Extracellular signal-dependent nuclear import of Stat1 is mediated by nuclear pore-targeting complex formation with NPI-1, but not Rch1 - PubMed (original) (raw)

Extracellular signal-dependent nuclear import of Stat1 is mediated by nuclear pore-targeting complex formation with NPI-1, but not Rch1

T Sekimoto et al. EMBO J. 1997.

Abstract

In response to interferon-gamma (IFN-gamma), Stat1 is tyrosine phosphorylated and translocates to the nucleus where it activates transcription. In this study, we identified factors which mediate the nuclear import of Stat1. Tyrosine-phosphorylated Stat1 associated with the beta subunit (a 97 kDa component) of the nuclear pore-targeting complex via the NPI-1 family, but not the Rch1 family, of alpha subunit (a 58 kDa component) as a result of IFN-gamma stimulation. Antibodies against NPI-1 or beta subunit consistently inhibited the IFN-gamma-dependent nuclear import of Stat1 in living cells, although antibodies reactive to Rch1 had no effect. Solution binding assays with deletion mutants of NPI-1 showed that the Stat1-binding domain of NPI-1 was located in the carboxy-terminal region, which is clearly distinct from the SV40 large T antigen nuclear localization signal (NLS)-binding region. These results indicate that the extracellular signal-dependent nuclear transport of Stat1 is mediated by NPI-1, but not Rch1, in conjunction with beta subunit, and that these factors participate in, not only constitutive, but also the conditional nuclear import of proteins.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Curr Opin Cell Biol. 1995 Jun;7(3):310-8 - PubMed
    1. EMBO J. 1995 Aug 1;14(15):3617-26 - PubMed
    1. Science. 1996 Mar 15;271(5255):1513-8 - PubMed
    1. Trends Biochem Sci. 1991 Dec;16(12):478-81 - PubMed
    1. Mol Cell Biol. 1992 Dec;12(12):5640-51 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources