1
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Cuellar P, Castañeda-Ortiz EJ, Rosales-Zarza C, Martínez-Rodríguez CE, Canela-Pérez I, Rodríguez MA, Valdés J, Azuara-Liceaga E. Genome-Wide Classification of Myb Domain-Containing Protein Families in Entamoeba invadens. Genes (Basel) 2024; 15:201. [PMID: 38397191 PMCID: PMC10887745 DOI: 10.3390/genes15020201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Entamoeba histolytica, the causative agent of amebiasis, is the third leading cause of death among parasitic diseases globally. Its life cycle includes encystation, which has been mostly studied in Entamoeba invadens, responsible for reptilian amebiasis. However, the molecular mechanisms underlying this process are not fully understood. Therefore, we focused on the identification and characterization of Myb proteins, which regulate the expression of encystation-related genes in various protozoan parasites. Through bioinformatic analysis, we identified 48 genes in E. invadens encoding MYB-domain-containing proteins. These were classified into single-repeat 1R (20), 2R-MYB proteins (27), and one 4R-MYB protein. The in-silico analysis suggests that these proteins are multifunctional, participating in transcriptional regulation, chromatin remodeling, telomere maintenance, and splicing. Transcriptomic data analysis revealed expression signatures of eimyb genes, suggesting a potential orchestration in the regulation of early and late encystation-excystation genes. Furthermore, we identified probable target genes associated with reproduction, the meiotic cell cycle, ubiquitin-dependent protein catabolism, and endosomal transport. In conclusion, our findings suggest that E. invadens Myb proteins regulate stage-specific proteins and a wide array of cellular processes. This study provides a foundation for further exploration of the molecular mechanisms governing encystation and unveils potential targets for therapeutic intervention in amebiasis.
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Affiliation(s)
- Patricia Cuellar
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, Mexico City C.P. 03100, Mexico; (P.C.); (E.J.C.-O.)
| | - Elizabeth J. Castañeda-Ortiz
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, Mexico City C.P. 03100, Mexico; (P.C.); (E.J.C.-O.)
| | - César Rosales-Zarza
- Licenciatura Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, Mexico City C.P. 03100, Mexico;
| | | | - Israel Canela-Pérez
- Departamento de Bioquímica, CINVESTAV-IPN, Mexico City C.P. 07360, Mexico; (I.C.-P.); (J.V.)
| | - Mario Alberto Rodríguez
- Departamento de Infectómica y Patogénesis Molecular, CINVESTAV-IPN, Mexico City C.P. 07360, Mexico;
| | - Jesús Valdés
- Departamento de Bioquímica, CINVESTAV-IPN, Mexico City C.P. 07360, Mexico; (I.C.-P.); (J.V.)
| | - Elisa Azuara-Liceaga
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, Mexico City C.P. 03100, Mexico; (P.C.); (E.J.C.-O.)
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2
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Hou H, Jin Q, Ren Y, Chen Z, Wang Q, Xu Y. Structure of the SNAPc-bound RNA polymerase III preinitiation complex. Cell Res 2023; 33:565-568. [PMID: 37165065 PMCID: PMC10313668 DOI: 10.1038/s41422-023-00819-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 04/23/2023] [Indexed: 05/12/2023] Open
Affiliation(s)
- Haifeng Hou
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China
| | - Qianwei Jin
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China
| | - Yulei Ren
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China
| | - Zhenguo Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China
| | - Qianmin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China.
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai, China.
- The International Co-Laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai, China.
- Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China.
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3
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Genome-Scale Identification, Classification, and Expression Profiling of MYB Transcription Factor Genes in Cinnamomum camphora. Int J Mol Sci 2022; 23:ijms232214279. [PMID: 36430756 PMCID: PMC9693371 DOI: 10.3390/ijms232214279] [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: 10/20/2022] [Revised: 11/10/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
The camphor tree (Cinnamomum camphora (L.) Presl.) is the representative species of subtropical evergreen broadleaved forests in eastern Asia and an important raw material for essential oil production worldwide. Although MYBs have been comprehensively characterized and their functions have been partially resolved in many plants, it has not been explored in C. camphora. In this study, 121 CcMYBs were identified on 12 chromosomes in the whole genome of C. camphora and found that CcMYBs were mainly expanded by segmental duplication. They were divided into 28 subgroups based on phylogenetic analysis and gene structural characteristics. In the promoter regions, numerous cis-acting elements were related to biological processes. Analysis of RNA sequencing data from seven tissues showed that CcMYBs exhibited different expression profiles, suggesting that they have various roles in camphor tree development. In addition, combined with the correlation analysis of structural genes in the flavonoid synthesis pathway, we identified CcMYBs from three subgroups that might be related to the flavonoid biosynthesis pathway. This study systematically analyzed CcMYBs in C. camphora, which will set the stage for subsequent research on the functions of CcMYBs during their lifetime and provide valuable insights for the genetic improvement of camphor trees.
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Sun J, Li X, Hou X, Cao S, Cao W, Zhang Y, Song J, Wang M, Wang H, Yan X, Li Z, Roeder RG, Wang W. Structural basis of human SNAPc recognizing proximal sequence element of snRNA promoter. Nat Commun 2022; 13:6871. [PMID: 36369505 PMCID: PMC9652321 DOI: 10.1038/s41467-022-34639-1] [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: 05/27/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022] Open
Abstract
In eukaryotes, small nuclear RNAs (snRNAs) function in many fundamental cellular events such as precursor messenger RNA splicing, gene expression regulation, and ribosomal RNA processing. The snRNA activating protein complex (SNAPc) exclusively recognizes the proximal sequence element (PSE) at snRNA promoters and recruits RNA polymerase II or III to initiate transcription. In view that homozygous gene-knockout of SNAPc core subunits causes mouse embryonic lethality, functions of SNAPc are almost housekeeping. But so far, the structural insight into how SNAPc assembles and regulates snRNA transcription initiation remains unclear. Here we present the cryo-electron microscopy structure of the essential part of human SNAPc in complex with human U6-1 PSE at an overall resolution of 3.49 Å. This structure reveals the three-dimensional features of three conserved subunits (N-terminal domain of SNAP190, SNAP50, and SNAP43) and explains how they are assembled into a stable mini-SNAPc in PSE-binding state with a "wrap-around" mode. We identify three important motifs of SNAP50 that are involved in both major groove and minor groove recognition of PSE, in coordination with the Myb domain of SNAP190. Our findings further elaborate human PSE sequence conservation and compatibility for SNAPc recognition, providing a clear framework of snRNA transcription initiation, especially the U6 system.
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Affiliation(s)
- Jianfeng Sun
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China ,grid.27255.370000 0004 1761 1174Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China ,grid.134907.80000 0001 2166 1519Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, 10065 USA
| | - Xue Li
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Xuben Hou
- grid.27255.370000 0004 1761 1174School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Sujian Cao
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Wenjin Cao
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Ye Zhang
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Jinyang Song
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Manfu Wang
- grid.512077.6Wuxi Biortus Biosciences Co. Ltd., Jiangyin, 214437 China
| | - Hao Wang
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China
| | - Xiaodong Yan
- grid.512077.6Wuxi Biortus Biosciences Co. Ltd., Jiangyin, 214437 China
| | - Zengpeng Li
- grid.453137.70000 0004 0406 0561Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
| | - Robert G. Roeder
- grid.134907.80000 0001 2166 1519Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, 10065 USA
| | - Wei Wang
- grid.27255.370000 0004 1761 1174Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012 China ,grid.27255.370000 0004 1761 1174Interventional Medicine Department, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250033 China
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Genome-wide identification of R2R3-MYB gene family and association with anthocyanin biosynthesis in Brassica species. BMC Genomics 2022; 23:441. [PMID: 35701743 PMCID: PMC9199147 DOI: 10.1186/s12864-022-08666-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 06/01/2022] [Indexed: 11/22/2022] Open
Abstract
Brassica species include important oil crops and vegetables in the world. The R2R3-MYB gene participates in a variety of plant functions, including the activation or inhibition of anthocyanin biosynthesis. Although previous studies have reported its phylogenetic relationships, gene structures, and expression patterns in Arabidopsis, the number and sequence variation of this gene family in Brassica crops and its involvement in the natural quantitative variation in anthocyanin biosynthesis regulation are still largely unknown. In this study, by using whole genome sequences and comprehensive genome-wide comparative analysis among the six cultivated Brassica species, 2120 R2R3-MYB genes were identified in six Brassica species, in total These R2R3-MYB genes were phylogenetically clustered into 12 groups. The R2R3-MYB family between A and C subgenomes showed better collinearity than between B and C and between A and B. From comparing transcriptional changes of five Brassica species with the purple and green leaves for the detection of the R2R3-MYB genes associated with anthocyanin biosynthesis, 7 R2R3-MYB genes were co-differentially expressed. The promoter and structure analysis of these genes showed that some variations between non-coding region, but they were highly conserved at the protein level and spatial structure. Co-expression analysis of anthocyanin-related genes and R2R3-MYBs indicated that MYB90 was strongly co-expressed with TT8, and they were co-expressed with structural genes F3H, LDOX, ANS and UF3GT at the same time. These results further clarified the roles of the R2R3-MYBs for leaf coloration in Brasica species, which provided new insights into the functions of the R2R3-MYB gene family in Brasica species.
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6
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Hou X, Zhu C, Xu M, Chen X, Sun C, Nashan B, Guang S, Feng X. The SNAPc complex mediates starvation-induced trans-splicing in Caenorhabditis elegans. J Genet Genomics 2022; 49:952-964. [DOI: 10.1016/j.jgg.2022.02.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 02/20/2022] [Accepted: 02/22/2022] [Indexed: 11/16/2022]
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7
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Yoshino Y, Roy B, Dwivedi Y. Corticosterone-mediated regulation and functions of miR-218-5p in rat brain. Sci Rep 2022; 12:194. [PMID: 34996981 PMCID: PMC8742130 DOI: 10.1038/s41598-021-03863-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/02/2021] [Indexed: 12/20/2022] Open
Abstract
Chronic stress is one of the key precipitating factors in major depressive disorder (MDD). Stress associated studies have underscored the mechanistic role of epigenetic master players like microRNAs (miRNAs) in depression pathophysiology at both preclinical and clinical levels. Previously, we had reported changes in miR-218-5p expression in response to corticosterone (CORT) induced chronic stress. MiR-218-5p was one of the most significantly induced miRNAs in the prefrontal cortex (PFC) of rats under chronic stress. In the present report, we have investigated how chronic CORT exposure mechanistically affected miR-218-5p expression in the rat brain and how miR-218 could trigger molecular changes on its downstream regulatory pathways. Elevated expression of miR-218-5p was found in the PFC of CORT-treated rats. A glucocorticoid receptor (GR) targeted Chromatin-Immunoprecipitation (ChIP) assay revealed high GR occupancy on the promoter region of Slit3 gene hosting miR-218-2 in its 3rd intron. RNA-sequencing data based on RNA Induced silencing Complex Immunoprecipitation (RISC-IP) with AGO2 in SH-SY5Y cells detected six consistent target genes of miR-218-5p (APOL4, DTWD1, BNIP1, METTL22, SNAPC1, and HDAC6). The expression of all five genes, except APOL4, was successfully validated with qPCR in CORT-treated rat PFC. Further, Hdac6-based ChIP-seq experiment helped in mapping major genomic loci enriched for intergenic regions in the PFC of CORT-treated rat. A proximity-based gene ontology (GO) analysis revealed a majority of the intergenic sites to be part of key genes implicated in central nervous system functions, notably synapse organization, neuron projection morphogenesis, and axonogenesis. Our results suggest that the upregulation of miR-218-5p in PFC of CORT-treated rats possibly resulted from GR biding in the promoter region of Slit3 gene. Interestingly, Hdac6 was one of the consistent target genes potentially found to regulate CNS related genes by chromatin modification. Collectively, these findings establish the role of miR-218-5p in chronic stress and the epigenetic function it plays to induce chromatin-based transcriptional changes of several CNS genes in triggering stress-induced disorders, including depression. This also opens up the scope to understand the role of miR-218-5p as a potential target for noncoding RNA therapeutics in clinical depression.
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Affiliation(s)
- Yuta Yoshino
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Bhaskar Roy
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Yogesh Dwivedi
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
- UAB Mood Disorder Program, Division of Behavioral Neurobiology, Department of Psychiatry and Behavioral Neurobiology, UAB Depression and Suicide Center, University of Alabama at Birmingham, SC711 Sparks Center, 1720 7th Avenue South, Birmingham, AL, USA.
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8
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Structural basis of SNAPc-dependent snRNA transcription initiation by RNA polymerase II. Nat Struct Mol Biol 2022; 29:1159-1169. [PMID: 36424526 PMCID: PMC9758055 DOI: 10.1038/s41594-022-00857-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 09/29/2022] [Indexed: 11/27/2022]
Abstract
RNA polymerase II (Pol II) carries out transcription of both protein-coding and non-coding genes. Whereas Pol II initiation at protein-coding genes has been studied in detail, Pol II initiation at non-coding genes, such as small nuclear RNA (snRNA) genes, is less well understood at the structural level. Here, we study Pol II initiation at snRNA gene promoters and show that the snRNA-activating protein complex (SNAPc) enables DNA opening and transcription initiation independent of TFIIE and TFIIH in vitro. We then resolve cryo-EM structures of the SNAPc-containing Pol IIpre-initiation complex (PIC) assembled on U1 and U5 snRNA promoters. The core of SNAPc binds two turns of DNA and recognizes the snRNA promoter-specific proximal sequence element (PSE), located upstream of the TATA box-binding protein TBP. Two extensions of SNAPc, called wing-1 and wing-2, bind TFIIA and TFIIB, respectively, explaining how SNAPc directs Pol II to snRNA promoters. Comparison of structures of closed and open promoter complexes elucidates TFIIH-independent DNA opening. These results provide the structural basis of Pol II initiation at non-coding RNA gene promoters.
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9
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Thiedig K, Weisshaar B, Stracke R. Functional and evolutionary analysis of the Arabidopsis 4R-MYB protein SNAPc4 as part of the SNAP complex. PLANT PHYSIOLOGY 2021; 185:1002-1020. [PMID: 33693812 PMCID: PMC8133616 DOI: 10.1093/plphys/kiaa067] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 11/15/2020] [Indexed: 06/12/2023]
Abstract
Transcription initiation of the genes coding for small nuclear RNA (snRNA) has been extensively analyzed in humans and fruit fly, but only a single ortholog of a snRNA-activating protein complex (SNAPc) subunit has so far been characterized in plants. The genome of the model plant Arabidopsis thaliana encodes orthologs of all three core SNAPc subunits, including A. thaliana SNAP complex 4 (AtSNAPc4)-a 4R-MYB-type protein with four-and-a-half adjacent MYB repeat units. We report the conserved role of AtSNAPc4 as subunit of a protein complex involved in snRNA gene transcription and present genetic evidence that AtSNAPc4 is an essential gene in gametophyte and zygote development. We present experimental evidence that the three A. thaliana SNAPc subunits assemble into a SNAP complex and demonstrate the binding of AtSNAPc4 to snRNA promoters. In addition, co-localization studies show a link between AtSNAPc4 accumulation and Cajal bodies, known to aggregate at snRNA gene loci in humans. Moreover, we show the strong evolutionary conservation of single-copy 4R-MYB/SNAPc4 genes in a broad range of eukaryotes and present additional shared protein features besides the MYB domain, suggesting a conservation of the snRNA transcription initiation machinery along the course of the eukaryotic evolution.
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Affiliation(s)
- Katharina Thiedig
- Faculty of Biology, Genetics and Genomics of Plants, Bielefeld University, Sequenz 1, Bielefeld 33615, Germany
| | - Bernd Weisshaar
- Faculty of Biology, Genetics and Genomics of Plants, Bielefeld University, Sequenz 1, Bielefeld 33615, Germany
| | - Ralf Stracke
- Faculty of Biology, Genetics and Genomics of Plants, Bielefeld University, Sequenz 1, Bielefeld 33615, Germany
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10
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Choi CP, Tay RJ, Starostik MR, Feng S, Moresco JJ, Montgomery BE, Xu E, Hammonds MA, Schatz MC, Montgomery TA, Yates JR, Jacobsen SE, Kim JK. SNPC-1.3 is a sex-specific transcription factor that drives male piRNA expression in C. elegans. eLife 2021; 10:e60681. [PMID: 33587037 PMCID: PMC7884074 DOI: 10.7554/elife.60681] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 02/02/2021] [Indexed: 12/29/2022] Open
Abstract
Piwi-interacting RNAs (piRNAs) play essential roles in silencing repetitive elements to promote fertility in metazoans. Studies in worms, flies, and mammals reveal that piRNAs are expressed in a sex-specific manner. However, the mechanisms underlying this sex-specific regulation are unknown. Here we identify SNPC-1.3, a male germline-enriched variant of a conserved subunit of the small nuclear RNA-activating protein complex, as a male-specific piRNA transcription factor in Caenorhabditis elegans. SNPC-1.3 colocalizes with the core piRNA transcription factor, SNPC-4, in nuclear foci of the male germline. Binding of SNPC-1.3 at male piRNA loci drives spermatogenic piRNA transcription and requires SNPC-4. Loss of snpc-1.3 leads to depletion of male piRNAs and defects in male-dependent fertility. Furthermore, TRA-1, a master regulator of sex determination, binds to the snpc-1.3 promoter and represses its expression during oogenesis. Loss of TRA-1 targeting causes ectopic expression of snpc-1.3 and male piRNAs during oogenesis. Thus, sexually dimorphic regulation of snpc-1.3 expression coordinates male and female piRNA expression during germline development.
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Affiliation(s)
- Charlotte P Choi
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Rebecca J Tay
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | | | - Suhua Feng
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los AngelesLos AngelesUnited States
| | - James J Moresco
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical CenterDallasUnited States
| | | | - Emily Xu
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Maya A Hammonds
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Michael C Schatz
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
- Department of Computer Science, Johns Hopkins UniversityBaltimoreUnited States
| | | | - John R Yates
- Department of Molecular Medicine, The Scripps Research InstituteLa JollaUnited States
| | - Steven E Jacobsen
- Department of Molecular, Cell and Developmental Biology, University of California, Los AngelesLos AngelesUnited States
- Howard Hughes Medical Institute, University of California, Los AngelesLos AngelesUnited States
| | - John K Kim
- Department of Biology, Johns Hopkins UniversityBaltimoreUnited States
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11
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Zhang X, Wu S, Liu S, Takano T. The Arabidopsis sucrose non-fermenting-1-related protein kinase AtSnRK2.4 interacts with a transcription factor, AtMYB21, that is involved in salt tolerance. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 303:110685. [PMID: 33487368 DOI: 10.1016/j.plantsci.2020.110685] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 05/02/2023]
Abstract
Sucrose non-fermenting-1-related protein kinase 2 s (SnRK2 s) are important stress-related plant protein kinases in plants. The interaction partners and phosphorylation substrates of group II and III SnRK2 s in Arabidopsis thaliana have been identified, but similar data for group I SnRK2 s are very limited. Here, we used a yeast two-hybrid (Y2H) screen to find proteins that interact with Arabidopsis AtSnRK2.4, a group I SnRK2. The transcription factor AtMYB21 was identified as an AtSnRK2.4 interaction partner, and its interaction with AtSnRK2.4 was confirmed by an in vitro pull-down assay and a bimolecular fluorescence complementation (BiFC) assay. A subcellular localization assay demonstrated that AtSnRK2.4 and AtMYB21 were located in the cytoplasm and nucleus of onion epidermal cells. AtSnRK2.4 and AtMYB21 were expressed in many tissues and upregulated in response to NaCl stress. Transgenic plants that overexpressed AtSnRK2.4 or AtMYB21 gene exhibited enhanced tolerance to salt stress at germination and post-germination stages. Moreover, the expression of downstream stress-responsive genes was upregulated in salt-stressed AtSnRK2.4 and AtMYB21 transgenic Arabidopsis. These results suggest that AtSnRK2.4 may act synergistically with AtMYB21 to mediate the response to salt stress through the upregulation of downstream stress-responsive genes.
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Affiliation(s)
- Xinxin Zhang
- Institute of Fruit Tree Research, Guangdong Academy of Agricultural Sciences; Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization (MOA); Guangdong Province Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangzhou, 510640, China; Key Laboratory of Saline-Alkali Vegetation Ecology Restoration (SAVER), Ministry of Education; Alkali Soil Natural Environmental Science Center (ASNESC), Northeast Forestry University, Harbin 150040, China.
| | - Shan Wu
- Key Laboratory of Saline-Alkali Vegetation Ecology Restoration (SAVER), Ministry of Education; Alkali Soil Natural Environmental Science Center (ASNESC), Northeast Forestry University, Harbin 150040, China
| | - Shenkui Liu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Tetsuo Takano
- Asian Natural Environment Science Center (ANESC), The University of Tokyo, 1-1-1 Midori Cho, Nishitokyo-shi, Tokyo 188-0002, Japan
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12
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Millard PS, Kragelund BB, Burow M. R2R3 MYB Transcription Factors - Functions outside the DNA-Binding Domain. TRENDS IN PLANT SCIENCE 2019; 24:934-946. [PMID: 31358471 DOI: 10.1016/j.tplants.2019.07.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 07/02/2019] [Accepted: 07/05/2019] [Indexed: 05/20/2023]
Abstract
Several transcription factor (TF) families, including the MYB family, regulate a wide array of biological processes. TFs contain DNA-binding domains (DBDs) and regulatory regions; although information on protein structure is scarce for plant MYB TFs, various in silico methods suggest that the non-MYB regions contain extensive intrinsically disordered regions (IDRs). Although IDRs do not fold into stable globular structures, they comprise functional regions including interaction motifs, and recent research has shown that IDRs perform crucial biological roles. We map here domain organization, disorder predictions, and functional regions across the entire Arabidopsis thaliana R2R3 MYB TF family, and highlight where an increased research focus will be necessary to shape a new understanding of structure-function relationships in plant TFs.
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Affiliation(s)
- Peter S Millard
- DynaMo Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark; Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Meike Burow
- DynaMo Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark; Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark.
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13
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Ramsay EP, Vannini A. Structural rearrangements of the RNA polymerase III machinery during tRNA transcription initiation. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:285-294. [PMID: 29155071 DOI: 10.1016/j.bbagrm.2017.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 11/07/2017] [Accepted: 11/11/2017] [Indexed: 01/03/2023]
Abstract
RNA polymerase III catalyses the synthesis of tRNAs in eukaryotic organisms. Through combined biochemical and structural characterisation, multiple auxiliary factors have been identified alongside RNA Polymerase III as critical in both facilitating and regulating transcription. Together, this machinery forms dynamic multi-protein complexes at tRNA genes which are required for polymerase recruitment, DNA opening and initiation and elongation of the tRNA transcripts. Central to the function of these complexes is their ability to undergo multiple conformational changes and rearrangements that regulate each step. Here, we discuss the available biochemical and structural data on the structural plasticity of multi-protein complexes involved in RNA Polymerase III transcriptional initiation and facilitated re-initiation during tRNA synthesis. Increasingly, structural information is becoming available for RNA polymerase III and its functional complexes, allowing for a deeper understanding of tRNA transcriptional initiation. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
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MESH Headings
- Animals
- Eukaryotic Cells/metabolism
- Humans
- Models, Genetic
- Multiprotein Complexes/metabolism
- Promoter Regions, Genetic/genetics
- Protein Subunits
- RNA Polymerase III/chemistry
- RNA Polymerase III/metabolism
- RNA, Transfer/biosynthesis
- RNA, Transfer/genetics
- RNA, Transfer, Amino Acid-Specific/biosynthesis
- RNA, Transfer, Amino Acid-Specific/genetics
- Transcription Elongation, Genetic
- Transcription Factors/genetics
- Transcription Initiation, Genetic
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14
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Hwang SS, Kim LK, Lee GR, Flavell RA. Role of OCT-1 and partner proteins in T cell differentiation. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1859:825-31. [PMID: 27126747 DOI: 10.1016/j.bbagrm.2016.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 12/24/2022]
Abstract
The understanding of CD4 T cell differentiation gives important insights into the control of immune responses against various pathogens and in autoimmune diseases. Naïve CD4 T cells become effector T cells in response to antigen stimulation in combination with various environmental cytokine stimuli. Several transcription factors and cis-regulatory regions have been identified to regulate epigenetic processes on chromatin, to allow the production of proper effector cytokines during CD4 T cell differentiation. OCT-1 (Pou2f1) is well known as a widely expressed transcription factor in most tissues and cells. Although the importance of OCT-1 has been emphasized during development and differentiation, its detailed molecular underpinning and precise role are poorly understood. Recently, a series of studies have reported that OCT-1 plays a critical role in CD4 T cells through regulating gene expression during differentiation and mediating long-range chromosomal interactions. In this review, we will describe the role of OCT-1 in CD4 T cell differentiation and discuss how this factor orchestrates the fate and function of CD4 effector T cells.
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Affiliation(s)
- Soo Seok Hwang
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Lark Kyun Kim
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Severance Biomedical Science Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonjuro, Gangnam-gu, Seoul 135-720, South Korea
| | - Gap Ryol Lee
- Department of Life-Science, Sogang University, Baekbeom-ro, Seoul 121-742, South Korea
| | - Richard A Flavell
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA.
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15
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Dumay-Odelot H, Durrieu-Gaillard S, El Ayoubi L, Parrot C, Teichmann M. Contributions of in vitro transcription to the understanding of human RNA polymerase III transcription. Transcription 2015; 5:e27526. [PMID: 25764111 DOI: 10.4161/trns.27526] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human RNA polymerase III transcribes small untranslated RNAs that contribute to the regulation of essential cellular processes, including transcription, RNA processing and translation. Analysis of this transcription system by in vitro transcription techniques has largely contributed to the discovery of its transcription factors and to the understanding of the regulation of human RNA polymerase III transcription. Here we review some of the key steps that led to the identification of transcription factors and to the definition of minimal promoter sequences for human RNA polymerase III transcription.
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Affiliation(s)
- Hélène Dumay-Odelot
- a INSERM U869; University of Bordeaux; Institut Européen de Chimie et Biologie (IECB); 33607 Pessac, France
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16
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Kasper DM, Wang G, Gardner KE, Johnstone TG, Reinke V. The C. elegans SNAPc component SNPC-4 coats piRNA domains and is globally required for piRNA abundance. Dev Cell 2015; 31:145-58. [PMID: 25373775 DOI: 10.1016/j.devcel.2014.09.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 08/25/2014] [Accepted: 09/25/2014] [Indexed: 11/26/2022]
Abstract
The Piwi/Piwi-interacting RNA (piRNA) pathway protects the germline from the activity of foreign sequences such as transposons. Remarkably, tens of thousands of piRNAs arise from a minimal number of discrete genomic regions. The extent to which clustering of these small RNA genes contributes to their coordinated expression remains unclear. We show that C. elegans SNPC-4, the Myb-like DNA-binding subunit of the small nuclear RNA activating protein complex, binds piRNA clusters in a germline-specific manner and is required for global piRNA expression. SNPC-4 localization is mutually dependent with localization of piRNA biogenesis factor PRDE-1. SNPC-4 exhibits an atypical widely distributed binding pattern that "coats" piRNA domains. Discrete peaks within the domains occur frequently at RNA-polymerase-III-occupied transfer RNA (tRNA) genes, which have been implicated in chromatin organization. We suggest that SNPC-4 binding establishes a positive expression environment across piRNA domains, providing an explanation for the conserved clustering of individually transcribed piRNA genes.
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Affiliation(s)
- Dionna M Kasper
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Guilin Wang
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kathryn E Gardner
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Timothy G Johnstone
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Valerie Reinke
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA.
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17
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Kang YS, Kurano M, Stumph WE. The Myb domain of the largest subunit of SNAPc adopts different architectural configurations on U1 and U6 snRNA gene promoter sequences. Nucleic Acids Res 2014; 42:12440-54. [PMID: 25324315 PMCID: PMC4227766 DOI: 10.1093/nar/gku905] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The small nuclear RNA (snRNA) activating protein complex (SNAPc) is essential for transcription of genes that encode the snRNAs. Drosophila melanogaster SNAPc (DmSNAPc) consists of three subunits (DmSNAP190, DmSNAP50 and DmSNAP43) that form a stable complex that recognizes an snRNA gene promoter element called the PSEA. Although all three subunits are required for sequence-specific DNA binding activity, only DmSNAP190 possesses a canonical DNA binding domain consisting of 4.5 tandem Myb repeats homologous to the Myb repeats in the DNA binding domain of the Myb oncoprotein. In this study, we use site-specific protein–DNA photo-cross-linking technology followed by site-specific protein cleavage to map domains of DmSNAP190 that interact with specific phosphate positions in the U6 PSEA. The results indicate that at least two DmSNAP190 Myb repeats contact the DNA in a significantly different manner when DmSNAPc binds to a U6 PSEA versus a U1 PSEA, even though the two PSEA sequences differ at only 5 of 21 nucleotide positions. The results are consistent with a model in which the specific DNA sequences of the U1 and U6 PSEAs differentially alter the conformation of DmSNAPc, leading to the subsequent recruitment of different RNA polymerases to the U1 and U6 gene promoters.
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Affiliation(s)
- Yoon Soon Kang
- Department of Chemistry and Biochemistry, Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
| | - Michelle Kurano
- Department of Biology, Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
| | - William E Stumph
- Department of Chemistry and Biochemistry, Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
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18
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Ma X, Liu Y, Zhang H, Qiu R, Zhao H, Xin Q, Shan S, Dang J, Li J, Yang Z, Gong Y, Liu Q. Evidence for Genetic Association of CARD9 and SNAPC4 with Ankylosing Spondylitis in a Chinese Han Population. J Rheumatol 2013; 41:318-24. [DOI: 10.3899/jrheum.130519] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Objective.A genome-wide association study and 2 replication studies identified 2 single-nucleotide polymorphisms (SNP) of caspase recruitment domain-containing protein 9 (CARD9) and small nuclear RNA-activating complex polypeptide 4 (SNAPC4) at Chr 9q34.3 associated with ankylosing spondylitis (AS) in whites. We explored a possible association of SNP in CARD9 and SNAPC4 and AS in a Chinese Han population from Shandong.Methods.The study included 1150 patients with AS and 1120 healthy controls who underwent genotyping for 4 SNP of CARD9 and 2 of SNAPC4; we replicated the results in another 490 patients and 380 healthy controls of Ningxia Han Chinese during the same time. We used quantitative real-time PCR (qRT-PCR) to measure CARD9 and SNAPC4 mRNA expression in peripheral leukocytes from 44 patients and 36 controls and allele-specific mRNA expression of CARD9 and SNAPC4 in leukocytes from 130 controls.Results.We validated that an SNP in SNAPC4, rs11145835, was significantly associated with AS in our Chinese Han population (p = 0.001) and replicated the association in samples from the Chinese Ningxia Han population (p = 0.002). Carrying the G allele of rs11145835 was associated with increased risk of AS (OR 1.34, 95% CI 1.12–1.59) and with decreased expression of CARD9 (p = 0.001) and SNAPC4 (p = 0.02) in leukocytes. SNAPC4 mRNA expression was lower in leukocytes from patients than from controls (p = 0.0002).Conclusion.Our study confirmed that an SNP rs11145835 in 9q34.3 that harbors CARD9 and SNAPC4 is associated with AS in a Chinese Han population, and rs11145835 in SNAPC4 is a potential causal variant.
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19
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Gjidoda A, Henry RW. RNA polymerase III repression by the retinoblastoma tumor suppressor protein. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1829:385-92. [PMID: 23063750 PMCID: PMC3549324 DOI: 10.1016/j.bbagrm.2012.09.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 09/28/2012] [Accepted: 09/30/2012] [Indexed: 12/29/2022]
Abstract
The retinoblastoma (RB) tumor suppressor protein regulates multiple pathways that influence cell growth, and as a key regulatory node, its function is inactivated in most cancer cells. In addition to its canonical roles in cell cycle control, RB functions as a global repressor of RNA polymerase (Pol) III transcription. Indeed, Pol III transcripts accumulate in cancer cells and their heightened levels are implicated in accelerated growth associated with RB dysfunction. Herein we review the mechanisms of RB repression for the different types of Pol III genes. For type 1 and type 2 genes, RB represses transcription through direct contacts with the core transcription machinery, notably Brf1-TFIIIB, and inhibits preinitiation complex formation and Pol III recruitment. A contrasting model for type 3 gene repression indicates that RB regulation involves stable and simultaneous promoter association by RB, the general transcription machinery including SNAPc, and Pol III, suggesting that RB may impede Pol III promoter escape or elongation. Interestingly, analysis of published genomic association data for RB and Pol III revealed added regulatory complexity for Pol III genes both during active growth and during arrested growth associated with quiescence and senescence. This article is part of a Special Issue entitled: Transcription by Odd Pols.
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Affiliation(s)
- Alison Gjidoda
- Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824
| | - R. William Henry
- Department of Biochemistry & Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824
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20
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Doherty MT, Kang YS, Lee C, Stumph WE. Architectural arrangement of the small nuclear RNA (snRNA)-activating protein complex 190 subunit (SNAP190) on U1 snRNA gene promoter DNA. J Biol Chem 2012; 287:39369-79. [PMID: 23038247 PMCID: PMC3501025 DOI: 10.1074/jbc.m112.407775] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/01/2012] [Indexed: 11/06/2022] Open
Abstract
Myb repeats ∼52 amino acid residues in length were first characterized in the oncogenic Myb transcription factor, which contains three tandem Myb repeats in its DNA-binding domain. Proteins of this family normally contain either one, two, or three tandem Myb repeats that are involved in protein-DNA interactions. The small nuclear RNA (snRNA)-activating protein complex (SNAPc) is a heterotrimeric transcription factor that is required for expression of small nuclear RNA genes. This complex binds to an essential promoter element, the proximal sequence element, centered ∼50 base pairs upstream of the transcription start site of snRNA genes. SNAP190, the largest subunit of SNAPc, uncharacteristically contains 4.5 tandem Myb repeats. Little is known about the arrangement of the Myb repeats in the SNAPc-DNA complex, and it has not been clear whether all 4.5 Myb repeats contact the DNA. By using a site-specific protein-DNA photo-cross-linking assay, we have now mapped specific nucleotides where each of the Myb repeats of Drosophila melanogaster SNAP190 interacts with a U1 snRNA gene proximal sequence element. The results reveal the topological arrangement of the 4.5 SNAP190 Myb repeats relative to the DNA and to each other when SNAP190 is bound to a U1 promoter as a subunit of SNAPc.
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Affiliation(s)
| | - Yoon Soon Kang
- Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Cheryn Lee
- Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - William E. Stumph
- Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
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21
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Requirement for SNAPC1 in transcriptional responsiveness to diverse extracellular signals. Mol Cell Biol 2012; 32:4642-50. [PMID: 22966203 DOI: 10.1128/mcb.00906-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Initiation of transcription of RNA polymerase II (RNAPII)-dependent genes requires the participation of a host of basal transcription factors. Among genes requiring RNAPII for transcription, small nuclear RNAs (snRNAs) display a further requirement for a factor known as snRNA-activating protein complex (SNAPc). The scope of the biological function of SNAPc and its requirement for transcription of protein-coding genes has not been elucidated. To determine the genome-wide occupancy of SNAPc, we performed chromatin immunoprecipitation followed by high-throughput sequencing using antibodies against SNAPC4 and SNAPC1 subunits. Interestingly, while SNAPC4 occupancy was limited to snRNA genes, SNAPC1 chromatin residence extended beyond snRNA genes to include a large number of transcriptionally active protein-coding genes. Notably, SNAPC1 occupancy on highly active genes mirrored that of elongating RNAPII extending through the bodies and 3' ends of protein-coding genes. Inhibition of transcriptional elongation resulted in the loss of SNAPC1 from the 3' ends of genes, reflecting a functional association between SNAPC1 and elongating RNAPII. Importantly, while depletion of SNAPC1 had a small effect on basal transcription, it diminished the transcriptional responsiveness of a large number of genes to two distinct extracellular stimuli, epidermal growth factor (EGF) and retinoic acid (RA). These results highlight a role for SNAPC1 as a general transcriptional coactivator that functions through elongating RNAPII.
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22
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Voz ML, Coppieters W, Manfroid I, Baudhuin A, Von Berg V, Charlier C, Meyer D, Driever W, Martial JA, Peers B. Fast homozygosity mapping and identification of a zebrafish ENU-induced mutation by whole-genome sequencing. PLoS One 2012; 7:e34671. [PMID: 22496837 PMCID: PMC3319596 DOI: 10.1371/journal.pone.0034671] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 03/06/2012] [Indexed: 02/03/2023] Open
Abstract
Forward genetics using zebrafish is a powerful tool for studying vertebrate development through large-scale mutagenesis. Nonetheless, the identification of the molecular lesion is still laborious and involves time-consuming genetic mapping. Here, we show that high-throughput sequencing of the whole zebrafish genome can directly locate the interval carrying the causative mutation and at the same time pinpoint the molecular lesion. The feasibility of this approach was validated by sequencing the m1045 mutant line that displays a severe hypoplasia of the exocrine pancreas. We generated 13 Gb of sequence, equivalent to an eightfold genomic coverage, from a pool of 50 mutant embryos obtained from a map-cross between the AB mutant carrier and the WIK polymorphic strain. The chromosomal region carrying the causal mutation was localized based on its unique property to display high levels of homozygosity among sequence reads as it derives exclusively from the initial AB mutated allele. We developed an algorithm identifying such a region by calculating a homozygosity score along all chromosomes. This highlighted an 8-Mb window on chromosome 5 with a score close to 1 in the m1045 mutants. The sequence analysis of all genes within this interval revealed a nonsense mutation in the snapc4 gene. Knockdown experiments confirmed the assertion that snapc4 is the gene whose mutation leads to exocrine pancreas hypoplasia. In conclusion, this study constitutes a proof-of-concept that whole-genome sequencing is a fast and effective alternative to the classical positional cloning strategies in zebrafish.
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Affiliation(s)
- Marianne L Voz
- Laboratoire de Biologie Moléculaire et de Génie Génétique, Université de Liège, Sart Tilman, Belgium.
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23
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Xiao T, Wang Y, Luo H, Liu L, Wei G, Chen X, Sun Y, Chen X, Skogerbø G, Chen R. A differential sequencing-based analysis of the C. elegans noncoding transcriptome. RNA (NEW YORK, N.Y.) 2012; 18:626-639. [PMID: 22345127 PMCID: PMC3312551 DOI: 10.1261/rna.030965.111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 12/22/2011] [Indexed: 05/31/2023]
Abstract
Noncoding RNAs are increasingly being recognized as important players in eukaryote biology. However, despite major efforts in mapping the Caenorhabditis elegans transcriptome over the last couple of years, nonpolyadenylated and intermediate-size noncoding RNAs (is-ncRNAs) are still incompletely explored. We have combined an enzymatic approach with full-length RNA-Seq of is-ncRNAs in C. elegans. A total of 473 novel is-ncRNAs has been identified, of which a substantial fraction was associated with transcription factor binding sites and developmentally regulated expression patterns. Analysis of sequence and secondary structure permitted classification of more than 200 is-ncRNAs into several known RNA classes, while another 33 is-ncRNAs were identified as belonging to two previously uncharacterized groups of is-ncRNAs. Three of the unclassified is-ncRNAs contain the 5' Alu domain common to SRP RNAs and specifically bound with the SRP9/14 heterodimer in vitro. One of these (inc394) showed 65% sequence identity with the human, neuron-specific BC200 RNA. Structure-based clustering analysis and in vitro binding experiments supported the notion that the nematode stem-bulge RNAs (sbRNAs) are homologs (or functional analogs) of the Y RNAs. Moreover, analysis of the differential libraries showed that some mature snoRNAs undergo secondary 5' cap modification after processing of the primary transcript, thus suggesting the existence of a wider range of functional RNAs arising from processed and modified fragments of primary transcripts.
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Affiliation(s)
- Tengfei Xiao
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Yunfei Wang
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Huaxia Luo
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Lihui Liu
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Guifeng Wei
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Xiaowei Chen
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Yu Sun
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Graduate School of the Chinese Academy of Science, Beijing 100080, China
| | - Xiaomin Chen
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Geir Skogerbø
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Runsheng Chen
- Laboratory of Bioinformatics and Noncoding RNA, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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24
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Hung KH, Stumph WE. Localization of residues in a novel DNA-binding domain of DmSNAP43 required for DmSNAPc DNA-binding activity. FEBS Lett 2012; 586:841-6. [PMID: 22449969 DOI: 10.1016/j.febslet.2012.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/05/2012] [Accepted: 02/09/2012] [Indexed: 11/28/2022]
Abstract
Transcription of snRNA genes depends upon the recognition of the proximal sequence element (PSE) by the snRNA activating protein complex SNAPc. In Drosophila melanogaster, all subunits of DmSNAPc (DmSNAP43, DmSNAP50, and DmSNAP190) are required for PSE-binding activity. Previous work demonstrated that a non-canonical DmSNAP43 domain bounded by residues 193-272 was essential for DmSNAPc to bind to the PSE. In this study, the contribution of amino acid residues within this domain to DNA binding by DmSNAPc was investigated by alanine-scanning mutagenesis. The results have identified two clusters of residues within this domain required for the sequence-specific DNA-binding activity of DmSNAPc.
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Affiliation(s)
- Ko-Hsuan Hung
- Department of Biology, San Diego State University, San Diego, CA 92182-1030, United States
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25
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Selvakumar T, Gjidoda A, Hovde SL, Henry RW. Regulation of human RNA polymerase III transcription by DNMT1 and DNMT3a DNA methyltransferases. J Biol Chem 2012; 287:7039-50. [PMID: 22219193 DOI: 10.1074/jbc.m111.285601] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human small nuclear RNA (snRNA) and small cytoplasmic RNA (scRNA) gene families encode diverse non-coding RNAs that influence cellular growth and division. Many snRNA and scRNA genes are related via their compact and yet powerful promoters that support RNA polymerase III transcription. We have utilized the human U6 snRNA gene family to examine the mechanism for regulated transcription of these potent transcription units. Analysis of nine U6 family members showed enriched CpG density within the promoters of actively transcribed loci relative to inert genes, implying a relationship between gene potency and DNA methylation. Indeed, both pharmacological inhibition of DNA methyltransferase (DNMT) activity and the forced diminution of DNMT-1, DNMT-3a, and DNMT-3b by siRNA targeting resulted in increased U6 levels in asynchronously growing MCF7 adenocarcinoma cells. In vitro transcription assays further showed that template methylation impedes U6 transcription by RNA polymerase III. Both DNMT-1 and DNMT-3a were detected at the U6-1 locus by chromatin immunoprecipitation directly linking these factors to RNA polymerase III regulation. Despite this association, the endogenous U6-1 locus was not substantially methylated in actively growing cells. However, both DNMT occupancy and low frequency methylation were correlated with increased Retinoblastoma tumor suppressor (RB) expression, suggesting that the RB status can influence specific epigenetic marks.
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Affiliation(s)
- Tharakeswari Selvakumar
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824, USA
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26
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Prouse MB, Campbell MM. The interaction between MYB proteins and their target DNA binding sites. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:67-77. [DOI: 10.1016/j.bbagrm.2011.10.010] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 02/02/2023]
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27
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Mutation of zebrafish Snapc4 is associated with loss of the intrahepatic biliary network. Dev Biol 2011; 363:128-37. [PMID: 22222761 DOI: 10.1016/j.ydbio.2011.12.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 12/13/2011] [Accepted: 12/16/2011] [Indexed: 10/14/2022]
Abstract
Biliary epithelial cells line the intrahepatic biliary network, a complex three-dimensional network of conduits. The loss of differentiated biliary epithelial cells is the primary cause of many congenital liver diseases. We identified a zebrafish snapc4 (small nuclear RNA-activating complex polypeptide 4) mutant in which biliary epithelial cells initially differentiate but subsequently disappear. In these snapc4 mutant larvae, biliary epithelial cells undergo apoptosis, leading to degeneration of the intrahepatic biliary network. Consequently, in snapc4 mutant larvae, biliary transport of ingested fluorescent lipids to the gallbladder is blocked. Snapc4 is the largest subunit of a protein complex that regulates small nuclear RNA (snRNA) transcription. The snapc4(s445) mutation causes a truncation of the C-terminus, thereby deleting the domain responsible for a specific interaction with Snapc2, a vertebrate specific subunit of the SNAP complex. This mutation leads to a hypomorphic phenotype, as only a subset of snRNA transcripts are quantitatively altered in snapc4(s445) mutant larvae. snapc2 knockdown also disrupts the intrahepatic biliary network in a similar fashion as in snapc4(s445) mutant larvae. These data indicate that the physical interaction between Snapc2 and Snapc4 is important for the expression of a subset of snRNAs and biliary epithelial cell survival in zebrafish.
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28
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Feller A, Machemer K, Braun EL, Grotewold E. Evolutionary and comparative analysis of MYB and bHLH plant transcription factors. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 66:94-116. [PMID: 21443626 DOI: 10.1111/j.1365-313x.2010.04459.x] [Citation(s) in RCA: 685] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The expansion of gene families encoding regulatory proteins is typically associated with the increase in complexity characteristic of multi-cellular organisms. The MYB and basic helix-loop-helix (bHLH) families provide excellent examples of how gene duplication and divergence within particular groups of transcription factors are associated with, if not driven by, the morphological and metabolic diversity that characterize the higher plants. These gene families expanded dramatically in higher plants; for example, there are approximately 339 and 162 MYB and bHLH genes, respectively, in Arabidopsis, and approximately 230 and 111, respectively, in rice. In contrast, the Chlamydomonas genome has only 38 MYB genes and eight bHLH genes. In this review, we compare the MYB and bHLH gene families from structural, evolutionary and functional perspectives. The knowledge acquired on the role of many of these factors in Arabidopsis provides an excellent reference to explore sequence-function relationships in crops and other plants. The physical interaction and regulatory synergy between particular sub-classes of MYB and bHLH factors is perhaps one of the best examples of combinatorial plant gene regulation. However, members of the MYB and bHLH families also interact with a number of other regulatory proteins, forming complexes that either activate or repress the expression of sets of target genes that are increasingly being identified through a diversity of high-throughput genomic approaches. The next few years are likely to witness an increasing understanding of the extent to which conserved transcription factors participate at similar positions in gene regulatory networks across plant species.
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Affiliation(s)
- Antje Feller
- Plant Biotechnology Center and Department of Molecular Genetics, Ohio State University, Columbus, OH 43210, USA
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Novel core promoter elements and a cognate transcription factor in the divergent unicellular eukaryote Trichomonas vaginalis. Mol Cell Biol 2011; 31:1444-58. [PMID: 21245378 DOI: 10.1128/mcb.00745-10] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A highly conserved DNA initiator (Inr) element has been the only core promoter element described in the divergent unicellular eukaryote Trichomonas vaginalis, although genome analyses reveal that only ∼75% of protein-coding genes appear to contain an Inr. In search of another core promoter element(s), a nonredundant database containing 5' untranslated regions of expressed T. vaginalis genes was searched for overrepresented DNA motifs and known eukaryotic core promoter elements. In addition to identifying the Inr, two elements that lack sequence similarity to the known protein-coding gene core promoter, motif 3 (M3) and motif 5 (M5), were identified. Mutational and functional analyses demonstrate that both are novel core promoter elements. M3 [(A/G/T)(A/G)C(G/C)G(T/C)T(T/A/G)] resembles a Myb recognition element (MRE) and is bound specifically by a unique protein with a Myb-like DNA binding domain. The M5 element (CCTTT) overlaps the transcription start site and replaces the Inr as an alternative, gene-specific initiator element. Transcription specifically initiates at the second cytosine within M5, in contrast to characteristic initiation by RNA polymerase II at an adenosine. In promoters that combine M3 with either M5 or Inr, transcription initiation is regulated by the M3 motif.
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Niu W, Lu ZJ, Zhong M, Sarov M, Murray JI, Brdlik CM, Janette J, Chen C, Alves P, Preston E, Slightham C, Jiang L, Hyman AA, Kim SK, Waterston RH, Gerstein M, Snyder M, Reinke V. Diverse transcription factor binding features revealed by genome-wide ChIP-seq in C. elegans. Genome Res 2010; 21:245-54. [PMID: 21177963 DOI: 10.1101/gr.114587.110] [Citation(s) in RCA: 179] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Regulation of gene expression by sequence-specific transcription factors is central to developmental programs and depends on the binding of transcription factors with target sites in the genome. To date, most such analyses in Caenorhabditis elegans have focused on the interactions between a single transcription factor with one or a few select target genes. As part of the modENCODE Consortium, we have used chromatin immunoprecipitation coupled with high-throughput DNA sequencing (ChIP-seq) to determine the genome-wide binding sites of 22 transcription factors (ALR-1, BLMP-1, CEH-14, CEH-30, EGL-27, EGL-5, ELT-3, EOR-1, GEI-11, HLH-1, LIN-11, LIN-13, LIN-15B, LIN-39, MAB-5, MDL-1, MEP-1, PES-1, PHA-4, PQM-1, SKN-1, and UNC-130) at diverse developmental stages. For each factor we determined candidate gene targets, both coding and non-coding. The typical binding sites of almost all factors are within a few hundred nucleotides of the transcript start site. Most factors target a mixture of coding and non-coding target genes, although one factor preferentially binds to non-coding RNA genes. We built a regulatory network among the 22 factors to determine their functional relationships to each other and found that some factors appear to act preferentially as regulators and others as target genes. Examination of the binding targets of three related HOX factors--LIN-39, MAB-5, and EGL-5--indicates that these factors regulate genes involved in cellular migration, neuronal function, and vulval differentiation, consistent with their known roles in these developmental processes. Ultimately, the comprehensive mapping of transcription factor binding sites will identify features of transcriptional networks that regulate C. elegans developmental processes.
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Affiliation(s)
- Wei Niu
- Department of Genetics, Yale University, New Haven, Connecticut 06520, USA
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Hung KH, Stumph WE. Regulation of snRNA gene expression by the Drosophila melanogaster small nuclear RNA activating protein complex (DmSNAPc). Crit Rev Biochem Mol Biol 2010; 46:11-26. [PMID: 20925482 DOI: 10.3109/10409238.2010.518136] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The small nuclear RNAs (snRNAs) are an essential class of non-coding RNAs first identified over 30 years ago. Many of the well-characterized snRNAs are involved in RNA processing events. However, it is now evident that other small RNAs, synthesized using similar mechanisms, play important roles at many stages of gene expression. The accurate and efficient control of the expression of snRNA (and related) genes is thus critical for cell survival. All snRNA genes share a very similar promoter structure, and their transcription is dependent upon the same multi-subunit transcription factor, termed the snRNA activating protein complex (SNAPc). Despite those similarities, some snRNA genes are transcribed by RNA polymerase II (Pol II), but others are transcribed by RNA polymerase III (Pol III). Thus snRNA genes provide a unique opportunity to understand how RNA polymerase specificity is determined and how distinct transcription machineries can interact with a common factor. This review will describe efforts taken toward solving those questions by using the fruit fly as a model organism. Drosophila melanogaster SNAPc (DmSNAPc) binds to a proximal sequence element (PSEA) present in both Pol II and Pol III snRNA promoters. Just a few differences in nucleotide sequence in the Pol II and Pol III PSEAs play a major role in determining RNA polymerase specificity. Furthermore, these same nucleotide differences result in alternative conformations of DmSNAPc on Pol II and Pol III snRNA gene promoters. It seems likely that these DNA-induced alternative DmSNAPc conformations are responsible for the differential recruitment of the distinct transcriptional machineries.
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Affiliation(s)
- Ko-Hsuan Hung
- Department of Biology and Molecular Biology Institute, San Diego State University, San Diego, CA 92182-1030, USA
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Pointon JJ, Harvey D, Karaderi T, Appleton LH, Farrar C, Stone MA, Sturrock RD, Brown MA, Wordsworth BP. Elucidating the chromosome 9 association with AS; CARD9 is a candidate gene. Genes Immun 2010; 11:490-6. [PMID: 20463747 PMCID: PMC2933507 DOI: 10.1038/gene.2010.17] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Ankylosing spondylitis (AS) is polygenic with contributions from the immunologically relevant genes HLA-B*27, ERAP1 and IL23R. A recent genome-wide association study (GWAS) identified associations (p~0.005) with the non-synonymous single nucleotide polymorphisms (nsSNPs), rs4077515 and rs3812571, in CARD9 and SNAPC4 on chromosome 9q that had previously been linked to AS. We replicated these associations in a study of 730 AS patients compared to 2879 historic disease controls, (rs4077515 p = 0.0004 odds ratio (OR) (95% confidence interval) = 1.2 (1.1-1.4); rs3812571 p = 0.0003 OR = 1.2 (1.1-1.4)). Meta-analysis revealed strong associations of both SNPs with AS, rs4077515 p = 0.000005 OR = 1.2 (1.1-1.3) and rs3812571 p = 0.000006 OR = 1.2 (1.1-1.3). We then typed 1604 AS cases and 1020 controls for 13 tagging SNPs; 6 showed at least nominal association, 5 of which were in CARD9. We imputed genotypes for 13 additional SNPs but none was more strongly associated with AS than the tagging SNPs. Finally, interrogation of an mRNA expression database revealed that the SNPs most strongly associated AS (or in strong linkage disequilibrium) were those most associated with CARD9 expression. CARD9 is a plausible candidate for AS given its central role in the innate immune response.
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Affiliation(s)
- J J Pointon
- NIHR Oxford Musculoskeletal Biomedical Research Unit and Botnar Research Centre, Oxford, UK.
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Kim MK, Kang YS, Lai HT, Barakat NH, Magante D, Stumph WE. Identification of SNAPc subunit domains that interact with specific nucleotide positions in the U1 and U6 gene promoters. Mol Cell Biol 2010; 30:2411-23. [PMID: 20212087 PMCID: PMC2863707 DOI: 10.1128/mcb.01508-09] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 12/15/2009] [Accepted: 02/25/2010] [Indexed: 11/20/2022] Open
Abstract
The small nuclear RNA (snRNA)-activating protein complex (SNAPc) is essential for transcription of genes coding for the snRNAs (U1, U2, etc.). In Drosophila melanogaster, the heterotrimeric DmSNAPc recognizes a 21-bp DNA sequence, the proximal sequence element A (PSEA), located approximately 40 to 60 bp upstream of the transcription start site. Upon binding the PSEA, DmSNAPc establishes RNA polymerase II preinitiation complexes on U1 to U5 promoters but RNA polymerase III preinitiation complexes on U6 promoters. Minor differences in nucleotide sequence of the U1 and U6 PSEAs determine RNA polymerase specificity; moreover, DmSNAPc adopts different conformations on these different PSEAs. We have proposed that such conformational differences in DmSNAPc play a key role in determining the different polymerase specificities of the U1 and U6 promoters. To better understand the structure of DmSNAPc-PSEA complexes, we have developed a novel protocol that combines site-specific protein-DNA photo-cross-linking with site-specific chemical cleavage of the protein. This protocol has allowed us to map regions within each of the three DmSNAPc subunits that contact specific nucleotide positions within the U1 and U6 PSEAs. These data help to establish the orientation of each DmSNAPc subunit on the DNA and have revealed cases in which different domains of the subunits differentially contact the U1 versus U6 PSEAs.
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Affiliation(s)
- Mun Kyoung Kim
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Yoon Soon Kang
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Hsien-Tsung Lai
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Nermeen H. Barakat
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - Deodato Magante
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
| | - William E. Stumph
- Molecular Biology Institute, Department of Biology, Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030
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Hung KH, Titus M, Chiang SC, Stumph WE. A map of Drosophila melanogaster small nuclear RNA-activating protein complex (DmSNAPc) domains involved in subunit assembly and DNA binding. J Biol Chem 2009; 284:22568-79. [PMID: 19556241 DOI: 10.1074/jbc.m109.027961] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription of genes coding for the small nuclear RNAs (snRNAs) is dependent upon a unique transcription factor known as the small nuclear RNA-activating protein complex (SNAPc). SNAPc binds to an essential proximal sequence element located about 40-65 base pairs upstream of the snRNA transcription start site. In the fruit fly Drosophila melanogaster, DmSNAPc contains three distinct polypeptides (DmSNAP190, DmSNAP50, and DmSNAP43) that are stably associated with each other and bind to the DNA as a complex. We have used mutational analysis to identify domains within each subunit that are involved in complex formation with the other two subunits in vivo. We have also identified domains in each subunit required for sequence-specific DNA binding. With one exception, domains required for subunit-subunit interactions lie in the most evolutionarily conserved regions of the proteins. However, DNA binding by DmSNAPc is dependent not only upon the conserved regions but is also highly dependent upon domains outside the conserved regions. Comparison with functional domains identified in human SNAPc indicates many parallels but also reveals significant differences in this ancient yet rapidly evolving system.
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Affiliation(s)
- Ko-Hsuan Hung
- Molecular Biology Institute, Department of Biology, San Diego State University, San Diego, California 92182-1030, USA
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Jawdekar GW, Henry RW. Transcriptional regulation of human small nuclear RNA genes. BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1779:295-305. [PMID: 18442490 PMCID: PMC2684849 DOI: 10.1016/j.bbagrm.2008.04.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 04/01/2008] [Accepted: 04/02/2008] [Indexed: 01/06/2023]
Abstract
The products of human snRNA genes have been frequently described as performing housekeeping functions and their synthesis refractory to regulation. However, recent studies have emphasized that snRNA and other related non-coding RNA molecules control multiple facets of the central dogma, and their regulated expression is critical to cellular homeostasis during normal growth and in response to stress. Human snRNA genes contain compact and yet powerful promoters that are recognized by increasingly well-characterized transcription factors, thus providing a premier model system to study gene regulation. This review summarizes many recent advances deciphering the mechanism by which the transcription of human snRNA and related genes are regulated.
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Affiliation(s)
- Gauri W. Jawdekar
- Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, CA 90095
| | - R. William Henry
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824
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Gu L, Husain-Ponnampalam R, Hoffmann-Benning S, Henry RW. The protein kinase CK2 phosphorylates SNAP190 to negatively regulate SNAPC DNA binding and human U6 transcription by RNA polymerase III. J Biol Chem 2007; 282:27887-96. [PMID: 17670747 DOI: 10.1074/jbc.m702269200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human U6 small nuclear RNA gene transcription by RNA polymerase III requires the general transcription factor SNAP(C), which binds to human small nuclear RNA core promoter elements and nucleates pre-initiation complex assembly with the Brf2-TFIIIB complex. Multiple components in this pathway are phosphorylated by the protein kinase CK2, including the Bdp1 subunit of the Brf2-TFIIIB complex, and RNA polymerase III, with negative and positive outcomes for U6 transcription, respectively. However, a role for CK2 phosphorylation of SNAP(C) in U6 transcription has not been defined. In this report, we investigated the role of CK2 in modulating the transcriptional properties of SNAP(C) and demonstrate that within SNAP(C), CK2 phosphorylates the N-terminal half of the SNAP190 subunit at two regions (amino acids 20-63 and 514-545) that each contain multiple CK2 consensus sites. SNAP190 phosphorylation by CK2 inhibits both SNAP(C) DNA binding and U6 transcription activity. Mutational analyses of SNAP190 support a model wherein CK2 phosphorylation triggers an allosteric inhibition of the SNAP190 Myb DNA binding domain.
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Affiliation(s)
- Liping Gu
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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37
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Hernandez G, Valafar F, Stumph WE. Insect small nuclear RNA gene promoters evolve rapidly yet retain conserved features involved in determining promoter activity and RNA polymerase specificity. Nucleic Acids Res 2006; 35:21-34. [PMID: 17148477 PMCID: PMC1761439 DOI: 10.1093/nar/gkl982] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In animals, most small nuclear RNAs (snRNAs) are synthesized by RNA polymerase II (Pol II), but U6 snRNA is synthesized by RNA polymerase III (Pol III). In Drosophila melanogaster, the promoters for the Pol II-transcribed snRNA genes consist of approximately 21 bp PSEA and approximately 8 bp PSEB. U6 genes utilize a PSEA but have a TATA box instead of the PSEB. The PSEAs of the two classes of genes bind the same protein complex, DmSNAPc. However, the PSEAs that recruit Pol II and Pol III differ in sequence at a few nucleotide positions that play an important role in determining RNA polymerase specificity. We have now performed a bioinformatic analysis to examine the conservation and divergence of the snRNA gene promoter elements in other species of insects. The 5' half of the PSEA is well-conserved, but the 3' half is divergent. Moreover, within each species positions exist where the PSEAs of the Pol III-transcribed genes differ from those of the Pol II-transcribed genes. Interestingly, the specific positions vary among species. Nevertheless, we speculate that these nucleotide differences within the 3' half of the PSEA act similarly to induce conformational alterations in DNA-bound SNAPc that result in RNA polymerase specificity.
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Affiliation(s)
- Genaro Hernandez
- Department of Chemistry and Biochemistry, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
- Department of Computer Science, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
| | - Faramarz Valafar
- Department of Computer Science, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
| | - William E. Stumph
- Department of Chemistry and Biochemistry, San Diego State University5500 Campanile Drive, San Diego, CA 92182-1030, USA
- To whom correspondence should be addressed. Tel: +1 619 594 5575; Fax: +1 619 594-4634;
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Jawdekar GW, Hanzlowsky A, Hovde SL, Jelencic B, Feig M, Geiger JH, Henry RW. The unorthodox SNAP50 zinc finger domain contributes to cooperative promoter recognition by human SNAPC. J Biol Chem 2006; 281:31050-60. [PMID: 16901896 DOI: 10.1074/jbc.m603810200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human small nuclear RNA gene transcription by RNA polymerases II and III depends upon promoter recognition by the SNAPC general transcription factor. DNA binding by SNAPC involves direct DNA contacts by the SNAP190 subunit in cooperation with SNAP50 and SNAP43. The data presented herein shows that SNAP50 plays an important role in DNA binding by SNAPC through its zinc finger domain. The SNAP50 zinc finger domain contains 15 cysteine and histidine residues configured in two potential zinc coordination arrangements. Individual alanine substitution of each cysteine and histidine residue demonstrated that eight sites are important for DNA binding by SNAPC. However, metal binding studies revealed that SNAPC contains a single zinc atom indicating that only one coordination site functions as a zinc finger. Of the eight residues critical for DNA binding, four cysteine residues were also essential for both U1 and U6 transcription by RNA polymerase II and III, respectively. Surprisingly, the remaining four residues, although critical for U1 transcription could support partial U6 transcription. DNA binding studies showed that defects in DNA binding by SNAPC alone could be suppressed through cooperative DNA binding with another member of the RNA polymerase III general transcription machinery, TFIIIB. These results suggest that these eight cysteine and histidine residues perform different functions during DNA binding with those residues involved in zinc coordination likely performing a dominant role in domain stabilization and the others involved in DNA binding. These data further define the unorthodox SNAP50 zinc finger region as an evolutionarily conserved DNA binding domain.
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Affiliation(s)
- Gauri W Jawdekar
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, USA
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López-Bayghen E, Cruz-Solís I, Corona M, López-Colomé AM, Ortega A. Glutamate-induced octamer DNA binding and transcriptional control in cultured radial glia cells. J Neurochem 2006; 98:851-9. [PMID: 16787415 DOI: 10.1111/j.1471-4159.2006.03929.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glutamate, the main excitatory neurotransmitter in the vertebrate brain, is critically involved in gene expression regulation in neurons and in glia cells. Neuron-glia interactions provide the framework for synaptic plasticity. Retinal and cerebellar radial glia cells surround glutamatergic excitatory synapses and sense synaptic activity through glutamate receptors expressed in their membranes. Several glutamate-dependent membrane to nuclei signaling cascades have been described in these cells. Octamer DNA binding factors, namely Oct-1 and Oct-2 recognize similar DNA sequences on regulatory regions, but their final transcriptional effect depends on several factors. By these means, different responses can be achieved in different cell types. Here, we describe a comparison between the glutamate-induced DNA binding of octamer factors and their functional activities in two important types of radial glia, retinal Müller and cerebellar Bergmann glial cells. While Oct-1 is expressed in both cell types and in both glutamate treatments results in an increase in Oct-1 DNA binding, this complex is capable of transactivating a reporter gene only in Müller glia cells. In contrast, Oct-2 expression is restricted to Bergmann glia cells in which glutamate treatment results in an augmentation of Oct-2 DNA binding complexes and the repression of kainate binding protein gene transcription. Our present findings demonstrate a differential role for Oct-1 and Oct-2 transcription factors in glial glutamate signaling, and further strengthen the notion of an important role for glial cells in glutamatergic transactions in the central nervous system.
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Affiliation(s)
- Esther López-Bayghen
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México
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Emran F, Florens L, Ma B, Swanson SK, Washburn MP, Hernandez N. A role for Yin Yang-1 (YY1) in the assembly of snRNA transcription complexes. Gene 2006; 377:96-108. [PMID: 16769183 DOI: 10.1016/j.gene.2006.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 03/17/2006] [Accepted: 03/20/2006] [Indexed: 10/24/2022]
Abstract
The RNA polymerase (pol) II and III human small nuclear RNA (snRNA) genes have very similar promoters and recruit a number of common factors. In particular, both types of promoters utilize the small nuclear RNA activating protein complex (SNAP(c)) and the TATA box binding protein (TBP) for basal transcription, and are activated by Oct-1. We find that SNAP(c) purified from cell lines expressing tagged SNAP(c) subunits is associated with Yin Yang-1 (YY1), a factor implicated in both activation and repression of transcription. Recombinant YY1 accelerates the binding of SNAP(c) to the proximal sequence element, its target within snRNA promoters. Moreover, it enhances the formation of a complex on the pol III U6 snRNA promoter containing all the factors (SNAP(c), TBP, TFIIB-related factor 2 (Brf2), and B double prime 1 (Bdp1)) that are sufficient to direct in vitro U6 transcription when complemented with purified pol III, as well as that of a subcomplex containing TBP, Brf2, and Bdp1. YY1 is found on both the RNA polymerase II U1 and the RNA polymerase III U6 promoters as determined by chromatin immunoprecipitations. Thus, YY1 represents a new factor that participates in transcription complexes formed on both pol II and III promoters.
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Affiliation(s)
- Farida Emran
- Stony Brook University, Graduate Program in Molecular and Cellular Pharmacology, Stony Brook, NY 11794, USA
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Hanzlowsky A, Jelencic B, Jawdekar G, Hinkley CS, Geiger JH, Henry RW. Co-expression of multiple subunits enables recombinant SNAPC assembly and function for transcription by human RNA polymerases II and III. Protein Expr Purif 2006; 48:215-23. [PMID: 16603380 PMCID: PMC2714255 DOI: 10.1016/j.pep.2006.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Revised: 02/07/2006] [Accepted: 02/19/2006] [Indexed: 11/21/2022]
Abstract
Human small nuclear (sn) RNA genes are transcribed by either RNA polymerase II or III depending upon the arrangement of their core promoter elements. Regardless of polymerase specificity, these genes share a requirement for a general transcription factor called the snRNA activating protein complex or SNAP(C). This multi-subunit complex recognizes the proximal sequence element (PSE) commonly found in the upstream promoters of human snRNA genes. SNAP(C) consists of five subunits: SNAP190, SNAP50, SNAP45, SNAP43, and SNAP19. Previous studies have shown that a partial SNAP(C) composed of SNAP190 (1-514), SNAP50, and SNAP43 expressed in baculovirus is capable of PSE-specific DNA binding and transcription of human snRNA genes by RNA polymerases II and III. Expression in a baculovirus system yields active complex but the concentration of such material is insufficient for many bio-analytical methods. Herein, we describe the co-expression in Escherichia coli of a partial SNAP(C) containing SNAP190 (1-505), SNAP50, SNAP43, and SNAP19. The co-expressed complex binds DNA specifically and recruits TBP to U6 promoter DNA. Importantly, this partial complex functions in reconstituted transcription of both human U1 and U6 snRNA genes by RNA polymerases II and III, respectively. This co-expression system will facilitate the functional characterization of this unusual multi-protein transcription factor that plays an important early role for transcription by two different polymerases.
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Affiliation(s)
- Andrej Hanzlowsky
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Blanka Jelencic
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Gauri Jawdekar
- Department of Microbiology and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Craig S. Hinkley
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - James H. Geiger
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
- Corresponding authors. Fax: +1 517 353 9334. E-mail addresses: (J.H. Geiger), (R.W. Henry)
| | - R. William Henry
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- Corresponding authors. Fax: +1 517 353 9334. E-mail addresses: (J.H. Geiger), (R.W. Henry)
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Heckman CA, Duan H, Garcia PB, Boxer LM. Oct transcription factors mediate t(14;18) lymphoma cell survival by directly regulating bcl-2 expression. Oncogene 2006; 25:888-98. [PMID: 16186795 DOI: 10.1038/sj.onc.1209127] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oct-1 and Oct-2 are members of the POU homeodomain family of transcriptional regulators and are critical for normal embryonic development. Gene-targeting studies showed that Oct-1 and Oct-2 are largely dispensable for B-cell development and immunoglobulin production, although both Oct-2 and Bob-1 are required for a proper immune response and germinal center formation. In these studies, we investigated the role of Oct factors in B-cell lymphomas. Recent investigations have shown increased expression of Oct-2 and Bob-1 in lymphomas, and we observed greatly increased levels of Oct-2 in lymphoma cells with the t(14;18) translocation. Decreased expression of Oct-1, Oct-2, or Bob-1 by RNA interference resulted in apoptosis and down-regulation of bcl-2 expression. Furthermore, Oct-2 induced bcl-2 promoter activity and mediated this effect through three regions in the bcl-2 P2 promoter. Although these regions did not contain canonical octamer motifs, we observed the direct interaction of Oct-2 with all three sites both in vitro by EMSA and in vivo by chromatin immunoprecipitation assay. Moreover, by mutation analysis we found that the ability of Oct-2 to activate bcl-2 required C/EBP, Cdx, and TATA-binding sites. Oct-2, therefore, acts as a cell survival factor in t(14;18) lymphoma cells by directly activating the antiapoptotic gene bcl-2.
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Affiliation(s)
- C A Heckman
- Center for Molecular Biology in Medicine, Palo Alto VAHCS, Palo Alto, CA, USA
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Schimanski B, Nguyen TN, Günzl A. Characterization of a multisubunit transcription factor complex essential for spliced-leader RNA gene transcription in Trypanosoma brucei. Mol Cell Biol 2005; 25:7303-13. [PMID: 16055738 PMCID: PMC1190248 DOI: 10.1128/mcb.25.16.7303-7313.2005] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the unicellular human parasites Trypanosoma brucei, Trypanosoma cruzi, and Leishmania spp., the spliced-leader (SL) RNA is a key molecule in gene expression donating its 5'-terminal region in SL addition trans splicing of nuclear pre-mRNA. While there is no evidence that this process exists in mammals, it is obligatory in mRNA maturation of trypanosomatid parasites. Hence, throughout their life cycle, these organisms crucially depend on high levels of SL RNA synthesis. As putative SL RNA gene transcription factors, a partially characterized small nuclear RNA-activating protein complex (SNAP(c)) and the TATA-binding protein related factor 4 (TRF4) have been identified thus far. Here, by tagging TRF4 with a novel epitope combination termed PTP, we tandem affinity purified from crude T. brucei extracts a stable and transcriptionally active complex of six proteins. Besides TRF4 these were identified as extremely divergent subunits of SNAP(c) and of transcription factor IIA (TFIIA). The latter finding was unexpected since genome databases of trypanosomatid parasites appeared to lack general class II transcription factors. As we demonstrate, the TRF4/SNAP(c)/TFIIA complex binds specifically to the SL RNA gene promoter upstream sequence element and is absolutely essential for SL RNA gene transcription in vitro.
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Affiliation(s)
- Bernd Schimanski
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, 06030-3710, USA
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Rave-Harel N, Miller NLG, Givens ML, Mellon PL. The Groucho-related gene family regulates the gonadotropin-releasing hormone gene through interaction with the homeodomain proteins MSX1 and OCT1. J Biol Chem 2005; 280:30975-83. [PMID: 16002402 PMCID: PMC2773698 DOI: 10.1074/jbc.m502315200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) is exclusively expressed in a unique population of hypothalamic neurons that controls reproductive function. GnRH gene expression is highly dynamic. Its transcriptional activity is regulated in a complex spatiotemporal manner during embryonic development and postnatal life. Although a variety of transcription factors have been identified as regulators of GnRH transcription, most are promiscuous in their DNA-binding requirements, and none are solely expressed in GnRH neurons. Their specific activity is probably determined by interactions with distinct cofactors. Here we find that the Groucho-related gene (GRG) family of co-repressors is expressed in a model cell line for the GnRH neuron and co-expresses with GnRH during prenatal development. GRG proteins associate in vivo with the GnRH promoter. Furthermore, GRG proteins interact with two regulators of GnRH transcription, the homeodomain proteins MSX1 and OCT1. Co-transfection experiments indicate that GRG proteins regulate GnRH promoter activity. The long GRG forms enhance MSX1 repression and counteract OCT1 activation of the GnRH gene. In contrast, the short form, GRG5, has a dominant-negative effect on MSX1-dependent repression. Taken together, these data suggest that the dynamic switch between activation and repression of GnRH transcription is mediated by recruitment of the GRG co-regulators.
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Affiliation(s)
- Naama Rave-Harel
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California, 92093-0674
| | - Nichol L. G. Miller
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California, 92093-0674
| | - Marjory L. Givens
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California, 92093-0674
| | - Pamela L. Mellon
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California, 92093-0674
- Department of Neurosciences, University of California, San Diego, La Jolla, California, 92093-0674
- To whom correspondence should be addressed: Dept. of Reproductive Medicine, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0674. Tel.: 858-534-1312; Fax: 858-534-1438;
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Gu L, Esselman WJ, Henry RW. Cooperation between small nuclear RNA-activating protein complex (SNAPC) and TATA-box-binding protein antagonizes protein kinase CK2 inhibition of DNA binding by SNAPC. J Biol Chem 2005; 280:27697-704. [PMID: 15955816 DOI: 10.1074/jbc.m503206200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein kinase CK2 regulates RNA polymerase III transcription of human U6 small nuclear RNA (snRNA) genes both negatively and positively depending upon whether the general transcription machinery or RNA polymerase III is preferentially phosphorylated. Human U1 snRNA genes share similar promoter architectures as that of U6 genes but are transcribed by RNA polymerase II. Herein, we report that CK2 inhibits U1 snRNA gene transcription by RNA polymerase II. Decreased levels of endogenous CK2 correlates with increased U1 expression, whereas CK2 associates with U1 gene promoters, indicating that it plays a direct role in U1 gene regulation. CK2 phosphorylates the general transcription factor small nuclear RNA-activating protein complex (SNAP(C)) that is required for both RNA polymerase II and III transcription, and SNAP(C) phosphorylation inhibits binding to snRNA gene promoters. However, restricted promoter access by phosphorylated SNAP(C) can be overcome by cooperative interactions with TATA-box-binding protein at a U6 promoter but not at a U1 promoter. Thus, CK2 may have the capacity to differentially regulate U1 and U6 transcription even though SNAP(C) is universally utilized for human snRNA gene transcription.
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Affiliation(s)
- Liping Gu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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Gridasova AA, Henry RW. The p53 tumor suppressor protein represses human snRNA gene transcription by RNA polymerases II and III independently of sequence-specific DNA binding. Mol Cell Biol 2005; 25:3247-60. [PMID: 15798209 PMCID: PMC1069601 DOI: 10.1128/mcb.25.8.3247-3260.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human U1 and U6 snRNA genes are transcribed by RNA polymerases II and III, respectively. While the p53 tumor suppressor protein is a general repressor of RNA polymerase III transcription, whether p53 regulates snRNA gene transcription by RNA polymerase II is uncertain. The data presented herein indicate that p53 is an effective repressor of snRNA gene transcription by both polymerases. Both U1 and U6 transcription in vitro is repressed by recombinant p53, and endogenous p53 occupancy at these promoters is stimulated by UV light. In response to UV light, U1 and U6 transcription is strongly repressed. Human U1 genes, but not U6 genes, contain a high-affinity p53 response element located within the core promoter region. Nonetheless, this element is not required for p53 repression and mutant p53 molecules that do not bind DNA can maintain repression, suggesting a reliance on protein interactions for p53 promoter recruitment. Recruitment may be mediated by the general transcription factors TATA-box binding protein and snRNA-activating protein complex, which interact well with p53 and function for both RNA polymerase II and III transcription.
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Affiliation(s)
- Anastasia A Gridasova
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824.
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Méndez JA, López-Bayghen E, Ortega A. Glutamate activation of Oct-2 in cultured chick Bergmann glia cells: Involvement of NFκB. J Neurosci Res 2005; 81:21-30. [PMID: 15929072 DOI: 10.1002/jnr.20519] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glutamate, the major excitatory neurotransmitter in the central nervous system, is critically involved in gene expression regulation at the transcriptional and translational levels. Its activity through ionotropic as well as metabotropic receptors modifies the protein repertoire in neurons and glial cells. In avian cerebellar Bergmann glia cells, glutamate receptors trigger a diverse array of signaling cascades that include activity-dependent transcription factors such as the activator protein-1, the cAMP response-element binding protein, and Oct-2. We analyze the upstream regulatory elements involved in Oct-2 activation. Our results demonstrate that Ca2+ influx, protein kinase C, phosphatidylinositol-3 kinase, Src, and nuclear factor (NF)kappaB are involved in this signaling pathway. Our findings link alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor activation to a negative phase of chkbp gene regulation, controlled by NFkappaB.
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Affiliation(s)
- J Alfredo Méndez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios, Avanzados del Instituto Politécnico Nacional, México
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Tao W, Wang M, Voss ED, Cocklin RR, Smith JA, Cooper SH, Broxmeyer HE. Comparative Proteomic Analysis of Human CD34+Stem/Progenitor Cells and Mature CD15+Myeloid Cells. Stem Cells 2004; 22:1003-14. [PMID: 15536191 DOI: 10.1634/stemcells.22-6-1003] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Human CD34(+) cells, highly enriched for hematopoietic stem and progenitors, and CD15(+) cells, more terminally differentiated myeloid cells in blood, represent distinct maturation/differentiation stages. A proteomic approach was used to identify proteins differentially present in these two populations from human cord blood. Cytosolic proteins were extracted and subjected to two-dimensional gel electrophoresis followed by mass spectrometry. On average, 460 protein spots on each gel were detected; 112 and 15 proteins, respectively, were found to be differentially expressed or post-translationally modified in CD34(+) and CD15(+) cells. This suggests that CD34(+) cells have a relatively larger proteome than mature CD15(+) myeloid cells and production of many stem/progenitor cell-associated proteins ceases or is dramatically down-regulated as the CD34(+) cells undergo differentiation. Of approximately 140 protein spots, 47 different proteins were positively identified by mass spectrometry and database search; these proteins belong to several functional categories, including cell signaling, transcription factors, cytoskeletal proteins, metabolism, protein folding, and vesicle trafficking. Multiple heat shock proteins and chaperones, as well as proteins important for intracellular trafficking, were predominantly present in CD34(+) cells. Most of the identified proteins in CD34(+) cells are expressed in germ cell tumors, as well as in embryonal carcinoma and neuroblastoma. Approximately eight novel proteins, whose functions are unknown, were identified. This study presents, for the first time, global cellular protein expression patterns in human CD34(+) and CD15(+) cells, which should help to better understand intracellular processes involved in myeloid differentiation and add insight into the functional capabilities of these distinct cell types.
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Affiliation(s)
- Wen Tao
- Department of Microbiology and Immunology, Indiana University School of Medicine, 950 West Walnut Street, Indianapolis, Indiana 46202, USA.
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Li C, Harding GA, Parise J, McNamara-Schroeder KJ, Stumph WE. Architectural arrangement of cloned proximal sequence element-binding protein subunits on Drosophila U1 and U6 snRNA gene promoters. Mol Cell Biol 2004; 24:1897-906. [PMID: 14966271 PMCID: PMC350556 DOI: 10.1128/mcb.24.5.1897-1906.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription of snRNA genes by either RNA polymerase II (U1 to U5) or RNA polymerase III (U6) is dependent upon a proximal sequence element (PSE) located approximately 40 to 60 bp upstream of the transcription start site. In Drosophila melanogaster, RNA polymerase specificity is determined by as few as three nucleotide differences within the otherwise well-conserved 21-bp PSE. Previous photo-cross-linking studies revealed that the D. melanogaster PSE-binding protein, DmPBP, contains three subunits (DmPBP45, DmPBP49, and DmPBP95) that associate with the DNA to form complexes that are conformationally distinct depending upon whether the protein is bound to a U1 or a U6 PSE. We have identified and cloned the genes that code for these subunits of DmPBP by virtue of their similarity to three of the five subunits of SNAP(c), the human PBP. When expressed in S2 cells, each of the three cloned gene products is incorporated into a protein complex that functionally binds to a PSE. We also find that the conformational difference referred to above is particularly pronounced for DmPBP45, herein identified as the ortholog of human SNAP43. DmPBP45 cross-linked strongly to DNA for two turns of the DNA helix downstream of the U1 PSE, but it cross-linked strongly for only a half turn of the helix downstream of a U6 PSE. These substantial differences in the cross-linking pattern are consistent with those of a model in which conformational differences in DmPBP-DNA complexes lead to selective RNA polymerase recruitment to U1 and U6 promoters.
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Affiliation(s)
- Cheng Li
- Department of Chemistry and Molecular Biology Institute, San Diego State University, San Diego, California 92182-1030, USA
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Hinkley CS, Hirsch HA, Gu L, LaMere B, Henry RW. The small nuclear RNA-activating protein 190 Myb DNA binding domain stimulates TATA box-binding protein-TATA box recognition. J Biol Chem 2003; 278:18649-57. [PMID: 12621023 DOI: 10.1074/jbc.m204247200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human U6 small nuclear RNA (snRNA) gene transcription by RNA polymerase III requires cooperative promoter binding involving the snRNA-activating protein complex (SNAP(c)) and the TATA-box binding protein (TBP). To investigate the role of SNAP(c) for TBP function at U6 promoters, TBP recruitment assays were performed using full-length TBP and a mini-SNAP(c) containing SNAP43, SNAP50, and a truncated SNAP190. Mini-SNAP(c) efficiently recruits TBP to the U6 TATA box, and two SNAP(c) subunits, SNAP43 and SNAP190, directly interact with the TBP DNA binding domain. Truncated SNAP190 containing only the Myb DNA binding domain is sufficient for TBP recruitment to the TATA box. Therefore, the SNAP190 Myb domain functions both to specifically recognize the proximal sequence element present in the core promoters of human snRNA genes and to stimulate TBP recognition of the neighboring TATA box present in human U6 snRNA promoters. The SNAP190 Myb domain also stimulates complex assembly with TBP and Brf2, a subunit of a snRNA-specific TFIIIB complex. Thus, interactions between the DNA binding domains of SNAP190 and TBP at juxtaposed promoter elements define the assembly of a RNA polymerase III-specific preinitiation complex.
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Affiliation(s)
- Craig S Hinkley
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
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