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Scherrer K. Primary transcripts: From the discovery of RNA processing to current concepts of gene expression - Review. Exp Cell Res 2018; 373:1-33. [PMID: 30266658 DOI: 10.1016/j.yexcr.2018.09.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 12/15/2022]
Abstract
The main purpose of this review is to recall for investigators - and in particular students -, some of the early data and concepts in molecular genetics and biology that are rarely cited in the current literature and are thus invariably overlooked. There is a growing tendency among editors and reviewers to consider that only data produced in the last 10-20 years or so are pertinent. However this is not the case. In exact science, sound data and lucid interpretation never become obsolete, and even if forgotten, will resurface sooner or later. In the field of gene expression, covered in the present review, recent post-genomic data have indeed confirmed many of the earlier results and concepts developed in the mid-seventies, well before the start of the recombinant DNA revolution. Human brains and even the most powerful computers, have difficulty in handling and making sense of the overwhelming flow of data generated by recent high-throughput technologies. This was easier when low throughput, more integrative methods based on biochemistry and microscopy dominated biological research. Nowadays, the need for organising concepts is ever more important, otherwise the mass of available data can generate only "building ruins" - the bricks without an architect. Concepts such as pervasive transcription of genomes, large genomic domains, full domain transcripts (FDTs) up to 100 kb long, the prevalence of post-transcriptional events in regulating eukaryotic gene expression, and the 3D-genome architecture, were all developed and discussed before 1990, and are only now coming back into vogue. Thus, to review the impact of earlier concepts on later developments in the field, I will confront former and current data and ideas, including a discussion of old and new methods. Whenever useful, I shall first briefly report post-genomic developments before addressing former results and interpretations. Equally important, some of the terms often used sloppily in scientific discussions will be clearly defined. As a basis for the ensuing discussion, some of the issues and facts related to eukaryotic gene expression will first be introduced. In chapter 2 the evolution in perception of biology over the last 60 years and the impact of the recombinant DNA revolution will be considered. Then, in chapter 3 data and theory concerning the genome, gene expression and genetics will be reviewed. The experimental and theoretical definition of the gene will be discussed before considering the 3 different types of genetic information - the "Triad" - and the importance of post-transcriptional regulation of gene expression in the light of the recent finding that 90% of genomic DNA seems to be transcribed. Some previous attempts to provide a conceptual framework for these observations will be recalled, in particular the "Cascade Regulation Hypothesis" (CRH) developed in 1967-85, and the "Gene and Genon" concept proposed in 2007. A knowledge of the size of primary transcripts is of prime importance, both for experimental and theoretical reasons, since these molecules represent the primary units of the "RNA genome" on which most of the post-transcriptional regulation of gene expression occurs. In chapter 4, I will first discuss some current post-genomic topics before summarising the discovery of the high Mr-RNA transcripts, and the investigation of their processing spanning the last 50 years. Since even today, a consensus concerning the real form of primary transcripts in eukaryotic cells has not yet been reached, I will refer to the viral and specialized cellular models which helped early on to understand the mechanisms of RNA processing and differential splicing which operate in cells and tissues. As a well-studied example of expression and regulation of a specific cellular gene in relation to differentiation and pathology, I will discuss the early and recent work on expression of the globin genes in nucleated avian erythroblasts. An important concept is that the primary transcript not only embodies protein-coding information and regulation of its expression, but also the 3D-structure of the genomic DNA from which it was derived. The wealth of recent post-genomic data published in this field emphasises the importance of a fundamental principle of genome organisation and expression that has been overlooked for years even though it was already discussed in the 1970-80ties. These issues are addressed in chapter 5 which focuses on the involvement of the nuclear matrix and nuclear architecture in DNA and RNA biology. This section will make reference to the Unified Matrix Hypothesis (UMH), which was the first molecular model of the 3D organisation of DNA and RNA. The chapter on the "RNA-genome and peripheral memories" discusses experimental data on the ribonucleoprotein complexes containing pre-mRNA (pre-mRNPs) and mRNA (mRNPs) which are organised in nuclear and cytoplasmic spaces respectively. Finally, "Outlook " will enumerate currently unresolved questions in the field, and will propose some ideas that may encourage further investigation, and comprehension of available experimental data still in need of interpretation. In chapter 8, some propositions and paradigms basic to the authors own analysis are discussed. "In conclusion" the raison d'être of this review is recalled and positioned within the overall framework of scientific endeavour.
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Affiliation(s)
- Klaus Scherrer
- Institute Jacques Monod, CNRS, University Paris Diderot, Paris, France.
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2
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Abstract
Active and silenced chromatin domains are often in close juxtaposition to one another, and enhancer and silencer elements operate over large distances to regulate the genes in these domains. The lack of promiscuity in the function of these elements suggests that active mechanisms exist to restrict their activity. Insulators are DNA elements that restrict the effects of long-range regulatory elements. Studies on different insulators from different organisms have identified common themes in their mode of action. Numerous insulators map to promoters of genes or have binding sites for transcription factors and like active chromatin hubs and silenced loci, insulators also cluster in the nucleus. These results bring into focus potential conserved mechanisms by which these elements might function in the nucleus.
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Affiliation(s)
- Lourdes Valenzuela
- Unit on Chromatin and Transcription, NICHD/NIH, Bethesda, Maryland 20892, USA
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3
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Abstract
The construction of a recombinant virus in the late region of simian virus 40 is presented. The small intervening sequence of late 19S RNA (0.760 to 0.765 map unit) was cloned and inserted into the EcoRI site (1.0 map unit) in the late region of simian virus 40. This is a mutant virus that now has two intervening sequences, one at the normal position (0.760 map unit) and another out of the context of its flanking sequence and now at 1.0 map unit. The recombinant appears poisonous, as repeated attempts to plaque it as a virus with a standard helper virus were unsuccessful. The transcription of this recombinant was, therefore, studied after direct DNA transfection onto CV-1 cells. Nuclease S1 analysis of mutant RNA indicates that the major nuclear transcript was a spliced but nuclear 16S RNA species. Normally, 16S RNA is not found in the nucleus. This result was shown to be an artifact of the DNA transfection protocol. When the glycerol shock was done after infection with virus, a similar alteration in the makeup of nuclear RNA was seen. A transient stock of this double-intron mutant was finally obtained, using a nonrevertable helper virus. The transcriptional analysis of this mutant showed that unspliced 19S RNA was not transported and remained within the nucleus, whereas spliced 19S and 16S RNAs were transported. We conclude that the retention of nuclear transcripts within the nucleus is not simply due to the presence of intronic sequences, as spliced 19S and 16S RNAs which contain the second intron were efficiently transported.
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Villarreal LP, Carr S. Genetic test for involvement of intervening sequences in transport of nuclear RNA. Mol Cell Biol 2003; 2:1550-7. [PMID: 14582196 PMCID: PMC369963 DOI: 10.1128/mcb.2.12.1550-1557.1982] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The construction of a recombinant virus in the late region of simian virus 40 is presented. The small intervening sequence of late 19S RNA (0.760 to 0.765 map unit) was cloned and inserted into the EcoRI site (1.0 map unit) in the late region of simian virus 40. This is a mutant virus that now has two intervening sequences, one at the normal position (0.760 map unit) and another out of the context of its flanking sequence and now at 1.0 map unit. The recombinant appears poisonous, as repeated attempts to plaque it as a virus with a standard helper virus were unsuccessful. The transcription of this recombinant was, therefore, studied after direct DNA transfection onto CV-1 cells. Nuclease S1 analysis of mutant RNA indicates that the major nuclear transcript was a spliced but nuclear 16S RNA species. Normally, 16S RNA is not found in the nucleus. This result was shown to be an artifact of the DNA transfection protocol. When the glycerol shock was done after infection with virus, a similar alteration in the makeup of nuclear RNA was seen. A transient stock of this double-intron mutant was finally obtained, using a nonrevertable helper virus. The transcriptional analysis of this mutant showed that unspliced 19S RNA was not transported and remained within the nucleus, whereas spliced 19S and 16S RNAs were transported. We conclude that the retention of nuclear transcripts within the nucleus is not simply due to the presence of intronic sequences, as spliced 19S and 16S RNAs which contain the second intron were efficiently transported.
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Affiliation(s)
- L P Villarreal
- Department of Microbiology and Immunology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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5
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Iarovaia O, Razin SV, Linares-Cruz G, Sjakste N, Scherrer K. In chicken leukemia cells globin genes are fully transcribed but their rnas are retained in the perinucleolar area. Exp Cell Res 2001; 270:159-65. [PMID: 11640880 DOI: 10.1006/excr.2001.5332] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using hybridization in situ with a ribo-probe recognizing transcripts of the chicken alpha A globin gene, we show here that in proliferating AEV-transformed erythroblasts this gene is strongly transcribed, but the corresponding transcripts are retained in the nuclei. Most surprisingly, this globin RNA accumulates in the perinucleolar areas in a pattern never observed before. Upon induction of cells to differentiate, leading to productive expression of the hemoglobins, the transcripts of the alpha A globin gene were found for the most part in the cytoplasm. In the nuclei of differentiated cells, the globin RNA is concentrated in one or two specific spots, which are likely to represent the "processing centers" (PCs) of the globin RNA. The results presented indicate that posttranscriptional steps of regulation involving in particular the perinuclear areas are of major importance for erythroid differentiation.
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Affiliation(s)
- O Iarovaia
- Institut Jacques Monod, Université Paris 7, 2 Place Jussieu, Tour 43, Paris cedex 05, 75251, France
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6
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De Conto F, Missorini S, Arcangeletti C, Pinardi F, Montarras D, Pinset C, Vassy J, Géraud G, Chezzi C, Scherrer K. Prosome cytodistribution relative to desmin and actin filaments in dividing C2.7 myoblasts and during myotube formation in vitro. Exp Cell Res 1997; 233:99-117. [PMID: 9184080 DOI: 10.1006/excr.1997.3561] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Prosomes constitute the multicatalytic proteinase (MCP) core of the 26S proteasomes, but were first observed as subcomplexes of untranslated mRNP; this suggests that they play a putative role in the control of protein biosynthesis in addition to their catabolic enzymatic function. In previous investigations it was shown that some prosomes colocalize with the intermediate filaments (IF) of the cytoskeleton, of the cytokeratin type in epithelial cells, and of the vimentin type in fibroblasts. Studies on adult rat muscle carried out with prosome-specific monoclonal antibodies (p-mAbs) have shown, surprisingly, that specific types of prosomes predominantly occupy a particular zone in between the M and the Z lines of the sarcomeric structure. The data presented here show that the subunit composition of prosomes changes when the dividing C2.7 myoblasts fuse into myotubes. We show furthermore that, in dividing C2.7 myoblasts, prosomes colocalize with the desmin network as well as with that of actin, in a distribution that changes with the subunit pattern of the prosomes investigated by individual p-mAbs. Surprisingly, when myogenic fusion is induced, specific types of prosomes move first to the nuclei; later on, they reappear in the cytoplasm. There, superimposing initially onto the reorganizing desmin filaments that run from one pole of the prefusion myoblast to the other, prosomes gradually colocalize with the actin fibers in the fusing myotubes, finally forming a "pearl on a string" pattern. These results are discussed in relation to parallel observations of prosome distribution between the actin and IF networks not only in epithelial cells but also in fusing muscle satellite cells, which made it possible to monitor the complete buildup of the sarcomeric structure.
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Affiliation(s)
- F De Conto
- Institut Jacques Monod du CNRS, Université Paris 7, France
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Olink-Coux M, Arcangeletti C, Pinardi F, Minisini R, Huesca M, Chezzi C, Scherrer K. Cytolocation of prosome antigens on intermediate filament subnetworks of cytokeratin, vimentin and desmin type. J Cell Sci 1994. [DOI: 10.1242/jcs.107.3.353] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Analysis by double-label indirect immunofluorescence of PtK1 and HeLa cells had previously demonstrated that prosome* antigens form networks that superimpose on those of the intermediate filaments of the cytokeratin type. We show here that in PtK1 cells various prosomal antigens also reside to a variable extent on intermediate filaments subnetworks of the vimentin type. In proliferating human fibroblasts the prosome and vimentin networks were found to coincide, while in proliferating myoblasts of the C2.7 mouse myogenic cell line the prosomal antigens seem to superimpose on the intermediate filaments of the desmin type. Thus, the prosomes, which are RNP particles of variable composition and subcomplexes of untranslated mRNP, and carry a multicatalytic proteinase activity, seem to co-localize with the specific kind of cytoplasmic intermediate filament in relation to the cell type. These results, which generalize the previous data, are discussed in view of possible role(s) for prosomes in mRNA metabolism and/or intermediate filaments remodelling.
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Affiliation(s)
- M. Olink-Coux
- Institut Jacques Monod, CNRS, Universite Paris 7, France
| | | | - F. Pinardi
- Institut Jacques Monod, CNRS, Universite Paris 7, France
| | - R. Minisini
- Institut Jacques Monod, CNRS, Universite Paris 7, France
| | - M. Huesca
- Institut Jacques Monod, CNRS, Universite Paris 7, France
| | - C. Chezzi
- Institut Jacques Monod, CNRS, Universite Paris 7, France
| | - K. Scherrer
- Institut Jacques Monod, CNRS, Universite Paris 7, France
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Rund D, Dowling C, Najjar K, Rachmilewitz EA, Kazazian HH, Oppenheim A. Two mutations in the beta-globin polyadenylylation signal reveal extended transcripts and new RNA polyadenylylation sites. Proc Natl Acad Sci U S A 1992; 89:4324-8. [PMID: 1374896 PMCID: PMC49074 DOI: 10.1073/pnas.89.10.4324] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Two mutations in the beta-globin poly(A) signal were identified in Israeli patients with beta +-thalassemia by sequence analysis following PCR. One is a point mutation (AATAAA----AATAAG) and the other is a 5-base-pair deletion (AATAAA----A----). The mutant genes were used to investigate the function of the poly(A) signal in vivo and to evaluate the mechanism whereby these mutations lead to a thalassemic phenotype. Analysis of RNA derived from peripheral blood demonstrated the presence of elongated RNA species in patients carrying either mutation. Other aspects of RNA processing (initiation, splicing) were unimpaired. RNA obtained from the patients carrying the point mutation contained four discrete, extended RNA species, 1500-2900 nucleotides long, which were found to be polyadenylated. Some normal cleavage-polyadenylylation was also observed. The 5-base-pair deletion completely abolished cleavage at the normal site. This deletion mutation resulted in a phenotype of beta +-thalassemia, thus providing evidence that the extended mRNAs are translatable in vivo. Furthermore, additional transcripts, greater than 5 kilobases, presumably mRNA precursors, were found in all RNA samples, including those of nonthalassemic controls. The extended transcripts of the poly(A) mutants, together with the high molecular weight precursors, suggest that the human beta-globin gene transcription unit is significantly longer than previously recognized.
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Affiliation(s)
- D Rund
- Hadassah University Hospital, Jerusalem, Israel
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9
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Broders F, Zahraoui A, Scherrer K. The chicken alpha-globin gene domain is transcribed into a 17-kilobase polycistronic RNA. Proc Natl Acad Sci U S A 1990; 87:503-7. [PMID: 1689044 PMCID: PMC53293 DOI: 10.1073/pnas.87.2.503] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The 5' start sites and the 3' ends of giant transcripts of the approximately 20-kilobase (kb)-long chicken alpha-globin gene domain were identified by reverse transcription with specific primers and by nuclease S1 mapping using cloned and sequenced restriction fragments of the domain. A transcriptional unit of approximately 17 kb was found that includes all three embryonic and adult genes of the cluster. The largest transcript initiates 8 kb upstream of the gene, within a cluster of A + T-rich sequences placed upstream of a matrix attachment point, at one of several CAA(A)T boxes framing a cluster of four TATA boxes. The 5' ends of a group of 2.5-, 5-, and 12-kb globin transcripts accumulating in avian erythroblastosis virus-transformed cells, which transcribe globin genes abortively, map to the sequence ATATATAATAA 1 kb upstream of the embryonic pi-globin gene. This sequence might correspond to a site of RNA processing or of alternative transcription initiation. Transcription of the domain ends about 2 kb downstream of the last gene of the cluster, downstream of an enhancer and immediately upstream of a CR1 repetitive element in an A + T-rich sequence that includes a matrix attachment site. These data indicate that full-domain transcripts including embryonic as well as adult alpha-globin genes exist, and that the region transcribed is framed by A + T-rich linkers and matrix attachment points.
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Affiliation(s)
- F Broders
- Institut Jacques Monod, Paris, France
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10
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Grossi de Sa MF, Martins de Sa C, Harper F, Olink-Coux M, Huesca M, Scherrer K. The association of prosomes with some of the intermediate filament networks of the animal cell. J Cell Biol 1988; 107:1517-30. [PMID: 2459130 PMCID: PMC2115241 DOI: 10.1083/jcb.107.4.1517] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The small RNP complexes of defined morphology and biochemical composition termed prosomes, first isolated from the cytoplasm associated with repressed mRNA (Martins de Sa, C., M.-F. Grossi de Sa, O. Akhayat, F. Broders, and K. Scherrer. J. Mol. Biol. 1986. 187:47-493), were found also in the nucleus (Grossi de Sa, M.-F., C. Martins de Sa, F. Harper, O. Coux, O. Akhayat, P. Gounon, J. K. Pal, Y. Florentin, and K. Scherrer. 1988. J. Cell Sci. 89:151-165). Immunofluorescence, immunoelectron microscopy, and immunochemical studies using mAbs directed against some of the prosomal proteins of duck erythroblasts indicate that in the cytoplasm of HeLa and PtK cells, prosome antigens are associated with the intermediate filament network of the cytokeratin type.
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Naora H, Miyahara K, Curnow RN. Origin of noncoding DNA sequences: molecular fossils of genome evolution. Proc Natl Acad Sci U S A 1987; 84:6195-9. [PMID: 3476940 PMCID: PMC299037 DOI: 10.1073/pnas.84.17.6195] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The total amount of noncoding sequences on chromosomes of contemporary organisms varies significantly from species to species. We propose a hypothesis for the origin of these noncoding sequences that assumes that (i) an approximately equal to 0.55-kilobase (kb)-long reading frame composed the primordial gene and (ii) a 20-kb-long single-stranded polynucleotide is the longest molecule (as a genome) that was polymerized at random and without a specific template in the primordial soup/cell. The statistical distribution of stop codons allows examination of the probability of generating reading frames of approximately equal to 0.55 kb in this primordial polynucleotide. This analysis reveals that with three stop codons, a run of at least 0.55-kb equivalent length of nonstop codons would occur in 4.6% of 20-kb-long polynucleotide molecules. We attempt to estimate the total amount of noncoding sequences that would be present on the chromosomes of contemporary species assuming that present-day chromosomes retain the prototype primordial genome structure. Theoretical estimates thus obtained for most eukaryotes do not differ significantly from those reported for these specific organisms, with only a few exceptions. Furthermore, analysis of possible stop-codon distributions suggests that life on earth would not exist, at least in its present form, had two or four stop codons been selected early in evolution.
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Broders F, Scherrer K. Transcription of the alpha globin gene domain in normal and AEV-transformed chicken erythroblasts: mapping of giant globin-specific RNA including embryonic and adult genes. MOLECULAR & GENERAL GENETICS : MGG 1987; 209:210-20. [PMID: 2823073 DOI: 10.1007/bf00329645] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The genomic domain of about 20 kbp of the chicken alpha-type globin genes, framed by AT-rich linkers (ATRLs; Moreau et al. 1982) and repetitive sequences (Broders et al. 1986), was cut into 13 fragments and subcloned. The in vitro labelled individual restriction fragments were used to test the extent of the transcribed domain by blot-hybridization of nuclear RNA in large excess from normal adult chicken and Avian Erythroblastosis Virus (AEV)-transformed erythroblasts. In both these types of cells, the AT-rich segments situated 6 kbp upstream of the first gene as well as all the domain including the embryonic pi and the adult alpha D and alpha A genes down to the AT-rich segment placed 3 kbp downstream were found to be transcribed. Electrophoresis of nuclear RNA, Northern blotting and hybridization with most of the nick-translated DNA probes revealed in all cases the presence of heterogeneous globin RNA molecules in the 3-12 kb range, as well as some distinct RNA bands. Single-stranded RNA probes of some genomic segments indicated asymmetrical transcription of the minus strand. A 12 kb globin-specific RNA including the pi and alpha A genes but not the intervening alpha D gene was observed in AEV-transformed cells: it includes sequences located far upstream and downstream from the alpha globin genes and might represent a processing product of a full length transcript spanning the whole domain. Reverse transcription by extension of primers placed in the first exon of each of the three globin genes confirmed the presence of continuous transcripts of the domain including the two adult and the embryonic globin genes.
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Affiliation(s)
- F Broders
- Institut Jacques Monod, Université Paris VII, France
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13
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Kretsovali A, Müller MM, Weber F, Marcaud L, Farache G, Schreiber E, Schaffner W, Scherrer K. A transcriptional enhancer located between adult beta-globin and embryonic epsilon-globin genes in chicken and duck. Gene 1987; 58:167-75. [PMID: 3428615 DOI: 10.1016/0378-1119(87)90373-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have detected a transcriptional enhancer sequence downstream from the adult beta-globin (beta A-globin) genes of chicken and duck. DNA segments from the beta-globin coding and flanking sequences were cloned into expression vectors containing the SV40 promoter linked to either the T antigen gene or the cat gene. The expression of these genes was measured in a chicken erythroid cell line transfected with the recombinant plasmids. We found that segments located about 400 bp downstream from the poly(A) site of both the chicken and duck beta A-globin genes (and about 1.5 kb upstream from the embryonic epsilon-globin gene) stimulate transcription of the test genes about five-fold. In chicken essentially the same segment was also found by others to act as an erythroid cell-specific enhancer [Hesse et al., Proc. Natl. Acad. Sci. USA 83 (1986) 4312-4316; Choi and Engel, Nature 323 (1986) 731-734]. The sequence containing this enhancer is conserved in evolution. A high degree of homology, reaching 84% in a segment 180 bp in length, was found between chicken and duck despite an evolutionary divergence of 70 myr.
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Kretsovali A, Marcaud L, Moreau J, Scherrer K. Conservation and variation in the large scale organisation of the globin gene domains of duck and chicken. MOLECULAR & GENERAL GENETICS : MGG 1986; 203:193-201. [PMID: 3016478 DOI: 10.1007/bf00333954] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The genomic DNA of cloned recombinants containing the duck globin genes was compared to that of the analogous domains of the chicken. A 36 kb insert including the three alpha-type globin genes was isolated from a newly prepared duck genomic library in the cosmid PJB8; another recombinant contained a 45 kb insert with the four beta globin genes. In the alpha globin gene domain, the relative positions of genes, of repetitive sequences, and of the A + T-rich segments (AT-rich linkers, ATRLs) which frame the gene cluster (Moreau et al. 1982), were found to be closely maintained between duck and chicken. Although ATRLs and repetitive sequences also frame the gene cluster in the beta globin domains of duck and chicken, there is more genetic drift in their relative positions than in the alpha domain. It is of interest that several repetitive DNA segments were detected in the chicken beta globin domain which do not exist in corresponding positions in the duck. In view of the strict conservation in both species of genes and their relative positions in the cluster, this observation seems to exclude a simple function of repetitive sequences in the control of individual genes. The data are discussed with regard to the possible significance of repetitive and AT-rich DNA segments in genome organisation and function.
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15
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Broders F, Razin S, Farache G, Moreau J, Scherrer K. Correlations of repetitive and AT-rich DNA segments within the chicken globin gene domains. Mol Biol Rep 1986; 11:177-87. [PMID: 3020393 DOI: 10.1007/bf00419739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The repetitive DNA segments were mapped within a 30 Kbp genomic domain including (in 5' to 3' order) the chicken embryonic pi and adult alpha D (minor) and alpha A (major) globin genes. Two repeats map 5 and 8 Kbp upstream from the embryonic pi gene and another 3 Kbp downstream of the adult alpha A gene. These repetitive DNA sequences are placed within, or immediately adjacent to the AT-rich DNA segments framing this domain. Similar correlations exist also within the chicken beta globin gene domain. The positions of these AT-rich and repetitive DNA segments framing the alpha globin gene domain also correlate with other already explored features of long range DNA organisation, as clusters of sites of DNAse I hypersensitivity and differential methylation, sites of Matrix-DNA attachment, and with the beginning and end of the transcribed domain.
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16
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Frankis RC, Weise MJ, Nair RM, Paddock GV. Globin proteins of the normal and anemic duck. Arch Biochem Biophys 1985; 238:178-86. [PMID: 3985613 DOI: 10.1016/0003-9861(85)90154-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The red blood cells of normal adult ducks contain two main hemoglobins. The most abundant type, HbA, comprises approximately 80% of the total, with the remaining 20% being made up of HbD. An attempt was made to determine whether during hemolytic anemia a special alpha globin chain (alpha s) replaces the alpha chain of HbA found in normal animals. This special stress alpha globin, whose existence has been seriously questioned, was originally postulated to explain the sequence discrepancies obtained between alpha chains of normal and anemic chickens and ducks. Using gel electrophoresis, isoelectric focusing, and HPLC peptide mapping techniques no qualitative differences between the alpha A globins of normal and anemic animals were found. The nature of the beta globin chains present in adult ducks has also never been rigorously established. In this work, a variety of techniques, including HPLC, gel electrophoresis, and microcolumn amino acid analysis, were used to examine the beta chains from each hemoglobin. Using these methods, no differences were found between the beta globin chains of the two hemoglobins.
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Allan M, Lanyon WG, Paul J. Multiple origins of transcription in the 4.5 Kb upstream of the epsilon-globin gene. Cell 1983; 35:187-97. [PMID: 6194897 DOI: 10.1016/0092-8674(83)90221-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
By a combination of primer extension and S1 mapping, we have identified and characterized at least nine epsilon-globin initiation sites in the 4.5 kb upstream of the canonical mRNA cap site. These occur in four regions, -65 to -250, -900, -1480, and -4500 bp from the translation initiation codon ATG. Transcripts from eight sites yield sufficient material for direct RNA analysis and in all of these instances the molecules are capped. Approximately 10%-15% of epsilon-globin transcripts originate from these upstream sites in both an erythroleukemic cell line and purified erythroblasts from first-trimester human embryos. In three established cell lines derived from adult non-erythroid tissue, low levels of transcription of the epsilon-globin gene occur, but the RNA molecules originate exclusively from one of the upstream sites identified in erythroid cells. These findings suggest modification of the current models of transcription of globin genes.
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Tosta Z, Chabaud O, Chebath J. Identification of thyroglobulin mRNA sequences in the nucleus and the cytoplasm of cultured thyroid cells: a post-transcriptional effect of thyrotropin. Biochem Biophys Res Commun 1983; 116:54-61. [PMID: 6639666 DOI: 10.1016/0006-291x(83)90379-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cytoplasmic and nuclear RNA were isolated from porcine thyroid cells cultured with or without thyrotropin. After denaturation by glyoxal-DMSO treatment, the RNAs were analyzed on agarose gels, transferred onto nitrocellulose filters and hybridized with a [32P]-labelled thyroglobulin cDNA clone. In the cytoplasmic RNA a single mature thyroglobulin mRNA molecule (9 Kb) was present whereas in the nuclear RNA several molecular species (24 to 3.3 Kb) were identified. In the nucleus only the 9 Kb mRNA was polyadenylated. In cytoplasmic preparations the level of mature thyroglobulin mRNA was two-fold higher when cells were cultured with thyrotropin. In nuclear preparations only the level of the mature transcript was affected by the presence of thyrotropin, increasing relative to the concentration of the higher molecular weight species. These results suggest a hormonal effect at the post-transcriptional level that may serve to stabilize the mature mRNA molecule.
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Abstract
We have analyzed the differential expression of a family of beta-like globin genes during the development of rabbits, from four days post implantation to one week before birth. The family is composed of four genes, arranged 5'-beta 4-beta 3-psi beta 2-beta 1-3' on the chromosome; psi beta 2 is an inactive pseudogene. Using the technique of hybrid-arrested translation in vitro, we have identified the embryo-specific globin polypeptides encoded by genes beta 3 and beta 4. The beta 3 and beta 4 globins are replaced by the adult beta 1 globin halfway through gestation; this corresponds temporally with the switch in site of erythropoiesis from the embryonic yolk sac to the fetal liver. The decline in production of beta 3 globin polypeptide precedes the decline in beta 4 globin. Transcripts from genes beta 1, beta 3 and beta 4 were analyzed at progressive stages of gestation by a blot-hybridization assay and by an S1 nuclease protection assay. Mature messenger RNA and presumptive precursor RNAs from genes beta 3 and beta 4 are synthesized abundantly in embryonic erythroid cells but only at very low levels later in fetal development. Conversely, precursor and mature mRNA from gene beta 1 are found at very low levels in embryos but are abundant in fetal and adult erythroid cells. The co-ordinate appearance of precursor RNA, mRNA and polypeptide from all three active genes indicates that the primary developmental regulation of this gene family is exerted at the level of transcription. RNA species larger than the expected precursors were observed when the RNA was denatured with formaldehyde but not when methylmercury was the denaturant. These large RNAs are a formaldehyde-generated artifact, possibly a result of cross-linking globin transcripts to ribosomal RNA. We observe no extensive stable transcripts from the 5' or 3' flanking regions of these genes.
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Analysis of the adult chicken beta-globin gene. Nucleotide sequence of the locus, microheterogeneity at the 5'-end of beta-globin mRNA, and aberrant nuclear RNA species. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32764-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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21
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Knowler JT. An assessment of the evidence for the role of ribonucleoprotein particles in the maturation of eukaryote mRNA. INTERNATIONAL REVIEW OF CYTOLOGY 1983; 84:103-53. [PMID: 6196313 DOI: 10.1016/s0074-7696(08)61016-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
This article has sought to draw together, on the one hand, what is known of mRNA processing and its control and, on the other hand, what is known of the structure and validity of hnRNP and snRNP particles. At the same time, it has attempted to synthesize these two themes into a critical assessment of the evidence which suggests that the particles are intimately involved in processing. It cannot be said that the case is proven. The evidence is compelling but circumstantial. The last few years have seen the development of the first in vitro splicing systems (Weingartner and Keller, 1981; Goldenberg and Raskus, 1981; Kole and Weissman, 1982), the isolation of monoclonal antibodies to defined snRNP (Lerner et al., 1981a; Billings et al., 1982) and hnRNP proteins (Hugle et al., 1982), and the ability to use artificial lipid vesicles to transfer antisera (Lenk et al., 1982) and radioactive snRNA (Gross and Cetron, 1982) into cells. It is to be hoped that further refinements of these and other techniques will allow us to solve this, one of the major outstanding problems of molecular biology.
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Alan M, Grindlay GJ, Stefani L, Paul J. Epsilon globin gene transcripts originating upstream of the mRNA cap site in K562 cells and normal human embryos. Nucleic Acids Res 1982; 10:5133-47. [PMID: 6292831 PMCID: PMC320860 DOI: 10.1093/nar/10.17.5133] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
RNA transcribed from the human epsilon globin gene was studied in K562 cells and human embryos of 5-10 weeks gestation. Using both primer extension and S1 analysis RNA molecules were found which extend 53 +/- 1 bp, 55 +/- 1 bp and 270 +/- 1 bp upstream from the first coding base and are colinear with the gene. The first pair of molecules represent transcripts initiating at the canonical cap site but the other species represents a transcript over 200 nucleotides longer which initiates upstream of the CAAT and ATAA boxes.
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Imaizumi-Scherrer MT, Maundrell K, Civelli O, Scherrer K. Transcriptional and post-transcriptional regulation in duck erythroblasts. Dev Biol 1982; 93:126-38. [PMID: 6127272 DOI: 10.1016/0012-1606(82)90246-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Villeponteau B, Landes GM, Pankratz MJ, Martinson HG. The chicken beta globin gene region. Delineation of transcription units and developmental regulation of interspersed DNA repeats. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33926-7] [Citation(s) in RCA: 17] [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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Frankis R, Paddock GV. Abbreviated 3' non-coding region in duck alpha D globin messenger RNA defines evolutionarily conserved sequences. J Mol Biol 1982; 157:681-6. [PMID: 7120405 DOI: 10.1016/0022-2836(82)90506-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Therwath A, Scherrer K. Precursors of distinct size for chicken alpha A, alpha D and beta globin mRNAs. FEBS Lett 1982; 142:12-6. [PMID: 7106278 DOI: 10.1016/0014-5793(82)80208-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Moreau J, Marcaud L, Maschat F, Kejzlarova-Lepesant J, Lepesant JA, Scherrer K. A + T-rich linkers define functional domains in eukaryotic DNA. Nature 1982; 295:260-2. [PMID: 6460190 DOI: 10.1038/295260a0] [Citation(s) in RCA: 81] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Gasaryan KG. Genome activity and gene expression in avian erythroid cells. INTERNATIONAL REVIEW OF CYTOLOGY 1982; 74:95-126. [PMID: 6181005 DOI: 10.1016/s0074-7696(08)61170-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Kessler-Icekson G, Moreau J, Scherrer K. Isolation of globin pre-messenger RNA on thiol-agarose by terminally mercurated complementary DNA. Mol Biol Rep 1981; 7:83-92. [PMID: 6910589 DOI: 10.1007/bf00778737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A mercurated DNA complementary to globin mRNA was prepared by the addition of mercurated poly(dC) tails to the 3'-end of the molecule using the enzyme terminal deoxynucleotidyl transferase. The mercurated complementary DNA was retained efficiently on thiol-agarose from which it was eluted by 2-mercaptoethanol. Hybridization of the mercurated probe to globin mRNA led to a specific selection of the latter from a mixed population of RNA through hybrid retention on thiol-agarose. In some pilot experiments this technique was applied for the isolation of globin gene-specific pre-mRNA. Pulse-labeled RNA up to 3 X 10(6) MW was thus isolated with prominent peaks of 1.5 kb ('15 S'), 4.0 kb ('28 S') and up to about 10 kb. Electron microscopical analysis revealed pre-mRNA molecules of up to 1.2 mu (about 4.5 kb) in length isolated by hybridization to (Hg)cDNA; in control experiments, hybridization of this high MW RNA was competed out by highly purified globin mRNA. These data provide another indication for the existence of globin gene transcripts in the 10 kb range, i.e. transcripts larger than the about 1 500 nucleotides long '15 S' pre-mRNA, the substrate to final splicing. Such 'giant' transcripts can be interpreted as either the obligatory primary pre-mRNA or only facultative transcripts of the globin genes.
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Marcaud L, Reynaud CA, Therwath A, Scherrer K. Modification of the methylation pattern in the vicinity of the chicken globin genes in avian erythroblastosis virus transformed cells. Nucleic Acids Res 1981; 9:1841-51. [PMID: 6264396 PMCID: PMC326807 DOI: 10.1093/nar/9.8.1841] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Having previously found a reduced transcription of globin genes and an abortive processing of the already transcribed globin pre-mRNA in Avian Erythroblastosis Virus (AEV) transformed cells (1), we compared the genomic DNA of these cells with that of normal chicken erythroblasts, using 32-P-labelled cDNA probes specific for the beta, alpha A and alpha D globin sequences. Restriction endonuclease digestion, electrophoresis of digests in agarose gels, Southern blotting and hybridization were carried out. Our results show that the overall genome organization is not disturbed in the immediate neighbourhood of the adult globin genes; the observed restriction fragments are identical for both DNAs after EcoRI, HindIII, BamHI and XbaI digestion, using the beta, alpha A and alpha D globin cDNA probes. However, we observe specific modifications at some methylation sites in the beta, beta-like and alpha D regions: after HpaII or MspI digestion in the alpha D region and after HhaI digestion in the beta and beta-like region, heavier bands appear in the transformed cell DNA in addition to the ones observed in normal DNA. This implies that, at some specific sites, the transformed cell DNA is more methylated than the normal erythroblast DNA. The possible significance of this observation is discussed.
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Maxwell ES, Maundrell K, Scherrer K. Two low molecular weight nuclear RNAs, isolated from avian erythroblast nuclear ribonucleoprotein complexes, hybridize to duck pre-messenger and globin messenger RNA. Biochem Biophys Res Commun 1980; 97:875-82. [PMID: 7470155 DOI: 10.1016/0006-291x(80)91458-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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