The roles of multiple importins for nuclear import of murine aristaless-related homeobox protein.

ABSTRACT: Nuclear import of proteins with nuclear localization signals (NLSs) is mediated by shuttling carriers, the importins. Some cargoes display more than a single NLS, and among these are homeodomain proteins such as Arx, which is critical for development of multiple tissues. Arx has two functional NLSs. The present studies show that several pathways can import Arx via its NLS2, which is within its DNA binding homeodomain. Using an in vitro nuclear import assay, we show that import of Arx via NLS2 can be mediated by importin beta1, importin 9, or importin 13, with binding being strongest to importin beta1. All binding is sensitive to RanGTP. Experiments based on precise domain deletions indicate that NLS2 binds impbeta1, imp9, and imp13 and includes both an importin binding subdomain and a regu

SUBMITTER: Lin W 

PROVIDER: S-EPMC2740467 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature