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Park MW, Lee HS, Kim EY, Lee KA. RNA Polymerase II Inhibitor, α-Amanitin, Affects Gene Expression for Gap Junctions and Metabolic Capabilities of Cumulus Cells, but Not Oocyte, during in vitro Mouse Oocyte Maturation. Dev Reprod 2015; 17:63-72. [PMID: 25949122 PMCID: PMC4282216 DOI: 10.12717/dr.2013.17.1.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 03/15/2013] [Accepted: 03/18/2013] [Indexed: 11/17/2022]
Abstract
A specific inhibitor of RNA polymerase II, α-amanitin is broadly used to block transcriptional activities in cells. Previous studies showed that α-amanitin affects in vitro maturation of cumulus-oocyte-complex (COC). In this study, we evaluated the target of α-amanitin, and whether it affects oocytes or cumulus cells (CCs), or both. We treated α-amanitin with different time period during in vitro culture of denuded oocytes (DOs) or COCs in comparison, and observed the changes in morphology and maturation status. Although DOs did not show any change in morphology and maturation rates with α-amanitin treatment, oocytes from COCs were arrested at metaphase I (MI) stage and CCs were more scattered than control groups. To discover causes of meiotic arrest and scattering of CCs, we focused on changes of cumulus expansion, gap junctions, and cellular metabolism which to be the important factors for the successful in vitro maturation of COCs. Expression of genes for cumulus expansion markers (Ptx3, Has2, and Tnfaip6) and gap junctional proteins (Gja1, Gja4, and Gjc1) decreased in α-amanitin-treated CCs. However, these changes were not observed in oocytes. In addition, expression of genes related to metabolism (Prps1, Rpe, Rpia, Taldo1, and Tkt) decreased in α -amanitin-treated CCs but not in oocytes. Therefore, we concluded that the transcriptional activities of CCs for supporting suitable transcripts, especially for its metabolic activities and formation of gap junctions among CCs as well as with oocytes, are important for oocytes maturation in COCs.
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Affiliation(s)
- Min-Woo Park
- Department of Biomedical Science, College of Life Science, CHA University, CHA Research Institute, Fertility Center, CHA General Hospital, Seoul 135-081, Korea
| | - Hyun-Seo Lee
- DNA Repair Research Center, Chosun University, Gwangju 501-759, Korea
| | - Eun-Young Kim
- Department of Biomedical Science, College of Life Science, CHA University, CHA Research Institute, Fertility Center, CHA General Hospital, Seoul 135-081, Korea
| | - Kyung-Ah Lee
- Department of Biomedical Science, College of Life Science, CHA University, CHA Research Institute, Fertility Center, CHA General Hospital, Seoul 135-081, Korea
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Psarra AMG, Sekeris CE. Glucocorticoids induce mitochondrial gene transcription in HepG2 cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1814-21. [DOI: 10.1016/j.bbamcr.2011.05.014] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/23/2011] [Accepted: 05/24/2011] [Indexed: 01/16/2023]
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Psarra AMG, Sekeris CE. Glucocorticoid receptors and other nuclear transcription factors in mitochondria and possible functions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:431-6. [PMID: 19100710 DOI: 10.1016/j.bbabio.2008.11.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Revised: 11/17/2008] [Accepted: 11/24/2008] [Indexed: 11/16/2022]
Abstract
The central role of mitochondria in basic physiological processes has rendered this organelle a receiver and integrator of multiple regulatory signals. Steroid and thyroid hormones are major modulators of mitochondrial functions and the question arises as to how these molecules act at the molecular level. The detection in mitochondria of steroid and thyroid hormone receptors suggested their direct action on mitochondrial functions within the context of the organelle. The interaction of the receptors with regulatory elements of the mitochondrial genome and the activation of gene transcription underlies the hormonal stimulation of energy yield. Glucocorticoid activation of hepatocyte RNA synthesis is one of the experimental models exploited in this respect. Furthermore, the interaction of the receptors with apoptotic/antiapoptotic factors is possibly associated with the survival-death effects of the hormones. In addition to the steroid/thyroid hormone receptors, several other receptors belonging to the superfamily of nuclear receptors, as well as transcription factors with well defined nuclear actions, have been found in mitochondria. How these molecules act and interact and how they can affect the broad spectrum of mitochondrial functions is an emerging exciting field.
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Affiliation(s)
- Anna-Maria G Psarra
- Biomedical Research Foundation, Academy of Athens, Center for Basic Research, 4 Soranou Efesiou, 11527, Athens, Greece
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Gillery P, Georges N, Wegrowski J, Randoux A, Borel JP. Protein synthesis in collagen lattice-cultured fibroblasts is controlled at the ribosomal level. FEBS Lett 1995; 357:287-9. [PMID: 7835429 DOI: 10.1016/0014-5793(94)01375-b] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fibroblasts cultivated in three-dimensional lattices exhibit a large decrease of protein synthesis, mainly through transcriptional control. However, no previous work was devoted to a potential ribosomal regulation. We evaluated ribosomal ribonucleic acid (RNA) in monolayer- and collagen lattice-cultured fibroblasts. After one week of culture, total RNA was 60% lower in lattice-cultured fibroblasts than in monolayer-cultured cells. The decrease was identical for 18 S and 28 S rRNA subfractions. The half-life of RNA was much shorter in collagen lattice-cultured fibroblasts than in monolayers. These results suggest that protein synthesis in lattice-cultured fibroblasts is partly regulated at the ribosomal level.
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Affiliation(s)
- P Gillery
- Laboratory of Biochemistry and Molecular Biology, Faculty of Medicine, University of Reims-Champagne-Ardenne, France
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MAHARAJAN PRATIBHA, GARGIULO CIRO, MAHARAJAN VEERAMANI. Stage specific inhibition of sea urchin development by α-amanitin. INVERTEBR REPROD DEV 1989. [DOI: 10.1080/07924259.1989.9672016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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6
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Zagris N, Matthopoulos D. Gene expression in chick morula. ACTA ACUST UNITED AC 1988; 197:298-301. [DOI: 10.1007/bf00380024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/1988] [Accepted: 05/20/1988] [Indexed: 11/29/2022]
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7
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Zagris N, Matthopoulos D. Induction of gastrulation in the chick embryo. DEVELOPMENTAL GENETICS 1987; 8:83-9. [PMID: 3502969 DOI: 10.1002/dvg.1020080204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Interaction between the epiblast and the primary hypoblast in chick blastula results in induction of the primitive streak (PS) in the epiblast. Alpha-amanitin, a specific inhibitor of poly A-containing RNA synthesis, inhibits formation of the definitive PS. This inhibition is associated with qualitative changes in the pattern of protein synthesis in the hypoblast but not in the epiblast. The protein pattern of the component areas of the epiblast shows increase in some polypeptides after treatment with alpha-amanitin. By contrast, alpha-amanitin resulted in a decrease in synthesis of several polypeptides, which are either undetectable or weakly present in the hypoblast. The alpha-amanitin-sensitive translational products of the embryonic genome that are observed in the hypoblast may have specific functions in the control of PS induction and stabilization.
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Affiliation(s)
- N Zagris
- Department of Biology, University of Patras, Greece
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8
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Nicoloff H, Rieger R. Mutations in rDNA : 3. Modulatory action of α-amanitin on aberration induction in nucleolus organizer regions. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1985; 70:178-184. [PMID: 24254177 DOI: 10.1007/bf00275319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/1984] [Accepted: 09/04/1984] [Indexed: 06/02/2023]
Abstract
The action of α-amanitin, an inhibitor of RNA synthesis, on the induction by hydroxyurea (HU) of chromosomal aberrations in nucleolus organizer regions of barley was studied. The data obtained show that α-amanitin can effectively modify aberration induction in rDNA. Administered before mutagen treatment or in combination with the mutagen, the toxin significantly decreased the HU-induced aberration frequencies in NORs. The data obtained provide further evidence that α-amanitin is an effective modulator of aberration induction in NORs either by interfering with RNA synthesis or by modifying chromatin structure.
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Affiliation(s)
- H Nicoloff
- Zentralinstitut für Genetik und Kulturpflanzenforschung, DDR-4325, Gatersleben, German Democratic Republic
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Bertout M. Endocrine regulation of spermatogenesis in Nereis diversicolor (annelida polychaeta): experimental study of the control of meiotic differentiation. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1983; 226:151-61. [PMID: 6189962 DOI: 10.1002/jez.1402260118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In Nereidae, spermatogenesis is regulated by a hormone secreted by the supraesophageal ganglion (brain hormone). The hormonal concentration decreases with worm age. Spermatogonial proliferation in young worms proceeds under a high hormonal level whereas differentiation of spermatozoa in aged worms occurs in the absence of brain hormone. Spermatogonia were removed from the endocrine influence of the brain in vitro by the organ culture method. Isolated parapodia produced spermatozoa after 13 days. Control cultures were obtained by associating a parapodium with the prostomium of a young worm. It seems that the brain hormone inhibits the spermatocyte differentiation since removal of the brain results in increased RNA synthesis, followed by DNA replication, meiosis, and spermiogenesis (Bertout, '83). Modalities of the hormonal control of meiosis, especially at the level of the RNA syntheses related to meiotic differentiation, were investigated. Effects of reintroducing the hormonal influence during meiotic differentiation were studied through parapodium-prostomium associations at various time after the brain inhibition has been lifted. Effects or RNA inhibitors (actinomycin D, alpha-amanitin, cordycepin) were also tested. The results lead us to propose a hypothesis according to which brain hormone would interfere with molecular events related to the transition from the stage of spermatogonial proliferation (mitotic behavior) to the stage of meiotic differentiation (meiotic behavior).
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Schindler J, Sherman MI. Effects of α-amanitin on programming of mouse blastocyst development. Dev Biol 1981; 84:332-40. [DOI: 10.1016/0012-1606(81)90401-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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Riddiford LM, Chen AC, Graves BJ, Curtis AT. RNA and protein synthesis during the change to pupal commitment of Manduca sexta epidermis. ACTA ACUST UNITED AC 1981. [DOI: 10.1016/0020-1790(81)90050-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Jendrisak J. The use of alpha-amanitin to inhibit in vivo RNA synthesis and germination in wheat embryos. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(18)43529-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Braude P, Pelham H, Flach G, Lobatto R. Post-transcriptional control in the early mouse embryo. Nature 1979; 282:102-5. [PMID: 503184 DOI: 10.1038/282102a0] [Citation(s) in RCA: 140] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The earliest stages of mouse embryogenesis, from fertilisation to the two-cell stage, are characterised by an extremely low level of RNA synthesis. Indeed, during this period, RNA polymerase II activity and incorporation of labelled precurosrs into heterogeneous RNA are not detectable, and there is no increase in the poly(A) content of the embryo, but rather a slight decrease. The rate of protein synthesis remains low and relatively constant throughout the one- and two-cell stages. However, qualitative analysis of the protein synthetic profile on SDS gels has revealed changes which appear around the late one-cell to early two-cell stage. This early change in the pattern of polypeptide synthesis represents the first major qualitative molecular change found so far in development. We present evidence which suggests that the increased synthesis at the early two-cell stage of a small number of polypeptides of molecular weight 35,000 is not dependent on transcription, but rather represents control at a post-transcriptional level using mRNAs synthesised before fertilisation.
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17
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Rohrer H, Otten U, Thoenen H. On the role of RNA synthesis in the selective induction of tyrosine hydroxylase by nerve growth factor. Brain Res 1978; 159:436-9. [PMID: 31965 DOI: 10.1016/0006-8993(78)90554-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Panyim S, Ohno T, Jost JP. In vitro RNA synthesis and expression of vitellogenin gene in isolated chicken liver nuclei. Nucleic Acids Res 1978; 5:1353-70. [PMID: 652525 PMCID: PMC342083 DOI: 10.1093/nar/5.4.1353] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Optimal conditions for prolonged in vitro synthesis of RNA in isolated chicken liver nuclei have been described. It is shown by incorporation of gamma32P-GTP into RNA, analysis of the product on sucrose density gradient, and digestion with alkaline phosphatase and ribonuclease A that there is reinitiation of RNA synthesis. Polynucleotide kinase activity has been ruled out as explanation for the incorporation of gamma32P-GTP. alpha-Amanitin inhibits RNA synthesis by about 50%. Nuclei prepared from estradiol-treated chicks have twice the RNA synthesis activity as the controls. RNA is synthesized in the presence of Hg-UTP and the mercurated product separated by affinity chromatography on sulfhydryl-Sepharose column under stringent conditions. Vitellogenin mRNA sequences are measured by hybridization with DNA complementary to vitellogenin mRNA. Estradiol treatment leads to a 10-fold increase in vitellogenin mRNA sequences.
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19
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Connan G, Rabotti GF. Effects of alpha-amanitin on RNA synthesis in cultured chicken fibroblasts transformed by Rous sarcoma virus. Biochimie 1978; 60:85-90. [PMID: 206293 DOI: 10.1016/s0300-9084(78)80203-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Levey IL, Brinster RL. Effects of alpha-amanitin on RNA synthesis by mouse embryos in culture. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1978; 203:351-60. [PMID: 641476 DOI: 10.1002/jez.1402030303] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Investigations were conducted to test the effects of alpha-amanitin on RNA synthesis in preimplantation mouse embryos. Exposure of embryos in culture to 1-100 microgram/ml alpha-amanitin produced a dose- and time-dependence suppression of total RNA synthesis as measured by incorporation of [3H]uridine. Synthesis of polyadenylated RNA in blastocyst-stage embryos was abolished by alpha-amanitin-treatment at concentrations and exposure times that suppressed total RNA synthesis by less than 15%. DNA-dependent RNA polymerase activity was measured in lysates of embryos at several stages of preimplantation development. alpha-Amanitin suppressed total polymerase activity assayed under ionic conditions favorable to the detection of RNA polymerase II. Electrophoretic analyses revealed that preincubation of blastocysts in 100 microgram/ml alpha-amanitin reduced labelling of cytoplasmic 28S and 18S RNA by inhibition of both synthesis and maturation of nucleolar 45SrRNA-precursor. This action of alpha-amanitin on nucleolar RNA synthesis cannot be correlated with the minimal suppression of nucleolar RNA polymerase activity and suggests that the synthesis and processing of rRNA may be under control of nucleoplasmic gene products.
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21
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Morrissey JJ, Lovenberg W. Synthesis of RNA in the pineal gland during N-acetyltransferase induction. The effects of actinomycin D, alpha-amanitin and cordycepin. Biochem Pharmacol 1978; 27:557-62. [PMID: 305246 DOI: 10.1016/0006-2952(78)90394-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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22
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Hadjiolov AA, Nikolaev N. Maturation of ribosomal ribonucleic acids and the biogenesis of ribosomes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1978; 31:95-144. [PMID: 790469 DOI: 10.1016/0079-6107(78)90006-8] [Citation(s) in RCA: 115] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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23
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Vergleichende Untersuchungen der Kernveränderungen von Rattenhepatocyten nach Actinomycin D- und α-Amanitin-Vergiftung. ACTA ACUST UNITED AC 1977. [DOI: 10.1007/bf02889123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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24
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Warner CM, Hearn TF. The effect of alpha-amanitin on nucleic acid synthesis in preimplantation mouse embryos. Differentiation 1977; 7:89-97. [PMID: 838208 DOI: 10.1111/j.1432-0436.1977.tb01501.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
It has been hypothesized that multiple forms of RNA polymerase may play a role in the control of development and differentiation in eukaryotic organisms. For this to be true, three criteria must be met. First, multiple forms of RNA polymerase must be demonstrated. Second, the relative proportion of the enzyme forms must be shown to change with development or differentiation. And third, the types of RNA synthesized must correlate with the types of RNA polymerase present at each developmental stage. We have previously reported data satisfying the first two criteria for preimplantation mouse embryos. The present paper probes the third criterion in this differentiating system. It was found that although the proportion of the RNA polymerase enzyme forms changes from the 8-cell to the blastocyst stage of development, the types of newly synthesized nucleic acids at each of these stages were similar. Furthermore, inhibition of rRNA, mRNA, and tRNA, by alpha-amanitin, was identical for 8-cell and blastocyst embryos. The only difference between these two stages was that DNA synthesis in blastocysts was more sensitive to inhibition by alpha-amanitin than DNA synthesis in 8-cell embryos. We conclude that the synthesis of different classes of RNA by preimplantation mouse embryos is not simply controlled by changes in the levels of the multiple forms of RNA polymerase.
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25
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Laval M, Bouteille M, Moulé Y. Effect of the ionic environment on the transcriptional activity of rat liver nucleoli. Exp Cell Res 1976; 102:365-75. [PMID: 976353 DOI: 10.1016/0014-4827(76)90052-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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26
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Louis C, Sekeris CE. Isolation of informoferes from rat liver. Effects of alpha-amanitin and actinomycin D. Exp Cell Res 1976; 102:317-28. [PMID: 976351 DOI: 10.1016/0014-4827(76)90047-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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28
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Ro-Choi TS, Raj NB, Pike LM, Busch H. Effects of alpha-amanitin, cycloheximide, and thioacetamide on low molecular weight nuclear RNA. Biochemistry 1976; 15:3823-8. [PMID: 182218 DOI: 10.1021/bi00662a027] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Studies were made on the effects of alpha-amanitin, cycloheximide, and thioacetamide on synthesis and content of low molecular weight nuclear RNA. Cycloheximide, an inhibitor of protein synthesis and the synthesis of 45S pre-rRNA and 5S RNA, also inhibited synthesis of nuclear U1 and U3 RNAs. alpha-Amanitin, an inhibited the synthesis of U1 and U2 low molecular weight nuclear RNA. Thioacetamide, which induces nucleolar hypertrophy and increased nucleolar RNA polymerase activity, markedly increased synthesis of 5.8S RNA and U3 RNA. These results show that syntheses of individual low molecular weight nuclear (LMWN) RNAs are controlled by different regulatory mechanisms. In particular, there appears to be a specific relationship between U3 RNA and functional states of the nucleolus.
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Biswas BB, Ganguly A, Das A. Eukaryotic RNA polymerases and the factors that control them. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1975; 15:145-84. [PMID: 166413 DOI: 10.1016/s0079-6603(08)60119-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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30
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31
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Kedinger C, Simard R. The action of alpha-amanitin on RNA synthesis in Chinese hamster ovary cells. Ultrastructural and biochemical studies. J Cell Biol 1974; 63:831-42. [PMID: 4474178 PMCID: PMC2109362 DOI: 10.1083/jcb.63.3.831] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
alpha-Amanitin acts in vitro as a selective inhibitor of the nucleoplasmic form B RNA polymerases. Treatment of Chinese hamster ovary (CHO) cells with this drug leads principally to a severe fragmentation of the nucleoli. While the ultrastructural lesions induced by alpha-amanitin in CHO cells and in rat or mouse liver are quite similar, the results diverge concerning the effect on RNA synthesis. It has been shown that in rat or mouse liver alpha-amanitin blocks both extranucleolar and nucleolar RNA synthesis. Our autoradiographic and biochemical evidence indicates that in CHO cells high molecular weight extranucleolar RNA synthesis (HnRNA) is blocked by the alpha-amanitin treatment, whereas nucleolar RNA (preribosomal RNA) synthesis remains unaffected even several hours after the inhibition of extranucleolar RNA synthesis. Furthermore, the processing of this RNA as well as its transport to the cytoplasm seem only slightly affected by the treatment. Finally, under these conditions, the synthesis of the low molecular RNA species (4-5S) still occurs, though less actively. The results are interpreted as evidence for a selective impairment of HnRNA synthesis by alpha-amanitin in CHO cells.
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Hadjiolov AA, Dabeva MD, Mackedonski VV. The action of alpha-amanitin in vivo on the synthesis and maturation of mouse liver ribonucleic acids. Biochem J 1974; 138:321-34. [PMID: 4473981 PMCID: PMC1166217 DOI: 10.1042/bj1380321a] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
alpha-Amanitin acts in vitro and in vivo as a selective inhibitor of nucleoplasmic RNA polymerases. Treatment of mice with low doses of alpha-amanitin causes the following changes in the synthesis, maturation and nucleocytoplasmic transfer of liver RNA species. 1. The synthesis of the nuclear precursor of mRNA is strongly inhibited and all electrophoretic components are randomly affected. The labelling of cytoplasmic mRNA is blocked. These effects may be correlated with the rapid and lasting inhibition of nucleoplasmic RNA polymerase. 2. The synthesis and maturation of the nuclear precursor of rRNA is inhibited within 30min. (a) The initial effect is a strong (about 80%) inhibition of the early steps of 45S precursor rRNA maturation. (b) The synthesis of 45S precursor rRNA is also inhibited and the effect increases from about 30% at 30min to more than 70% at 150min. (c) The labelling of nuclear and cytoplasmic 28S and 18S rRNA is almost completely blocked. The labelling of nuclear 5S rRNA is inhibited by about 50%, but that of cytoplasmic 5S rRNA is blocked. (d) The action of alpha-amanitin on the synthesis of precursor rRNA cannot be correlated with the slight gradual decrease of nucleolar RNA polymerase activity (only 10-20% inhibition at 150min). (e) The inhibition of precursor rRNA maturation and synthesis precedes the ultrastructural lesions of the nucleolus detected by standard electron microscopy. 3. The synthesis of nuclear 4.6S precursor of tRNA is not affected by alpha-amanitin. However, the labelling of nuclear and cytoplasmic tRNA is decreased by about 50%, which indicates an inhibition of precursor tRNA maturation. The results of this study suggest that the synthesis and maturation of the precursor of rRNA and the maturation of the precursor of tRNA are under the control of nucleoplasmic gene products. The regulator molecules may be either RNA or proteins with exceedingly fast turnover.
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Schmid W, Sekeris CE. Possible involvement of nuclear DNA-like RNA in the control of ribosomal RNA synthesis. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 312:549-54. [PMID: 4737500 DOI: 10.1016/0005-2787(73)90453-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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