title: Cloning and characterization of carboxyl terminus of heat shock cognate 70-interacting protein gene from the silkworm, Bombyx mori.
abstract: Carboxyl terminus of heat shock cognate 70-interacting protein (CHIP) is an evolutionarily conserved E3 ubiquitin ligase across different eukaryotic species and is known to play a key role in protein quality control. CHIP has two distinct functional domains, an N-terminal tetratricopeptide repeat (TPR) and a C-terminal U-box domain, which are required for the ubiquitination of numerous labile client proteins that are chaperoned by heat shock proteins (HSPs) and heat shock cognate proteins (HSCs). During our screen for CHIP-like proteins in the Bombyx mori databases, we found a novel silkworm gene, Bombyx mori CHIP. Phylogenetic analysis showed that BmCHIP belongs to Lepidopteran lineages. Quantitative reverse transcription-PCR analysis indicated that BmCHIP was relatively highly expressed in the gonad and fat body. A pull-down experiment and auto-ubiquitination assay showed that BmCHIP interacted with BmHSC70 and had E3 ligase activity. Additionally, immunohistochemical analysis revealed that BmCHIP was partially co-localized with ubiquitin in BmN4 cells. These data support that BmCHIP plays an important role in the ubiquitin proteasome system as an E3 ubiquitin ligase in B. mori.
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ohsawa
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Tsunakawa
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Shibano
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kawasaki
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi 321-8505, Japan. Electronic address: iwanaga@cc.utsunomiya-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Iwanaga
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology* / Q000235:genetics*; D003001:Cloning, Molecular; D015971:Gene Expression Regulation, Enzymologic; D010802:Phylogeny; D021381:Protein Transport; D044767:Ubiquitin-Protein Ligases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D044767:Ubiquitin-Protein Ligases
keywords: Bombyx mori; Carboxyl terminus of heat shock cognate 70-interacting protein (CHIP); E3 ligase; Ubiquitin proteasome system