1
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Chen YL, Hsieh JWA, Kuo SC, Kao CT, Tung CC, Yu JH, Chang TH, Ku C, Xie J, Zhang D, Li Q, Lin YCJ. Merit of integrating in situ transcriptomics and anatomical information for cell annotation and lineage construction in single-cell analyses of Populus. Genome Biol 2024; 25:85. [PMID: 38570851 PMCID: PMC10988922 DOI: 10.1186/s13059-024-03227-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 03/27/2024] [Indexed: 04/05/2024] Open
Abstract
Cell type annotation and lineage construction are two of the most critical tasks conducted in the analyses of single-cell RNA sequencing (scRNA-seq). Four recent scRNA-seq studies of differentiating xylem propose four models on differentiating xylem development in Populus. The differences are mostly caused by the use of different strategies for cell type annotation and subsequent lineage interpretation. Here, we emphasize the necessity of using in situ transcriptomes and anatomical information to construct the most plausible xylem development model.
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Affiliation(s)
- Ying-Lan Chen
- Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
| | | | - Shang-Che Kuo
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan
| | - Chung-Ting Kao
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | - Chia-Chun Tung
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Jhong-He Yu
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan
| | | | - Chuan Ku
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | - Jianbo Xie
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Deqiang Zhang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Quanzi Li
- State Key Laboratory of Tree Genetics and Breeding, Chinese Academy of Forestry, Beijing, China
| | - Ying-Chung Jimmy Lin
- Department of Life Science, National Taiwan University, Taipei, Taiwan.
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan.
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan.
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2
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Antika TR, Nazilah KR, Lee YH, Lo YT, Yeh CS, Yeh FL, Chang TH, Wang TL, Wang CC. Human Thg1 displays tRNA-inducible GTPase activity. Nucleic Acids Res 2022; 50:10015-10025. [PMID: 36107775 PMCID: PMC9508852 DOI: 10.1093/nar/gkac768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/22/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
tRNAHis guanylyltransferase (Thg1) catalyzes the 3′-5′ incorporation of guanosine into position -1 (G-1) of tRNAHis. G-1 is unique to tRNAHis and is crucial for recognition by histidyl-tRNA synthetase (HisRS). Yeast Thg1 requires ATP for G-1 addition to tRNAHis opposite A73, whereas archaeal Thg1 requires either ATP or GTP for G-1 addition to tRNAHis opposite C73. Paradoxically, human Thg1 (HsThg1) can add G-1 to tRNAsHis with A73 (cytoplasmic) and C73 (mitochondrial). As N73 is immediately followed by a CCA end (positions 74–76), how HsThg1 prevents successive 3′-5′ incorporation of G-1/G-2/G-3 into mitochondrial tRNAHis (tRNAmHis) through a template-dependent mechanism remains a puzzle. We showed herein that mature native human tRNAmHis indeed contains only G-1. ATP was absolutely required for G-1 addition to tRNAmHis by HsThg1. Although HsThg1 could incorporate more than one GTP into tRNAmHisin vitro, a single-GTP incorporation prevailed when the relative GTP level was low. Surprisingly, HsThg1 possessed a tRNA-inducible GTPase activity, which could be inhibited by ATP. Similar activity was found in other high-eukaryotic dual-functional Thg1 enzymes, but not in yeast Thg1. This study suggests that HsThg1 may downregulate the level of GTP through its GTPase activity to prevent multiple-GTP incorporation into tRNAmHis.
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Affiliation(s)
- Titi Rindi Antika
- Department of Life Sciences, National Central University , Zhongli District, Taoyuan 320317, Taiwan
| | - Kun Rohmatan Nazilah
- Department of Life Sciences, National Central University , Zhongli District, Taoyuan 320317, Taiwan
| | - Yi-Hsueh Lee
- Department of Life Sciences, National Central University , Zhongli District, Taoyuan 320317, Taiwan
| | - Ya-Ting Lo
- Department of Life Sciences, National Central University , Zhongli District, Taoyuan 320317, Taiwan
| | - Chung-Shu Yeh
- Genomics Research Center , Academia Sinica, Nankang District, Taipei 11529, Taiwan
| | - Fu-Lung Yeh
- Genomics Research Center , Academia Sinica, Nankang District, Taipei 11529, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center , Academia Sinica, Nankang District, Taipei 11529, Taiwan
| | - Tzu-Ling Wang
- Graduate Institute of Mathematics and Science Education, National Tsing Hua University , Hsinchu City 30014, Taiwan
| | - Chien-Chia Wang
- Department of Life Sciences, National Central University , Zhongli District, Taoyuan 320317, Taiwan
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3
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Tsai NC, Hsu TS, Kuo SC, Kao CT, Hung TH, Lin DG, Yeh CS, Chu CC, Lin JS, Lin HH, Ko CY, Chang TH, Su JC, Lin YCJ. Large-scale data analysis for robotic yeast one-hybrid platforms and multi-disciplinary studies using GateMultiplex. BMC Biol 2021; 19:214. [PMID: 34560855 PMCID: PMC8461970 DOI: 10.1186/s12915-021-01140-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 09/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Yeast one-hybrid (Y1H) is a common technique for identifying DNA-protein interactions, and robotic platforms have been developed for high-throughput analyses to unravel the gene regulatory networks in many organisms. Use of these high-throughput techniques has led to the generation of increasingly large datasets, and several software packages have been developed to analyze such data. We previously established the currently most efficient Y1H system, meiosis-directed Y1H; however, the available software tools were not designed for processing the additional parameters suggested by meiosis-directed Y1H to avoid false positives and required programming skills for operation. RESULTS We developed a new tool named GateMultiplex with high computing performance using C++. GateMultiplex incorporated a graphical user interface (GUI), which allows the operation without any programming skills. Flexible parameter options were designed for multiple experimental purposes to enable the application of GateMultiplex even beyond Y1H platforms. We further demonstrated the data analysis from other three fields using GateMultiplex, the identification of lead compounds in preclinical cancer drug discovery, the crop line selection in precision agriculture, and the ocean pollution detection from deep-sea fishery. CONCLUSIONS The user-friendly GUI, fast C++ computing speed, flexible parameter setting, and applicability of GateMultiplex facilitate the feasibility of large-scale data analysis in life science fields.
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Affiliation(s)
- Ni-Chiao Tsai
- Department of Life Science and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - Tzu-Shu Hsu
- Department of Pharmacy, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan
| | - Shang-Che Kuo
- Department of Pharmacy, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, 10617, Taiwan
| | - Chung-Ting Kao
- Department of Life Science and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - Tzu-Huan Hung
- Biotechnology Division, Taiwan Agricultural Research Institute, Taichung, 41362, Taiwan
| | - Da-Gin Lin
- Biotechnology Division, Taiwan Agricultural Research Institute, Taichung, 41362, Taiwan
| | - Chung-Shu Yeh
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Chia-Chen Chu
- Department of Life Science and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, 10617, Taiwan
| | - Jeng-Shane Lin
- Department of Life Sciences, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Hsin-Hung Lin
- Department of Horticulture and Biotechnology, Chinese Culture University, Taipei, 11114, Taiwan
| | - Chia-Ying Ko
- Department of Life Sciences and Institute of Fisheries Science, National Taiwan University, Taipei, 10617, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
| | - Jung-Chen Su
- Department of Pharmacy, National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan.
| | - Ying-Chung Jimmy Lin
- Department of Life Science and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei, 10617, Taiwan.
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, 10617, Taiwan.
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4
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Yeh FL, Chang SL, Ahmed GR, Liu HI, Tung L, Yeh CS, Lanier LS, Maeder C, Lin CM, Tsai SC, Hsiao WY, Chang WH, Chang TH. Activation of Prp28 ATPase by phosphorylated Npl3 at a critical step of spliceosome remodeling. Nat Commun 2021; 12:3082. [PMID: 34035302 PMCID: PMC8149812 DOI: 10.1038/s41467-021-23459-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 04/29/2021] [Indexed: 11/10/2022] Open
Abstract
Splicing, a key step in the eukaryotic gene-expression pathway, converts precursor messenger RNA (pre-mRNA) into mRNA by excising introns and ligating exons. This task is accomplished by the spliceosome, a macromolecular machine that must undergo sequential conformational changes to establish its active site. Each of these major changes requires a dedicated DExD/H-box ATPase, but how these enzymes are activated remain obscure. Here we show that Prp28, a yeast DEAD-box ATPase, transiently interacts with the conserved 5' splice-site (5'SS) GU dinucleotide and makes splicing-dependent contacts with the U1 snRNP protein U1C, and U4/U6.U5 tri-snRNP proteins, Prp8, Brr2, and Snu114. We further show that Prp28's ATPase activity is potentiated by the phosphorylated Npl3, but not the unphosphorylated Npl3, thus suggesting a strategy for regulating DExD/H-box ATPases. We propose that Npl3 is a functional counterpart of the metazoan-specific Prp28 N-terminal region, which can be phosphorylated and serves as an anchor to human spliceosome.
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Affiliation(s)
- Fu-Lung Yeh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | | | - Hsin-I Liu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Luh Tung
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Chung-Shu Yeh
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Leah Stands Lanier
- Department of Biology, Washington and Lee University, Lexington, VA, USA
| | - Corina Maeder
- Department of Chemistry, Trinity University, San Antonio, TX, USA
| | - Che-Min Lin
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Shu-Chun Tsai
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Wan-Yi Hsiao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Wei-Hau Chang
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
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5
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Chin YPH, Hou ZY, Lee MY, Chu HM, Wang HH, Lin YT, Gittin A, Chien SC, Nguyen PA, Li LC, Chang TH, Li YCJ. A patient-oriented, general-practitioner-level, deep-learning-based cutaneous pigmented lesion risk classifier on a smartphone. Br J Dermatol 2020; 182:1498-1500. [PMID: 31907926 DOI: 10.1111/bjd.18859] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Y P H Chin
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Biomedical Informatics, Harvard Medical School, Boston, MA, U.S.A
| | - Z Y Hou
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan
| | - M Y Lee
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan
| | - H M Chu
- Department of Computer Science and Information Engineering, National Taiwan University, Taipei, Taiwan
| | - H H Wang
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Dermatology, Taipei Municipal Wan Fang Hospital, Taipei, Taiwan
| | - Y T Lin
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Dermatology, Taipei Municipal Wan Fang Hospital, Taipei, Taiwan
| | - A Gittin
- Department of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - S C Chien
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan
| | - P A Nguyen
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan
| | - L C Li
- International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan
| | - T H Chang
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Clinical Big Data Research Centre, Taipei Medical University Hospital, Taipei, Taiwan
| | - Y C J Li
- Graduate Institute of Biomedical Informatics, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,International Centre for Health Information Technology, Taipei Medical University, Taipei, Taiwan.,Department of Dermatology, Taipei Municipal Wan Fang Hospital, Taipei, Taiwan
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6
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Chuang TJ, Chen YJ, Chen CY, Mai TL, Wang YD, Yeh CS, Yang MY, Hsiao YT, Chang TH, Kuo TC, Cho HH, Shen CN, Kuo HC, Lu MY, Chen YH, Hsieh SC, Chiang TW. Integrative transcriptome sequencing reveals extensive alternative trans-splicing and cis-backsplicing in human cells. Nucleic Acids Res 2019; 46:3671-3691. [PMID: 29385530 PMCID: PMC6283421 DOI: 10.1093/nar/gky032] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/13/2018] [Indexed: 01/16/2023] Open
Abstract
Transcriptionally non-co-linear (NCL) transcripts can originate from trans-splicing (trans-spliced RNA; 'tsRNA') or cis-backsplicing (circular RNA; 'circRNA'). While numerous circRNAs have been detected in various species, tsRNAs remain largely uninvestigated. Here, we utilize integrative transcriptome sequencing of poly(A)- and non-poly(A)-selected RNA-seq data from diverse human cell lines to distinguish between tsRNAs and circRNAs. We identified 24,498 NCL events and found that a considerable proportion (20-35%) of them arise from both tsRNAs and circRNAs, representing extensive alternative trans-splicing and cis-backsplicing in human cells. We show that sequence generalities of exon circularization are also observed in tsRNAs. Recapitulation of NCL RNAs further shows that inverted Alu repeats can simultaneously promote the formation of tsRNAs and circRNAs. However, tsRNAs and circRNAs exhibit quite different, or even opposite, expression patterns, in terms of correlation with the expression of their co-linear counterparts, expression breadth/abundance, transcript stability, and subcellular localization preference. These results indicate that tsRNAs and circRNAs may play different regulatory roles and analysis of NCL events should take the joint effects of different NCL-splicing types and joint effects of multiple NCL events into consideration. This study describes the first transcriptome-wide analysis of trans-splicing and cis-backsplicing, expanding our understanding of the complexity of the human transcriptome.
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Affiliation(s)
- Trees-Juen Chuang
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan.,Genome and Systems Biology Degree Program, National Taiwan University, Taipei 10617 & Academia Sinica, Taipei 11529, Taiwan
| | - Yen-Ju Chen
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan.,Genome and Systems Biology Degree Program, National Taiwan University, Taipei 10617 & Academia Sinica, Taipei 11529, Taiwan
| | - Chia-Ying Chen
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Te-Lun Mai
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Da Wang
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Chung-Shu Yeh
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan.,Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Min-Yu Yang
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Yu-Ting Hsiao
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | | | - Tzu-Chien Kuo
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Hsin-Hua Cho
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Chia-Ning Shen
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Hung-Chih Kuo
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Mei-Yeh Lu
- High Throughput Genomics Core, Biodiversity Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Hua Chen
- High Throughput Genomics Core, Biodiversity Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Shan-Chi Hsieh
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Tai-Wei Chiang
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
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7
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Lee YH, Lo YT, Chang CP, Yeh CS, Chang TH, Chen YW, Tseng YK, Wang CC. Naturally occurring dual recognition of tRNA His substrates with and without a universal identity element. RNA Biol 2019; 16:1275-1285. [PMID: 31179821 DOI: 10.1080/15476286.2019.1626663] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The extra 5' guanine nucleotide (G-1) on tRNAHis is a nearly universal feature that specifies tRNAHis identity. The G-1 residue is either genome encoded or post-transcriptionally added by tRNAHis guanylyltransferase (Thg1). Despite Caenorhabditis elegans being a Thg1-independent organism, its cytoplasmic tRNAHis (CetRNAnHis) retains a genome-encoded G-1. Our study showed that this eukaryote possesses a histidyl-tRNA synthetase (CeHisRS) gene encoding two distinct HisRS isoforms that differ only at their N-termini. Most interestingly, its mitochondrial tRNAHis (CetRNAmHis) lacks G-1, a scenario never observed in any organelle. This tRNA, while lacking the canonical identity element, can still be efficiently aminoacylated in vivo. Even so, addition of G-1 to CetRNAmHis strongly enhanced its aminoacylation efficiency in vitro. Overexpression of CeHisRS successfully bypassed the requirement for yeast THG1 in the presence of CetRNAnHis without G-1. Mutagenesis assays showed that the anticodon takes a primary role in CetRNAHis identity recognition, being comparable to the universal identity element. Consequently, simultaneous introduction of both G-1 and the anticodon of tRNAHis effectively converted a non-cognate tRNA to a tRNAHis-like substrate. Our study suggests that a new balance between identity elements of tRNAHis relieves HisRS from the absolute requirement for G-1.
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Affiliation(s)
- Yi-Hsueh Lee
- a Department of Life Sciences, National Central University , Taoyuan , Taiwan
| | - Ya-Ting Lo
- a Department of Life Sciences, National Central University , Taoyuan , Taiwan
| | - Chia-Pei Chang
- a Department of Life Sciences, National Central University , Taoyuan , Taiwan
| | - Chung-Shu Yeh
- b Genomics Research Center, Academia Sinica , Taipei , Taiwan
| | | | - Yu-Wei Chen
- c Department of Neurology, Landseed International Hospital , Taoyuan , Taiwan
| | - Yi-Kuan Tseng
- d Graduate Institute of Statistics, National Central University , Taoyuan , Taiwan
| | - Chien-Chia Wang
- a Department of Life Sciences, National Central University , Taoyuan , Taiwan
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8
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Yeh CS, Wang Z, Miao F, Ma H, Kao CT, Hsu TS, Yu JH, Hung ET, Lin CC, Kuan CY, Tsai NC, Zhou C, Qu GZ, Jiang J, Liu G, Wang JP, Li W, Chiang VL, Chang TH, Lin YCJ. A novel synthetic-genetic-array-based yeast one-hybrid system for high discovery rate and short processing time. Genome Res 2019; 29:1343-1351. [PMID: 31186303 PMCID: PMC6673709 DOI: 10.1101/gr.245951.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/06/2019] [Indexed: 12/18/2022]
Abstract
Eukaryotic gene expression is often tightly regulated by interactions between transcription factors (TFs) and their DNA cis targets. Yeast one-hybrid (Y1H) is one of the most extensively used methods to discover these interactions. We developed a high-throughput meiosis-directed yeast one-hybrid system using the Magic Markers of the synthetic genetic array analysis. The system has a transcription factor–DNA interaction discovery rate twice as high as the conventional diploid-mating approach and a processing time nearly one-tenth of the haploid-transformation method. The system also offers the highest accuracy in identifying TF–DNA interactions that can be authenticated in vivo by chromatin immunoprecipitation. With these unique features, this meiosis-directed Y1H system is particularly suited for constructing novel and comprehensive genome-scale gene regulatory networks for various organisms.
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Affiliation(s)
- Chung-Shu Yeh
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Zhifeng Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Fang Miao
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Hongyan Ma
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Chung-Ting Kao
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Tzu-Shu Hsu
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan.,Institute of Biomedical Informatics and Center for Systems and Synthetic Biology, National Yang-Ming University, Taipei 11221, Taiwan
| | - Jhong-He Yu
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Er-Tsi Hung
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chia-Chang Lin
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chen-Yu Kuan
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Ni-Chiao Tsai
- Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chenguang Zhou
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Guan-Zheng Qu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Jing Jiang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Guifeng Liu
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Jack P Wang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.,Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina 27695, USA
| | - Wei Li
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China
| | - Vincent L Chiang
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.,Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina 27695, USA
| | | | - Ying-Chung Jimmy Lin
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China.,Department of Life Sciences and Institute of Plant Biology, College of Life Science, National Taiwan University, Taipei 10617, Taiwan.,Forest Biotechnology Group, Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, North Carolina 27695, USA
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9
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Chang SL, Wang HK, Tung L, Chang TH. Adaptive transcription-splicing resynchronization upon losing an essential splicing factor. Nat Ecol Evol 2018; 2:1818-1823. [PMID: 30297747 DOI: 10.1038/s41559-018-0684-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/31/2018] [Indexed: 01/21/2023]
Abstract
Essential genes form the core of a genome and are therefore thought to be indispensable for cellular viability. However, recent findings have challenged this notion in that cells may survive in the absence of some essential genes provided that relevant genetic modifiers are in existence. We therefore hypothesized that the loss of an essential gene may not always be fatefully detrimental; instead, it may pave the way towards genome evolution. We experimentally tested this hypothesis in the context of pre-messenger RNA splicing by evolving yeast cells harbouring a permanent loss of the essential splicing factor Prp28 in the presence of a genetic modifier. Here, we show that cellular fitness can be restored by compensatory mutations that alter either the splicing machinery per se or the Spt-Ada-Gcn5 acetyltransferase transcription co-activator complex in the cells with no Prp28. Biochemical and genetic analysis revealed that slowing down transcription compensates for splicing deficiency, which in turn boosts cellular fitness. In addition, we found that inefficient splicing also conversely decreases nascent RNA production. Taken together, our data suggest that transcription-splicing synchronization contributes to robustness in the gene-expression pathway and argue that the intrinsic interconnectivity within a biological system can be exploited for compensatory evolution and system re-optimization.
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Affiliation(s)
| | - Hsuan-Kai Wang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.,Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan
| | - Luh Tung
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan. .,Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan.
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10
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Lin YS, Chang TH, Chen MC. 214Inhibition of LXR/RXR pathway through septal pacing: novel mechanism of myopathy induced by pacing. Europace 2018. [DOI: 10.1093/europace/euy015.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Y S Lin
- Chang Gung Memorial Hospital Kaohsiung, Divisions of Cardiology, Kaohsiung, Taiwan ROC
| | - T H Chang
- Taipei Medical University Hospital, Taipei, Taiwan ROC
| | - M C Chen
- Chang Gung Memorial Hospital Kaohsiung, Divisions of Cardiology, Kaohsiung, Taiwan ROC
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Yeh CS, Chang SL, Chen JH, Wang HK, Chou YC, Wang CH, Huang SH, Larson A, Pleiss JA, Chang WH, Chang TH. The conserved AU dinucleotide at the 5' end of nascent U1 snRNA is optimized for the interaction with nuclear cap-binding-complex. Nucleic Acids Res 2017; 45:9679-9693. [PMID: 28934473 PMCID: PMC5766165 DOI: 10.1093/nar/gkx608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/05/2017] [Indexed: 11/13/2022] Open
Abstract
Splicing is initiated by a productive interaction between the pre-mRNA and the U1 snRNP, in which a short RNA duplex is established between the 5' splice site of a pre-mRNA and the 5' end of the U1 snRNA. A long-standing puzzle has been why the AU dincucleotide at the 5'-end of the U1 snRNA is highly conserved, despite the absence of an apparent role in the formation of the duplex. To explore this conundrum, we varied this AU dinucleotide into all possible permutations and analyzed the resulting molecular consequences. This led to the unexpected findings that the AU dinucleotide dictates the optimal binding of cap-binding complex (CBC) to the 5' end of the nascent U1 snRNA, which ultimately influences the utilization of U1 snRNP in splicing. Our data also provide a structural interpretation as to why the AU dinucleotide is conserved during evolution.
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Affiliation(s)
- Chung-Shu Yeh
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan.,Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | - Jui-Hui Chen
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Hsuan-Kai Wang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan.,Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei, Taiwan
| | - Yue-Chang Chou
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | | | - Shih-Hsin Huang
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan.,Chemical Biology and Molecular Biophysics program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
| | - Amy Larson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jeffrey A Pleiss
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Wei-Hau Chang
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Tien-Hsien Chang
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan.,Genomics Research Center, Academia Sinica, Taipei, Taiwan
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12
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Chen JJ, Chen CH, Hwang TL, Chang TH. New Isoflavones from the Fuits of Psoralea corylifolia and their Anti-inflammatory Activity. Am J Transl Res 2017. [DOI: 10.1055/s-0037-1608132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- JJ Chen
- Faculty of Pharmacy, School of Pharmaceutical Sciences, National Yang-Ming University, Taipei 112, Taiwan
| | - CH Chen
- Department of Pharmacy, Tajen University, Pingtung 907, Taiwan
| | - TL Hwang
- Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
| | - TH Chang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan
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13
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Tsai PW, Chien CY, Yeh YC, Tung L, Chen HF, Chang TH, Lan CY. Candida albicans Hom6 is a homoserine dehydrogenase involved in protein synthesis and cell adhesion. J Microbiol Immunol Infect 2016; 50:863-871. [PMID: 27089825 DOI: 10.1016/j.jmii.2016.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/22/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND/PURPOSE Candida albicans is a common fungal pathogen in humans. In healthy individuals, C. albicans represents a harmless commensal organism, but infections can be life threatening in immunocompromised patients. The complete genome sequence of C. albicans is extremely useful for identifying genes that may be potential drug targets and important for pathogenic virulence. However, there are still many uncharacterized genes in the Candida genome database. In this study, we investigated C. albicans Hom6, the functions of which remain undetermined experimentally. METHODS HOM6-deleted and HOM6-reintegrated mutant strains were constructed. The mutant strains were compared with wild-type in their growth in various media and enzyme activity. Effects of HOM6 deletion on translation were further investigated by cell susceptibility to hygromycin B or cycloheximide, as well as by polysome profiling, and cell adhesion to polystyrene was also determined. RESULTS C. albicans Hom6 exhibits homoserine dehydrogenase activity and is involved in the biosynthesis of methionine and threonine. HOM6 deletion caused translational arrest in cells grown under amino acid starvation conditions. Additionally, Hom6 protein was found in both cytosolic and cell-wall fractions of cultured cells. Furthermore, HOM6 deletion reduced C. albicans cell adhesion to polystyrene, which is a common plastic used in many medical devices. CONCLUSION Given that there is no Hom6 homologue in mammalian cells, our results provided an important foundation for future development of new antifungal drugs.
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Affiliation(s)
- Pei-Wen Tsai
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chu-Yang Chien
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ying-Chieh Yeh
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Luh Tung
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Hsueh-Fen Chen
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Nankang, Taipei, Taiwan
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan; Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan.
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14
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Wu JS, Chen TY, Chang S, Chang TH, Chang WH. A Single-Molecule FRET Strategy that Enables the Ordering the Proximities of Yeast Specific U1 Proteins to the 5 Splice Site. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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15
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Yao HY, Jiang JY, Cheng YS, Chen ZY, Her TH, Chang TH. Modal analysis and efficient coupling of TE₀₁ mode in small-core THz Bragg fibers. Opt Express 2015; 23:27266-27281. [PMID: 26480387 DOI: 10.1364/oe.23.027266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report a design of low-loss THz Bragg fibers with a core size on the order of wavelength that operates near the cutoff frequency of its TE01 mode. We also propose a broadband Y-type mode converter based on branched rectangular metallic waveguides to facilitate coupling between the TE01 mode of the Bragg fiber and the TEM mode in free space with 60% efficiency. Our fiber holds strong promise to facilitate beam-wave interaction in gyrotron for high-efficiency THz generation.
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16
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Chang SL, Leu JY, Chang TH. A population study of killer viruses reveals different evolutionary histories of two closely related Saccharomyces sensu stricto yeasts. Mol Ecol 2015; 24:4312-22. [PMID: 26179470 DOI: 10.1111/mec.13310] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 06/29/2015] [Accepted: 07/07/2015] [Indexed: 12/25/2022]
Abstract
Microbes have evolved ways of interference competition to gain advantage over their ecological competitors. The use of secreted killer toxins by yeast cells through acquiring double-stranded RNA viruses is one such prominent example. Although the killer behaviour has been well studied in laboratory yeast strains, our knowledge regarding how killer viruses are spread and maintained in nature and how yeast cells co-evolve with viruses remains limited. We investigated these issues using a panel of 81 yeast populations belonging to three Saccharomyces sensu stricto species isolated from diverse ecological niches and geographic locations. We found that killer strains are rare among all three species. In contrast, killer toxin resistance is widespread in Saccharomyces paradoxus populations, but not in Saccharomyces cerevisiae or Saccharomyces eubayanus populations. Genetic analyses revealed that toxin resistance in S. paradoxus is often caused by dominant alleles that have independently evolved in different populations. Molecular typing identified one M28 and two types of M1 killer viruses in those killer strains. We further showed that killer viruses of the same type could lead to distinct killer phenotypes under different host backgrounds, suggesting co-evolution between the viruses and hosts in different populations. Taken together, our data suggest that killer viruses vary in their evolutionary histories even within closely related yeast species.
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Affiliation(s)
- Shang-Lin Chang
- Genomics Research Center, Academia Sinica, 128 Sec. 2, Academia Road, Nankang, Taipei, 115, Taiwan
| | - Jun-Yi Leu
- Institute of Molecular Biology, Academia Sinica, 128 Sec. 2, Academia Road, Taipei, 115, Taiwan
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, 128 Sec. 2, Academia Road, Nankang, Taipei, 115, Taiwan
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17
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Hsu HE, Liu TN, Yeh CS, Chang TH, Lo YC, Kao CF. Feedback Control of Snf1 Protein and Its Phosphorylation Is Necessary for Adaptation to Environmental Stress. J Biol Chem 2015; 290:16786-96. [PMID: 25947383 DOI: 10.1074/jbc.m115.639443] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Indexed: 12/26/2022] Open
Abstract
Snf1, a member of the AMP-activated protein kinase family, plays a critical role in metabolic energy control in yeast cells. Snf1 activity is activated by phosphorylation of Thr-210 on the activation loop of its catalytic subunit; following activation, Snf1 regulates stress-responsive transcription factors. Here, we report that the level of Snf1 protein is dramatically decreased in a UBP8- and UBP10-deleted yeast mutant (ubp8Δ ubp10Δ), and this is independent of transcriptional regulation and proteasome-mediated degradation. Surprisingly, most Snf1-mediated functions, including glucose limitation regulation, utilization of alternative carbon sources, stress responses, and aging, are unaffected in this strain. Snf1 phosphorylation in ubp8Δ ubp10Δ cells is hyperactivated upon stress, which may compensate for the loss of the Snf1 protein and protect cells against stress and aging. Furthermore, artificial elevation of Snf1 phosphorylation (accomplished through deletion of REG1, which encodes a protein that regulates Snf1 dephosphorylation) restored Snf1 protein levels and the regulation of Snf1 activity in ubp8Δ ubp10Δ cells. Our results reveal the existence of a feedback loop that controls Snf1 protein level and its phosphorylation, which is masked by Ubp8 and Ubp10 through an unknown mechanism. We propose that this dynamic modulation of Snf1 phosphorylation and its protein level may be important for adaptation to environmental stress.
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Affiliation(s)
- Hsiang-En Hsu
- From the Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taipei, Taiwan
| | - Tzu-Ning Liu
- the Institute of Food Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei 10617
| | - Chung-Shu Yeh
- the Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei 11221, and the Genomics Research Center and
| | - Tien-Hsien Chang
- the Institute of Biochemistry and Molecular Biology, National Yang Ming University, Taipei 11221, and the Genomics Research Center and
| | - Yi-Chen Lo
- the Institute of Food Science and Technology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei 10617,
| | - Cheng-Fu Kao
- From the Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taipei, Taiwan
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18
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19
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Chang TH, Tung L, Yeh FL, Chen JH, Chang SL. Functions of the DExD/H-box proteins in nuclear pre-mRNA splicing. Biochim Biophys Acta 2013; 1829:764-74. [PMID: 23454554 DOI: 10.1016/j.bbagrm.2013.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/05/2013] [Accepted: 02/13/2013] [Indexed: 01/09/2023]
Abstract
In eukaryotes, many genes are transcribed as precursor messenger RNAs (pre-mRNAs) that contain exons and introns, the latter of which must be removed and exons ligated to form the mature mRNAs. This process is called pre-mRNA splicing, which occurs in the nucleus. Although the chemistry of pre-mRNA splicing is identical to that of the self-splicing Group II introns, hundreds of proteins and five small nuclear RNAs (snRNAs), U1, U2, U4, U5, and U6, are essential for executing pre-mRNA splicing. Spliceosome, arguably the most complex cellular machine made up of all those proteins and snRNAs, is responsible for carrying out pre-mRNA splicing. In contrast to the transcription and the translation machineries, spliceosome is formed anew onto each pre-mRNA and undergoes a series of highly coordinated reconfigurations to form the catalytic center. This amazing process is orchestrated by a number of DExD/H-proteins that are the focus of this article, which aims to review the field in general and to project the exciting challenges and opportunities ahead. This article is part of a Special Issue entitled: The Biology of RNA helicases - Modulation for life.
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20
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Shea FF, Rowell JL, Li Y, Chang TH, Alvarez CE. Mammalian α arrestins link activated seven transmembrane receptors to Nedd4 family e3 ubiquitin ligases and interact with β arrestins. PLoS One 2012; 7:e50557. [PMID: 23236378 PMCID: PMC3517545 DOI: 10.1371/journal.pone.0050557] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 10/25/2012] [Indexed: 01/14/2023] Open
Abstract
The complement of fungal cell surface proteins is widely regulated by ubiquitination of membrane proteins, which results in their endocytosis and vacuolar degradation. For diverse fungal transporters, the specificity of ubiquitination is conferred by alpha arrestin adaptors, which recruit the Nedd4 family E3 ubiquitin ligase Rsp5. A recent study showed that one mammalian alpha arrestin also mediates ubiquitination and lysosomal trafficking of an activated plasma membrane receptor. Here we first screen all five widely-expressed human alpha arrestins for subcellular localization in ligand-stimulated and -unstimulated cells overexpressing the seven transmembrane receptor vasopressin 2. We then characterize the effects of alpha arrestins ARRDC3 and ARRDC4 upon activation of the seven transmembrane receptors vasopressin 2 and beta adrenergic 2. Using biochemical and imaging approaches, we show that ligand-activated receptors interact with alpha arrestins, and this results in recruitment of Nedd4 family E3 ubiquitin ligases and receptor ubiquitination - which are known to result in lysosomal trafficking. Our time course studies show these effects occur in the first 1-5 minutes after ligand activation, the same time that beta arrestins are known to have roles in receptor endocytic trafficking and kinase signaling. We tested the possibility that alpha and beta arrestins function coordinately and found co-immunoprecipitation and colocalization evidence to support this. Others recently reported that Arrdc3 knockout mice are lean and resistant to obesity. In the course of breeding our own Arrdc3-deficient mice, we observed two novel phenotypes in homozygotes: skin abnormalities, and embryonic lethality on normal chow diet, but not on high fat diet. Our findings suggest that alpha and beta arrestins function coordinately to maintain the optimal complement and function of cell surface proteins according to cellular physiological context and external signals. We discuss the implications of the alpha arrestin functions in fungi having evolved into coordinated alpha/beta arrestin functions in animals.
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Affiliation(s)
- Fortune F. Shea
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Jennie L. Rowell
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- College of Nursing, The Ohio State University, Columbus, Ohio, United States of America
| | - Yechaowei Li
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | | | - Carlos E. Alvarez
- Center for Molecular and Human Genetics, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, United States of America
- College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States of America
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21
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Levenson SM, Chang TH, Kan-Gruber D, Gruber C, Steinberg JJ, Liu X, Watford A, Freundlich L, Rojkind M. Accelerating effects of nonviable Staphylococcus aureus, its cell wall, and cell wall peptidoglycan. Wound Repair Regen 2012; 4:461-9. [PMID: 17309697 DOI: 10.1046/j.1524-475x.1996.40410.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously reported that local application of viable Staphylococcus aureus dramatically accelerates wound healing, but viable Staphylococcus epidermidis does not. Because the S. aureus effect occurred in the absence of infection and because the cell walls of the two bacterial species differ, we hypothesized that nonviable S. aureus, its cell wall, and its cell wall component(s) would accelerate healing. Nonviable S. aureus was prepared by chemical and physical means, and its cell wall and peptidoglycan was prepared from heat-killed cultures. In a large number of experiments, nonviable S. aureus (independent of the strain's protein A content), its cell wall, and peptidoglycan when instilled locally at the time of wounding each significantly increased the breaking strength of rat skin incisions (tested both in the fresh state and after formalin fixation). These agents also enhanced subcutaneous polyvinyl alcohol sponge reparative tissue collagen accumulation, generally by a factor of two. Histologic features of treated and control incisions were similar. In contrast, the reparative tissue of treated sponges contained more neutrophils, macrophages, capillaries, and collagen. These experimental data thus confirm our previous studies, as well as our hypothesis, and extend these observations of enhanced wound healing to specific fractions of the bacterial cell wall.
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Affiliation(s)
- S M Levenson
- Department of Surgery, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA
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Liu X, Levenson SE, Chang TH, Steinberg JJ, Imegwu O, Rojkind M. Molecular mechanisms underlying wound healing acceleration by Staphylococcus aureus peptidoglycan. Wound Repair Regen 2012; 4:470-6. [PMID: 17309698 DOI: 10.1046/j.1524-475x.1996.40411.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Molecular mechanisms involved in wound healing acceleration by Staphylococcus aureus peptidoglycan were investigated with the use of polyvinyl alcohol sponges implanted under the dorsal skin of rats. Total collagen and RNA content and messenger RNA levels of alpha1(I) and alpha1(III) procollagen, transforming growth factor-beta1, and matrix metalloproteinase-1 were analyzed in saline solution- and S. aureus peptidoglycan-inoculated sponges at 4, 7, 14, and 21 days after implantation. S. aureus peptidoglycan-inoculated sponges on the fourth and seventh post-operative day were surrounded and penetrated by a thick capsule of reparative connective tissue. They were considerably heavier and contained more collagen and total RNA than saline solution-inoculated sponges. Histologically, the S. aureus peptidoglycan-inoculated sponges early on contained a denser infiltrate of polymorphonuclear cells than saline solution-inoculated sponges, and later fibroblasts, macrophages, collagen, and newly formed blood vessels were more abundant in the S. aureus peptidoglycan sponges. Matrix metalloproteinase-1 messenger RNA expression was elevated at 4 days in both sponge types. However, although matrix metalloproteinase-1 mRNA levels decreased to undetectable levels by 14 days in saline solution-inoculated sponges, they remained elevated throughout the 21-day study period in S. aureus peptidoglycan-inoculated sponges. No other significant differences in the parameters analyzed were detected. These results suggest that S. aureus peptidoglycan induces an accelerated but normal wound healing process in which the markedly increased early deposition of connective tissue is rapidly remodeled likely because of a sustained expression of matrix metalloproteinase-1.
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Affiliation(s)
- X Liu
- Department of Surgery,Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA
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Wang CY, Wen WL, Nilsson D, Sunnerhagen P, Chang TH, Wang SW. Analysis of stress granule assembly in Schizosaccharomyces pombe. RNA 2012; 18:694-703. [PMID: 22328580 PMCID: PMC3312557 DOI: 10.1261/rna.030270.111] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 12/11/2011] [Indexed: 05/20/2023]
Abstract
Stress granules (SGs) are cytoplasmic aggregates of RNA and proteins in eukaryotic cells that are rapidly induced in response to environmental stress, but are not seen in cells growing under favorable conditions. SGs have been primarily studied in mammalian cells. The existence of SGs in the fission yeast and the distantly related budding yeast was demonstrated only recently. In both species, they contain many orthologs of the proteins seen in mammalian SGs. In this study, we have characterized these proteins and determined their involvement in the assembly of fission yeast SGs, in particular, the homolog of human G3BP proteins. G3BP interacts with the deubiquitinating protease USP10 and plays an important role in the assembly of SGs. We have also identified Ubp3, an ortholog of USP10, as an interaction partner of the fission yeast G3BP-like protein Nxt3 and required for its stability. Under thermal stress, like their human orthologs, both Nxt3 and Ubp3 rapidly relocalize to cytoplasmic foci that contain the SG marker poly(A)-binding protein Pabp. However, in contrast to G3BP1 and USP10, neither deletion nor overexpression of nxt3(+) or ubp3(+) affected the assembly of fission yeast SGs as judged by the relocalization of Pabp. Similar results were observed in mutants defective in orthologs of SG components that are known to affect SG assembly in human and in budding yeast, such as ataxia-2 and TIA-like proteins. Together, our data indicate that despite similar protein compositions, the underlying molecular mechanisms for the assembly of SGs could be distinct between species.
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Affiliation(s)
- Chun-Yu Wang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan
| | - Wei-Ling Wen
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan
| | - Daniel Nilsson
- Department of Cell and Molecular Biology, Lundberg Laboratory, University of Gothenburg, S-405 30 Göteborg, Sweden
| | - Per Sunnerhagen
- Department of Cell and Molecular Biology, Lundberg Laboratory, University of Gothenburg, S-405 30 Göteborg, Sweden
| | - Tien-Hsien Chang
- Genomics Research Center, Academia Sinica, Nankang, Taipei 11529, Taiwan
| | - Shao-Win Wang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County 350, Taiwan
- Corresponding author.E-mail .
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Shieh GS, Pan CH, Wu JH, Sun YJ, Wang CC, Hsiao WC, Lin CY, Tung L, Chang TH, Fleming AB, Hillyer C, Lo YC, Berger SL, Osley MA, Kao CF. H2B ubiquitylation is part of chromatin architecture that marks exon-intron structure in budding yeast. BMC Genomics 2011; 12:627. [PMID: 22188810 PMCID: PMC3274495 DOI: 10.1186/1471-2164-12-627] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 12/22/2011] [Indexed: 11/23/2022] Open
Abstract
Background The packaging of DNA into chromatin regulates transcription from initiation through 3' end processing. One aspect of transcription in which chromatin plays a poorly understood role is the co-transcriptional splicing of pre-mRNA. Results Here we provide evidence that H2B monoubiquitylation (H2BK123ub1) marks introns in Saccharomyces cerevisiae. A genome-wide map of H2BK123ub1 in this organism reveals that this modification is enriched in coding regions and that its levels peak at the transcribed regions of two characteristic subgroups of genes. First, long genes are more likely to have higher levels of H2BK123ub1, correlating with the postulated role of this modification in preventing cryptic transcription initiation in ORFs. Second, genes that are highly transcribed also have high levels of H2BK123ub1, including the ribosomal protein genes, which comprise the majority of intron-containing genes in yeast. H2BK123ub1 is also a feature of introns in the yeast genome, and the disruption of this modification alters the intragenic distribution of H3 trimethylation on lysine 36 (H3K36me3), which functionally correlates with alternative RNA splicing in humans. In addition, the deletion of genes encoding the U2 snRNP subunits, Lea1 or Msl1, in combination with an htb-K123R mutation, leads to synthetic lethality. Conclusion These data suggest that H2BK123ub1 facilitates cross talk between chromatin and pre-mRNA splicing by modulating the distribution of intronic and exonic histone modifications.
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Affiliation(s)
- Grace S Shieh
- Institute of Statistical Sciences, Academia Sinica, Academia Road, Nankang, Taipei 115, Taiwan
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Abstract
To uncover the intriguing non-thermal microwave effect, an experiment was conducted using an amplifier rather than an oscillator as the radiation source, which was injected into an applicator with strong electromagnetic field enhancement. The characteristics of the applicator are discussed and the enhancement of the microwave field is illustrated and explained. Thermal distribution is simulated based on the calculated microwave field profile. It was demonstrated that the proposed system heated a SiC susceptor to a temperature of 637 °C with the input power of 60 W. The reasons for such an efficient heating are discussed.
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Affiliation(s)
- T H Chang
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan.
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Su CH, Shih CH, Chang TH, Tsai HK. Genome-wide analysis of the cis-regulatory modules of divergent gene pairs in yeast. Genomics 2010; 96:352-61. [PMID: 20826206 DOI: 10.1016/j.ygeno.2010.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 08/27/2010] [Accepted: 08/27/2010] [Indexed: 01/16/2023]
Abstract
In budding yeast, approximately a quarter of adjacent genes are divergently transcribed (divergent gene pairs). Whether genes in a divergent pair share the same regulatory system is still unknown. By examining transcription factor (TF) knockout experiments, we found that most TF knockout only altered the expression of one gene in a divergent pair. This prompted us to conduct a comprehensive analysis in silico to estimate how many divergent pairs are regulated by common sets of TFs (cis-regulatory modules, CRMs) using TF binding sites and expression data. Analyses of ten expression datasets show that only a limited number of divergent gene pairs share CRMs in any single dataset. However, around half of divergent pairs do share a regulatory system in at least one dataset. Our analysis suggests that genes in a divergent pair tend to be co-regulated in at least one condition; however, in most conditions, they may not be co-regulated.
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Affiliation(s)
- Chien-Hao Su
- Institute of Information Science, Academia Sinica, Taipei 115, Taiwan.
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Chang TH, Shew BY, Wu CY, Chen NC. X-ray microfabrication and measurement of a terahertz mode converter. Rev Sci Instrum 2010; 81:054701. [PMID: 20515160 DOI: 10.1063/1.3385685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Mode converters are critical for frequency-tunable terahertz gyrotrons. This study reports the development of a broadband TE(02) mode converter centered at 0.2 THz. An octafeed sidewall coupling structure was employed and the mode purity was analyzed. The converter was built using the technique of x-ray microfabrication. The x rays irradiated on the SU-8 resist and generated a template of very high thickness of 1.295 mm. Pulse electroplating technique was used to deposit copper on the structure along the template. The parts then went through precise machining and the residual resist was removed via high-flux radical etching. A computer-aided diagnostic system was introduced to measure the performance of the converter. Results suggest that the frequency response of resistivity should be taken into consideration for the devices in terahertz region.
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Affiliation(s)
- T H Chang
- Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan.
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Chen KT, Lu CS, Chang TH, Lai YY, Chang TH, Wu CW, Chen CC. Comparison of photodegradative efficiencies and mechanisms of Victoria Blue R assisted by Nafion-coated and fluorinated TiO2 photocatalysts. J Hazard Mater 2010; 174:598-609. [PMID: 19815344 DOI: 10.1016/j.jhazmat.2009.09.094] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 08/26/2009] [Accepted: 09/17/2009] [Indexed: 05/28/2023]
Abstract
The purposes of this research were to study the effects of two modified photocatalysts, Nafion-coated TiO(2) and fluorinated TiO(2), and photocatalytic degradation of Victoria Blue R in aqueous solution. Photocatalytic degradation of Victoria Blue R was accelerated by the modified photocatalysts. Bulk and surface characterizations of the resulting powders were carried out. Attachment of the anions to the TiO(2) surface using the Nafion-coated-TiO(2) possibly results in increased adsorption of the cationic dye, and the degradation rate is larger for the cationic dye. It was found that Victoria Blue R on the two illuminated TiO(2) surfaces underwent very different changes. To obtain a better understanding on the mechanistic details of this modified-TiO(2)-assisted photodegradation of the Victoria Blue R dye with UV irradiation, a large number of intermediates of the process were separated, identified, and characterized by a high-performance liquid chromatography-mass spectrometry technique. Several probable photodegradation pathways were proposed and discussed.
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Affiliation(s)
- K T Chen
- Department of General Education, Ming Hsing University of Science and Technology, 304 Taiwan, ROC
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29
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Sung HM, Wang TY, Wang D, Huang YS, Wu JP, Tsai HK, Tzeng J, Huang CJ, Lee YC, Yang P, Hsu J, Chang T, Cho CY, Weng LC, Lee TC, Chang TH, Li WH, Shih MC. Roles of trans and cis variation in yeast intraspecies evolution of gene expression. Mol Biol Evol 2009; 26:2533-8. [PMID: 19648464 DOI: 10.1093/molbev/msp171] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Both cis and trans mutations contribute to gene expression divergence within and between species. We used Saccharomyces cerevisiae as a model organism to estimate the relative contributions of cis and trans variations to the expression divergence between a laboratory (BY) and a wild (RM) strain of yeast. We examined whether genes regulated by a single transcription factor (TF; single input module, SIM genes) or genes regulated by multiple TFs (multiple input module, MIM genes) are more susceptible to trans variation. Because a SIM gene is regulated by a single immediate upstream TF, the chance for a change to occur in its trans-acting factors would, on average, be smaller than that for a MIM gene. We chose 232 genes that exhibited expression divergence between BY and RM to test this hypothesis. We examined the expression patterns of these genes in a BY-RM coculture system and in a BY-RM diploid hybrid. We found that trans variation is far more important than cis variation for expression divergence between the two strains. However, because in 75% of the genes studied, cis variation has significantly contributed to expression divergence, cis change also plays a significant role in intraspecific expression evolution. Interestingly, we found that the proportion of genes with diverged expression between BY and RM is larger for MIM genes than for SIM genes; in fact, the proportion tends to increase with the number of transcription factors that regulate the gene. Moreover, MIM genes are, on average, subject to stronger trans effects than SIM genes, though the difference between the two types of genes is not conspicuous.
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Affiliation(s)
- Huang-Mo Sung
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
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Hage R, Tung L, Du H, Stands L, Rosbash M, Chang TH. A targeted bypass screen identifies Ynl187p, Prp42p, Snu71p, and Cbp80p for stable U1 snRNP/Pre-mRNA interaction. Mol Cell Biol 2009; 29:3941-52. [PMID: 19451230 PMCID: PMC2704744 DOI: 10.1128/mcb.00384-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 04/22/2009] [Accepted: 05/07/2009] [Indexed: 11/20/2022] Open
Abstract
To understand how DEXD/H-box proteins recognize and interact with their cellular substrates, we have been studying Prp28p, a DEXD/H-box splicing factor required for switching the U1 snRNP with the U6 snRNP at the precursor mRNA (pre-mRNA) 5' splice site. We previously demonstrated that the requirement for Prp28p can be eliminated by mutations that alter either the U1 snRNA or the U1C protein, suggesting that both are targets of Prp28p. Inspired by this finding, we designed a bypass genetic screen to specifically search for additional, novel targets of Prp28p. The screen identified Prp42p, Snu71p, and Cbp80p, all known components of commitment complexes, as well as Ynl187p, a protein of uncertain function. To examine the role of Ynl187p in splicing, we carried out extensive genetic and biochemical analysis, including chromatin immunoprecipitation. Our data suggest that Ynl187p acts in concert with U1C and Cbp80p to help stabilize the U1 snRNP-5' splice site interaction. These findings are discussed in the context of DEXD/H-box proteins and their role in vivo as well as the potential need for more integral U1-snRNP proteins in governing the fungal 5' splice site RNA-RNA interaction compared to the number of U1 snRNP proteins needed by metazoans.
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Affiliation(s)
- Rosemary Hage
- Department of Molecular Genetics, The Ohio State University, 484 West 12th Ave., Columbus, OH 43210, USA
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31
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Zhu LY, Peng JC, Reimer PE, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Mueller BA, Nord PM, Papavassiliou V, Park BK, Petitt G, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Wise DK, Young GR. Measurement of angular distributions of Drell-Yan dimuons in p+p interactions at 800 GeV/c. Phys Rev Lett 2009; 102:182001. [PMID: 19518860 DOI: 10.1103/physrevlett.102.182001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Indexed: 05/27/2023]
Abstract
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a hydrogen target. The polar and azimuthal angular distribution parameters have been extracted over the kinematic range 4.5<m micromicro<15 GeV/c2 (excluding the Upsilon resonance region), 0<p T <4 GeV/c, and 0<x F<0.8. The p+p angular distributions are similar to those of p+d, and both data sets are compared with models which attribute the cos2varphi distribution either to the presence of the transverse-momentum-dependent Boer-Mulders structure function h1 perpendicular to 1 or to QCD effects. The data indicate the need to include QCD effects before reliable information on the Boer-Mulders function can be extracted. The validity of the Lam-Tung relation in p+p Drell-Yan data is also tested.
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Affiliation(s)
- L Y Zhu
- Hampton University, Hampton, Virginia 23187, USA
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Abstract
The rotary joint is a useful microwave component that connects a fixed part to a rotatable part. This study systematically analyzes the effect of the discontinuity on the interface of a rotary joint for several waveguide modes. Simulation results indicate that the transmission of the TE(01) mode is independent of the geometry of the joint, and thus is ideal for such application. A rotary joint consisting of two identical TE(01) mode converters, clasped each other by a bearing, is designed, fabricated, and tested. Back-to-back transmission measurements exhibit an excellent agreement to the results of computer simulations. The measured optimum transmission is 97% with a 3 dB bandwidth of 8.5 GHz, centered at 35.0 GHz. The cold measurement shows that the results are independent of the angle of rotation. In addition, a high-power experiment is conducted. The just developed rotary joint can operate up to a peak input power of 210 W with a duty of 18%. The working principle, although demonstrated in the millimeter-wave region, can be applied up to the terahertz region where the joint gap is generally critical except for the operating TE(01) mode.
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Affiliation(s)
- T H Chang
- Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan.
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Zhu LY, Reimer PE, Mueller BA, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Howell DE, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Nord PM, Papavassiliou V, Park BK, Petitt G, Peng JC, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Winter P, Wise DK, Yin Y, Young GR. Measurement of Upsilon production for p + p and p + d interactions at 800 GeV/c. Phys Rev Lett 2008; 100:062301. [PMID: 18352463 DOI: 10.1103/physrevlett.100.062301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2007] [Indexed: 05/26/2023]
Abstract
We report a high statistics measurement of Upsilon production with an 800 GeV/c proton beam on hydrogen and deuterium targets. The dominance of the gluon-gluon fusion process for Upsilon production at this energy implies that the cross section ratio, sigma(p+d-->Upsilon)/2sigma(p+p-->Upsilon), is sensitive to the gluon content in the neutron relative to that in the proton. Over the kinematic region 0<x(F)<0.6, this ratio is found to be consistent with unity, in striking contrast to the behavior of the Drell-Yan cross section ratio sigma(p+d)(DY)/2sigma(p+p)(DY). This result shows that the gluon distributions in the proton and neutron are very similar. The Upsilon production cross sections are also compared with the p+d and p+Cu cross sections from earlier measurements.
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Affiliation(s)
- L Y Zhu
- University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Abstract
Lead zirconate titanate (Pb(1.1)(Zr(0.52)Ti(0.48))O(3)) thin films of thickness 260 nm on Pt/Ti/SiO(2)/Si substrates were densified by 2.45 GHz microwave annealing. The PZT thin films were annealed at various annealing temperatures from 400 to 700 °C for 30 min. X-ray diffraction showed that the pyrochlore phase was transformed to the perovskite phase at 450 °C and the film was fully crystallized. The secondary (again pyrochlore) phase was observed in the PZT thin films, which were annealed above 550 °C. The surface morphologies were changed above 550 °C of the PZT thin films due to the secondary phase. Higher dielectric constant (ε(r)) and lower dielectric loss coercive field (E(c)) were achieved for the 450 °C film than for the other annealed films.
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Affiliation(s)
- Ankam Bhaskar
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan 30013, Republic of China
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Zhu LY, Peng JC, Reimer PE, Awes TC, Brooks ML, Brown CN, Bush JD, Carey TA, Chang TH, Cooper WE, Gagliardi CA, Garvey GT, Geesaman DF, Hawker EA, He XC, Isenhower LD, Kaplan DM, Kaufman SB, Klinksiek SA, Koetke DD, Lee DM, Lee WM, Leitch MJ, Makins N, McGaughey PL, Moss JM, Mueller BA, Nord PM, Papavassiliou V, Park BK, Petitt G, Sadler ME, Sondheim WE, Stankus PW, Thompson TN, Towell RS, Tribble RE, Vasiliev MA, Webb JC, Willis JL, Wise DK, Young GR. Measurement of angular distributions of Drell-Yan dimuons in p+d interactions at 800 GeV/c. Phys Rev Lett 2007; 99:082301. [PMID: 17930942 DOI: 10.1103/physrevlett.99.082301] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Indexed: 05/25/2023]
Abstract
We report a measurement of the angular distributions of Drell-Yan dimuons produced using an 800 GeV/c proton beam on a deuterium target. The muon angular distributions in the dilepton rest frame have been measured over the kinematic range 4.5<m{mu mu}<15 GeV/c{2}, 0<p{T}<4 GeV/c, and 0<x{F}<0.8. No significant cos2phi dependence is found in these proton-induced Drell-Yan data, in contrast with the situation for pion-induced Drell-Yan data. The data are compared with expectations from models which attribute the cos2phi distribution to a QCD vacuum effect or to the presence of the transverse-momentum-dependent Boer-Mulders structure function h{1}{perpendicular}. Constraints on the magnitude of the sea-quark h{1}{perpendicular} structure functions are obtained.
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Affiliation(s)
- L Y Zhu
- University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Imegwu O, Chang TH, Steinberg JJ, Levenson SM. Staphylococcus aureus peptidoglycan ameliorates cyclophosphamide-induced impairment of wound healing. Wound Repair Regen 2007; 5:364-72. [PMID: 16984447 DOI: 10.1046/j.1460-9568.1997.50411.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cyclophosphamide given systemically to rats leads to impaired wound healing, characterized by decreases in the inflammatory reaction, fibroplasia, neovascularization, reparative collagen accumulation, and wound breaking strength. In contrast, the local application of Staphylococcus aureus peptidoglycan at the time of wounding increases all of these processes in normal rats. Accordingly, we hypothesized that inoculation of S. aureus peptidoglycan into wounds of cyclophosphamide-treated rats would ameliorate the otherwise impaired healing. Dorsal bilateral skin incisions and subcutaneous implantation of polyvinyl alcohol sponges (two on each side) were performed on male Sprague-Dawley rats receiving either saline or cyclophosphamide (24 mg/kg) intraperitoneally at the time of operation, on postoperative days 1, 2, 3, 4 (for rats killed on postoperative day 7), and also on day 8 (for rats killed on postoperative day 14). The incisions on one side were inoculated at the time of closure with 0.2 ml of saline solution, and the incisions on the other side with 6 mg S. aureus peptidoglycan in 0.2 ml saline solution (860 microg/cm incision). The sponges were instilled with 0.1 ml saline solution on the saline solution-instilled incision side or with S. aureus peptidoglycan 0.5 mg/sponge) in 0.1 ml saline solution on the other side. In control rats receiving saline solution intraperitoneally, incisions treated with S. aureus peptidoglycan were significantly stronger than saline solution-treated incisions by a factor of 1.8 at 1 week (p < 0.001); at 2 weeks the increase was small and not significant. Cardiac blood leukocytes and platelets fell markedly (90%) in cyclophosphamide- treated rats, and there was a decrease in wound breaking strength of their saline-treated incisions at both 7 and 14 days compared with saline solution-treated incisions of control rats. S. aureus peptidoglycan treatment of the wounds completely prevented this effect at 7 days, and partially at 14 days. Polyvinyl alcohol sponge reparative tissue hydroxyproline, 7 days after surgery, was decreased in cyclophosphamide-treated rats; this was completely prevented by S. aureus peptidoglycan treatment of the sponges. Histologically, the inflammatory response to the wounding, influx of macrophages and fibroblasts, angiogenesis, and collagen accumulation were all reduced at day 7 and 14 after surgery in the sponge reparative tissue of cyclophosphamide- treated rats; this was prevented by S. aureus peptidoglycan treatment of the sponges. In conclusion, a single local application of S. aureus peptidoglycan ameliorates cyclophosphamide-impaired wound healing.
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Affiliation(s)
- O Imegwu
- Department of Surgery, Albert Einstein College of Medicine, Jack and Pearl Resnick Campus and Montefiore Medical Center, Bronx, NY 10461, USA
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Chang TH, Patel M, Watford A, Freundlich L, Steinberg JJ. Single local instillation of nonviable Staphylococcus aureus or its peptidoglycan ameliorates glucocorticoid-induced impaired wound healing. Wound Repair Regen 2007; 5:184-90. [PMID: 16984429 DOI: 10.1046/j.1524-475x.1997.50211.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An excess in glucocorticoid steroids, either from endogenous or exogenous sources, has been shown to inhibit wound repair. Key to this impairment is a diminution of the inflammatory response to wounding, fibroplasia, capillary formation, reparative tissue collagen accumulation, and wound breaking strength. Because a single local application at operation of nonviable Staphylococcus aureus or its peptidoglycan increases all of these processes in normal rats, we hypothesized that nonviable S. aureus and S. aureus peptidoglycan would each ameliorate glucocorticoid-induced impaired healing. Sprague-Dawley male rats aseptically received two 7 cm paravertebral skin incisions and underwent subcutaneous implantation of polyvinyl alcohol sponges. Two glucocorticoids were used: hydrocortisone, 8 mg intramuscularly, daily beginning 1 day before operation and continuing during the postoperative period; or a single dose of a long-acting preparation of methylprednisolone, 6 or 8 mg intramuscularly, on the day before operation. Controls received intramuscular injections of saline solution at the same respective times. At the time of the operation, one incision and the polyvinyl alcohol sponges on one side of the animal were instilled with saline solution while the incision and sponges on the opposite side were instilled with nonviable S. aureus (hydrocortisone study) or S. aureus peptidoglycan (two methylprednisolone studies). The data showed that, at postoperative day 7, the single local application at wounding of nonviable S. aureus or S. aureus peptidoglycan increased wound breaking strength in the control rats by factors of 1.6 in the hydrocortisone experiment and 1.4 and 1.6 in the methylprednisolone studies. These treatments prevented (in hydrocortisone-treated rats) or mitigated (in methylprednisolone-treated rats) the glucocorticoid-induced decrease in wound breaking strength. In addition, these treatments prevented the glucocorticoid-induced decreases in the inflammatory (largely mononuclear cells) response to wounding and in the accumulation within the polyvinyl alcohol sponge of reparative tissue fibroblasts, capillaries, and collagen.
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Affiliation(s)
- T H Chang
- Department of Surgery, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY 10461, USA
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Abstract
Correct interactions between transcription factors (TFs) and their binding sites (TFBSs) are of central importance to gene regulation. Recently developed chromatin-immunoprecipitation DNA chip (ChIP-chip) techniques and the phylogenetic footprinting method provide ways to identify TFBSs with high precision. In this study, we constructed a user-friendly interactive platform for dynamic binding site mapping using ChIP-chip data and phylogenetic footprinting as two filters. MYBS (Mining Yeast Binding Sites) is a comprehensive web server that integrates an array of both experimentally verified and predicted position weight matrixes (PWMs) from eleven databases, including 481 binding motif consensus sequences and 71 PWMs that correspond to 183 TFs. MYBS users can search within this platform for motif occurrences (possible binding sites) in the promoters of genes of interest via simple motif or gene queries in conjunction with the above two filters. In addition, MYBS enables users to visualize in parallel the potential regulators for a given set of genes, a feature useful for finding potential regulatory associations between TFs. MYBS also allows users to identify target gene sets of each TF pair, which could be used as a starting point for further explorations of TF combinatorial regulation. MYBS is available at http://cg1.iis.sinica.edu.tw/~mybs/.
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Affiliation(s)
- Huai-Kuang Tsai
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
- *To whom correspondence should be addressed. 886-2-27883799 886-2-27824814 Correspondence may also be addressed to Wen-Hsiung Li. 1-773-702-3104
| | - Meng-Yuan Chou
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
| | - Ching-Hua Shih
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
| | - Grace Tzu-Wei Huang
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
| | - Tien-Hsien Chang
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
| | - Wen-Hsiung Li
- Institute of Information Science, Genomics Research Center, Academia Sinica, Taipei, 115 Taiwan, Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 and Department of Ecology and Evolution, University of Chicago, 1101 East 57th Street, Chicago, IL 60637, USA
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Chang SW, Chang TH, Abler RAB, Jung G. Variation in Bentgrass Susceptibility to Typhula incarnata and in Isolate Aggressiveness Under Controlled Environment Conditions. Plant Dis 2007; 91:446-452. [PMID: 30781188 DOI: 10.1094/pdis-91-4-0446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Typhula incarnata, the causal agent of gray snow mold, is an important winter pathogen of turfgrasses in the northern United States. The relative susceptibility of cultivars of three bent-grass species (creeping, colonial, and velvet bentgrass) to Typhula incarnata and the aggressiveness of 15 T. incarnata isolates obtained from infected turfgrasses on golf courses in Michigan, Minnesota, and Wisconsin were evaluated under controlled conditions. A hypersensitive type of resistance response to T. incarnata was not observed in any cultivar. Disease severity increased with higher inoculum concentration of T. incarnata. Colonization by gray snow mold gradually decreased with increasing plant age from 11 weeks after seeding in most cultivars tested, suggesting that age-related resistance was expressed over time. There were significant differences in disease severity among the three bentgrass species, particularly between tetraploid (creeping and colonial) and diploid (velvet) species, and among cultivars within each species, indicating varying levels of susceptibility to T. incarnata. All 15 isolates were pathogenic on bentgrass and were significantly different in aggressiveness, but aggressiveness was not related to geographic origin. Therefore, turfgrass breeders should be able to use one or a few virulent representative isolates of the pathogen to screen for resistance.
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Affiliation(s)
- S W Chang
- Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst 01003
| | - T H Chang
- Department of Plant Resources, College of Life Science and Natural Resources, Sangju National University, Sangju-city, Gyeongsang Buk-Do, 742-711, South Korea
| | - R A B Abler
- Biological Sciences, University of Wisconsin-Manitowoc, Manitowoc 54220
| | - G Jung
- Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst 01003
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Pao KF, Chang TH, Chen SH, Chu KR. Rise and fall time behavior of the gyrotron backward-wave oscillator. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 74:046405. [PMID: 17155180 DOI: 10.1103/physreve.74.046405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Indexed: 05/12/2023]
Abstract
The rise and fall time behavior of a pulsed microwave oscillator is a problem of academic interest. It is also of importance to radar and other applications because it can lead to phase and frequency jitters or even lock the entire pulse into an undesired mode. Here we present a study of the rise and fall time behavior in the gyrotron backward-wave oscillator (gyro-BWO). Single-mode simulations reveal that, during the rise and fall portions of the electron beam pulse, oscillation frequencies of the axial modes vary in such a way that their transit angles remain at the respective optimum values. Thus, axial mode competition and mode switching can readily take place in these transient stages. Time-dependent simulations demonstrate that, under both the gradual and instant turn-on conditions, the axial modes compete in a pattern governed by the characteristic asymmetry of the mode profiles. Other aspects of physics interest include the analysis and explanation of a resultant hysteresis effect between the rise and fall portions of the beam pulse. These understandings are expected to provide the basis for achieving a stable gyro-BWO operating at a single mode throughout the entire beam pulse.
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Affiliation(s)
- K F Pao
- Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan
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Kapadia F, Pryor A, Chang TH, Johnson LF. Nuclear localization of poly(A)+ mRNA following siRNA reduction of expression of the mammalian RNA helicases UAP56 and URH49. Gene 2006; 384:37-44. [PMID: 16949217 DOI: 10.1016/j.gene.2006.07.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 06/10/2006] [Accepted: 07/03/2006] [Indexed: 11/20/2022]
Abstract
UAP56 is a eukaryotic RNA helicase that is important for mRNA splicing and nuclear export. Although most eukaryotes have a single protein corresponding to UAP56, we have shown previously that in human and mouse cells there is a second protein, URH49, which is 90% identical to UAP56. Both proteins interact with the mRNA export factor Aly and both are able to rescue the loss of Sub2p (the yeast homolog of UAP56), suggesting that both proteins have similar functions. However, the two helicases have different expression profiles in different tissues and in growth-stimulated cells, which raises the possibility that they might be involved in the splicing and export of non-identical populations of mRNA. In the present study, we have used RNA interference to further explore the functions of these two helicases. Reducing the expression of either URH49 or UAP56 in HeLa cells had little effect on cell proliferation or expression of a co-transfected gene. However, analysis of poly(A)+ RNA localization by fluorescent in situ hybridization revealed a speckled pattern of RNA accumulation throughout the nucleus. Reducing the expression of both helicases resulted in a major reduction in reporter gene expression as well as cell death within 72 h. We also observed a more prominent speckled pattern of nuclear poly(A)+ RNA accumulation as well as reduced accumulation in the cytoplasmic compartment. These observations suggest that both helicases have essential but largely overlapping functions in the processing and export of mammalian mRNAs.
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Affiliation(s)
- Fehmida Kapadia
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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Chang TH, Chen NC. Transition of absolute instability from global to local modes in a gyrotron traveling-wave amplifier. Phys Rev E Stat Nonlin Soft Matter Phys 2006; 74:016402. [PMID: 16907193 DOI: 10.1103/physreve.74.016402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Indexed: 05/11/2023]
Abstract
The gyrotron traveling-wave amplifier employing the distributed-loss scheme is capable of very high gain and effective in suppressing the global absolute instabilities. This study systematically characterizes the local absolute instabilities and their transitional behavior. The local absolute instabilities are analyzed using a model that incorporates the penetration of the field from the copper section into the lossy section. The axial modes were characterized from the perspective of beam-wave interaction and were found to share many characteristics with the global modes. The transition from global modes to local modes as the distributed loss increases was demonstrated. The electron transit angle in the copper section, which determines the feedback criterion, governs the survivability of an oscillation. In addition, the oscillation thresholds predicted using this model are more accurate than those obtained using a simplified model.
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Affiliation(s)
- T H Chang
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
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Chang SW, Chang TH, Tredway L, Jung G. Aggressiveness of Typhula ishikariensis Isolates to Cultivars of Bentgrass Species (Agrostis spp.) Under Controlled Environment Conditions. Plant Dis 2006; 90:951-956. [PMID: 30781036 DOI: 10.1094/pd-90-0951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Speckled snow mold, caused by Typhula ishikariensis, is one of the most important Typhula snow molds in subarctic zones of the Northern Hemisphere. Nine isolates of three T. ishikariensis varieties (var. ishikariensis, var. canadensis, and var. idahoensis) isolated from infected turfgrasses on golf course fairways throughout Wisconsin were evaluated for their aggressiveness toward nine cultivars of three bentgrass species (three creeping, three colonial, and three velvet cultivars) under controlled environmental conditions. Speckled snow mold severity increased as inoculum concentration of T. ishikariensis was increased. In general, bentgrass susceptibility increased between 9 and 11 weeks after seeding but gradually decreased thereafter, suggesting expression of age-related resistance as plants matured. Significant differences in aggressiveness were detected within and among T. ishikariensis varieties. Significant interactions between T. ishikariensis varieties or isolates and bentgrass species were detected, but there was no interaction between pathogen isolates and bentgrass cultivars. Disease severity evaluations showed significant differences among bentgrass cultivars and species in their response to T. ishikariensis. Since bentgrass species exhibit differential responses to T. ishikariensis varieties, representative isolates of each variety should be employed for screening of bentgrass germplasm for resistance to speckled snow mold.
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Affiliation(s)
- S W Chang
- Department of Plant Pathology, University of Wisconsin, Madison 53706
| | - T H Chang
- Department of Plant Pathology, University of Wisconsin, Madison 53706
| | - L Tredway
- Department of Plant Pathology, North Carolina State University, Raleigh 27695
| | - G Jung
- Department of Plant Pathology, University of Wisconsin, Madison 53706
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Affiliation(s)
- T H Chang
- GENETICS FOUNDATION, DEPARTMENT OF ZOOLOGY, UNIVERSITY OF TEXAS
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Pao KF, Chang TH, Fan CT, Chen SH, Yu CF, Chu KR. Dynamics of mode competition in the gyrotron backward-wave oscillator. Phys Rev Lett 2005; 95:185101. [PMID: 16383909 DOI: 10.1103/physrevlett.95.185101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Indexed: 05/05/2023]
Abstract
The axial modes of the gyrotron backward-wave oscillator (gyro-BWO) each exhibit a distinctive asymmetry in axial field profile. As a result, and in sharp contrast to the behavior of the familiar resonator-based gyrotron oscillator, particle simulations of the gyro-BWO reveal a radically different pattern of mode competition in which a fast-growing and well-established mode is subsequently suppressed by a later-starting mode with a more favorable field profile. This is verified in a Ka-band experiment and the interaction dynamics are elucidated with a time-frequency analysis.
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Affiliation(s)
- K F Pao
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
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Burckin T, Nagel R, Mandel-Gutfreund Y, Shiue L, Clark TA, Chong JL, Chang TH, Squazzo S, Hartzog G, Ares M. Exploring functional relationships between components of the gene expression machinery. Nat Struct Mol Biol 2005; 12:175-82. [PMID: 15702072 DOI: 10.1038/nsmb891] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 12/06/2004] [Indexed: 11/09/2022]
Abstract
Eukaryotic gene expression requires the coordinated activity of many macromolecular machines including transcription factors and RNA polymerase, the spliceosome, mRNA export factors, the nuclear pore, the ribosome and decay machineries. Yeast carrying mutations in genes encoding components of these machineries were examined using microarrays to measure changes in both pre-mRNA and mRNA levels. We used these measurements as a quantitative phenotype to ask how steps in the gene expression pathway are functionally connected. A multiclass support vector machine was trained to recognize the gene expression phenotypes caused by these mutations. In several cases, unexpected phenotype assignments by the computer revealed functional roles for specific factors at multiple steps in the gene expression pathway. The ability to resolve gene expression pathway phenotypes provides insight into how the major machineries of gene expression communicate with each other.
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Affiliation(s)
- Todd Burckin
- Department of Molecular, Cell & Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
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Tsai WC, Chang TH, Chen NC, Chu KR, Song HH, Luhmann NC. Absolute instabilities in a high-order-mode gyrotron traveling-wave amplifier. Phys Rev E Stat Nonlin Soft Matter Phys 2004; 70:056402. [PMID: 15600760 DOI: 10.1103/physreve.70.056402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2004] [Indexed: 05/24/2023]
Abstract
The absolute instability is a subject of considerable physics interest as well as a major source of self-oscillations in the gyrotron traveling-wave amplifier (gyro-TWT). We present a theoretical study of the absolute instabilities in a TE01 mode, fundamental cyclotron harmonic gyro-TWT with distributed wall losses. In this high-order-mode circuit, absolute instabilities arise in a variety of ways, including overdrive of the operating mode, fundamental cyclotron harmonic interactions with lower-order modes, and second cyclotron harmonic interaction with a higher-order mode. The distributed losses, on the other hand, provide an effective means for their stabilization. The combined configuration thus allows a rich display of absolute instability behavior together with the demonstration of its control. We begin with a study of the field profiles of absolute instabilities, which exhibit a range of characteristics depending in large measure upon the sign and magnitude of the synchronous value of the propagation constant. These profiles in turn explain the sensitivity of oscillation thresholds to the beam and circuit parameters. A general recipe for oscillation stabilization has resulted from these studies and its significance to the current TE01 -mode, 94-GHz gyro-TWT experiment at UC Davis is discussed.
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Affiliation(s)
- W C Tsai
- Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
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Abstract
The evolutionarily conserved DExD/H-box proteins are essential for all RNA-related biological processes. They are thought to modulate the structure and function of specific RNAs and/or ribonucleoprotein particles by using their intrinsic RNA-dependent ATPase activities to achieve the desired conformational changes. A number of DExD/H-box proteins have been shown to unwind short RNA duplexes in vitro, a hallmark of the so-called RNA helicases or unwindases. However, some are unable to do so, perhaps because of requirements for cofactors. Here, we present a "solid-state" method that may allow investigators to overcome such problems.
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Chong JL, Chuang RY, Tung L, Chang TH. Ded1p, a conserved DExD/H-box translation factor, can promote yeast L-A virus negative-strand RNA synthesis in vitro. Nucleic Acids Res 2004; 32:2031-8. [PMID: 15064363 PMCID: PMC390370 DOI: 10.1093/nar/gkh519] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Viruses are intracellular parasites that must use the host machinery to multiply. Identification of the host factors that perform essential functions in viral replication is thus of crucial importance to the understanding of virus-host interactions. Here we describe Ded1p, a highly conserved DExD/H-box translation factor, as a possible host factor recruited by the yeast L-A double-stranded RNA (dsRNA) virus. We found that Ded1p interacts specifically and strongly with Gag, the L-A virus coat protein. Further analysis revealed that Ded1p interacts with the L-A virus in an RNA-independent manner and, as a result, L-A particles can be affinity purified via this interaction. The affinity-purified L-A particles are functional, as they are capable of synthesizing RNA in vitro. Critically, using purified L-A particles, we demonstrated that Ded1p specifically promotes L-A dsRNA replication by accelerating the rate of negative-strand RNA synthesis in vitro. In light of these data, we suggest that Ded1p may be a part of the long sought after activity shown to promote yeast viral dsRNA replication. This and the fact that Ded1p is also required for translating brome mosaic virus RNA2 in yeast thus raise the intriguing possibility that Ded1p is one of the key host factors favored by several evolutionarily related RNA viruses, including the human hepatitis C virus.
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Affiliation(s)
- Jean-Leon Chong
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA
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