title: Induction of extremely low protein expression level by fusion of C-terminal region of Nef.
abstract: Nef is one of the accessory proteins of human immunodeficiency viruses. Here, we noted that the relative expression level of Nef(NL4-3) is much lower than that of NefJR-CSF in HEK293 cells. By evaluating the expression level using a Nef mutant, it was indicated that amino acids 129-206 of Nef(NL4-3), that is, the C-terminal region named NLAA129-206, could contain the region responsible for the induction of the low protein expression level. In addition, the expression levels of the enhanced green fluorescent protein and Renilla luciferase became extremely low with the fusion of NLAA129-206. Interestingly, the NLAA129-206-corresponding sequences of other Nef variants with relatively high expression levels also induced the extremely low protein expression level by fusion. These results suggest that the C-terminal region of Nef can generally induce an extremely low protein expression level. Here, we propose that the C-terminal region of Nef could become an excellent tool for the induction of an extremely low expression level of arbitrary proteins by attachment as fusion proteins.
authors.affiliation: Department of Pharmaceutical Biochemistry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan. tkmnnbtk@gpo.kumamoto-u.ac.jp.
authors.forename: Nobutoki
authors.initials: N
authors.lastname: Takamune
authors.forename: Yukari
authors.initials: Y
authors.lastname: Irisaka
authors.forename: Minami
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Harada
authors.forename: Shozo
authors.initials: S
authors.lastname: Shoji
authors.forename: Shogo
authors.initials: S
authors.lastname: Misumi
mesh_terms: D015153:Blotting, Western; D005434:Flow Cytometry; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D015693:Gene Products, nef / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D049410:Luciferases, Renilla / Q000378:metabolism; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D015693:Gene Products, nef; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D049410:Luciferases, Renilla