PubMed:15607655
Annnotations
{"target":"https://pubannotation.org/docs/sourcedb/PubMed/sourceid/15607655","sourcedb":"PubMed","sourceid":"15607655","source_url":"http://www.ncbi.nlm.nih.gov/pubmed/15607655","text":"A fibroin secretion-deficient silkworm mutant, Nd-sD, provides an efficient system for producing recombinant proteins.\nThe silkworm Nd-s(D) mutant is silk fibroin-secretion deficient. In the mutant, a disulfide linkage between the heavy (H) and light (L) chains, which is essential for the intracellular transport and secretion of fibroin, is not formed because of a partial deletion of the L-chain gene. To utilize the inactivity of the mutant L-chain, we investigated the possibility of using the Nd-s(D) mutant for the efficient production of recombinant proteins in the silkworm. A germ line transformation of the mutant with a normal L-chain-GFP fusion gene was performed. In the transgenic mutant, normal development of the posterior silk gland (PSG) was restored and it formed a normal cocoon. The biochemical analysis showed that the transgenic silkworms expressed the introduced gene in PSG cells, produced a large amount of the recombinant protein, secreted it into the PSG lumen, and used it to construct the cocoon. The molar ratio of silk proteins, H-chain:L-chain-GFP:fibrohexamerin, in the lumen and cocoon in the transgenic silkworm was 6:6:1, and the final product of the fusion gene formed about 10% of the cocoon silk. This indicates that the transgenic mutant silkworm possesses the capacity to produce and secrete the recombinant proteins in a molar ratio equal to that of the fibroin H-chain, contributing around half molecules of the total PSG silk proteins.","tracks":[{"project":"silkworm","denotations":[{"id":"T1","span":{"begin":2,"end":9},"obj":"Gene:693047"},{"id":"T2","span":{"begin":30,"end":38},"obj":"Species:7091"},{"id":"T3","span":{"begin":123,"end":131},"obj":"Species:7091"},{"id":"T4","span":{"begin":155,"end":162},"obj":"Gene:693047"},{"id":"T5","span":{"begin":201,"end":210},"obj":"Chemical:MESH:D004220"},{"id":"T6","span":{"begin":331,"end":338},"obj":"Gene:693047"},{"id":"T7","span":{"begin":574,"end":582},"obj":"Species:7091"},{"id":"T8","span":{"begin":853,"end":862},"obj":"Species:7091"},{"id":"T9","span":{"begin":1082,"end":1096},"obj":"Gene:100146105"},{"id":"T10","span":{"begin":1140,"end":1148},"obj":"Species:7091"},{"id":"T11","span":{"begin":1280,"end":1288},"obj":"Species:7091"},{"id":"T12","span":{"begin":1398,"end":1413},"obj":"Gene:693030"}],"attributes":[{"subj":"T1","pred":"source","obj":"silkworm"},{"subj":"T2","pred":"source","obj":"silkworm"},{"subj":"T3","pred":"source","obj":"silkworm"},{"subj":"T4","pred":"source","obj":"silkworm"},{"subj":"T5","pred":"source","obj":"silkworm"},{"subj":"T6","pred":"source","obj":"silkworm"},{"subj":"T7","pred":"source","obj":"silkworm"},{"subj":"T8","pred":"source","obj":"silkworm"},{"subj":"T9","pred":"source","obj":"silkworm"},{"subj":"T10","pred":"source","obj":"silkworm"},{"subj":"T11","pred":"source","obj":"silkworm"},{"subj":"T12","pred":"source","obj":"silkworm"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"silkworm","color":"#ecae93","default":true}]}]}}