TNPO3
Description
The TNPO3 (transportin 3) is a protein-coding gene located on chromosome 7.
TNPO3 is a protein that in humans is encoded by the TNPO3 gene. It is a nuclear import receptor for serine/arginine-rich (SR) proteins, including Serine/arginine-rich splicing factor 1, which are essential precursor-mRNA splicing factors. The TNPO3-IRF5 locus is implicated in primary biliary cirrhosis and systemic sclerosis.
TNPO3, also known as Importin-12 or Transportin-SR, is a nuclear import receptor that transports target proteins into the nucleus. It specifically mediates the nuclear import of splicing factor serine/arginine (SR) proteins, such as RBM4, SFRS1, and SFRS2, by recognizing phosphorylated SR domains. TNPO3 also mediates the nuclear import of the SR protein CPSF6, independently of CPSF6 phosphorylation. The nuclear import process is regulated by the small GTPase Ran, which partitions between the cytoplasm and nucleus in the predominantly GDP- and GTP-bound forms, respectively. TNPO3 associates with target cargo proteins in the cytoplasm, and the competitive binding of GTP-bound Ran induces the release of cargos in the nucleus.
TNPO3 is also known as IPO12, LGMD1F, LGMDD2, MTR10A, TRN-SR, TRN-SR2, TRNSR.
