title: Identification of a cuticle protein with unique repeated motifs in the silkworm, Bombyx mori.
abstract: The insect cuticle is non-cellular matrix secreted from a monolayer of epidermal cells. After abrasion of the larval cuticle of the silkworm, Bombyx mori, a protein with molecular mass of 135 kDa is newly detected in the cuticle. Mass spectrometric analysis of the tryptic fragments from this protein revealed that the 135-kDa protein is encoded by the Cb10 gene. In the predicted amino acid sequence of Cb10, three repeated motifs with [YxGGFGGppG(L/V)L] sequence are found in the C-terminal region. In addition to the repeated motifs, Cb10 has seventeen CxxxxC motifs randomly distributed throughout the polypeptide chain and serine rich region at the N-terminal region. The Cb10 gene is strongly expressed in epidermal cells after pupal ecdysis, and its expression in the larval epidermal cells is induced not only by cuticular abrasion, but also by bacterial infection. These expression patterns suggest some specific roles of this protein in pupal cuticle formation and defense reactions.
authors: Department of Biological Sciences, Tokyo Metropolitan University, Hachioji-shi, Tokyo, Japan. asano-tsunaki@tmu.ac.jp
authors: Tsunaki
authors: T
authors: Asano
authors: Masato
authors: M
authors: Taoka
authors: Takashi
authors: T
authors: Shinkawa
authors: Yoshio
authors: Y
authors: Yamauchi
authors: Toshiaki
authors: T
authors: Isobe
authors: Dan
authors: D
authors: Sato
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D006090:Gram-Negative Bacteria / Q000502:physiology; D006094:Gram-Positive Bacteria / Q000502:physiology; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D017386:Sequence Homology, Amino Acid
chemical_list: D019476:Insect Proteins; C047663:cuticle proteins, insects