title: Nucleoporin Nup358 facilitates nuclear import of Methoprene-tolerant (Met) in an importin β- and Hsp83-dependent manner.
abstract: The bHLH-PAS transcription factor, Methoprene-tolerant (Met)1, functions as a juvenile hormone (JH) receptor and transduces JH signals by directly binding to E-box like motifs in the regulatory regions of JH response genes. Nuclear localization of Met is crucial for its transcriptional activity. Our previous studies have shown that the chaperone protein Hsp83 facilitates JH-induced Met nuclear import in Drosophila melanogaster. However, the exact molecular mechanisms of Met nuclear transport are not fully elucidated. Using DNA affinity chromatography, we have previously detected binding of the nucleoporin Nup358, in the presence of JH, to the JH response region (JHRR) sequences isolated from the Krüppel-homolog 1 (Kr-h1) promoter. Here, we have demonstrated that Nup358 regulates JH-Hsp83-induced Met nuclear localization. RNAi-mediated knockdown of Nup358 expression in Drosophila fat body perturbs Met nuclear transport during the 3 h after initiation of wandering, when the JH titer is high. The accompanying reduced expression of the transport receptor importin β in Nup358 RNAi flies could be one of the reasons accounting for Met mislocalization. Furthermore, a tetratricopeptide repeat (TPR) domain at the N-terminal end of Nup358 interacts with Hsp83 and is indispensable for Met nuclear localization. Overexpression of the TPR domain in Drosophila fat body prevents Met nuclear localization resulting in a decrease in JHRR-driven reporter activity and Kr-h1 expression. These data show that Nup358 facilitates JH-induced Met nuclear transport in a manner dependent on importin β and Hsp83.
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
authors.forename: Qianyu
authors.initials: Q
authors.lastname: He
authors.affiliation: Environmental Monitoring Center Station, DaQing Environmental Protection Agency, Daqing 163316, China.
authors.forename: Yuanxi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
authors.forename: DanDan
authors.initials: D
authors.lastname: Xu
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
authors.forename: Wentao
authors.initials: W
authors.lastname: Dong
authors.affiliation: The Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Sciences and School of Life Sciences, South China Normal University, Guangzhou 510631, China. Electronic address: lisheng01@sibs.ac.cn.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, China. Electronic address: fuhewu@126.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Wu
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D004330:Drosophila / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007605:Juvenile Hormones; D018832:Molecular Chaperones / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D028961:beta Karyopherins / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D029721:Drosophila Proteins; D006360:Heat-Shock Proteins; D007605:Juvenile Hormones; D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; D028961:beta Karyopherins; C424162:Fs(2)Ket protein, Drosophila; C089272:Hsp83 protein, Drosophila; C111234:MET protein, Drosophila; C094493:ran-binding protein 2
keywords: Drosophila; JH receptor; Nuclear localization; Nup358