1
|
Skurat AV, Segvich DM, Contreras CJ, Hu YC, Hurley TD, DePaoli-Roach AA, Roach PJ. Impaired malin expression and interaction with partner proteins in Lafora disease. J Biol Chem 2024; 300:107271. [PMID: 38588813 PMCID: PMC11063907 DOI: 10.1016/j.jbc.2024.107271] [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: 02/17/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
Lafora disease (LD) is an autosomal recessive myoclonus epilepsy with onset in the teenage years leading to death within a decade of onset. LD is characterized by the overaccumulation of hyperphosphorylated, poorly branched, insoluble, glycogen-like polymers called Lafora bodies. The disease is caused by mutations in either EPM2A, encoding laforin, a dual specificity phosphatase that dephosphorylates glycogen, or EMP2B, encoding malin, an E3-ubiquitin ligase. While glycogen is a widely accepted laforin substrate, substrates for malin have been difficult to identify partly due to the lack of malin antibodies able to detect malin in vivo. Here we describe a mouse model in which the malin gene is modified at the C-terminus to contain the c-myc tag sequence, making an expression of malin-myc readily detectable. Mass spectrometry analyses of immunoprecipitates using c-myc tag antibodies demonstrate that malin interacts with laforin and several glycogen-metabolizing enzymes. To investigate the role of laforin in these interactions we analyzed two additional mouse models: malin-myc/laforin knockout and malin-myc/LaforinCS, where laforin was either absent or the catalytic Cys was genomically mutated to Ser, respectively. The interaction of malin with partner proteins requires laforin but is not dependent on its catalytic activity or the presence of glycogen. Overall, the results demonstrate that laforin and malin form a complex in vivo, which stabilizes malin and enhances interaction with partner proteins to facilitate normal glycogen metabolism. They also provide insights into the development of LD and the rescue of the disease by the catalytically inactive phosphatase.
Collapse
Affiliation(s)
- Alexander V Skurat
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Dyann M Segvich
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Christopher J Contreras
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Yueh-Chiang Hu
- Division of Developmental Biology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Thomas D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
| | - Anna A DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA.
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| |
Collapse
|
2
|
Li Y, Huang J, Bao L, Zhu J, Duan W, Zheng H, Wang H, Jiang Y, Liu W, Zhang M, Yu Y, Yi C, Ji X. RNA Pol II preferentially regulates ribosomal protein expression by trapping disassociated subunits. Mol Cell 2023; 83:1280-1297.e11. [PMID: 36924766 DOI: 10.1016/j.molcel.2023.02.028] [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: 03/30/2022] [Revised: 12/12/2022] [Accepted: 02/23/2023] [Indexed: 03/17/2023]
Abstract
RNA polymerase II (RNA Pol II) has been recognized as a passively regulated multi-subunit holoenzyme. However, the extent to which RNA Pol II subunits might be important beyond the RNA Pol II complex remains unclear. Here, fractions containing disassociated RPB3 (dRPB3) were identified by size exclusion chromatography in various cells. Through a unique strategy, i.e., "specific degradation of disassociated subunits (SDDS)," we demonstrated that dRPB3 functions as a regulatory component of RNA Pol II to enable the preferential control of 3' end processing of ribosomal protein genes directly through its N-terminal domain. Machine learning analysis of large-scale genomic features revealed that the little elongation complex (LEC) helps to specialize the functions of dRPB3. Mechanistically, dRPB3 facilitates CBC-PCF11 axis activity to increase the efficiency of 3' end processing. Furthermore, RPB3 is dynamically regulated during development and diseases. These findings suggest that RNA Pol II gains specific regulatory functions by trapping disassociated subunits in mammalian cells.
Collapse
Affiliation(s)
- Yuanjun Li
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Lijun Bao
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Junyi Zhu
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Wenjia Duan
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Haonan Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Hui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Yongpeng Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Weiwei Liu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Meiling Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yang Yu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Chengqi Yi
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Department of Chemical Biology and Synthetic and Functional Biomolecules Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| |
Collapse
|
3
|
Ma L, Wang L, Gao M, Zhang X, Zhao X, Xie D, Zhang J, Wang Z, Hou L, Zeng F. Rtr1 is required for Rpb1-Rpb2 assembly of RNAPII and prevents their cytoplasmic clump formation. FASEB J 2022; 36:e22585. [PMID: 36190433 DOI: 10.1096/fj.202200698rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/03/2022] [Accepted: 09/20/2022] [Indexed: 11/11/2022]
Abstract
RNA polymerase II (RNAPII) is an essential machinery for catalyzing mRNA synthesis and controlling cell fate in eukaryotes. Although the structure and function of RNAPII have been relatively defined, the molecular mechanism of its assembly process is not clear. The identification and functional analysis of assembly factors will provide new understanding to transcription regulation. In this study, we identify that RTR1, a known transcription regulator, is a new multicopy genetic suppressor of mutants of assembly factors Gpn3, Gpn2, and Rba50. We demonstrate that Rtr1 is directly required to assemble the two largest subunits of RNAPII by coordinating with Gpn3 and Npa3. Deletion of RTR1 leads to cytoplasmic clumping of RNAPII subunit and multiple copies of RTR1 can inhibit the formation of cytoplasmic clump of RNAPII subunit in gpn3-9 mutant, indicating a new layer function of Rtr1 in checking proper assembly of RNAPII. In addition, we find that disrupted activity of Rtr1 phosphatase does not trigger the formation of cytoplasmic clump of RNAPII subunit in a catalytically inactive mutant of RTR1. Based on these results, we conclude that Rtr1 cooperates with Gpn3 and Npa3 to assemble RNAPII core.
Collapse
Affiliation(s)
- Lujie Ma
- State Key Laboratory of North China Crop Improvement and Regulation, Baoding, China.,College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Le Wang
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Mengdi Gao
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Xinjie Zhang
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Xiangdong Zhao
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Debao Xie
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Jing Zhang
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Zhen Wang
- State Key Laboratory of North China Crop Improvement and Regulation, Baoding, China.,College of Science & Technology, Hebei Agricultural University, Cangzhou, China
| | - Lifeng Hou
- College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Fanli Zeng
- State Key Laboratory of North China Crop Improvement and Regulation, Baoding, China.,College of Life Sciences, Hebei Agricultural University, Baoding, China
| |
Collapse
|
4
|
Li Y, Huang J, Zhu J, Bao L, Wang H, Jiang Y, Tian K, Wang R, Zheng H, Duan W, Lai W, Yi X, Zhu Y, Guo T, Ji X. Targeted protein degradation reveals RNA Pol II heterogeneity and functional diversity. Mol Cell 2022; 82:3943-3959.e11. [PMID: 36113479 DOI: 10.1016/j.molcel.2022.08.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/14/2022] [Accepted: 08/18/2022] [Indexed: 10/14/2022]
Abstract
RNA polymerase II (RNA Pol II) subunits are thought to be involved in various transcription-associated processes, but it is unclear whether they play different regulatory roles in modulating gene expression. Here, we performed nascent and mature transcript sequencing after the acute degradation of 12 mammalian RNA Pol II subunits and profiled their genomic binding sites and protein interactomes to dissect their molecular functions. We found that RNA Pol II subunits contribute differently to RNA Pol II cellular localization and transcription processes and preferentially regulate RNA processing (such as RNA splicing and 3' end maturation). Genes sensitive to the depletion of different RNA Pol II subunits tend to be involved in diverse biological functions and show different RNA half-lives. Sequences, associated protein factors, and RNA structures are correlated with RNA Pol II subunit-mediated differential gene expression. These findings collectively suggest that the heterogeneity of RNA Pol II and different genes appear to depend on some of the subunits.
Collapse
Affiliation(s)
- Yuanjun Li
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Jie Huang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Junyi Zhu
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Lijun Bao
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Hui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Yongpeng Jiang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Kai Tian
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Rui Wang
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Haonan Zheng
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - WenJia Duan
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Weifeng Lai
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Xiao Yi
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Yi Zhu
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Tiannan Guo
- Westlake Laboratory of Life Sciences and Biomedicine, Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China; Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| | - Xiong Ji
- Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
| |
Collapse
|
5
|
Garrido-Godino AI, Martín-Expósito M, Gutiérrez-Santiago F, Perez-Fernandez J, Navarro F. Rpb4/7, a key element of RNA pol II to coordinate mRNA synthesis in the nucleus with cytoplasmic functions in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194846. [PMID: 35905859 DOI: 10.1016/j.bbagrm.2022.194846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/11/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Affiliation(s)
- A I Garrido-Godino
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| | - M Martín-Expósito
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| | - F Gutiérrez-Santiago
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| | - J Perez-Fernandez
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain.
| | - F Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; Instituto Universitario de Investigación en Olivar y Aceites de Oliva, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071, Jaén, Spain.
| |
Collapse
|
6
|
Mechanisms of cellular mRNA transcript homeostasis. Trends Cell Biol 2022; 32:655-668. [PMID: 35660047 DOI: 10.1016/j.tcb.2022.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 11/20/2022]
Abstract
For most genes, mRNA transcript abundance scales with cell size to ensure a constant concentration. Scaling of mRNA synthesis rates with cell size plays an important role, with regulation of the activity and abundance of RNA polymerase II (Pol II) now emerging as a key point of control. However, there is also considerable evidence for feedback mechanisms that kinetically couple the rates of mRNA synthesis, nuclear export, and degradation to allow cells to compensate for changes in one by adjusting the others. Researchers are beginning to integrate results from these different fields to reveal the mechanisms underlying transcript homeostasis. This will be crucial for moving beyond our current understanding of relative gene expression towards an appreciation of how absolute transcript levels are linked to other aspects of the cellular phenotype.
Collapse
|
7
|
Couvillion M, Harlen KM, Lachance KC, Trotta KL, Smith E, Brion C, Smalec BM, Churchman LS. Transcription elongation is finely tuned by dozens of regulatory factors. eLife 2022; 11:e78944. [PMID: 35575476 PMCID: PMC9154744 DOI: 10.7554/elife.78944] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/15/2022] [Indexed: 11/30/2022] Open
Abstract
Understanding the complex network that regulates transcription elongation requires the quantitative analysis of RNA polymerase II (Pol II) activity in a wide variety of regulatory environments. We performed native elongating transcript sequencing (NET-seq) in 41 strains of Saccharomyces cerevisiae lacking known elongation regulators, including RNA processing factors, transcription elongation factors, chromatin modifiers, and remodelers. We found that the opposing effects of these factors balance transcription elongation and antisense transcription. Different sets of factors tightly regulate Pol II progression across gene bodies so that Pol II density peaks at key points of RNA processing. These regulators control where Pol II pauses with each obscuring large numbers of potential pause sites that are primarily determined by DNA sequence and shape. Antisense transcription varies highly across the regulatory landscapes analyzed, but antisense transcription in itself does not affect sense transcription at the same locus. Our findings collectively show that a diverse array of factors regulate transcription elongation by precisely balancing Pol II activity.
Collapse
Affiliation(s)
- Mary Couvillion
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kevin M Harlen
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kate C Lachance
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Kristine L Trotta
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Erin Smith
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Christian Brion
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - Brendan M Smalec
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| | - L Stirling Churchman
- Blavatnik Institute, Department of Genetics, Harvard Medical SchoolBostonUnited States
| |
Collapse
|
8
|
Garrido-Godino AI, Cuevas-Bermúdez A, Gutiérrez-Santiago F, Mota-Trujillo MDC, Navarro F. The Association of Rpb4 with RNA Polymerase II Depends on CTD Ser5P Phosphatase Rtr1 and Influences mRNA Decay in Saccharomyces cerevisiae. Int J Mol Sci 2022; 23:ijms23042002. [PMID: 35216121 PMCID: PMC8875030 DOI: 10.3390/ijms23042002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 02/04/2023] Open
Abstract
Rtr1 is an RNA polymerase II (RNA pol II) CTD-phosphatase that influences gene expression during the transition from transcription initiation to elongation and during transcription termination. Rtr1 interacts with the RNA pol II and this interaction depends on the phosphorylation state of the CTD of Rpb1, which may influence dissociation of the heterodimer Rpb4/7 during transcription. In addition, Rtr1 was proposed as an RNA pol II import factor in RNA pol II biogenesis and participates in mRNA decay by autoregulating the turnover of its own mRNA. Our work shows that Rtr1 acts in RNA pol II assembly by mediating the Rpb4/7 association with the rest of the enzyme. RTR1 deletion alters RNA pol II assembly and increases the amount of RNA pol II associated with the chromatin that lacks Rpb4, decreasing Rpb4-mRNA imprinting and, consequently, increasing mRNA stability. Thus, Rtr1 interplays RNA pol II biogenesis and mRNA decay regulation. Our data also indicate that Rtr1 mediates mRNA decay regulation more broadly than previously proposed by cooperating with Rpb4. Interestingly, our data include new layers in the mechanisms of gene regulation and in the crosstalk between mRNA synthesis and decay by demonstrating how the association of Rpb4/7 to the RNA pol II influences mRNA decay.
Collapse
Affiliation(s)
- Ana I. Garrido-Godino
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Abel Cuevas-Bermúdez
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Francisco Gutiérrez-Santiago
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Maria del Carmen Mota-Trujillo
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
- Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
- Correspondence: ; Tel.: +34-953-212-771; Fax: +34-953-211-875
| |
Collapse
|
9
|
Gopalakrishnan R, Winston F. The histone chaperone Spt6 is required for normal recruitment of the capping enzyme Abd1 to transcribed regions. J Biol Chem 2021; 297:101205. [PMID: 34543624 PMCID: PMC8511950 DOI: 10.1016/j.jbc.2021.101205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/20/2021] [Accepted: 09/15/2021] [Indexed: 10/29/2022] Open
Abstract
The histone chaperone Spt6 is involved in promoting elongation of RNA polymerase II (RNAPII), maintaining chromatin structure, regulating cotranscriptional histone modifications, and controlling mRNA processing. These diverse functions of Spt6 are partly mediated through its interactions with RNAPII and other factors in the transcription elongation complex. In this study, we used mass spectrometry to characterize the differences in RNAPII-interacting factors between wildtype cells and those depleted for Spt6, leading to the identification of proteins that depend on Spt6 for their interaction with RNAPII. The altered association of some of these factors could be attributed to changes in steady-state protein levels. However, Abd1, the mRNA cap methyltransferase, had decreased association with RNAPII after Spt6 depletion despite unchanged Abd1 protein levels, showing a requirement for Spt6 in mediating the Abd1-RNAPII interaction. Genome-wide studies showed that Spt6 is required for maintaining the level of Abd1 over transcribed regions, as well as the level of Spt5, another protein known to recruit Abd1 to chromatin. Abd1 levels were particularly decreased at the 5' ends of genes after Spt6 depletion, suggesting a greater need for Spt6 in Abd1 recruitment over these regions. Together, our results show that Spt6 is important in regulating the composition of the transcription elongation complex and reveal a previously unknown function for Spt6 in the recruitment of Abd1.
Collapse
Affiliation(s)
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA.
| |
Collapse
|
10
|
LeBlanc BM, Moreno RY, Escobar EE, Venkat Ramani MK, Brodbelt JS, Zhang Y. What's all the phos about? Insights into the phosphorylation state of the RNA polymerase II C-terminal domain via mass spectrometry. RSC Chem Biol 2021; 2:1084-1095. [PMID: 34458825 PMCID: PMC8341212 DOI: 10.1039/d1cb00083g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 06/03/2021] [Indexed: 12/31/2022] Open
Abstract
RNA polymerase II (RNAP II) is one of the primary enzymes responsible for expressing protein-encoding genes and some small nuclear RNAs. The enigmatic carboxy-terminal domain (CTD) of RNAP II and its phosphorylation state are critically important in regulating transcription in vivo. Early methods of identifying phosphorylation on the CTD heptad were plagued by issues of low specificity and ambiguous signals. However, advancements in the field of mass spectrometry (MS) have presented the opportunity to gain new insights into well-studied processes as well as explore new frontiers in transcription. By using MS, residues which are modified within the CTD heptad and across repeats are now able to be pinpointed. Likewise, identification of kinase and phosphatase specificity towards residues of the CTD has reached a new level of accuracy. Now, MS is being used to investigate the crosstalk between modified residues of the CTD and may be a critical technique for understanding how phosphorylation plays a role in the new LLPS model of transcription. Herein, we discuss the development of various MS techniques and evaluate their capabilities. By highlighting the pros and cons of each technique, we aim to provide future investigators with a comprehensive overview of how MS can be used to investigate the complexities of RNAP-II mediated transcription.
Collapse
Affiliation(s)
- Blase M LeBlanc
- Department of Molecular Biosciences, University of Texas Austin USA
| | - R Yvette Moreno
- Department of Molecular Biosciences, University of Texas Austin USA
| | | | | | | | - Yan Zhang
- Department of Molecular Biosciences, University of Texas Austin USA
- Institute of Cellular and Molecular Biology, University of Texas Austin USA
| |
Collapse
|
11
|
Peck Justice SA, McCracken NA, Victorino JF, Qi GD, Wijeratne AB, Mosley AL. Boosting Detection of Low-Abundance Proteins in Thermal Proteome Profiling Experiments by Addition of an Isobaric Trigger Channel to TMT Multiplexes. Anal Chem 2021; 93:7000-7010. [PMID: 33908254 PMCID: PMC8153406 DOI: 10.1021/acs.analchem.1c00012] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
The study of low-abundance
proteins is a challenge to discovery-based
proteomics. Mass spectrometry (MS) applications, such as thermal proteome
profiling (TPP), face specific challenges in the detection of the
whole proteome as a consequence of the use of nondenaturing extraction
buffers. TPP is a powerful method for the study of protein thermal
stability, but quantitative accuracy is highly dependent on consistent
detection. Therefore, TPP can be limited in its amenability to study
low-abundance proteins that tend to have stochastic or poor detection
by MS. To address this challenge, we incorporated an affinity-purified
protein complex sample at submolar concentrations as an isobaric trigger
channel into a mutant TPP (mTPP) workflow to provide reproducible
detection and quantitation of the low-abundance subunits of the cleavage
and polyadenylation factor (CPF) complex. The inclusion of an isobaric
protein complex trigger channel increased detection an average of
40× for previously detected subunits and facilitated detection
of CPF subunits that were previously below the limit of detection.
Importantly, these gains in CPF detection did not cause large changes
in melt temperature (Tm) calculations
for other unrelated proteins in the samples, with a high positive
correlation between Tm estimates in samples
with and without isobaric trigger channel addition. Overall, the incorporation
of an affinity-purified protein complex as an isobaric trigger channel
within a tandem mass tag (TMT) multiplex for mTPP experiments is an
effective and reproducible way to gather thermal profiling data on
proteins that are not readily detected using the original TPP or mTPP
protocols.
Collapse
Affiliation(s)
- Sarah A Peck Justice
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Neil A McCracken
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - José F Victorino
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Guihong D Qi
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Aruna B Wijeratne
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
| |
Collapse
|
12
|
Viktorovskaya O, Chuang J, Jain D, Reim NI, López-Rivera F, Murawska M, Spatt D, Churchman LS, Park PJ, Winston F. Essential histone chaperones collaborate to regulate transcription and chromatin integrity. Genes Dev 2021; 35:698-712. [PMID: 33888559 PMCID: PMC8091981 DOI: 10.1101/gad.348431.121] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 03/30/2021] [Indexed: 12/15/2022]
Abstract
Histone chaperones are critical for controlling chromatin integrity during transcription, DNA replication, and DNA repair. Three conserved and essential chaperones, Spt6, Spn1/Iws1, and FACT, associate with elongating RNA polymerase II and interact with each other physically and/or functionally; however, there is little understanding of their individual functions or their relationships with each other. In this study, we selected for suppressors of a temperature-sensitive spt6 mutation that disrupts the Spt6-Spn1 physical interaction and that also causes both transcription and chromatin defects. This selection identified novel mutations in FACT. Surprisingly, suppression by FACT did not restore the Spt6-Spn1 interaction, based on coimmunoprecipitation, ChIP, and mass spectrometry experiments. Furthermore, suppression by FACT bypassed the complete loss of Spn1. Interestingly, the FACT suppressor mutations cluster along the FACT-nucleosome interface, suggesting that they alter FACT-nucleosome interactions. In agreement with this observation, we showed that the spt6 mutation that disrupts the Spt6-Spn1 interaction caused an elevated level of FACT association with chromatin, while the FACT suppressors reduced the level of FACT-chromatin association, thereby restoring a normal Spt6-FACT balance on chromatin. Taken together, these studies reveal previously unknown regulation between histone chaperones that is critical for their essential in vivo functions.
Collapse
Affiliation(s)
- Olga Viktorovskaya
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - James Chuang
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dhawal Jain
- Department of Biomedical Informatics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Natalia I Reim
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Francheska López-Rivera
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Magdalena Murawska
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Dan Spatt
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Peter J Park
- Department of Biomedical Informatics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Fred Winston
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| |
Collapse
|
13
|
Garrido-Godino AI, Gutiérrez-Santiago F, Navarro F. Biogenesis of RNA Polymerases in Yeast. Front Mol Biosci 2021; 8:669300. [PMID: 34026841 PMCID: PMC8136413 DOI: 10.3389/fmolb.2021.669300] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/31/2021] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic RNA polymerases (RNA pols) transcriptional processes have been extensively investigated, and the structural analysis of eukaryotic RNA pols has been explored. However, the global assembly and biogenesis of these heteromultimeric complexes have been narrowly studied. Despite nuclear transcription being carried out by three RNA polymerases in eukaryotes (five in plants) with specificity in the synthesis of different RNA types, the biogenesis process has been proposed to be similar, at least for RNA pol II, to that of bacteria, which contains only one RNA pol. The formation of three different interacting subassembly complexes to conform the complete enzyme in the cytoplasm, prior to its nuclear import, has been assumed. In Saccharomyces cerevisiae, recent studies have examined in depth the biogenesis of RNA polymerases by characterizing some elements involved in the assembly of these multisubunit complexes, some of which are conserved in humans. This study reviews the latest studies governing the mechanisms and proteins described as being involved in the biogenesis of RNA polymerases in yeast.
Collapse
Affiliation(s)
- Ana I Garrido-Godino
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain
| | | | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
| |
Collapse
|
14
|
Gamarra N, Narlikar GJ. Collaboration through chromatin: motors of transcription and chromatin structure. J Mol Biol 2021; 433:166876. [PMID: 33556407 DOI: 10.1016/j.jmb.2021.166876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 01/09/2023]
Abstract
Packaging of the eukaryotic genome into chromatin places fundamental physical constraints on transcription. Clarifying how transcription operates within these constraints is essential to understand how eukaryotic gene expression programs are established and maintained. Here we review what is known about the mechanisms of transcription on chromatin templates. Current models indicate that transcription through chromatin is accomplished by the combination of an inherent nucleosome disrupting activity of RNA polymerase and the action of ATP-dependent chromatin remodeling motors. Collaboration between these two types of molecular motors is proposed to occur at all stages of transcription through diverse mechanisms. Further investigation of how these two motors combine their basic activities is essential to clarify the interdependent relationship between genome structure and transcription.
Collapse
Affiliation(s)
- Nathan Gamarra
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States; TETRAD Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.
| |
Collapse
|
15
|
Ishida YI, Miyao S, Saito M, Hiraishi N, Nagahama M. Interactome analysis of the Tudor domain-containing protein SPF30 which associates with the MTR4-exosome RNA-decay machinery under the regulation of AAA-ATPase NVL2. Int J Biochem Cell Biol 2021; 132:105919. [PMID: 33422691 DOI: 10.1016/j.biocel.2021.105919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 12/24/2022]
Abstract
The AAA-ATPase NVL2 associates with an RNA helicase MTR4 and the nuclear RNA exosome in the course of ribosome biogenesis. In our proteomic screen, we had identified a ribosome biogenesis factor WDR74 as a MTR4-interacting partner, whose dissociation is stimulated by the ATP hydrolysis of NVL2. In this study, we report the identification of splicing factor 30 (SPF30), another MTR4-interacting protein with a similar regulatory mechanism. SPF30 is a pre-mRNA splicing factor harboring a Tudor domain in its central region, which regulates various cellular events by binding to dimethylarginine-modified proteins. The interaction between SPF30 and the exosome core is mediated by MTR4 and RRP6, a catalytic component of the nuclear exosome. The N- and C-terminal regions, but not the Tudor domain, of SPF30 are involved in the association with MTR4 and the exosome. The knockdown of SPF30 caused subtle delay in the 12S pre-rRNA processing to mature 5.8S rRNA, even though no obvious effect was observed on the ribosome subunit profile in the cells. Shotgun proteomic analysis to search for SPF30-interacting proteins indicated its role in ribosome biogenesis, pre-mRNA splicing, and box C/D snoRNA biogenesis. These results suggest that SPF30 collaborates with the MTR4-exosome machinery to play a functional role in multiple RNA metabolic pathways, some of which may be regulated by the ATP hydrolysis of NVL2.
Collapse
Affiliation(s)
- Yo-Ichi Ishida
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Sotaro Miyao
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Mitsuaki Saito
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Nobuhiro Hiraishi
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Masami Nagahama
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan.
| |
Collapse
|
16
|
Richard S, Gross L, Fischer J, Bendalak K, Ziv T, Urim S, Choder M. Numerous Post-translational Modifications of RNA Polymerase II Subunit Rpb4/7 Link Transcription to Post-transcriptional Mechanisms. Cell Rep 2021; 34:108578. [PMID: 33440147 DOI: 10.1016/j.celrep.2020.108578] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 07/24/2020] [Accepted: 12/09/2020] [Indexed: 01/25/2023] Open
Abstract
Rpb4/7 binds RNA polymerase II (RNA Pol II) transcripts co-transcriptionally and accompanies them throughout their lives. By virtue of its capacity to interact with key regulators (e.g., RNA Pol II, eIF3, and Pat1) temporally and spatially, Rpb4/7 regulates the major stages of the mRNA life cycle. Here we show that Rpb4/7 can undergo more than 100 combinations of post-translational modifications (PTMs). Remarkably, the Rpb4/7 PTM repertoire changes as the mRNA/Rpb4/7 complex progresses from one stage to the next. These temporal PTMs regulate Rpb4 interactions with key regulators of gene expression that control transcriptional and post-transcriptional stages. Moreover, one mutant type specifically affects mRNA synthesis, whereas the other affects mRNA synthesis and decay; both types disrupt the balance between mRNA synthesis and decay ("mRNA buffering") and the cell's capacity to respond to the environment. We propose that temporal Rpb4/7 PTMs mediate the cross-talk among the various stages of the mRNA life cycle.
Collapse
Affiliation(s)
- Stephen Richard
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Lital Gross
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Jonathan Fischer
- Computer Science Division, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Keren Bendalak
- Smoler Proteomics Center, Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Shira Urim
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Mordechai Choder
- Department of Molecular Microbiology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
| |
Collapse
|
17
|
Rogers CM, Sanders E, Nguyen PA, Smith-Kinnaman W, Mosley AL, Bochman ML. The Genetic and Physical Interactomes of the Saccharomyces cerevisiae Hrq1 Helicase. G3 (BETHESDA, MD.) 2020; 10:4347-4357. [PMID: 33115721 PMCID: PMC7718736 DOI: 10.1534/g3.120.401864] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/23/2020] [Indexed: 01/03/2023]
Abstract
The human genome encodes five RecQ helicases (RECQL1, BLM, WRN, RECQL4, and RECQL5) that participate in various processes underpinning genomic stability. Of these enzymes, the disease-associated RECQL4 is comparatively understudied due to a variety of technical challenges. However, Saccharomyces cerevisiae encodes a functional homolog of RECQL4 called Hrq1, which is more amenable to experimentation and has recently been shown to be involved in DNA inter-strand crosslink (ICL) repair and telomere maintenance. To expand our understanding of Hrq1 and the RecQ4 subfamily of helicases in general, we took a multi-omics approach to define the Hrq1 interactome in yeast. Using synthetic genetic array analysis, we found that mutations of genes involved in processes such as DNA repair, chromosome segregation, and transcription synthetically interact with deletion of HRQ1 and the catalytically inactive hrq1-K318A allele. Pull-down of tagged Hrq1 and mass spectrometry identification of interacting partners similarly underscored links to these processes and others. Focusing on transcription, we found that hrq1 mutant cells are sensitive to caffeine and that mutation of HRQ1 alters the expression levels of hundreds of genes. In the case of hrq1-K318A, several of the most highly upregulated genes encode proteins of unknown function whose expression levels are also increased by DNA ICL damage. Together, our results suggest a heretofore unrecognized role for Hrq1 in transcription, as well as novel members of the Hrq1 ICL repair pathway. These data expand our understanding of RecQ4 subfamily helicase biology and help to explain why mutations in human RECQL4 cause diseases of genomic instability.
Collapse
Affiliation(s)
- Cody M Rogers
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405
| | - Elsbeth Sanders
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405
| | - Phoebe A Nguyen
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405
| | - Whitney Smith-Kinnaman
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Matthew L Bochman
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405
| |
Collapse
|
18
|
Calvo O. RNA polymerase II phosphorylation and gene looping: new roles for the Rpb4/7 heterodimer in regulating gene expression. Curr Genet 2020; 66:927-937. [PMID: 32508001 DOI: 10.1007/s00294-020-01084-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/22/2022]
Abstract
In eukaryotes, cellular RNAs are produced by three nuclear RNA polymerases (RNAPI, II, and III), which are multisubunit complexes. They share structural and functional features, although they are specialized in the synthesis of specific RNAs. RNAPII transcribes the vast majority of cellular RNAs, including mRNAs and a large number of noncoding RNAs. The structure of RNAPII is highly conserved in all eukaryotes, consisting of 12 subunits (Rpb1-12) organized into five structural modules, among which the Rpb4 and Rpb7 subunits form the stalk. Early studies suggested an accessory role for Rpb4, because is required for specific gene transcription pathways. Far from this initial hypothesis, it is now well established that the Rpb4/7 heterodimer plays much wider roles in gene expression regulation. It participates in nuclear and cytosolic processes ranging from transcription to translation and mRNA degradation in a cyclical process. For this reason, Rpb4/7 is considered a coordinator of gene expression. New functions have been added to the list of stalk functions during transcription, which will be reviewed herein: first, a role in the maintenance of proper RNAPII phosphorylation levels, and second, a role in the establishment of a looped gene architecture in actively transcribed genes.
Collapse
Affiliation(s)
- Olga Calvo
- Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, C/ Zacarías González 2, Salamanca, 37007, España.
| |
Collapse
|
19
|
Gopalakrishnan R, Marr SK, Kingston RE, Winston F. A conserved genetic interaction between Spt6 and Set2 regulates H3K36 methylation. Nucleic Acids Res 2019; 47:3888-3903. [PMID: 30793188 PMCID: PMC6486648 DOI: 10.1093/nar/gkz119] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/05/2019] [Accepted: 02/13/2019] [Indexed: 12/28/2022] Open
Abstract
The transcription elongation factor Spt6 and the H3K36 methyltransferase Set2 are both required for H3K36 methylation and transcriptional fidelity in Saccharomyces cerevisiae. However, the nature of the requirement for Spt6 has remained elusive. By selecting for suppressors of a transcriptional defect in an spt6 mutant, we have isolated several highly clustered, dominant SET2 mutations (SET2sup mutations) in a region encoding a proposed autoinhibitory domain. SET2sup mutations suppress the H3K36 methylation defect in the spt6 mutant, as well as in other mutants that impair H3K36 methylation. We also show that SET2sup mutations overcome the requirement for certain Set2 domains for H3K36 methylation. In vivo, SET2sup mutants have elevated levels of H3K36 methylation and the purified Set2sup mutant protein has greater enzymatic activityin vitro. ChIP-seq studies demonstrate that the H3K36 methylation defect in the spt6 mutant, as well as its suppression by a SET2sup mutation, occurs at a step following the recruitment of Set2 to chromatin. Other experiments show that a similar genetic relationship between Spt6 and Set2 exists in Schizosaccharomyces pombe. Taken together, our results suggest a conserved mechanism by which the Set2 autoinhibitory domain requires multiple Set2 interactions to ensure that H3K36 methylation occurs specifically on actively transcribed chromatin.
Collapse
Affiliation(s)
| | - Sharon K Marr
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Robert E Kingston
- Department of Genetics, Harvard Medical School, Boston, MA, USA 02115.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Fred Winston
- Department of Genetics, Harvard Medical School, Boston, MA, USA 02115
| |
Collapse
|
20
|
Burriss KH, Mosley AL. Methods review: Mass spectrometry analysis of RNAPII complexes. Methods 2019; 159-160:105-114. [PMID: 30902665 DOI: 10.1016/j.ymeth.2019.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/04/2019] [Accepted: 03/17/2019] [Indexed: 12/20/2022] Open
Abstract
RNA Polymerase II (RNAPII) is responsible for transcribing multiple RNA species throughout eukaryotes. A variety of protein-protein interactions occur throughout the transcription cycle for coordinated regulation of transcription initiation, elongation, and/or termination. Taking a proteomics approach to study RNAPII transcription thereby offers a comprehensive view of both RNAPII biology and the variety of proteins that regulate the process itself. This review will focus on how mass spectrometry (MS) methods have expanded understanding of RNAPII and its transcription-regulatory interaction partners. The application of affinity purification mass spectrometry has led to the discovery of a number of novel groups of proteins that regulate an array of RNAPII biology ranging from nuclear import to regulation of phosphorylation state. Additionally, a number of methods have been developed using mass spectrometry to measure protein subunit stoichiometry within and across protein complexes and to perform various types of architectural analysis using structural proteomics approaches. The key methods that we will focus on related to RNAPII mass spectrometry analyses include: affinity purification mass spectrometry, protein post-translational modification analysis, crosslinking mass spectrometry, and native mass spectrometry.
Collapse
Affiliation(s)
- Katlyn Hughes Burriss
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46402, United States
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46402, United States; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN 46402, United States.
| |
Collapse
|
21
|
|
22
|
Willy JA, Young SK, Mosley AL, Gawrieh S, Stevens JL, Masuoka HC, Wek RC. Function of inhibitor of Bruton's tyrosine kinase isoform α (IBTKα) in nonalcoholic steatohepatitis links autophagy and the unfolded protein response. J Biol Chem 2017; 292:14050-14065. [PMID: 28710282 DOI: 10.1074/jbc.m117.799304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/03/2017] [Indexed: 01/15/2023] Open
Abstract
Nonalcoholic fatty liver disease (steatosis) is the most prevalent liver disease in the Western world. One of the advanced pathologies is nonalcoholic steatohepatitis (NASH), which is associated with induction of the unfolded protein response (UPR) and disruption of autophagic flux. However, the mechanisms by which these processes contribute to the pathogenesis of human diseases are unclear. Herein, we identify the α isoform of the inhibitor of Bruton's tyrosine kinase (IBTKα) as a member of the UPR, whose expression is preferentially translated during endoplasmic reticulum (ER) stress. We found that IBTKα is located in the ER and associates with proteins LC3b, SEC16A, and SEC31A and plays a previously unrecognized role in phagophore initiation from ER exit sites. Depletion of IBTKα helps prevent accumulation of autophagosome intermediates stemming from exposure to saturated free fatty acids and rescues hepatocytes from death. Of note, induction of IBTKα and the UPR, along with inhibition of autophagic flux, was associated with progression from steatosis to NASH in liver biopsies. These results indicate a function for IBTKα in NASH that links autophagy with activation of the UPR.
Collapse
Affiliation(s)
- Jeffrey A Willy
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126
| | - Sara K Young
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126
| | - Amber L Mosley
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126
| | - Samer Gawrieh
- Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202-5126
| | - James L Stevens
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126
| | - Howard C Masuoka
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126
| | - Ronald C Wek
- From the Departments of Biochemistry and Molecular Biology and Indianapolis, Indiana 46202-5126.
| |
Collapse
|
23
|
Different phosphoisoforms of RNA polymerase II engage the Rtt103 termination factor in a structurally analogous manner. Proc Natl Acad Sci U S A 2017; 114:E3944-E3953. [PMID: 28465432 DOI: 10.1073/pnas.1700128114] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II (Pol II) orchestrates dynamic recruitment of specific cellular machines during different stages of transcription. Signature phosphorylation patterns of Y1S2P3T4S5P6S7 heptapeptide repeats of the CTD engage specific "readers." Whereas phospho-Ser5 and phospho-Ser2 marks are ubiquitous, phospho-Thr4 is reported to only impact specific genes. Here, we identify a role for phospho-Thr4 in transcription termination at noncoding small nucleolar RNA (snoRNA) genes. Quantitative proteomics reveals an interactome of known readers as well as protein complexes that were not known to rely on Thr4 for association with Pol II. The data indicate a key role for Thr4 in engaging the machinery used for transcription elongation and termination. We focus on Rtt103, a protein that binds phospho-Ser2 and phospho-Thr4 marks and facilitates transcription termination at protein-coding genes. To elucidate how Rtt103 engages two distinct CTD modifications that are differentially enriched at noncoding genes, we relied on NMR analysis of Rtt103 in complex with phospho-Thr4- or phospho-Ser2-bearing CTD peptides. The structural data reveal that Rtt103 interacts with phospho-Thr4 in a manner analogous to its interaction with phospho-Ser2-modified CTD. The same set of hydrogen bonds involving either the oxygen on phospho-Thr4 and the hydroxyl on Ser2, or the phosphate on Ser2 and the Thr4 hydroxyl, can be formed by rotation of an arginine side chain, leaving the intermolecular interface otherwise unperturbed. This economy of design enables Rtt103 to engage Pol II at distinct sets of genes with differentially enriched CTD marks.
Collapse
|
24
|
Pause & go: from the discovery of RNA polymerase pausing to its functional implications. Curr Opin Cell Biol 2017; 46:72-80. [PMID: 28363125 DOI: 10.1016/j.ceb.2017.03.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/06/2017] [Accepted: 03/07/2017] [Indexed: 12/25/2022]
Abstract
The synthesis of nascent RNA is a discontinuous process in which phases of productive elongation by RNA polymerase are interrupted by frequent pauses. Transcriptional pausing was first observed decades ago, but was long considered to be a special feature of transcription at certain genes. This view was challenged when studies using genome-wide approaches revealed that RNA polymerase II pauses at promoter-proximal regions in large sets of genes in Drosophila and mammalian cells. High-resolution genomic methods uncovered that pausing is not restricted to promoters, but occurs globally throughout gene-body regions, implying the existence of key-rate limiting steps in nascent RNA synthesis downstream of transcription initiation. Here, we outline the experimental breakthroughs that led to the discovery of pervasive transcriptional pausing, discuss its emerging roles and regulation, and highlight the importance of pausing in human development and disease.
Collapse
|
25
|
Harlen KM, Trotta KL, Smith EE, Mosaheb MM, Fuchs SM, Churchman LS. Comprehensive RNA Polymerase II Interactomes Reveal Distinct and Varied Roles for Each Phospho-CTD Residue. Cell Rep 2016; 15:2147-2158. [PMID: 27239037 DOI: 10.1016/j.celrep.2016.05.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/22/2016] [Accepted: 04/26/2016] [Indexed: 12/11/2022] Open
Abstract
Transcription controls splicing and other gene regulatory processes, yet mechanisms remain obscure due to our fragmented knowledge of the molecular connections between the dynamically phosphorylated RNA polymerase II (Pol II) C-terminal domain (CTD) and regulatory factors. By systematically isolating phosphorylation states of the CTD heptapeptide repeat (Y1S2P3T4S5P6S7), we identify hundreds of protein factors that are differentially enriched, revealing unappreciated connections between the Pol II CTD and co-transcriptional processes. These data uncover a role for threonine-4 in 3' end processing through control of the transition between cleavage and termination. Furthermore, serine-5 phosphorylation seeds spliceosomal assembly immediately downstream of 3' splice sites through a direct interaction with spliceosomal subcomplex U1. Strikingly, threonine-4 phosphorylation also impacts splicing by serving as a mark of co-transcriptional spliceosome release and ensuring efficient post-transcriptional splicing genome-wide. Thus, comprehensive Pol II interactomes identify the complex and functional connections between transcription machinery and other gene regulatory complexes.
Collapse
Affiliation(s)
- Kevin M Harlen
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Kristine L Trotta
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Erin E Smith
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | | | - Stephen M Fuchs
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | | |
Collapse
|
26
|
Bedard LG, Dronamraju R, Kerschner JL, Hunter GO, Axley ED, Boyd AK, Strahl BD, Mosley AL. Quantitative Analysis of Dynamic Protein Interactions during Transcription Reveals a Role for Casein Kinase II in Polymerase-associated Factor (PAF) Complex Phosphorylation and Regulation of Histone H2B Monoubiquitylation. J Biol Chem 2016; 291:13410-20. [PMID: 27143358 DOI: 10.1074/jbc.m116.727735] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Indexed: 11/06/2022] Open
Abstract
Using affinity purification MS approaches, we have identified a novel role for casein kinase II (CKII) in the modification of the polymerase associated factor complex (PAF-C). Our data indicate that the facilitates chromatin transcription complex (FACT) interacts with CKII and may facilitate PAF complex phosphorylation. Posttranslational modification analysis of affinity-isolated PAF-C shows extensive CKII phosphorylation of all five subunits of PAF-C, although CKII subunits were not detected as interacting partners. Consistent with this, recombinant CKII or FACT-associated CKII isolated from cells can phosphorylate PAF-C in vitro, whereas no intrinsic kinase activity was detected in PAF-C samples. Significantly, PAF-C purifications combined with stable isotope labeling in cells (SILAC) quantitation for PAF-C phosphorylation from wild-type and CKII temperature-sensitive strains (cka1Δ cka2-8) showed that PAF-C phosphorylation at consensus CKII sites is significantly reduced in cka1Δ cka2-8 strains. Consistent with a role of CKII in FACT and PAF-C function, we show that decreased CKII function in vivo results in decreased levels of histone H2B lysine 123 monoubiquitylation, a modification dependent on FACT and PAF-C. Taken together, our results define a coordinated role of CKII and FACT in the regulation of RNA polymerase II transcription through chromatin via phosphorylation of PAF-C.
Collapse
Affiliation(s)
- Lynn Glowczewski Bedard
- From the Department of Biology, DePauw University, Greencastle, Indiana 46135, the Department of Biochemistry and Molecular Biology and
| | | | - Jenny L Kerschner
- the Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, and
| | | | | | - Asha K Boyd
- From the Department of Biology, DePauw University, Greencastle, Indiana 46135, the Department of Biochemistry and Molecular Biology and
| | - Brian D Strahl
- the Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, and Curriculum in Genetics and Molecular Biology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599
| | - Amber L Mosley
- the Department of Biochemistry and Molecular Biology and Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202, and
| |
Collapse
|
27
|
Garrido-Godino AI, García-López MC, García-Martínez J, Pelechano V, Medina DA, Pérez-Ortín JE, Navarro F. Rpb1 foot mutations demonstrate a major role of Rpb4 in mRNA stability during stress situations in yeast. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:731-43. [PMID: 27001033 DOI: 10.1016/j.bbagrm.2016.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 01/22/2023]
Abstract
The RPB1 mutants in the foot region of RNA polymerase II affect the assembly of the complex by altering the correct association of both the Rpb6 and the Rpb4/7 dimer. Assembly defects alter both transcriptional activity as well as the amount of enzyme associated with genes. Here, we show that the global transcriptional analysis of foot mutants reveals the activation of an environmental stress response (ESR), which occurs at a permissive temperature under optimal growth conditions. Our data indicate that the ESR that occurs in foot mutants depends mostly on a global post-transcriptional regulation mechanism which, in turn, depends on Rpb4-mRNA imprinting. Under optimal growth conditions, we propose that Rpb4 serves as a key to globally modulate mRNA stability as well as to coordinate transcription and decay. Overall, our results imply that post-transcriptional regulation plays a major role in controlling the ESR at both the transcription and mRNA decay levels.
Collapse
Affiliation(s)
- A I Garrido-Godino
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071 Jaén, Spain
| | - M C García-López
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071 Jaén, Spain
| | - J García-Martínez
- Departamento de Genética, Facultad de Biológicas, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain; ERI Biotecmed, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain
| | - V Pelechano
- European Molecular Biology Laboratories (EMBL), Genome Biology Unit, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - D A Medina
- ERI Biotecmed, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain; Departamento de Bioquímica y Biología Molecular, Facultad de Biológicas, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain
| | - J E Pérez-Ortín
- ERI Biotecmed, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain; Departamento de Bioquímica y Biología Molecular, Facultad de Biológicas, Universitat de València, Dr Moliner 50, E-46100 Burjassot, Valencia, Spain.
| | - F Navarro
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Paraje de las Lagunillas, s/n, 23071 Jaén, Spain.
| |
Collapse
|
28
|
Simon JM, Parker JS, Liu F, Rothbart SB, Ait-Si-Ali S, Strahl BD, Jin J, Davis IJ, Mosley AL, Pattenden SG. A Role for Widely Interspaced Zinc Finger (WIZ) in Retention of the G9a Methyltransferase on Chromatin. J Biol Chem 2015; 290:26088-102. [PMID: 26338712 PMCID: PMC4646261 DOI: 10.1074/jbc.m115.654459] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 08/23/2015] [Indexed: 11/06/2022] Open
Abstract
G9a and GLP lysine methyltransferases form a heterodimeric complex that is responsible for the majority of histone H3 lysine 9 mono- and di-methylation (H3K9me1/me2). Widely interspaced zinc finger (WIZ) associates with the G9a-GLP protein complex, but its role in mediating lysine methylation is poorly defined. Here, we show that WIZ regulates global H3K9me2 levels by facilitating the interaction of G9a with chromatin. Disrupting the association of G9a-GLP with chromatin by depleting WIZ resulted in altered gene expression and protein-protein interactions that were distinguishable from that of small molecule-based inhibition of G9a/GLP, supporting discrete functions of the G9a-GLP-WIZ chromatin complex in addition to H3K9me2 methylation.
Collapse
Affiliation(s)
- Jeremy M Simon
- From the Carolina Institute for Developmental Disabilities, Department of Cell Biology and Physiology, and the Department of Genetics, Curriculum in Bioinformatics and Computational Biology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Joel S Parker
- the Department of Genetics and the Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Feng Liu
- the Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599
| | - Scott B Rothbart
- the Center for Epigenetics, Van Andel Research Institute, Grand Rapids, Michigan 49503
| | - Slimane Ait-Si-Ali
- the Laboratoire Epigénétique et Destin Cellulaire, UMR7216, CNRS, Université Paris Diderot, Sorbonne Paris Cité, 75013 Paris, France
| | - Brian D Strahl
- the Lineberger Comprehensive Cancer Center, the Curriculum in Genetics and Molecular Biology, and the Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Jian Jin
- the Department of Structural and Chemical Biology, the Department of Oncological Sciences, and the Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Ian J Davis
- the Department of Genetics, the Lineberger Comprehensive Cancer Center, the Department of Pediatrics, and the Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, and
| | - Amber L Mosley
- the Department of Biochemistry and Molecular Biology and the Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Samantha G Pattenden
- the Center for Integrative Chemical Biology and Drug Discovery, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599,
| |
Collapse
|
29
|
Smith-Kinnaman WR, Berna MJ, Hunter GO, True JD, Hsu P, Cabello GI, Fox MJ, Varani G, Mosley AL. The interactome of the atypical phosphatase Rtr1 in Saccharomyces cerevisiae. MOLECULAR BIOSYSTEMS 2015; 10:1730-41. [PMID: 24671508 DOI: 10.1039/c4mb00109e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The phosphatase Rtr1 has been implicated in dephosphorylation of the RNA Polymerase II (RNAPII) C-terminal domain (CTD) during transcription elongation and in regulation of nuclear import of RNAPII. Although it has been shown that Rtr1 interacts with RNAPII in yeast and humans, the specific mechanisms that underlie Rtr1 recruitment to RNAPII have not been elucidated. To address this, we have performed an in-depth proteomic analysis of Rtr1 interacting proteins in yeast. Our studies revealed that hyperphosphorylated RNAPII is the primary interacting partner for Rtr1. To extend these findings, we performed quantitative proteomic analyses of Rtr1 interactions in yeast strains deleted for CTK1, the gene encoding the catalytic subunit of the CTD kinase I (CTDK-I) complex. Interestingly, we found that the interaction between Rtr1 and RNAPII is decreased in ctk1Δ strains. We hypothesize that serine-2 CTD phosphorylation is required for Rtr1 recruitment to RNAPII during transcription elongation.
Collapse
Affiliation(s)
- Whitney R Smith-Kinnaman
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Allepuz-Fuster P, Martínez-Fernández V, Garrido-Godino AI, Alonso-Aguado S, Hanes SD, Navarro F, Calvo O. Rpb4/7 facilitates RNA polymerase II CTD dephosphorylation. Nucleic Acids Res 2014; 42:13674-88. [PMID: 25416796 PMCID: PMC4267648 DOI: 10.1093/nar/gku1227] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/04/2014] [Accepted: 11/10/2014] [Indexed: 12/11/2022] Open
Abstract
The Rpb4 and Rpb7 subunits of eukaryotic RNA polymerase II (RNAPII) participate in a variety of processes from transcription, DNA repair, mRNA export and decay, to translation regulation and stress response. However, their mechanism(s) of action remains unclear. Here, we show that the Rpb4/7 heterodimer in Saccharomyces cerevisiae plays a key role in controlling phosphorylation of the carboxy terminal domain (CTD) of the Rpb1 subunit of RNAPII. Proper phosphorylation of the CTD is critical for the synthesis and processing of RNAPII transcripts. Deletion of RPB4, and mutations that disrupt the integrity of Rpb4/7 or its recruitment to the RNAPII complex, increased phosphorylation of Ser2, Ser5, Ser7 and Thr4 within the CTD. RPB4 interacted genetically with genes encoding CTD phosphatases (SSU72, FCP1), CTD kinases (KIN28, CTK1, SRB10) and a prolyl isomerase that targets the CTD (ESS1). We show that Rpb4 is important for Ssu72 and Fcp1 phosphatases association, recruitment and/or accessibility to the CTD, and that this correlates strongly with Ser5P and Ser2P levels, respectively. Our data also suggest that Fcp1 is the Thr4P phosphatase in yeast. Based on these and other results, we suggest a model in which Rpb4/7 helps recruit and potentially stimulate the activity of CTD-modifying enzymes, a role that is central to RNAPII function.
Collapse
Affiliation(s)
- Paula Allepuz-Fuster
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, Salamanca 37007, Spain
| | - Verónica Martínez-Fernández
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén 23071, Spain
| | - Ana I. Garrido-Godino
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén 23071, Spain
| | - Sergio Alonso-Aguado
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, Salamanca 37007, Spain
| | - Steven D. Hanes
- Department of Biochemistry and Molecular Biology, Upstate Medical University, Syracuse, NY 13210, USA
| | - Francisco Navarro
- Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén 23071, Spain
| | - Olga Calvo
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, Salamanca 37007, Spain
| |
Collapse
|
31
|
Viktorovskaya OV, Schneider DA. Functional divergence of eukaryotic RNA polymerases: unique properties of RNA polymerase I suit its cellular role. Gene 2014; 556:19-26. [PMID: 25445273 DOI: 10.1016/j.gene.2014.10.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/16/2014] [Accepted: 10/17/2014] [Indexed: 02/08/2023]
Abstract
Eukaryotic cells express at least three unique nuclear RNA polymerases. The selective advantage provided by this enhanced complexity is a topic of fundamental interest in cell biology. It has long been known that the gene targets and transcription initiation pathways for RNA polymerases (Pols) I, II and III are distinct; however, recent genetic, biochemical and structural data suggest that even the core enzymes have evolved unique properties. Among the three eukaryotic RNA polymerases, Pol I is considered the most divergent. Transcription of the ribosomal DNA by Pol I is unmatched in its high rate of initiation, complex organization within the nucleolus and functional connection to ribosome assembly. Furthermore, ribosome synthesis is intimately linked to cell growth and proliferation. Thus, there is intense selective pressure on Pol I. This review describes key features of Pol I transcription, discusses catalytic activities of the enzyme and focuses on recent advances in understanding its unique role among eukaryotic RNA polymerases.
Collapse
Affiliation(s)
- Olga V Viktorovskaya
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, United States
| | - David A Schneider
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, United States.
| |
Collapse
|
32
|
Abstract
What has been will be again, what has been done will be done again; there is nothing new under the sun. -Ecclesiastes 1:9 (New International Version) Posttranscriptional regulation of gene expression has an important role in defining the phenotypic characteristics of an organism. Well-defined steps in mRNA metabolism that occur in the nucleus-capping, splicing, and polyadenylation-are mechanistically linked to the process of transcription. Recent evidence suggests another link between RNA polymerase II (Pol II) and a posttranscriptional process that occurs in the cytoplasm-mRNA decay. This conclusion appears to represent a conundrum. How could mRNA synthesis in the nucleus and mRNA decay in the cytoplasm be mechanistically linked? After a brief overview of mRNA processing, we will review the recent evidence for transcription-coupled mRNA decay and the possible involvement of Snf1, the Saccharomyces cerevisiae ortholog of AMP-activated protein kinase, in this process.
Collapse
|
33
|
Hsu PL, Yang F, Smith-Kinnaman W, Yang W, Song JE, Mosley AL, Varani G. Rtr1 is a dual specificity phosphatase that dephosphorylates Tyr1 and Ser5 on the RNA polymerase II CTD. J Mol Biol 2014; 426:2970-81. [PMID: 24951832 PMCID: PMC4119023 DOI: 10.1016/j.jmb.2014.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 01/07/2023]
Abstract
The phosphorylation state of heptapeptide repeats within the C-terminal domain (CTD) of the largest subunit of RNA polymerase II (PolII) controls the transcription cycle and is maintained by the competing action of kinases and phosphatases. Rtr1 was recently proposed to be the enzyme responsible for the transition of PolII into the elongation and termination phases of transcription by removing the phosphate marker on serine 5, but this attribution was questioned by the apparent lack of enzymatic activity. Here we demonstrate that Rtr1 is a phosphatase of new structure that is auto-inhibited by its own C-terminus. The enzymatic activity of the protein in vitro is functionally important in vivo as well: a single amino acid mutation that reduces activity leads to the same phenotype in vivo as deletion of the protein-coding gene from yeast. Surprisingly, Rtr1 dephosphorylates not only serine 5 on the CTD but also the newly described anti-termination tyrosine 1 marker, supporting the hypothesis that Rtr1 and its homologs promote the transition from transcription to termination.
Collapse
Affiliation(s)
- Peter L. Hsu
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Fan Yang
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Whitney Smith-Kinnaman
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Wen Yang
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Jae-Eun Song
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Amber L. Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington, USA,Corresponding author. , telephone (206) 543-7113
| |
Collapse
|
34
|
Deshpande SM, Sadhale PP, Vijayraghavan U. Involvement of S. cerevisiae Rpb4 in subset of pathways related to transcription elongation. Gene 2014; 545:126-31. [DOI: 10.1016/j.gene.2014.04.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 04/10/2014] [Accepted: 04/25/2014] [Indexed: 11/28/2022]
|
35
|
Schulz D, Pirkl N, Lehmann E, Cramer P. Rpb4 subunit functions mainly in mRNA synthesis by RNA polymerase II. J Biol Chem 2014; 289:17446-52. [PMID: 24802753 DOI: 10.1074/jbc.m114.568014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
RNA polymerase II (Pol II) is the central enzyme that carries out eukaryotic mRNA transcription and consists of a 10-subunit catalytic core and a subcomplex of subunits Rpb4 and Rpb7 (Rpb4/7). Rpb4/7 has been proposed to dissociate from Pol II, enter the cytoplasm, and function there in mRNA translation and degradation. Here we provide evidence that Rpb4 mainly functions in nuclear mRNA synthesis by Pol II, as well as evidence arguing against an important cytoplasmic role in mRNA degradation. We used metabolic RNA labeling and comparative Dynamic Transcriptome Analysis to show that Rpb4 deletion in Saccharomyces cerevisiae causes a drastic defect in mRNA synthesis that is compensated by down-regulation of mRNA degradation, resulting in mRNA level buffering. Deletion of Rpb4 can be rescued by covalent fusion of Rpb4 to the Pol II core subunit Rpb2, which largely restores mRNA synthesis and degradation defects caused by Rpb4 deletion. Thus, Rpb4 is a bona fide Pol II core subunit that functions mainly in mRNA synthesis.
Collapse
Affiliation(s)
- Daniel Schulz
- From the Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich and
| | - Nicole Pirkl
- From the Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich and
| | - Elisabeth Lehmann
- From the Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich and
| | - Patrick Cramer
- From the Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich and the Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| |
Collapse
|
36
|
The RNA polymerase II Rpb4/7 subcomplex regulates cellular lifespan through an mRNA decay process. Biochem Biophys Res Commun 2013. [DOI: 10.1016/j.bbrc.2013.10.079] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
37
|
Fernández-Tornero C, Moreno-Morcillo M, Rashid UJ, Taylor NMI, Ruiz FM, Gruene T, Legrand P, Steuerwald U, Müller CW. Crystal structure of the 14-subunit RNA polymerase I. Nature 2013; 502:644-9. [PMID: 24153184 DOI: 10.1038/nature12636] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 09/04/2013] [Indexed: 01/21/2023]
Abstract
Protein biosynthesis depends on the availability of ribosomes, which in turn relies on ribosomal RNA production. In eukaryotes, this process is carried out by RNA polymerase I (Pol I), a 14-subunit enzyme, the activity of which is a major determinant of cell growth. Here we present the crystal structure of Pol I from Saccharomyces cerevisiae at 3.0 Å resolution. The Pol I structure shows a compact core with a wide DNA-binding cleft and a tightly anchored stalk. An extended loop mimics the DNA backbone in the cleft and may be involved in regulating Pol I transcription. Subunit A12.2 extends from the A190 jaw to the active site and inserts a transcription elongation factor TFIIS-like zinc ribbon into the nucleotide triphosphate entry pore, providing insight into the role of A12.2 in RNA cleavage and Pol I insensitivity to α-amanitin. The A49-A34.5 heterodimer embraces subunit A135 through extended arms, thereby contacting and potentially regulating subunit A12.2.
Collapse
Affiliation(s)
- Carlos Fernández-Tornero
- 1] Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain [2]
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Nayak D, Voss M, Windgassen T, Mooney RA, Landick R. Cys-pair reporters detect a constrained trigger loop in a paused RNA polymerase. Mol Cell 2013; 50:882-93. [PMID: 23769674 DOI: 10.1016/j.molcel.2013.05.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/10/2013] [Accepted: 05/07/2013] [Indexed: 01/22/2023]
Abstract
Transcriptional pausing, which regulates transcript elongation in both prokaryotes and eukaryotes, is thought to involve formation of alternative RNA polymerase conformations in which nucleotide addition is inhibited in part by restriction of trigger loop (TL) folding. The polymorphous TL must convert from a random coil to a helical hairpin that contacts the nucleotide triphosphate (NTP) substrate to allow rapid nucleotide addition. Understanding the distribution of TL conformations in different enzyme states is made difficult by the TL's small size and sensitive energetics. Here, we report a Cys-pair reporter strategy to elucidate the relative occupancies of different TL conformations in E. coli RNA polymerase based on the ability of Cys residues engineered into the TL and surrounding regions to form disulfide bonds. Our results indicate that a paused complex stabilized by a nascent RNA hairpin favors nonproductive TL conformations that persist after NTP binding but can be reversed by the elongation factor RfaH.
Collapse
Affiliation(s)
- Dhananjaya Nayak
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | | | | | | |
Collapse
|