Structural insight on the liquid silk from the middle silk gland of non-mulberry silkworm Antheraea assamensis

The presence of one or more TATATAA motifs in the flanking sequences of individual members of a multi-gene AGly1 family from the mulberry silkworm, Bombyx mori, negatively modulated the transcription of the gene copies. Characterization of proteins from posterior silk gland nuclear extracts, binding to the TATATAA motif, identified a novel 43kD protein, designated here as P43 TATA-box-binding factor (TBF). The protein was purified to homogeneity. P43 TBF binding was highly sequence-specific and showed a 100-fold-higher affinity for binding than the TATA-box-binding protein (TBP). The protein also showed binding to the TATAAA sequence of the actin5C promoter. P43 TBF inhibited transcription of all the tRNA genes examined, as well as RNA polymerase II transcription from the actin5C promoter. The amino acid sequence of eleven peptides generated from P43 TBF did not share homology with proteins that bind the TATA box, such as TBP, TRF (TBP-related factor) or TLFs (TBP-like factors) reported from other sources. Inhibition of transcription of tRNA genes by P43 TBF could not be reversed by TBP. The inhibitory effect appeared to be exerted through sequestration of the associated transcription factors.

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Variations in the Metallic Ion Concentration in the Silk Gland and Cocoon of Silkworm Antheraea assamensis helfer

Biological Trace Element Research ◽

10.1007/s12011-019-01919-9 ◽

2019 ◽

Vol 196 (1) ◽

pp. 285-289 ◽

Cited By ~ 1

Author(s):

Anurupa Goswami ◽

Dipali Devi

Keyword(s):

Silk Gland ◽

Ion Concentration ◽

Antheraea Assamensis

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Modulation of differential transcription of tRNA genes through chromatin organization

Biochemical Journal ◽

10.1042/bj20050304 ◽

2005 ◽

Vol 391 (2) ◽

pp. 371-381 ◽

Cited By ~ 2

Author(s):

Akhila Parthasarthy ◽

Karumathil P. Gopinathan

Keyword(s):

Internal Control ◽

Silk Gland ◽

Gene Copy ◽

Upstream Region ◽

Trna Genes ◽

Upstream Sequence ◽

Nuclear Extracts ◽

Mulberry Silkworm

In higher eukaryotes, tRNA multigene families comprise several copies encoding the same tRNA isoacceptor species. Of the 11 copies of a tRNA1Gly family from the mulberry silkworm Bombyx mori, individual members are differentially transcribed in vivo in the B. mori-derived BmN cell lines and in vitro in silk gland nuclear extracts. These genes have identical coding regions and hence harbour identical internal control sequences (the A and B boxes), but differ significantly in their 5′ and 3′ flanking regions. In the present study, we demonstrate the role of chromatin structure in the down-regulation of the poorly expressed copy, tRNA1Gly-6,7. Distinct footprints in the 5′-upstream region of the poorly transcribed gene in vitro as well as in vivo suggested the presence of nucleosomes. A theoretical analysis of the immediate upstream sequence of this gene copy also revealed a high propensity of nucleosome formation. The low transcription of tRNA1Gly-6,7 DNA was further impaired on assembly into chromatin and this inhibition was relieved by externally supplemented TFIIIC with an associated histone acetyltransferase activity. The inhibition due to nucleosome assembly was absent when the 5′-upstream region beyond −53 nt was deleted or entirely swapped with the 5′-upstream region of the highly transcribed gene copy, which does not position a nucleosome. Footprinting of the in vitro assembled tRNA1Gly-6,7 chromatin confirmed the presence of a nucleosome in the immediate upstream region potentially masking TFIIIB binding. Addition of TFIIIC unmasked the footprints present on account of the nucleosome. Our studies provide the first evidence for nucleosomal repression leading to differential expression of individual members from within a tRNA multigene family.

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The Fluorescent Pigment of Mulberry Transferred in the Body of Silkworm, Bombyx Mori

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.175-176.3 ◽

2011 ◽

Vol 175-176 ◽

pp. 3-7

Author(s):

Xiao Hong Liu ◽

Ye Feng Li ◽

Jian Xu ◽

Jun Zhou ◽

Xiao Ping Lu

Keyword(s):

Bombyx Mori ◽

Silk Gland ◽

The Body ◽

Pigment Synthesis ◽

Fluorescent Pigment ◽

Tlc Analysis ◽

Green Fluorescent ◽

Mulberry Silkworm ◽

Layer Chromatography ◽

Silkworm Bombyx Mori

Using silkworm (Bombyx mori, Dazao strain) as material, the fluorescent pigment of mulberry, silkworm blood, silk gland, cocoon shell, silkworm excrement, silkworm urine and moth urine were analyzed by using the technology of thin layer chromatography (TLC). The results indicated that there were 7 bands of fluorescent pigment from the extracts of green cocoon shell after TLC analysis. While, 2 bands in silkworm blood and its urine extracts, 4 bands in the silk gland extracts, as well as 5 bands in moth urine extracts were detected, but no band detection in the silkworm excrement extracts. The blue-violet fluorescent pigment which has the same Rf (0.35) was detected from the extracts of green cocoon shell, silk gland, silkworm urine, moth urine and mulberry after TLC analysis, but it cannot be found in silkworm blood and silkworm excrement. It was revealed that the blue-violet fluorescent pigment may be transferred directly from mulberry leaves, and then accumulated in the silk gland. Most of the pigment remained in the cocoon shell. And only a small amount of this kind of pigment was excreted through urine. There was also some yellow-green fluorescent pigment detected in the silkworm blood, silk gland and cocoon shell extracts, but it cannot be detected in both the mulberry and silkworm urine extracts. It was suggested that yellow-green fluorescent pigment synthesis pathway exist in the body of silkworm (Bombyx mori, Dazao strain).

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Composition and in silico structural analysis of fibroin from liquid silk of non-mulberry silkworm Antheraea assamensis

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2020.08.232 ◽

2020 ◽

Vol 163 ◽

pp. 1947-1958

Author(s):

Anurupa Goswami ◽

Nabajyoti Goswami ◽

Anupam Bhattacharya ◽

Probodh Borah ◽

Dipali Devi

Keyword(s):

Structural Analysis ◽

In Silico ◽

Antheraea Assamensis ◽

Mulberry Silkworm

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Quantitative Profile Analysis of Mulberry Silkworm Bombyx mori L. (CSR2XCSR4)

International Letters of Natural Sciences ◽

10.18052/www.scipress.com/ilns.34.34 ◽

2015 ◽

Vol 34 ◽

pp. 34-41 ◽

Cited By ~ 2

Author(s):

B. Venugopal Reddy ◽

P. Divya ◽

M. Anitha

Keyword(s):

Bombyx Mori ◽

Protein Concentration ◽

Profile Analysis ◽

Quantitative Estimation ◽

Silk Gland ◽

Silkworm Larvae ◽

Silk Production ◽

Silk Worm ◽

Bombyx Mori L ◽

Mulberry Silkworm

Bombyx mori. L. (CSR2XCSR4) is a bivolitne crossbreed that produces high quantity of silk. The weights of worms and glands are directly related to the yield of silk, higher larval weights leads to higher silk production. In the present study, quantitative parameters of 5th instar and pupal stages of silkworm larvae were observed. The analysis of quantitative estimation showed that the maximum weights and lengths of silk gland and silk worm were recorded on 7th day of 5th instar larval stage. The day dependent variation in protein concentration was observed in total silk gland 5th instar larval and pupal stages.

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