TNPO2
Function
Probably functions in nuclear protein import as nuclear transport receptor. Serves as receptor for nuclear localization signals (NLS) in cargo substrates. Is thought to mediate docking of the importin/substrate complex to the nuclear pore complex (NPC) through binding to nucleoporin and the complex is subsequently translocated through the pore by an energy requiring, Ran-dependent mechanism. At the nucleoplasmic side of the NPC, Ran binds to the importin, the importin/substrate complex dissociates and importin is re-exported from the nucleus to the cytoplasm where GTP hydrolysis releases Ran. The directionality of nuclear import is thought to be conferred by an asymmetric distribution of the GTP- and GDP-bound forms of Ran between the cytoplasm and nucleus (By similarity).
Involvement in disease
Intellectual developmental disorder with hypotonia, impaired speech, and dysmorphic facies
IDDHISD
An autosomal dominant disorder characterized by global developmental delay, impaired intellectual development, poor or absent speech, hypotonia, ophthalmologic abnormalities, and non-specific dysmorphic features. Some affected individuals have seizures, and a few have involvement of other organ systems.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the importin beta family. Importin beta-2 subfamily.
Cellular localization
- Cytoplasm
- Nucleus
Alternative names
Transportin-2, Karyopherin beta-2b, TNPO2