51
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Ueda H, Hirose S. Identification and purification of a Bombyx mori homologue of FTZ-F1. Nucleic Acids Res 1990; 18:7229-34. [PMID: 2124348 PMCID: PMC332857 DOI: 10.1093/nar/18.24.7229] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Extracts from embryos and from posterior and middle silk glands of the silkworm, Bombyx mori contain a sequence specific DNA binding factor termed BmFTZ-F1. The factor binds to the recognition site of FTZ-F1, a positive regulator of the fushi tarazu gene in Drosophila melanogaster. BmFTZ-F1 and FTZ-F1 share the same methylation interference patterns, the same chromatographic behaviors and similar protease digestion profiles. Anti-FTZ-F1 cross reacts with BmFTZ-F1. These results indicate that BmFTZ-F1 is a B. mori homologue of FTZ-F1. The mobility of the factor-DNA complex formed in the silk gland extract changes depending on the developmental stages. Purification of BmFTZF1 to an almost homogeneous state reveals that the factor is a 73 kd protein.
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Affiliation(s)
- H Ueda
- Genetic Stock Center, National Institute of Genetics, Mishima, Japan
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52
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Hui CC, Matsuno K, Suzuki Y. Fibroin gene promoter contains a cluster of homeodomain binding sites that interact with three silk gland factors. J Mol Biol 1990; 213:651-70. [PMID: 2359119 DOI: 10.1016/s0022-2836(05)80253-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
By nuclease protection and mobility shift assays, we have shown that the 5' flanking sequence of the Bombyx mori fibroin gene, which is known to be required for a maximal level of transcription in vitro, contains five regions (A to E) that bind protein factors from the posterior silk gland extract. A silk gland-specific factor (SGF-1) and a ubiquitous factor (FBF-A1) were found to interact with the proximal A region, while the related B region can only bind SGF-1. The three distal regions (C, D and E) bind one posterior silk gland-specific factor (SGF-2) and two ubiquitous factors (SGF-3 and -4). SGF-1 might play an important role in the expression of silk protein genes because it also binds to a similar site in the sericin-1 gene and potential SGF-1 binding sites can be found in two other silk protein genes of Bombyx mori and the fibroin gene of Antheraea yamamai. The three distal regions for SGF-2, -3 and -4 contain ten base-pairs of A + T-rich repeats that resemble the consensus binding site (TCAATTAAAT) of a number of homeodomain proteins. The TAAT motif in the core of these regions is shown to be important for the binding of these three proteins and, as described elsewhere, two Drosophila homeodomain proteins, ZEN (zerknüllt) and EVE (even-skipped). Interestingly, SGF-3 appears to be a Bombyx octamer binding protein and may also be involved in the regulation of the sericin-1 gene. The possibility that the fibroin gene and other silk protein genes may be a group of target genes for some members of the homeobox gene family is discussed.
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Affiliation(s)
- C C Hui
- Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
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53
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Hui CC, Suzuki Y, Kikuchi Y, Mizuno S. Homeodomain binding sites in the 5' flanking region of the Bombyx mori silk fibroin light-chain gene. J Mol Biol 1990; 213:395-8. [PMID: 1972197 DOI: 10.1016/s0022-2836(05)80201-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Multiple A + T-rich stretches in the 5' flanking region of the Bombyx mori fibroin light-chain gene have been shown to bind two Drosophila homeodomain proteins, EVE (even-skipped) and ZEN (zerknüllt), with high affinities. Some of these sites fall into a class that has the established consensus sequence of the binding sites (TCAATTAAAT) for a diverse group of Drosophila homeodomain proteins, while others are quite heterogenous except that they all possess a core TAAT motif. Since clusters of homeodomain binding sites can also be found in the promoters of other silk protein genes, the fibroin gene and the sericin-1 gene, these observations suggest a possible involvement of some homeobox genes in the regulation of a group of silk protein genes.
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Affiliation(s)
- C C Hui
- Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
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54
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Insect silk glands: their types, development and function, and effects of environmental factors and morphogenetic hormones on them. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0020-7322(90)90022-h] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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55
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56
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Matsuno K, Suzuki T, Takiya S, Suzuki Y. Complex formation with the fibroin gene enhancer through a protein-protein interaction analyzed by a modified DNA-binding assay. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83785-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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57
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Takiya S, Suzuki Y. Factors involved in preferential transcription of the fibroin gene. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 179:1-9. [PMID: 2917553 DOI: 10.1111/j.1432-1033.1989.tb14513.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Transcription factors for class II genes from a tissue source, the posterior silk glands of Bombyx mori, were fractionated by stepwise elution on a phosphocellulose column into five fractions: A (0.04 M KCl flow through), A' (0.1 M KCl eluate), B (0.3 M KCl eluate), C (0.5 M KCl eluate) and D (1 M KCl eluate). The minimal requirement for reconstruction of accurate initiation of transcription of the fibroin gene, as well as of the adenovirus 2 major late promoter, was the combination of fractions A, B and D, suggesting that transcription factors from B. mori can recognize general signals of the promoters for class II genes and that basic transcription factors are conserved even in distantly diverged species of eukaryotes. To detect activities stimulating the transcription governed by the promoter of fibroin gene, each fraction was tested for its function by supplementing a basal amount of HeLa cell extract. When circular templates were used, stimulatory activities specific for the fibroin gene were detected in fraction D. This preferential transcription is composed of at least three activities; the first and the second dependent on the upstream elements and the third dependent on the sequence downstream from the TATA box. However, when linear templates were used the preference for the fibroin gene was apparently lost and transcription activation by fraction D became general.
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Affiliation(s)
- S Takiya
- Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan
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58
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The expression of five middle silk gland specific genes is territorially regulated during the larval development of Bombyx mori. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0020-1790(89)90005-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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59
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Obara T, Suzuki Y. Temporal and spatial control of silk gene transcription analyzed by nuclear run-on assays. Dev Biol 1988; 127:384-91. [PMID: 3378671 DOI: 10.1016/0012-1606(88)90325-9] [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: 01/05/2023]
Abstract
In vivo transcriptional activity of the Bombyx mori fibroin and sericin genes was estimated by nuclear run-on assay. Tissue-specific and developmental stage-specific expression of the fibroin and sericin genes through larval development was shown to be primarily regulated at the level of transcription. The expression patterns of these two genes are quite different in their developmental profile, suggesting that they are probably regulated by different underlying mechanisms. A finer spatial control of transcription could be found. The sericin gene transcription is mostly restricted to the posterior region of the middle silk gland throughout the fifth larval instar. Interestingly, the fibroin gene transcription is observed only in the anterior region of the posterior silk gland on the first day of the fifth instar, and spreads toward the posterior region as the fifth instar stage proceeds.
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Affiliation(s)
- T Obara
- Laboratory of Cell Differentiation, National Institute for Basic Biology, Okazaki City, Japan
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60
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OHTA SHUNSUKE, SUZUKI YOSHIAKI, HARA WAJIRO, TAKIYA SHIGEHARU, SUZUKI TOSHIHARU. Fibroin Gene Transcription in the Embryonic Stages of the Silkworm, Bombyx mori. (fibroin gene/ faithful transcription/ embryonic stages/Bombyx mori). Dev Growth Differ 1988. [DOI: 10.1111/j.1440-169x.1988.00293.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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61
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Fujiwara H, Maekawa H, Takada N, Miyajima N, Ishikawa H. Small RNAs of the silkworm, Bombyx mori as revealed by in vitro capping and in vitro transcription. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1988; 91:383-8. [PMID: 3197405 DOI: 10.1016/0305-0491(88)90157-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
1. We characterized several small RNAs in various tissues and strains of the silkworm, Bombyx mori by the in vitro capping and in vitro transcription. 2. Three subspecies of 7SL RNA, which is believed to be involved in protein secretion, were detected in the commercial strains. Structural differences among the three molecules were due to the nucleotide substitution at two positions or more. 3. A very AU-rich RNA, which is about 500 bases long, was always present in any tissue of Bombyx mori while 55 base RNA was only observed in a substantial amount in the fat body and culture cells. 4. These small RNAs were also observed among the in vitro transcripts of total Bombyx DNA in the cell-free extracts from the silkgland and fat body.
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Affiliation(s)
- H Fujiwara
- Department of Technology, National Institute of Health, Tokyo, Japan
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62
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Couble P, Michaille JJ, Garel A, Couble ML, Prudhomme JC. Developmental switches of sericin mRNA splicing in individual cells of Bombyx mori silkgland. Dev Biol 1987; 124:431-40. [PMID: 3678608 DOI: 10.1016/0012-1606(87)90496-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Four mRNA of 10.5, 9.0, 4.0, and 2.8 kb are made from the sericin Ser1 gene by alternative maturation of a unique mRNA precursor. By means of RNA blots and in situ hybridization, we investigated variations in the distribution of these mRNA during the last larval instar in different territories of the middle silkgland. Taken together, the results from these two techniques show that 150 out of the 266 cells of this region of the organ express the Ser1 gene, but accumulate distinct mature mRNA species. Of these 150 cells 42 are specialized in a processing pathway resulting in the production of the 2.8-kb Ser1 mRNA throughout the larval instar. The 108 others perform successively three distinct splicing pathways leading to a development-dependent accumulation of, respectively, the 4.0-, the 10.5-, and the 9.0-kb mRNA. This suggests the occurrence of two switches in the splicing capacities of these cells during the fifth instar. The middle silkgland cells also express another sericin gene (Ser2) which encodes two mRNA of 5.4 and 3.1 kb, also arising by differential splicing. At the beginning of development, all the middle silkgland cells express this gene but, as development proceeds, expression becomes restricted to only the anterior cells. The biological consequence of this topological and temporal regulation of the mode of expression of these two genes is the sequential secretion and layering of the different sericins around the silk thread.
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Affiliation(s)
- P Couble
- UA CNRS 92, Laboratoire de Biologie Cellulaire, Université Claude Bernard Lyon, Villeurbanne, France
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63
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KOGA-BAN YASUNORI, SUZUKI YOSHIAKI. Changes of DNaseI Sensitivity of the Fibroin and Sericin Genes during the Silkworm Development. (DNaseI sensitivity/gene expression/silk gland/chromatin structure). Dev Growth Differ 1987. [DOI: 10.1111/j.1440-169x.1987.00363.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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64
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Kondo K, Aoshima Y, Hagiwara T, Ueda H, Mizuno S. Tissue-specific and periodic changes in the nuclease sensitivity of the fibroin gene chromatin in the silkworm Bombyx mori. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61184-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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65
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Fujiwara H, Ishikawa H. Structure of the Bombyx mori rDNA: initiation site for its transcription. Nucleic Acids Res 1987; 15:1245-58. [PMID: 3029701 PMCID: PMC340521 DOI: 10.1093/nar/15.3.1245] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The initiation site of rDNA transcription in Bombyx mori was determined to be located at 909bp upstream from the 5'- end of mature 18s rRNA by S1-nuclease mapping and primer extension experiment. An in vitro transcription system, which was constructed using posterior silk glands of Bombyx larvae, initiated the transcription of cloned rDNA at exactly the same site as determined for the in vivo transcription above. The primary transcript seemed to be processed at about 200b downstream of the initiation site both in vivo and in vitro. Sequence analyses of the flanking region of the initiation site revealed that short repetitive sequences are widely distributed throughout the NTS region, and that a highly AT-rich region resides immediately upstream of the initiation region.
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66
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Hamada Y, Yamashita O, Suzuki Y. Haemolymph control of sericin gene expression studied by organ transplantation. CELL DIFFERENTIATION 1987; 20:65-76. [PMID: 3815532 DOI: 10.1016/0045-6039(87)90466-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A factor that affects synthesis of sericin mRNAs of Bombyx mori was analyzed by organ transplantation and allatectomy. When silk glands of the third instar larvae were transplanted into the abdomen of fifth instar larvae, substantial amounts of sericin mRNAs were induced in the transplant. The induced sericin gene activity was suppressed upon re-transplantation into the abdomen of fourth instar larvae and induced again when the second hosts grew up to fifth instar larvae. An allatectomy performed on fourth instar larvae promoted production of these mRNAs, suggesting that the synthesis of sericin mRNA is regulated by the titer of juvenile hormone.
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67
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68
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Couble P, Chevillard M, Moine A, Ravel-Chapuis P, Prudhomme JC. Structural organization of the P25 gene of Bombyx mori and comparative analysis of its 5' flanking DNA with that of the fibroin gene. Nucleic Acids Res 1985; 13:1801-14. [PMID: 2987837 PMCID: PMC341112 DOI: 10.1093/nar/13.5.1801] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We have cloned a large portion of the P25 gene of Bombyx mori encoding the 25,000 dalton polypeptide which associates with fibroin to constitute the major silk protein. Its structure has been investigated by restriction mapping R-loop analysis, S1 nuclease protection experiments and nucleotide sequencing of the region spanning the 5' end of the gene and its flanking DNA. This has permitted a comparative sequence analysis of the DNA from the P25 and fibroin genes. The genes demonstrate no relatedness in their coding regions but they exhibit large blocks of sequence homology in their 5' flanking regions. In particular, the DNA upstream of the P25 gene possesses a sequence very similar to a region of fibroin 5' flanking DNA that is known to possess transcription modulation signals. The functional significance of these homologous regions is discussed with regard to the highly coordinated expression of these two genes.
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69
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ISHIKAWA ETSUKO, SUZUKI YOSHIAKI. Tissue- and Stage-Specific Expression of Sericin Genes in the Middle Silk Gland of Bombyx mori. (sericin mRNA/northern blotting/gene regulation). Dev Growth Differ 1985. [DOI: 10.1111/j.1440-169x.1985.00073.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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70
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KAULENAS MINDAUGASS. Molecular Biology: Protein Synthesis. Biochemistry 1985. [DOI: 10.1016/b978-0-08-030811-1.50014-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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71
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Silk Synthesis. Biochemistry 1985. [DOI: 10.1016/b978-0-08-030811-1.50023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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72
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Fujiwara H, Ogura T, Takada N, Miyajima N, Ishikawa H, Maekawa H. Introns and their flanking sequences of Bombyx mori rDNA. Nucleic Acids Res 1984; 12:6861-9. [PMID: 6091041 PMCID: PMC320122 DOI: 10.1093/nar/12.17.6861] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We obtained two different clones (16 kb and 13 kb) of B. mori rDNA with intron sequence within the 28S-rRNA coding region. The sequence surrounding the intron was found to be highly conserved as indicated in several eukaryotes (Tetrahymena, Drosophila and Xenopus). The 28S rRNA-coding sequence of 16 kb and 13 kb clone was interrupted at precisely the same sites as those where the D. melanogaster rDNA interrupted by the type I and type II intron, respectively. The intron sequences of B. mori were different from those of D. melanogaster. In 16 kb clone, the intron was flanked by 14 bp duplication of the junction sequence, which was also present once within the 28S rRNA-coding region of rDNA without intron. This 14 bp sequence was identical with those surrounding the introns of Dipteran rDNAs.
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73
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Couble P, Moine A, Garel A, Prudhomme JC. Developmental variations of a nonfibroin mRNA of Bombyx mori silkgland, encoding for a low-molecular-weight silk protein. Dev Biol 1983; 97:398-407. [PMID: 6852371 DOI: 10.1016/0012-1606(83)90096-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The characterization of a new silk protein mRNA (P25 mRNA) in posterior silkgland cells (PSG) and the developmental variations of its cell molecular concentration versus that of fibroin mRNA are described. A 80% pure P25 cDNA was obtained by class separation of total nonfibroin cDNA from PSG and used to identify the mRNA in blotted PSG mRNA as a single 1100 nucleotide long species. When purified from agarose gel and translated in a reticulocyte cell-free system, P25 mRNA yielded a 25-kD polypeptide (P25), identical to a 25-kD protein of the cocoon in terms of pI value and partial peptide mapping pattern. Moreover, this protein comigrated with an abundant polypeptide of the posterior silkgland (PSG) and of the middle silkgland (MSG). When tritiated leucine was injected in vivo, labeled P25 showed up in the PSG after a 2-hr pulse but appeared in the MSG only after 24 hr of labeling. Since MSG cells were found to be devoid of P25 mRNA, we concluded that P25 is exclusively synthesized in the PSG, that it accumulates in the MSG lumen and that it is spun out in the same way as fibroin. Specific probes were used to measure the concentrations of P25 mRNA and also fibroin mRNA in PSG total RNA by hybridization with an excess of cDNA. Both species are highly degraded in the few hours following the physiological arrest of feeding which precedes the fourth molting period. Their subsequent accumulation during the fifth intermolt is triggered by food uptake and proceeds in such a way that a constant 1:1 molar ratio is maintained during the period of silk secretion.
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74
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75
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Levy LS, Ganguly R, Ganguly N, Manning JE. The selection, expression, and organization of a set of head-specific genes in Drosophila. Dev Biol 1982; 94:451-64. [PMID: 6818066 DOI: 10.1016/0012-1606(82)90362-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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76
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Okamoto H, Ishikawa E, Suzuki Y. Structural analysis of sericin genes. Homologies with fibroin gene in the 5' flanking nucleotide sequences. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33412-4] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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77
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Chevallier A, Garel JP. Differential synthesis rates of tRNA species in the silk gland of Bombyx mori are required to promote tRNA adaptation to silk messages. EUROPEAN JOURNAL OF BIOCHEMISTRY 1982; 124:477-82. [PMID: 7106102 DOI: 10.1111/j.1432-1033.1982.tb06618.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In studying the mechanism of tRNA adaptation to silk fibroin and sericin mRNA translation, we investigated the accumulation rates of tRNA species rapidly labeled in vivo in the posterior and middle silk glands of the silkworm Bombyx mori during the last larval instar. We found that the rates of synthesis of total and individual tRNA species labeled with [3H]uridine during the growth and the secretion phases and separated by electrophoresis on polyacrylamide gels, are specific for each tRNA species and each tissue. We noted continuous variations of the tRNA levels designed to reflect changes in the population of mRNAs. The tRNA adaptation to silk mRNAs is completed roughly at the end of the growth phase and at the beginning of the secretion phase (day four of the Vth instar). Its stabilization during the secretion phase occurs by a reversal of the relative rates of predominant tRNA species, mainly tRNAGly. The sum total of the synthetic rates for each tRNA species corroborates their known adaptive distribution during the secretion phase of silk proteins. In addition, when coupled to the similarity of their turnover rates, observed previously, the data support a transcriptional control of tRNA genes.
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78
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Tsuda M, Suzuki Y. Faithful transcription initiation of fibroin gene in a homologous cell-free system reveals an enhancing effect of 5' flanking sequence far upstream. Cell 1981; 27:175-82. [PMID: 7326750 DOI: 10.1016/0092-8674(81)90371-8] [Citation(s) in RCA: 118] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
For the faithful initiation of transcription of exogenously added fibroin gene, a crude cellular extract was prepared from the posterior silk glands where fibroin gene is specifically transcribed. The faithful initiation was demonstrated by the assay with use of truncated fibroin gene templates and confirmed by nuclease S1 mapping. The transcription initiation of fibroin gene was detected also in the extract from the middle silk glands where fibroin gene is not transcribed, indicating that an expected suppression machinery for the gene was left behind during the extraction procedures. The promoter sequence of fibroin gene required in these homologous extracts (the nucleotide position -29 to +6) is the same as that in a heterologous HeLa cell extract. This result guarantees a limited usefulness of the HeLa cell extract in determining promotor sequence or analyzing general transcription machinery. In the homologous extracts, but not in the heterologous extract, however, it has been shown for the first time in vitro that the 5' flanking sequence upstream from -74 enhances the transcription initiation of fibroin gene. In addition, a remarkable fibroin gene preference in transcription over mouse beta globin and adenovirus 2 major late genes was observed in the homologous extracts. The fibroin gene preference is partly caused by the sequence element upstream from -74 of fibroin DNA.
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79
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Goldberg RB, Hoschek G, Ditta GS, Breidenbach RW. Developmental regulation of cloned superabundant embryo mRNAs in soybean. Dev Biol 1981; 83:218-31. [PMID: 6113180 DOI: 10.1016/0012-1606(81)90468-1] [Citation(s) in RCA: 132] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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