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Yu YCY, Hui TZ, Kao TH, Liao HF, Yang CY, Hou CC, Hsieh HT, Chang JY, Tsai YT, Pinskaya M, Yang KC, Chen YR, Morillon A, Tsai MH, Lin SP. Transient DNMT3L Expression Reinforces Chromatin Surveillance to Halt Senescence Progression in Mouse Embryonic Fibroblast. Front Cell Dev Biol 2020; 8:103. [PMID: 32195249 PMCID: PMC7064442 DOI: 10.3389/fcell.2020.00103] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/07/2020] [Indexed: 01/10/2023] Open
Abstract
Global heterochromatin reduction, which is one of the hallmarks of senescent cells, is associated with reduced transposable element repression and increased risk of chromatin instability. To ensure genomic integrity, the irreparable cells in a population exit permanently from the cell cycle, and this process is termed "senescence." However, senescence only blocks the expansion of unwanted cells, and the aberrant chromatin of senescent cells remains unstable. Serendipitously, we found that the transient ectopic expression of a repressive epigenetic modulator, DNA methyltransferase 3-like (DNMT3L) was sufficient to delay the premature senescence progression of late-passage mouse embryonic fibroblasts (MEFs) associated with a tightened global chromatin structure. DNMT3L induces more repressive H3K9 methylation on endogenous retroviruses and downregulates the derepressed transposons in aging MEFs. In addition, we found that a pulse of ectopic DNMT3L resulted in the reestablishment of H3K27me3 on polycomb repressive complex 2 (PRC2)-target genes that were derepressed in old MEFs. We demonstrated that ectopic DNMT3L interacted with PRC2 in MEFs. Our data also suggested that ectopic DNMT3L might guide PRC2 to redress deregulated chromatin regions in cells undergoing senescence. This study might lead to an epigenetic reinforcement strategy for overcoming aging-associated epimutation and senescence.
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Affiliation(s)
- Yoyo Chih-Yun Yu
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Tony Zk Hui
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.,Canada's Michael Smith Genome Sciences Centre, British Columbia Cancer Agency, Vancouver, BC, Canada
| | - Tzu-Hao Kao
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Hung-Fu Liao
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Chih-Yi Yang
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Chia-Chun Hou
- Center for Systems Biology, National Taiwan University, Taipei, Taiwan
| | - Hsin-Ting Hsieh
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Jen-Yun Chang
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Yi-Tzang Tsai
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Marina Pinskaya
- ncRNA, Epigenetic and Genome Fluidity, CNRS UMR 3244, Sorbonne Université, PSL University, Institut Curie, Centre de Recherche, Paris, France
| | - Kai-Chien Yang
- Graduate Institute and Department of Pharmacology, National Taiwan University School of Medicine, Taipei, Taiwan
| | - Yet-Ran Chen
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Antonin Morillon
- ncRNA, Epigenetic and Genome Fluidity, CNRS UMR 3244, Sorbonne Université, PSL University, Institut Curie, Centre de Recherche, Paris, France
| | - Mong-Hsun Tsai
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Shau-Ping Lin
- Institute of Biotechnology, National Taiwan University, Taipei, Taiwan.,Center for Systems Biology, National Taiwan University, Taipei, Taiwan.,Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan.,Research Center for Developmental Biology and Regenerative Medicine, Taipei, Taiwan
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Hsu HJ, Huang RF, Kao TH, Inbaraj BS, Chen BH. Preparation of carotenoid extracts and nanoemulsions from Lycium barbarum L. and their effects on growth of HT-29 colon cancer cells. Nanotechnology 2017; 28:135103. [PMID: 28266352 DOI: 10.1088/1361-6528/aa5e86] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Lycium barbarum L., a traditional Chinese herb widely used in Asian countries, has been demonstrated to be protective against chronic diseases such as age-related macular degeneration. The objectives of this study were to determine the carotenoid content in L. barbarum by high-performance liquid chromatography-mass spectrometry, followed by preparation of a carotenoid nanoemulsion to evaluate the mechanism of inhibition on HT-29 colon cancer cells. The highest extraction yield of carotenoids was attained by employing a solvent system of hexane-ethanol-acetone (1:1:1, v/v/v). Nine carotenoids, including neoxanthin (4.47 μg g-1), all-trans-zeaxanthin and its cis-isomers (1666.3 μg g-1), all-trans-β-cryptoxanthin (51.69 μg g-1), all-trans-β-carotene and its cis-isomers (20.11 μg g-1), were separated within 45 min and quantified using a YMC C30 column and a gradient mobile phase of methanol-water (9:1, v/v) (A) and methylene chloride (B). A highly stable carotenoid nanoemulsion composed of CapryolTM 90, Transcutol®HP, Tween 80 and deionized water was prepared with a mean particle size of 15.1 nm. Characterization of zeaxanthin standard, blank nanoemulsion, carotenoid extract and carotenoid nanoemulsion by differential scanning calorimetry curves and Fourier transform infrared spectra revealed a good dispersion of zeaxanthin-dominated carotenoid extract with no significant chemical change after incorporation into nanoemulsion. The in vitro release kinetic study showed a higher release profile at pH 5.2 than at physiological pH 7.4, suggesting a rapid release of carotenoids in the acidic environment (pH 4.5-6.5) characteristic of tumors. Both the carotenoid nanoemulsion and the extract were effective at inhibiting growth of HT-29 colon cancer cells, with an IC50 of 4.5 and 4.9 μg ml-1, respectively. Also, both treatments could up-regulate p53 and p21 expression and down-regulate CDK2, CDK1, cyclin A and cyclin B expression and arrest the cell cycle at G2/M. The study may form a basis for further exploration of L. barbarum nanoemulsion in cancer treatment.
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Affiliation(s)
- H J Hsu
- Department of Food Science, Fu Jen Catholic University, New Taipei City 242, Taiwan
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Liao HF, Mo CF, Wu SC, Cheng DH, Yu CY, Chang KW, Kao TH, Lu CW, Pinskaya M, Morillon A, Lin SS, Cheng WTK, Bourc'his D, Bestor T, Sung LY, Lin SP. Dnmt3l-knockout donor cells improve somatic cell nuclear transfer reprogramming efficiency. Reproduction 2015; 150:245-56. [PMID: 26159833 DOI: 10.1530/rep-15-0031] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 07/09/2015] [Indexed: 12/18/2022]
Abstract
Nuclear transfer (NT) is a technique used to investigate the development and reprogramming potential of a single cell. DNA methyltransferase-3-like, which has been characterized as a repressive transcriptional regulator, is expressed in naturally fertilized egg and morula/blastocyst at pre-implantation stages. In this study, we demonstrate that the use of Dnmt3l-knockout (Dnmt3l-KO) donor cells in combination with Trichostatin A treatment improved the developmental efficiency and quality of the cloned embryos. Compared with the WT group, Dnmt3l-KO donor cell-derived cloned embryos exhibited increased cell numbers as well as restricted OCT4 expression in the inner cell mass (ICM) and silencing of transposable elements at the blastocyst stage. In addition, our results indicate that zygotic Dnmt3l is dispensable for cloned embryo development at pre-implantation stages. In Dnmt3l-KO mouse embryonic fibroblasts, we observed reduced nuclear localization of HDAC1, increased levels of the active histone mark H3K27ac and decreased accumulation of the repressive histone marks H3K27me3 and H3K9me3, suggesting that Dnmt3l-KO donor cells may offer a more permissive epigenetic state that is beneficial for NT reprogramming.
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Affiliation(s)
- Hung-Fu Liao
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Chu-Fan Mo
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Shinn-Chih Wu
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Dai-Han Cheng
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Chih-Yun Yu
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Kai-Wei Chang
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Tzu-Hao Kao
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Chia-Wei Lu
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Marina Pinskaya
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Antonin Morillon
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Shih-Shun Lin
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, T
| | - Winston T K Cheng
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Déborah Bourc'his
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Timothy Bestor
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Li-Ying Sung
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan
| | - Shau-Ping Lin
- Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, Taichung 407, TaiwanINSERM U934/CNRS UMR3215Institut Curie, 75005 Paris, FranceDepartment of Genetics and DevelopmentCollege of Physicians and Surgeons of Columbia University, New York, New York 10032, USAAgricultural Biotechnology Research CenterAcademia Sinica, Taipei 115, TaiwanCenter for Systems BiologyResearch Center for Developmental Biology and Regenerative MedicineNational Taiwan University, Taipei 106, Taiwan Institute of BiotechnologyDepartment of Animal Science and TechnologyGenome and Systems Biology Degree ProgramNational Taiwan University, Taipei 106, TaiwanGenome and Systems Biology Degree ProgramAcademia Sinica, Taipei, TaiwanInstitut CurieCNRS UMR3244, Université Pierre et Marie Curie, 75248 Paris Cedex 05, FranceDepartment of Animal Science and BiotechnologyTunghai University, T
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Kao TH, Cheng CC, Huang CF, Chen JK. Using coaxial electrospinning to fabricate core/shell-structured polyacrylonitrile–polybenzoxazine fibers as nonfouling membranes. RSC Adv 2015. [DOI: 10.1039/c5ra09232a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We used coaxial electrospinning to produce core/shell polyacrylonitrile (PAN)–benzoxazine (BA) fibers. The PAN–PBA core/shell fibers that we obtained after curing exhibited low surface energies and excellent biononfouling properties.
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Affiliation(s)
- Tzu-Hao Kao
- Department of Materials Science and Engineering
- National Taiwan University of Science and Technology
- Taipei
- Republic of China
| | - Chih-Chia Cheng
- Graduate Institute of Applied Science and Technology
- National Taiwan University of Science and Technology
- Taipei
- Taiwan
| | - Chih-Feng Huang
- Department of Chemical Engineering
- National Chung Hsing University
- 402 Taichung
- Taiwan
| | - Jem-Kun Chen
- Department of Materials Science and Engineering
- National Taiwan University of Science and Technology
- Taipei
- Republic of China
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Babu KS, Anandkumar M, Tsai TY, Kao TH, Inbaraj BS, Chen BH. Cytotoxicity and antibacterial activity of gold-supported cerium oxide nanoparticles. Int J Nanomedicine 2014; 9:5515-31. [PMID: 25473288 PMCID: PMC4251533 DOI: 10.2147/ijn.s70087] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Cerium oxide nanoparticles (CeO2) have been shown to be a novel therapeutic in many biomedical applications. Gold (Au) nanoparticles have also attracted widespread interest due to their chemical stability and unique optical properties. Thus, decorating Au on CeO2 nanoparticles would have potential for exploitation in the biomedical field. Methods In the present work, CeO2 nanoparticles synthesized by a chemical combustion method were supported with 3.5% Au (Au/CeO2) by a deposition-precipitation method. The as-synthesized Au, CeO2, and Au/CeO2 nanoparticles were evaluated for antibacterial activity and cytotoxicity in RAW 264.7 normal cells and A549 lung cancer cells. Results The as-synthesized nanoparticles were characterized by X-ray diffraction, scanning and transmission electron microscopy, and ultraviolet-visible measurements. The X-ray diffraction study confirmed the formation of cubic fluorite-structured CeO2 nanoparticles with a size of 10 nm. All synthesized nanoparticles were nontoxic towards RAW 264.7 cells at doses of 0–1,000 μM except for Au at >100 μM. For A549 cancer cells, Au/CeO2 had the highest inhibitory effect, followed by both Au and CeO2 which showed a similar effect at 500 and 1,000 μM. Initial binding of nanoparticles occurred through localized positively charged sites in A549 cells as shown by a shift in zeta potential from positive to negative after 24 hours of incubation. A dose-dependent elevation in reactive oxygen species indicated that the pro-oxidant activity of the nanoparticles was responsible for their cytotoxicity towards A549 cells. In addition, cellular uptake seen on transmission electron microscopic images indicated predominant localization of nanoparticles in the cytoplasmic matrix and mitochondrial damage due to oxidative stress. With regard to antibacterial activity, both types of nanoparticles had the strongest inhibitory effect on Bacillus subtilis in monoculture systems, followed by Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus, while, in coculture tests with Lactobacillus plantarum, S. aureus was inhibited to a greater extent than the other bacteria. Conclusion Gold-supported CeO2 nanoparticles may be a potential nanomaterial for in vivo application owing to their biocompatible and antibacterial properties.
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Affiliation(s)
- K Suresh Babu
- Centre for Nano Sciences and Technology, Madanjeet School of Green Energy Technologies, Pondicherry University, Kalapet, India
| | - M Anandkumar
- Centre for Nano Sciences and Technology, Madanjeet School of Green Energy Technologies, Pondicherry University, Kalapet, India
| | - T Y Tsai
- Department of Food Science, Fu Jen University, Taipei, Taiwan
| | - T H Kao
- Department of Food Science, Fu Jen University, Taipei, Taiwan
| | | | - B H Chen
- Department of Food Science, Fu Jen University, Taipei, Taiwan ; Graduate Institute of Medicine, Fu Jen University, Taipei, Taiwan
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Liao HF, Chen WSC, Chen YH, Kao TH, Tseng YT, Lee CY, Chiu YC, Lee PL, Lin QJ, Ching YH, Hata K, Cheng WTK, Tsai MH, Sasaki H, Ho HN, Wu SC, Huang YH, Yen P, Lin SP. DNMT3L promotes quiescence in postnatal spermatogonial progenitor cells. Development 2014; 141:2402-13. [PMID: 24850856 DOI: 10.1242/dev.105130] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The ability of adult stem cells to reside in a quiescent state is crucial for preventing premature exhaustion of the stem cell pool. However, the intrinsic epigenetic factors that regulate spermatogonial stem cell quiescence are largely unknown. Here, we investigate in mice how DNA methyltransferase 3-like (DNMT3L), an epigenetic regulator important for interpreting chromatin context and facilitating de novo DNA methylation, sustains the long-term male germ cell pool. We demonstrated that stem cell-enriched THY1(+) spermatogonial stem/progenitor cells (SPCs) constituted a DNMT3L-expressing population in postnatal testes. DNMT3L influenced the stability of promyelocytic leukemia zinc finger (PLZF), potentially by downregulating Cdk2/CDK2 expression, which sequestered CDK2-mediated PLZF degradation. Reduced PLZF in Dnmt3l KO THY1(+) cells released its antagonist, Sal-like protein 4A (SALL4A), which is associated with overactivated ERK and AKT signaling cascades. Furthermore, DNMT3L was required to suppress the cell proliferation-promoting factor SALL4B in THY1(+) SPCs and to prevent premature stem cell exhaustion. Our results indicate that DNMT3L is required to delicately balance the cycling and quiescence of SPCs. These findings reveal a novel role for DNMT3L in modulating postnatal SPC cell fate decisions.
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Affiliation(s)
- Hung-Fu Liao
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Wendy S C Chen
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Yu-Hsiang Chen
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Tzu-Hao Kao
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Yen-Tzu Tseng
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Chien-Yueh Lee
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan
| | - Yu-Chiao Chiu
- Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 106, Taiwan
| | - Pei-Lung Lee
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Qian-Jia Lin
- Department of Biochemistry, Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei 110, Taiwan Center for Reproductive Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei 110, Taiwan
| | - Yung-Hao Ching
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan
| | - Kenichiro Hata
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Okura, Setagaya, Tokyo 157-8535, Japan
| | - Winston T K Cheng
- Department of Animal Science and Biotechnology, Tunghai University, Taichung 40704, Taiwan
| | - Mong-Hsun Tsai
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Hiroyuki Sasaki
- Department of Molecular Genetics, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Hong-Nerng Ho
- Department of Obstetrics and Gynecology, College of Medicine and the Hospital, National Taiwan University, Taipei 100, Taiwan
| | - Shinn-Chih Wu
- Department of Animal Science and Technology, National Taiwan University, Taipei, Taiwan
| | - Yen-Hua Huang
- Department of Biochemistry, Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei 110, Taiwan Center for Reproductive Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei 110, Taiwan
| | - Pauline Yen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Shau-Ping Lin
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan Center for Systems Biology, National Taiwan University, Taipei 106, Taiwan Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei 106, Taiwan
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7
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Inbaraj BS, Kao TH, Tsai TY, Chiu CP, Kumar R, Chen BH. The synthesis and characterization of poly(γ-glutamic acid)-coated magnetite nanoparticles and their effects on antibacterial activity and cytotoxicity. Nanotechnology 2011; 22:075101. [PMID: 21233545 DOI: 10.1088/0957-4484/22/7/075101] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Magnetite nanoparticles (MNPs) modified with sodium and calcium salts of poly(γ-glutamic acid) (NaPGA and CaPGA) were synthesized by the coprecipitation method, followed by characterization and evaluation of their antibacterial and cytotoxic effects. Superparamagnetic MNPs are particularly attractive for magnetic driving as well as bacterial biofilm and cell targeting in in vivo applications. Characterization of synthesized MNPs by the Fourier transform infrared spectra and magnetization curves confirmed the PGA coating on MNPs. The mean diameter of NaPGA- and CaPGA-coated MNPs as determined by transmission electron microscopy was 11.8 and 14 nm, respectively, while the x-ray diffraction pattern revealed the as-synthesized MNPs to be pure magnetite. Based on agar dilution assay, both NaPGA- and CaPGA-coated MNPs showed a lower minimum inhibitory concentration in Salmonella enteritidis SE 01 than the commercial antibiotics linezolid and cefaclor, but the former was effective against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 10832, whereas the latter was effective against Escherichia coli O157:H7 TWC 01. An in vitro cytotoxicity study in human skin fibroblast cells as measured by MTT assay implied the as-synthesized MNPs to be nontoxic. This outcome demonstrated that both γ-PGA-modified MNPs are cytocompatible and possess antibacterial activity in vitro, and thereby should be useful in in vivo studies for biomedical applications.
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8
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Wang TL, Kao TH, Inbaraj BS, Su YT, Chen BH. Inhibition effect of poly(γ-glutamic acid) on lead-induced toxicity in mice. J Agric Food Chem 2010; 58:12562-12567. [PMID: 21067144 DOI: 10.1021/jf1034509] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The objectives of this study were to evaluate the efficiency in treatment of lead-induced intoxication in mice with γ-PGA as chelating agent and compare with the drug (meso-2,3-dimercaptosuccinic acid). The results showed the incorporation of γ-PGA at 200 and 400 mg/kg could reduce the accumulation of lead in the liver, heart, and testis; however, the latter was more effective in decreasing the lead content in the kidney and spleen. Nevertheless, both doses failed to inhibit the lead accumulation in the lung and brain. Additionally, both doses of γ-PGA could reduce TBARs in the kidney and brain, as well as elevate δ-aminolevulinic acid dehydrase (δ-ALAD) activity in blood and decrease glutamic pyruvic transaminase (GPT) and lactic dehydrogenase (LDH) activities in the serum. For hematological parameters, both white blood cells (WBCs) and hematocrite (HCT) were raised by 400 mg/kg of γ-PGA, while for both doses of γ-PGA, a slight decline in hemoglobin (HGB), mean cell volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) was observed, with the red blood cells (RBCs) being unaffected.
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Affiliation(s)
- T L Wang
- Department of Emergency Medicine, Shin Kong Hospital, Taipei, Taiwan
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9
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Abstract
Soybean cake, a byproduct obtained during the processing of soybean oil, has been shown to be a rich source of isoflavones. The objectives of this study were to use soybean cake as raw material for processing into powder and to evaluate the anti-inflammatory activity. Eleven treatments, including powders of malonylglucoside, glucoside, acetylglucoside, aglycone, ISO-1, and ISO-2, as well as genistein standard, gamma-PGA, control, normal, and PDTC, were used for evaluation. A total of 77 mice were each provided daily with tube feeding for 4 weeks at a dose of 0.3 mL of aqueous solution from each treatment, and inflammation was induced with intraperitoneal injection of 1 mg/kg of body weight lipopolysaccharide (LPS). Results showed that all of the isoflavone powders and genistein standard were effective in inhibiting LPS-induced inflammation, lowering leukocyte number in mice blood and reducing production of IL-1beta, IL-6, NO, and PGE2 in both peritoneal exudate cell supernatant and peritoneal exudate fluid. All of the isoflavone treatments failed to retard T cell proliferation; however, both ISO-1 and ISO-2 could inhibit B cell proliferation. The difference in anti-inflammatory activity was minor between any of the isoflavone treatments.
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Affiliation(s)
- T H Kao
- Graduate Institute of Nutrition and Food Science, School of Medicine, College of Medicine, Fu Jen University, Taipei, Taiwan
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10
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Lan CM, Kao TH, Chen BH. Effects of heating time and antioxidants on the formation of heterocyclic amines in marinated foods. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 802:27-37. [PMID: 15035994 DOI: 10.1016/j.jchromb.2003.09.025] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of heating time and antioxidants on the heterocyclic amine (HAs) formation in marinated foods were studied. Food samples were cooked at 98 +/- 2 degrees C for 1, 2, 4, 8, 16 and 32 h in a closed pan in the presence of water, soy sauce and rock candy with or without antioxidants. The various HAs in marinated food samples and juice were analyzed by HPLC with photodiode-array detection. Results showed that the amount of HAs formed during heating followed an increased order for each increasing heating time. A larger variety and higher amount of HAs were generated in marinated pork when compared to marinated eggs and bean cake. In marinated juice, the levels of HAs were present in greater amount than in marinated foods. The incorporation of antioxidants Vitamin C, Vitamin E and BHT were found to be effective towards HAs inhibition, however, the effect was minor.
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Affiliation(s)
- C M Lan
- Department of Nutrition and Food Science, Fu Jen University, Taipei 242, Taiwan
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11
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Liu JC, Kao TH. Extraction of Cu and Pb from printed circuit board sludge using ammonia solutions. Water Sci Technol 2003; 47:167-172. [PMID: 12578190] [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] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sludge from a printed circuit board factory containing high concentrations of Cu and Pb was characterized. Aqueous ammonia solutions were used to extract metals from the sludge. The extraction reactions were completed within 6 hrs. The best extraction efficiency was found at pH of 10.0. Higher solid-liquid ratio and higher ammonia concentration resulted in better extraction efficiency. Fractionation experiments showed that Cu and Pb were mainly extracted from the Fe-Mn oxide-bound and carbonate-bound fractions. Extracted sludge could meet the TCLP regulation limit and be categorized as a non-hazardous waste. Results show that ammonia extraction is of potential in resource recovery and in detoxification of hazardous waste.
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Affiliation(s)
- J C Liu
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Chinese Taiwan
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12
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Fasano JM, Swanson SJ, Blancaflor EB, Dowd PE, Kao TH, Gilroy S. Changes in root cap pH are required for the gravity response of the Arabidopsis root. Plant Cell 2001; 13:907-21. [PMID: 11283344 PMCID: PMC135544 DOI: 10.1105/tpc.13.4.907] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2000] [Accepted: 02/06/2001] [Indexed: 05/19/2023]
Abstract
Although the columella cells of the root cap have been identified as the site of gravity perception, the cellular events that mediate gravity signaling remain poorly understood. To determine if cytoplasmic and/or wall pH mediates the initial stages of root gravitropism, we combined a novel cell wall pH sensor (a cellulose binding domain peptide-Oregon green conjugate) and a cytoplasmic pH sensor (plants expressing pH-sensitive green fluorescent protein) to monitor pH dynamics throughout the graviresponding Arabidopsis root. The root cap apoplast acidified from pH 5.5 to 4.5 within 2 min of gravistimulation. Concomitantly, cytoplasmic pH increased in columella cells from 7.2 to 7.6 but was unchanged elsewhere in the root. These changes in cap pH preceded detectable tropic growth or growth-related pH changes in the elongation zone cell wall by 10 min. Altering the gravity-related columella cytoplasmic pH shift with caged protons delayed the gravitropic response. Together, these results suggest that alterations in root cap pH likely are involved in the initial events that mediate root gravity perception or signal transduction.
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Affiliation(s)
- J M Fasano
- Biology Department, The Pennsylvania State University, 208 Mueller Lab, University Park, Pennsylvania 16802. USA
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13
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Abstract
PRK1, a receptor-like kinase that is expressed in pollen, pollen tubes, and ovaries, has been shown to play important roles in pollen development and embryo sac development in Petunia inflata. We have used the kinase domain of PRK1 as a bait in the yeast two-hybrid system to identify PRK1-interacting proteins. The screening resulted in isolation of a cDNA encoding a protein highly homologous to the human and yeast beta-subunit of translation initiation factor 2B (eIF2B-beta), which was designated NeIF2Bbeta. eIF2B is a guanine nucleotide exchange protein that functions in the regulation of translation in eukaryotic cells. Deletion mutants of NeIF2Bbeta were analyzed for their interaction with PRK1, and the results suggested that the N-terminal half of NeIF2Bbeta, especially the region between residue 103 and 235, is important for the interaction. This protein association was confirmed by in vitro binding assay of the recombinant NeIF2Bbeta and PRK1 proteins. Despite high sequence homology between NeIF2Bbeta and its yeast counterpart, the NeIF2Bbeta cDNA could not rescue the phenotype of the yeast mutant strain lacking the GCD7 gene encoding eIF2B-beta, when transferred into the mutant strain.
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Affiliation(s)
- S W Park
- Plant Cell Biotechnology Laboratory, Korea Research Institute of Bioscience and Biotechnology, Taejon
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14
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Abstract
Plants respond in complex ways to their environment, to their internal physiological status, and to the activity of other plants, pathogens, herbivores, and organisms. Plant Signaling 2000, a symposium sponsored by the Penn State Intercollege Graduate Program in Plant Physiology (May 18-20, 2000), explored the machinery underlying these responses and their potential for cross talk. We recount here some of the major themes emerging from this interdisciplinary symposium, which ranged from genetic and biochemical analyses of signaling pathways in Arabidopsis and other model plants to field studies of plants responding to insect damage.
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Affiliation(s)
- D J Cosgrove
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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15
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McCubbin AG, Wang X, Kao TH. Identification of self-incompatibility (S-) locus linked pollen cDNA markers in Petunia inflata. Genome 2000; 43:619-27. [PMID: 10984173] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Solanaceous type self-incompatibility (SI) is controlled by a single polymorphic locus, termed the S-locus. The only gene at the S-locus that has been characterized thus far is the S-RNase gene, which controls pistil function, but not pollen function, in SI interactions between pistil and pollen. One approach to identifying additional genes (including the pollen S-gene, which controls pollen function in SI) at the S-locus and to study the structural organization of the S-locus is chromosome walking from the S-RNase gene. However, the presence of highly repetitive sequences in its flanking regions has made this approach difficult so far. Here, we used RNA differential display to identify pollen cDNAs of Petunia inflata, a self-incompatible solanaceous species, which exhibited restriction fragment length polymorphism (RFLP) for at least one of the three S-haplotypes (S1, S2, and S3) examined. We found that the genes corresponding to 10 groups of pollen cDNAs are genetically tightly linked to the S-RNase gene. These cDNA markers will expedite the mapping and cloning of the chromosomal region of the Solanaceae S-locus by providing multiple starting points.
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Affiliation(s)
- A G McCubbin
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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16
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17
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Abstract
Flowering plants have evolved various genetic mechanisms to circumvent the tendency for self-fertilization created by the close proximity of male and female reproductive organs in a bisexual flower. One such mechanism is gametophytic self-incompatibility, which allows the female reproductive organ, the pistil, to distinguish between self pollen and non-self pollen; self pollen is rejected, whereas non-self pollen is accepted for fertilization. The Solanaceae family has been used as a model to study the molecular and biochemical basis of self/non-self-recognition and self-rejection. Discrimination of self and non-self pollen by the pistil is controlled by a single polymorphic locus, the S locus. The protein products of S alleles in the pistil, S proteins, were initially identified based on their cosegregation with S alleles. S proteins have recently been shown to indeed control the ability of the pistil to recognize and reject self pollen. S proteins are also RNases, and the RNase activity has been shown to be essential for rejection of self pollen, suggesting that the biochemical mechanism of self-rejection involves the cytotoxic action of the RNase activity. S proteins contain various numbers of N-linked glycans, but the carbohydrate moiety has been shown not to be required for the function of S proteins, suggesting that the S allele specificity determinant of S proteins lies in the amino acid sequence. The male component in self-incompatibility interactions, the pollen S gene, has not yet been identified. The possible nature of the pollen S gene product and the possible mechanism by which allele-specific rejection of pollen is accomplished are discussed.
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Affiliation(s)
- T H Kao
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802, USA
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18
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Richman AD, Kao TH, Schaeffer SW, Uyenoyama MK. S-allele sequence diversity in natural populations of Solanum carolinense (Horsenettle). Heredity (Edinb) 1995; 75 ( Pt 4):405-15. [PMID: 7591834 DOI: 10.1038/hdy.1995.153] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [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: 01/26/2023] Open
Abstract
S-allele diversity in Solanum carolinense was surveyed in two natural populations, located in Tennessee and North Carolina, with a molecular assay to determine the genotype of individual plants. A total of 13 different S-alleles were identified and sequenced. There is high overlap between the two populations sampled, with 10 alleles shared in common, one allele found only in Tennessee, and two found only in North Carolina. The number of alleles in this species appears to be extremely low compared with other species with gametophytic self-incompatibility. Sequence comparisons show that most alleles are extremely different one from another in their primary sequence and a phylogenetic analysis indicates extensive trans-specific evolution of S-lineages. In addition, some alleles appear to be derived much more recently. The implications of these observations are discussed in the light of recent theoretical results on S-allele population diversity and persistence.
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Affiliation(s)
- A D Richman
- Department of Zoology, Duke University, Durham, NC 27708-0325, USA
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19
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Tsai JJ, Wang TF, Wang SR, Kao TH. Eosinophil differentiation and hypodensity alteration activities in Dermatophagoides pteronyssinus-stimulated mononuclear cell culture supernatants derived from asthmatics. Int Arch Allergy Immunol 1995; 106:297-301. [PMID: 7888793 DOI: 10.1159/000236858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We investigated the contributing effect of Dermatophagoides pteronyssinus-stimulated mononuclear cell (MNC) cultured supernatants on the differentiation and density alteration of eosinophils. MNC, obtained from either normal subjects or asthmatics, were cultured with or without D. pteronyssinus. The supernatants were tested for the activity of eosinophil differentiation and density alteration. The results showed a significant increase in eosinophil differentiation activity in D. pteronyssinus-stimulated MNC supernatants of asthmatics when compared with normal subjects. This activity can be blocked by anti-IL-5 antibodies. Eosinophil hypodensity change was also noted after treatment with D. pteronyssinus-stimulated MNC supernatants or IL-5, but not after D. pteronyssinus treatment. In conclusion, MNCs, activated by D. pteronyssinus, might contribute to the eosinophil differentiation and hypodensity change in asthmatics.
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Affiliation(s)
- J J Tsai
- Section of Allergy and Clinical Immunology, Cathay General Hospital, Taipei, Taiwan
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20
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Karunanandaa B, Singh A, Kao TH. Characterization of a predominantly pistil-expressed gene encoding a gamma-thionin-like protein of Petunia inflata. Plant Mol Biol 1994; 26:459-64. [PMID: 7948892 DOI: 10.1007/bf00039555] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We isolated a cDNA clone from a pistil cDNA library of Petunia inflata which encodes a protein, PPT, with sequence similarity to gamma-thionins. Characterization of a genomic clone containing a PPT gene revealed the presence of a single intron. Northern analysis revealed that the PPT gene was predominantly expressed in the pistil during all stages of flower development. Since thionins have been implicated in plant defense against pathogens, PPT may play a role similar to that of other defense-related proteins found in the pistil, defending the pistil against pathogen infection.
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Affiliation(s)
- B Karunanandaa
- Graduate Program in Plant Physiology, Pennsylvania State University, University Park 16802
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21
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Huang S, Lee HS, Karunanandaa B, Kao TH. Ribonuclease activity of Petunia inflata S proteins is essential for rejection of self-pollen. Plant Cell 1994; 6:1021-8. [PMID: 8069103 PMCID: PMC160497 DOI: 10.1105/tpc.6.7.1021] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
S proteins, pistil-specific ribonucleases that cosegregate with S alleles, have previously been shown to control rejection of self-pollen in Petunia inflata and Nicotiana alata, two solanaceous species that display gametophytic self-incompatibility. The ribonuclease activity of S proteins was thought to degrade RNA of self-pollen tubes, resulting in the arrest of their growth in the style. However, to date no direct evidence has been obtained. Here, the ribonuclease activity of S3 protein of P. inflata was abolished, and the effect on the pistil's ability to reject S3 pollen was examined. The S3 gene was mutagenized by replacing the codon for His-93, which has been implicated in ribonuclease activity, with a codon for asparagine, and the mutant S3 gene was introduced into P. inflata plants of S1S2 genotype. Two transgenic plants produced a level of mutant S3 protein comparable to that of the S3 protein produced in self-incompatible S1S3 and S2S3 plants, yet they failed to reject S3 pollen. The mutant S3 protein produced in these two transgenic plants did not exhibit any detectable ribonuclease activity. We have previously shown that transgenic plants (S1S2 plants transformed with the wild-type S3 gene) producing a normal level of wild-type S3 protein acquired the ability to reject S3 pollen completely. Thus, the results reported here provide direct evidence that the biochemical mechanism of gametophytic self-incompatibility in P. inflata involves the ribonuclease activity of S proteins.
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Affiliation(s)
- S Huang
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802
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22
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Mu JH, Lee HS, Kao TH. Characterization of a pollen-expressed receptor-like kinase gene of Petunia inflata and the activity of its encoded kinase. Plant Cell 1994; 6:709-21. [PMID: 8038606 PMCID: PMC160470 DOI: 10.1105/tpc.6.5.709] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
From a pollen tube cDNA library of Petunia inflata, we isolated clones encoding a protein with structural features and biochemical properties characteristic of receptor-like kinases. It was designated PRK1 for pollen receptor-like kinase 1. The cytoplasmic domain of PRK1 is highly similar to the kinase domains of other plant receptor-like kinases and contains nearly all of the conserved amino acids for serine/threonine kinases. The extracellular domain of PRK1 contains leucine-rich repeats as found in some other plant receptor-like kinases, but overall its sequence in this region does not share significant similarity. Characterization of a gene encoding PRK1 revealed the presence of two introns. During pollen development, PRK1 mRNA was first detected in anthers containing mostly binucleate microspores; it reached the highest level of mature pollen and remained at a high level in in vitro-germinated pollen tubes. The recombinant cytoplasmic domain of PRK1 autophosphorylated on serine and tyrosine, suggesting that PRK1 may be a dual-specificity kinase. Monospecific immune serum to the recombinant extracellular domain of PRK1 detected a 69-kD protein in microsomal membranes of pollen and pollen tubes. The characteristics of PRK1 suggest that it may play a role in signal transduction events during pollen development and/or pollination.
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Affiliation(s)
- J H Mu
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park 16802
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23
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Abstract
We have previously shown that three Petunia inflata S-proteins, products of the multiallelic S-gene of the self-incompatibility system, are ribonucleases. Here we report the expression of cDNAs for two of these S-proteins using the baculovirus expression system. S2- and S3-proteins were found in both supernatants and lysates of Spodoptera frugiperda cells infected with recombinant baculoviruses. Both recombinant S-proteins contained glycosylated (25 kD) and nonglycosylated (23 kD) forms. Recombinant S2- and S3-proteins were purified from insect cell cultures, and the amino-terminal sequences determined from glycosylated S2- and S3-proteins indicated that the leader peptide encoded by each cDNA was correctly removed. Both glycosylated and nonglycosylated forms of S2- and S3-proteins exhibited ribonuclease activity.
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Affiliation(s)
- J Mu
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
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24
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Singh A, Evensen KB, Kao TH. Ethylene Synthesis and Floral Senescence following Compatible and Incompatible Pollinations in Petunia inflata. Plant Physiol 1992; 99:38-45. [PMID: 16668881 PMCID: PMC1080403 DOI: 10.1104/pp.99.1.38] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Ethylene production and floral senescence following compatible and incompatible pollinations were studied in a self-incompatible species, Petunia inflata. Both compatible and incompatible pollinations resulted in a burst of ethylene synthesis that peaked 3 hours after pollination. P. inflata pollen was found to carry large amounts of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). The amount of pollen-held ACC varied in different genetic backgrounds, and the magnitude of the peak correlated with the amount of ACC borne by the pollen. Aminooxyacetic acid (AOA), an inhibitor of ACC synthesis, had no inhibitory effect on this ethylene response, indicating that pollen-borne ACC was largely responsible for the early synthesis of ethylene. After compatible pollination, a second increase in ethylene synthesis began at 18 hours, and the first sign of senescence appeared at 36 hours. Upon treatment with AOA, the second phase of ethylene production was reduced by 95%, indicating that endogenous ACC synthesis was required for this phase of ethylene synthesis. AOA treatment also delayed senescence to 6 days after anthesis. After incompatible pollination, a second increase in ethylene production did not occur until 3 days, and the first sign of senescence occurred 12 hours later. Unpollinated flowers showed an increase in ethylene production 3 to 4 days after anthesis and displayed signs of senescence 1 day later. The significance of the early and late phases of pollination-induced ethylene synthesis is discussed.
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Affiliation(s)
- A Singh
- Department of Molecular and Cell Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
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25
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Affiliation(s)
- A Singh
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
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26
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Abstract
We identified two S-allele-associated proteins (S-proteins) in a self-compatible cultivar of Petunia hybrida based on their segregation in F1 hybrids between P. hybrida and its self-incompatible relative, Petunia inflata (with S2S2 genotype), and in selfed progeny of P. hybrida. These two S-proteins, designated Sx-protein (24 kDa) and So-protein (31 kDa), are pistil specific, and their expression follows a temporal and spatial pattern similar to that of S-proteins characterized in self-incompatible solanaceous species. Their amino-terminal sequences also share a high degree of similarity with those of solanaceous S-proteins. Selfing of P. hybrida yielded plants with SoSo,SxSo, and SxSx genotypes in an approximately 1:2:1 ratio, indicating that the Sx-and So-alleles, though expressed in the pistil, failed to elicit a self-incompatibility response. The S2-allele of P. inflata is expressed in all the F1 hybrids, rendering them capable of rejecting pollen bearing the S2-allele. The So-allele is not functional in the F1 hybrids, because all the F1 progeny with S2So genotype are self-compatible. However, in F1 hybrids with S2Sx genotype, approximately half are self-incompatible and half are self-compatible, indicating that the function of the Sx-allele depends on the genetic background. These results strongly suggest that the presence of functional S-alleles alone is not sufficient for expression of a self-incompatibility phenotype, and reaffirm the multigenic nature of gametophytic self-incompatibility suggested by earlier genetic studies.
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Affiliation(s)
- Y J Ai
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
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27
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Clark AG, Kao TH. Excess nonsynonymous substitution of shared polymorphic sites among self-incompatibility alleles of Solanaceae. Proc Natl Acad Sci U S A 1991; 88:9823-7. [PMID: 1946408 PMCID: PMC52813 DOI: 10.1073/pnas.88.21.9823] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The function of the self-incompatibility locus (S locus) of many plant species dictates that natural selection will favor high levels of protein diversity. Pairwise sequence comparisons between S alleles from four species of Solanaceae reveal remarkably high sequence diversity and evidence for shared polymorphism. The level of amino acid constraint was found to be significantly heterogeneous among different regions of the gene, with some regions being highly constrained and others appearing to be virtually unconstrained. In some regions of the protein, there was an excess of nonsynonymous over synonymous substitution, consistent with the strong diversifying selection that must operate on this locus. These hypervariable regions are candidates for the sites that determine functional allelic identity. Simple contingency table tests show that sites that have polymorphism shared between species have more nonsynonymous substitution than polymorphic sites that do not exhibit shared polymorphism. This is consistent with the idea that adaptive evolution favoring amino acid replacement is occurring at sites with shared polymorphism. Tests of clustered polymorphism reveal that an unusually low rate of recombination must be occurring in this locus, allowing very ancient alleles to preserve their identity.
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Affiliation(s)
- A G Clark
- Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park 16802
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Singh A, Ai Y, Kao TH. Characterization of Ribonuclease Activity of Three S-Allele-Associated Proteins of Petunia inflata. Plant Physiol 1991; 96:61-8. [PMID: 16668186 PMCID: PMC1080713 DOI: 10.1104/pp.96.1.61] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Three S-allele-associated proteins (S-proteins) of Petunia inflata, a species with gametophytic self-incompatibility, were previously found to share sequence similarity with two fungal ribonucleases, RNase T(2) and RNase Rh. In this study, the S-proteins from P. inflata plants of S(1)S(2) and S(2)S(3) genotypes were purified to homogeneity by gel filtration and cation-exchange chromatography, and their enzymatic properties were characterized. The three S-proteins (S(1), S(2), and S(3)), with pairwise sequence identity ranging from 73.1 to 80.5%, were similar in most of the enzymatic properties characterized. The ribonuclease activity had a pH optimum of 7.0 and a temperature optimum of 50 degrees C. Diethylpyrocarbonate at 1 millimolar almost completely abolished the ribonuclease activity; cupric sulfate and zinc sulfate at 1 millimolar reduced the ribonuclease activity of the three S-proteins by 50 to 75%. EDTA and RNasin had no inhibitory effect. All three S-proteins hydrolyzed polycytidylic acid preferentially, but varied in their nucleolytic activity toward polyadenylic acid and polyuridylic acid.
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Affiliation(s)
- A Singh
- Department of Molecular and Cell Biology, The Pennsylvania State University, University Park, Pennsylvania 16802
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Abstract
Sequences of 11 alleles of the gametophytic self-incompatibility locus (S locus) from three species of the Solanaceae family have recently been determined. Pairwise comparisons of these alleles reveal two unexpected observations: (i) amino acid sequence similarity can be as low as 40% within species and (ii) some interspecific similarities are higher than intraspecific similarities. The gene genealogy clearly illustrates this unusual pattern of relationships. The data suggest that some of the polymorphism at the S locus existed prior to the divergence of these species and has been maintained to the present. In support of this hypothesis, the number of shared polymorphic sites was found to exceed the number found in simulations with independent accumulation of mutations. Strictly neutral evolution is exceedingly unlikely to maintain the polymorphism for such a long time. The allele multiplicity and extreme age of the alleles is consistent with Wright's classic one-locus population genetic model of gametophytic self-incompatibility. Similarities between the plant S locus and the mammalian major histocompatibility complex are discussed.
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Affiliation(s)
- T R Ioerger
- Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802
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Xu BB, Mu JH, Nevins DL, Grun P, Kao TH. Cloning and sequencing of cDNAs encoding two self-incompatibility associated proteins in Solanum chacoense. Mol Gen Genet 1990; 224:341-6. [PMID: 2266940 DOI: 10.1007/bf00262427] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have isolated and sequenced cDNAs for S2- and S3-alleles of the self-incompatibility locus (S-locus) in Solanum chacoense Bitt., a wild potato species displaying gametophytic self-incompatibility. The S2- and S3-alleles encode pistil-specific proteins of 30 kDa and 31 kDa, respectively, which were previously identified based on cosegregation with their respective alleles in genetic crosses. The amino acid sequence homology between the S2- and S3-proteins is 41.5%. This high degree of sequence variability between alleles is a distinctive feature of the S-gene system. Of the 31 amino acid residues which were previously found to be conserved among three Nicotiana alata S-proteins (S2, S3, and S6) and two fungal ribonucleases (RNase T2 and RNase Rh), 27 are also conserved in the S2- and S3-proteins of S. chacoense. These residues include two histidines implicated in the active site of the RNase T2, six cysteines, four of which form disulfide bonds in RNase T2, and hydrophobic residues which might form the core structure of the protein. The finding that these residues are conserved among S-proteins with very divergent sequences suggests a functional role for the ribonuclease activity of the S-protein in gametophytic self-incompatibility.
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Affiliation(s)
- B B Xu
- Department of Horticulture, Pennsylvania State University, University Park 16802
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Fonoff RDN, Watanabe IS, Kao TH. [Sensory nerve endings of the medium and posterior parts of Cebus apella monkey's tongue mucosa]. Rev Odontol Univ Sao Paulo 1989; 3:377-82. [PMID: 2490836] [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] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Sensory nerve endings of tongue mucosa of Cebus apella monkey were studied using the silver impregnation technique (WINKELMANN & SCHIMITT). Subepithelial sensory nerve endings of different forms are present in the medium and posterior parts of tongue mucosa. The nerve fibers have their origin in the deep layers of the tongue and form single and complex sensory nerve endings. The fungiform papillae contain numerous ramified nerve fibers, which constitute a subepithelia network, but the filiform papillae usually possess single free nerve endings disposed longitudinally into the connective tissue.
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Affiliation(s)
- R de N Fonoff
- Biomedical Sciences Institute, University of São Paulo
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Kao TH, Watanabe IS, Fonoff RDN. Peculiar characteristics of the insertion area of the masseter muscle in rats. Scanning electron microscopic study. Rev Odontol Univ Sao Paulo 1989; 3:313-6. [PMID: 2639452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The structure of the bone surface of the insertion area of the masseter muscle was studied in 20 albinus Wistar rats. Specimens were fixed in a modified Karnovsky solution and treated according to the technique described by LESTER et alii and examined in a JEOL scanning electron microscope, JSM-P15. The results showed that the insertion area of the masseter muscle of rats presents a smooth surface covered by thick layers of calcified collagen fibers. In adjacent areas of the lower edge of the mandibular angle an irregular surface with bone reabsorption and foraminae was observed. The vascular foraminae measure from 30 to 50 microns in diameter and the distance between them ranges from 200 to 460 microns. Osteocyte lacunae were seen at the surface and their measures range from 18 to 25 microns in diameter, which were surrounded by collagen fiber bundles of longitudinal disposition.
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Abstract
We have previously reported the isolation and partial sequence analysis of a rice mitochondrial DNA fragment (6.9 kb) which contains a transferred copy of a chloroplast gene cluster coding for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL), beta and epsilon subunits of ATPase (atpB and atpE), methionine tRNA (trnM) and valine tRNA (trnV). We have now completely sequenced this 6.9 kb fragment and found it to also contain a sequence homologous to the chloroplast gene coding for the ribosomal protein L2 (rpl2), beginning at a site 430 bp downstream from the termination codon of rbcL. In the chloroplast genome, two copies of rpl2 are located at distances of 20 kb and 40 kb, respectively, from rbcL. We have sequenced these two copies of rice chloroplast rpl2 and found their sequences to be identical. In addition, a 151 bp sequence located upstream of the chloroplast rpl2 coding region is also found in the 3' noncoding region of chloroplast rbcL and other as yet undefined locations in the rice chloroplast genome. Hybridization analysis revealed that this 151 bp repeat sequence identified in rice is also present in several copies in 11 other plant species we have examined. Findings from these studies suggest that the translocation of rpl2 to the rbcL gene cluster found in the rice mitochondrial genome might have occurred through homologous recombination between the 151 bp repeat sequence present in both rpl2 and rbcL.
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Affiliation(s)
- E Moon
- Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853
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Abstract
We describe the isolation of two rice chloroplast HindIII fragments (9.5 kb and 5.3 kb) each containing a gene cluster coding for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL), beta and epsilon subunits of ATPase (atpB and atpE), tRNAmet (trnM) and tRNAval (trnV). All five genes contained in the 9.5 kb fragment are potentially functional, whereas in the 5.3 kb fragment, rbcL is truncated and atpB is frame-shift mutated. The copy number of the 9.5 kb fragment is 10 times that of the 5.3 kb fragment, indicating that the two fragments are probably located on different chloroplast genomes and represent two different (major and minor) genomic populations. Thus, the rice chloroplast genome appears to be heterogeneous, contrary to general belief. We also describe the isolation of a rice mitochondrial HindIII fragment (6.9 kb) which contains an almost complete transferred copy of this chloroplast gene cluster. In this transferred copy, the coding sequences of rbcL, atpE and trnM contain perfectly normal reading frames, whereas atpB has become grossly defective and trnV is truncated.
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Moon E, Kao TH, Wu R. Pea cytochrome oxidase subunit II gene has no intron and generates two mRNA transcripts with different 5'-termini. Nucleic Acids Res 1985; 13:3195-212. [PMID: 2987876 PMCID: PMC341229 DOI: 10.1093/nar/13.9.3195] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have isolated and sequenced the cytochrome oxidase subunit II (COII) gene from pea mitochondria. The coding sequence (777 bp) shows over 90% homology to the COII genes from three monocotyledonous plants (rice, maize and wheat) and one dicotyledonous plant (Oenothera berteriana). Several codons are deleted, however, in the pea COII gene. Of interest is the deletion in pea of the last three codons, including the stop codon, found at the 3' end of the other four COII genes. Instead, a new stop codon has been created due to a single-base substitution at the 13th bp downstream from the position of the original stop codon. This pea gene does not contain an intron which is found in all three monocots. Two distinct 5' termini of the pea COII transcripts have been identified by S1 nuclease mapping, one at 285 bp (site I) and the other at 302 bp (site II) upstream from the ATG codon. They are located at two identical sites within nearly perfect direct repeats. Transcripts with the 5' end corresponding to site I occur five time more frequently than those with the 5' end corresponding to site II. Both transcripts have the same 3' terminus which has been mapped to be at 193 to 195 bp downstream from the stop codon.
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Tso JY, Sun XH, Kao TH, Reece KS, Wu R. Isolation and characterization of rat and human glyceraldehyde-3-phosphate dehydrogenase cDNAs: genomic complexity and molecular evolution of the gene. Nucleic Acids Res 1985; 13:2485-502. [PMID: 2987855 PMCID: PMC341170 DOI: 10.1093/nar/13.7.2485] [Citation(s) in RCA: 1434] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Full length cDNAs encoding the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from rat and man have been isolated and sequenced. Many GAPDH gene-related sequences have been found in both genomes based on genomic blot hybridization analysis. Only one functional gene product is known. Results from genomic library screenings suggest that there are 300-400 copies of these sequences in the rat genome and approximately 100 in the human genome. Some of these related sequences have been shown to be processed pseudogenes. We have isolated several rat cDNA clones corresponding to these pseudogenes indicating that some pseudogenes are transcribed. Rat and human cDNAs are 89% homologous in the coding region, and 76% homologous in the first 100 base pairs of the 3'-noncoding region. Comparison of these two cDNA sequences with those of the chicken, Drosophila and yeast genes allows the analysis of the evolution of the GAPDH genes in detail.
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Chiu JK, Huang WH, Cheng KH, Chang IH, Teng WH, Kao TH. Three cases of worm proven human angiostrongyliasis in Taiwan. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1981; 14:247-50. [PMID: 7343202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Abstract
We report temperature-jump kinetic studies of the early melting transition of Escherichia coli 5S rRNA. A single measurable relaxation time tau, independent of concentration, was found at 266 nm. We monitored the transition temperature tm for this process (in the range from 0 to 40 degrees C) as a function of Mg2+, Na+, K+, spermidine, and H+ concentrations. Contrary to the usual effect of salts on nucleic acid stability, addition of mono- and multivalent counterions decreases tm for the early melting transition. Also unexpectedly, we found a strong dependence of tm on pH in the physiological range of 7--8. Quantitative analysis of the data indicates that about 0.7 protons are release when the ordered (low-temperature) form melts, whereas about 2 NA+ (or K+) and 0.5 Mg2+ are taken up by the melted (high-temperature) form. We estimate the enthalpy of the transition to be 15--20 kcal/mol (63--84 kJ/mol) and also report the forward and reverse rate constants and activation energies for the transition, along with the influence of ions on the transition dynamics. Diffusion constant measurements reveal that the low-temperature form has a frictional coefficient about 10% larger than that of the high-temperature form. The data imply a low-temperature tertiary structure capable of binding a proton. Increase of pH, temperature, or counterion concentration (all at near-physiological values) causes a tertiary conformational switch to a more compact form that has greater counterion binding but less proton binding. We discuss possible physiological roles for the transition.
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