title: Purification and characterization of coacervate-forming cuticular proteins from Papilio xuthus pupae.
abstract: The Papilio xuthus (Lepidoptera: Papilionidae) pupa expresses novel soluble proteins that undergo reversible temperature-dependent coacervate-formation. We purified two coacervate-forming proteins, PX-1 and PX-4, from the wings of pharate adults. PX-1 and PX-4 form coacervates upon warming. Transmission electron microscopy analysis revealed that these proteins assemble ordered bead-like ultrastructures. We cloned and sequenced PX-1 and PX-4 cDNAs. The PX-1 and PX-4 amino acid sequences contain many hydrophobic residues and show homologies to insect cuticular proteins. Moreover, when recombinant PX-1 and PX-4 were overexpressed in Escherichia coli, both recombinant proteins exhibited temperature-dependent coacervation. Furthermore, analyses of truncated mutants of PX-1 suggest that both the Val/Pro-rich region and Gly/lle-rich regions of PX-1 are involved in such coacervation.
authors.affiliation: Division of Life Sciences, Graduate school of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamanaka
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ishizaki
authors.forename: Taro
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Azuma
authors.initials: A
authors.lastname: Taoka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fukumori
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002080:Butterflies / Q000378:metabolism*; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D055827:Integumentary System Physiological Phenomena; D008969:Molecular Sequence Data; D009154:Mutation; D013696:Temperature
chemical_list: D019476:Insect Proteins