Nucleocytoplasmic translocation of Stat1 is regulated by a leucine-rich export signal in the coiled-coil domain.

ABSTRACT: Signal transducer and activator of transcription (Stat) proteins are latent transcription factors that reside in the cytoplasm before activation. On cytokine-induced tyrosine phosphorylation, these molecules dimerize and accumulate transiently in the nucleus. No specific signals mediating these processes have been identified to date. In this report, we examine the nuclear export of Stat1. We find that treatment of cells with the export inhibitor leptomycin B does not affect steady-state localization of Stat1 but impedes nuclear export after IFNgamma-induced nuclear accumulation. We identify a conserved leucine-rich helical segment in the coiled-coil domain of Stat1, which is responsible for the efficient nuclear export of this protein. Mutation of two hallmark leucines within this segment

SUBMITTER: Begitt A 

PROVIDER: S-EPMC27039 | biostudies-literature | 2000 Sep

REPOSITORIES: biostudies-literature