Transportin 1

Transportin-1 is a is_associated_with::protein that in humans is encoded by the TNPO1 is_associated_with::gene.

Function
This gene encodes the beta subunit of the karyopherin receptor complex which interacts with nuclear localization signals to target nuclear proteins to the nucleus. The is_associated_with::karyopherin receptor complex is a heterodimer of an alpha subunit which recognizes the nuclear localization signal and a beta subunit which docks the complex at nucleoporins. Alternate splicing of this gene results in two transcript variants encoding different proteins.

Targets
Transportin 1 (TRN1) is part of the non-classical nuclear import pathway. In conjunction with the is_associated_with::RanGTP hydroysis cascade TRN1 acts to import a selection of proteins into the nucleus of cells. These targets typically contain a PY-motif otherwise known as a M9 nuclear localisation signal. Well described examples include is_associated_with::hnRNP A1.

Clinical Significance
TRN1 has been implicated in the pathogenesis of two neurodegenerative diseases namely is_associated_with::Amyotrophic lateral sclerosis and frontotemporal dementia.

Interactions
Transportin 1 has been shown to interact with:
 * is_associated_with::RGPD5 and
 * is_associated_with::Ran (biology).