title: Nuclear export of the influenza virus ribonucleoprotein complex: Interaction of Hsc70 with viral proteins M1 and NS2.
abstract: The influenza virus replicates in the host cell nucleus, and the progeny viral ribonucleoprotein complex (vRNP) is exported to the cytoplasm prior to maturation. NS2 has a nuclear export signal that mediates the nuclear export of vRNP by the vRNP-M1-NS2 complex. We previously reported that the heat shock cognate 70 (Hsc70) protein binds to M1 protein and mediates vRNP export. However, the interactions among M1, NS2, and Hsc70 are poorly understood. In the present study, we demonstrate that Hsc70 interacts with M1 more strongly than with NS2 and competes with NS2 for M1 binding, suggesting an important role of Hsc70 in the nuclear export of vRNP.
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Saiko
authors.initials: S
authors.lastname: Noda
authors.affiliation: Department of Pharmacology, Tokyo Women's Medical University, School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Fujiko
authors.initials: F
authors.lastname: Tsukahara
authors.affiliation: Department of Pharmacology, Tokyo Women's Medical University, School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Maru
authors.affiliation: Laboratory of Molecular Biology of Infectious Agents, Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan ; Central Research Center, AVSS Corporation, 1-22, Wakaba-machi, Nagasaki 852-8137, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kobayashi
keywords: Dissociation constant; HA, hemagglutinin; Hsc70; Hsc70, heat shock cognate 70; Influenza virus; Kd, dissociation constant; M1; NA, neuraminidase; NES, nuclear export signal; NLS, nuclear localization signal; NS2; Nuclear export; vRNP, viral ribonucleoprotein complex