI: 10.1101/gad.1628208] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The addition of the poly(A) tail to the ends of eukaryotic mRNAs is catalyzed by poly(A) polymerase (PAP). PAP activity is known to be highly regulated, for example, by alternative splicing and phosphorylation. In this study we show that the small ubiquitin-like modifier (SUMO) plays multiple roles in regulating PAP function. Our discovery of SUMO-conjugated PAP began with the observation of a striking pattern of abundant higher-molecular-weight forms of PAP in certain mouse tissues and cell lines. PAP constitutes an unusual SUMO substrate in that, despite the absence of any consensus sumoylation sites, PAP interacts very strongly with the SUMO E2 enzyme ubc9 and can be extensively sumoylated both in vitro and in vivo. Six sites of sumoylation in PAP were identified, with two overlapping one of two nuclear localization signals (NLS). Strikingly, mutation of the two lysines at the NLS to arginines, or coexpression of a SUMO protease with wild-type PAP, caused PAP to be localized to the cytoplasm, demonstrating that sumoylation is required to facilitate PAP nuclear localization. Sumoylation also contributes to PAP stability, as down-regulation of sumoylation led to decreases in PAP levels. Finally, the activity of purified PAP was shown to be inhibited by in vitro sumoylation. Our study thus shows that SUMO regulates PAP in numerous distinct ways and is integral to normal PAP function.
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Affiliation(s)
- Vasupradha Vethantham
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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43
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Finishing touches: post-translational modification of protein factors involved in mammalian pre-mRNA 3' end formation. Int J Biochem Cell Biol 2008; 40:2384-96. [PMID: 18468939 DOI: 10.1016/j.biocel.2008.03.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 03/20/2008] [Accepted: 03/25/2008] [Indexed: 11/27/2022]
Abstract
In eukaryotes, a pre-messenger RNA (pre-mRNA) must undergo several processing reactions before it is exported to the cytoplasm for translation. One of these reactions, endonucleolytic 3' cleavage at the polyadenylation site, prepares the pre-mRNA for addition of the poly(A) tail and defines the 3' untranslated region (UTR), which typically contains important gene expression regulatory sequences. While the protein factors responsible for the endonucleolytic cleavage have been largely identified, the means by which their action is limited to the 3' end of the transcription unit and coordinated with other co-transcriptional events remains unclear. In this review, we summarize and review recent findings revealing that the mammalian 3' cleavage factors undergo extensive post-translational modification. These modifications include: arginine methylation, lysine sumoylation, lysine acetylation, and the phosphorylation of serine, threonine and tyrosine residues. Every cleavage factor, though not every subunit, is affected. Human Fip1 and the 59 kDa subunit of cleavage factor I emerge as the most frequently modified core cleavage factor subunits. We outline and compare the various proteomic methods that have uncovered these modifications, and review emerging hypotheses concerning their function. The roles of these covalent but reversible modifications in other systems suggest that 3' end formation in mammals relies upon post-translational modification for proper function and regulation.
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