A new method for the modification of fibroin heavy chain protein in the transgenic silkworm.
We constructed a new plasmid vector for the production of a modified silk fibroin heavy chain protein (H-chain) in the transgenic silkworm. The plasmid (pHC-null) contained the promoter and the 3' region of a gene encoding the H-chain and the coding regions for the N-terminal domain and the C-terminal domain of the H-chain. For the model protein, we cloned a foreign gene that encoded EGFP between the N-terminal domain and the C-terminal domain in pHC-null and generated transgenic silkworms that produced a modified H-chain, HC-EGFP. Transgenic silkworms produced HC-EGFP in the posterior part of silk gland cells, secreted it into the lumen of the gland, and produced a cocoon with HC-EGFP as part of the fibroin proteins. N-terminal sequencing of HC-EGFP localized the signal sequence cleavage site to between positions A((21)) and N((22)). These results indicate that our new plasmid successfully produced the modified H-chain in a transgenic silkworm.
Kojima
Katsura
K
National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan. kojikei@affrc.go.jp
Kuwana
Yoshihiko
Y
Sezutsu
Hideki
H
Kobayashi
Isao
I
Uchino
Keiro
K
Tamura
Toshiki
T
Tamada
Yasushi
Y
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D012831:Bombyx / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D005349:Fibroins / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D021382:Protein Sorting Signals; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; C482288:fibroin, silkworm; D049452:Green Fluorescent Proteins; D005349:Fibroins