Identification and characterization of a novel sericin gene expressed in the anterior middle silk gland of the silkworm Bombyx mori

Takasu, Yoko; Yamada, Hiromi; Tamura, Toshiki; Sezutsu, Hideki; Mita, Kazuei; Tsubouchi, Kozo

doi:10.1016/j.ibmb.2007.07.009

Cited by 104 publications

(111 citation statements)

References 19 publications

(26 reference statements)

Supporting

Mentioning

105

Contrasting

Order By: Relevance

“…The heavy chains of fibroin and sericin are known to be composed of specific amino acid-enriched sequences: glycine (Ͼ45%) and alanine (Ͼ30%) are enriched in fibroin, whereas serine is enriched in sericin (Ͼ30%). Hence, silk gland-specific tRNAs with cognate anticodons for these two proteins accumulate heavily in the PSG and MSG due to massive production of fibroin and sericin (22,60,65). Such an abnormal tRNA composition may not be optimal for BmNPV replication and OB production.…”

Section: Discussionmentioning

confidence: 99%

Baculovirus-Encoded Protein BV/ODV-E26 Determines Tissue Tropism and Virulence in Lepidopteran Insects

Katsuma

Kobayashi

Koyano

et al. 2012

J Virol

View full text Add to dashboard Cite

Lepidopteran nucleopolyhedroviruses (NPVs) show distinct tissue tropism in host insect larvae. However, the molecular mechanism of this tropism is largely unknown. We quantitatively investigated NPV tissue tropism by measuring mRNA levels of viral genes in 16 tissues from Bombyx mori NPV (BmNPV)-infected B. mori larvae and found clear tissue tropism, i.e., BmNPV replicates poorly in the silk glands, midgut, and Malpighian tubule compared with other larval tissues. We next identified the viral genes determining tissue tropism in NPV infection by investigating the phenotypes of larvae infected with 44 BmNPV mutants in which one gene was functionally disrupted by a LacZ cassette insertion. We found that occlusion body (OB) production was markedly enhanced compared with that of the wild type in the middle silk glands (MSGs) of larvae infected with three mutants in which one of three tandemly arrayed genes (Bm7, Bm8, and Bm9) was disrupted. We generated additional mutants in which one or two genes of this gene cluster were partially deleted and showed that Bm8, also known as BV/ODV-E26, was solely required for the suppression of OB production in the MSGs of BmNPV-infected B. mori larvae. Western blotting showed that a LacZ cassette insertion in Bm7 or Bm9 resulted in aberrant expression of Bm8, presumably leading to abnormal OB production in the MSGs. Larval bioassays also revealed that disruption of Bm8 accelerated the death of B. mori larvae. These results suggest that the group I NPV-specific protein BV/ODV-E26 determines tissue tropism and virulence in host lepidopteran insects.

show abstract

Section: Discussionmentioning

confidence: 99%

Baculovirus-Encoded Protein BV/ODV-E26 Determines Tissue Tropism and Virulence in Lepidopteran Insects

Katsuma

Kobayashi

Koyano

et al. 2012

J Virol

View full text Add to dashboard Cite

show abstract

“…In addition to ser1, B. mori has two sericin genes (ser2 and ser3) that are expressed specifically in MSG-A and/or MSG-M (Fig. 1B) (35,36). As a first step to identify novel Antp target genes, we investigated whether ser2 and/or ser3 could be induced by Antp.…”

Section: Expression Of Sericin Genes Following Antp Misexpressionantpmentioning

confidence: 99%

A Hox Gene, Antennapedia, Regulates Expression of Multiple Major Silk Protein Genes in the Silkworm Bombyx mori

Tsubota

Tomita

Uchino

et al. 2016

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Hox genes play a pivotal role in the determination of anteroposterior axis specificity during bilaterian animal development. They do so by acting as a master control and regulating the expression of genes important for development. Recently, however, we showed that Hox genes can also function in terminally differentiated tissue of the lepidopteran Bombyx mori. In this species, Antennapedia (Antp) regulates expression of sericin-1, a major silk protein gene, in the silk gland. Here, we investigated whether Antp can regulate expression of multiple genes in this tissue. By means of proteomic, RT-PCR, and in situ hybridization analyses, we demonstrate that misexpression of Antp in the posterior silk gland induced ectopic expression of major silk protein genes such as sericin-3, fhxh4, and fhxh5. These genes are normally expressed specifically in the middle silk gland as is Antp. Therefore, the evidence strongly suggests that Antp activates these silk protein genes in the middle silk gland. The putative sericin-1 activator complex (middle silk gland-intermoltspecific complex) can bind to the upstream regions of these genes, suggesting that Antp directly activates their expression. We also found that the pattern of gene expression was well conserved between B. mori and the wild species Bombyx mandarina, indicating that the gene regulation mechanism identified here is an evolutionarily conserved mechanism and not an artifact of the domestication of B. mori. We suggest that Hox genes have a role as a master control in terminally differentiated tissues, possibly acting as a primary regulator for a range of physiological processes.

show abstract

“…Sericins are a group of glue proteins that coat and cement silk fibers, endowing silk with its specific characteristic. A total of three sericin proteins have been identified thus far [44,[70][71][72]. With the exception of cocoon silk, a small amount of silk is constantly produced by the silkworm during all larval stages, named larval silk.…”

Section: Lysine Acetylation May Be Involved In the Regulation Of Larvmentioning

confidence: 99%

Comprehensive profiling of lysine acetylation suggests the widespread function is regulated by protein acetylation in the silkworm, Bombyx mori

et al. 2015

View full text Add to dashboard Cite

Lysine acetylation in proteins is a dynamic and reversible PTM and plays an important role in diverse cellular processes. In this study, using lysine-acetylation (Kac) peptide enrichment coupled with nano HPLC/MS/MS, we initially identified the acetylome in the silkworms. Overall, a total of 342 acetylated proteins with 667 Kac sites were identified in silkworm. Sequence motifs analysis around Kac sites revealed an enrichment of Y, F, and H in the +1 position, and F was also enriched in the +2 and -2 positions, indicating the presences of preferred amino acids around Kac sites in the silkworm. Functional analysis showed the acetylated proteins were primarily involved in some specific biological processes. Furthermore, lots of nutrient-storage proteins, such as apolipophorin, vitellogenin, storage proteins, and 30 K proteins, were highly acetylated, indicating lysine acetylation may represent a common regulatory mechanism of nutrient utilization in the silkworm. Interestingly, Ser2 proteins, the coating proteins of larval silk, were found to contain many Kac sites, suggesting lysine acetylation may be involved in the regulation of larval silk synthesis. This study is the first to identify the acetylome in a lepidoptera insect, and expands greatly the catalog of lysine acetylation substrates and sites in insects.

show abstract

Identification and characterization of a novel sericin gene expressed in the anterior middle silk gland of the silkworm Bombyx mori

Cited by 104 publications

References 19 publications

Baculovirus-Encoded Protein BV/ODV-E26 Determines Tissue Tropism and Virulence in Lepidopteran Insects

Baculovirus-Encoded Protein BV/ODV-E26 Determines Tissue Tropism and Virulence in Lepidopteran Insects

A Hox Gene, Antennapedia, Regulates Expression of Multiple Major Silk Protein Genes in the Silkworm Bombyx mori

Comprehensive profiling of lysine acetylation suggests the widespread function is regulated by protein acetylation in the silkworm, Bombyx mori

Contact Info

Product

Resources

About