Transportin-2 (TNPO2)

Transportin-2 (TNPO2) is a highly conserved nuclear transport receptor of the karyopherin/importin-β superfamily that mediates the import and shuttling of proteins between the cytoplasm and nucleus through the nuclear pore complex[1][2][3][4]. TNPO2 recognizes and binds proteins with specific nuclear localization signals, especially PY-NLS motifs and arginine-glycine-glycine (RGG) domains, and facilitates their RanGTP-dependent passage into the nucleus[1][2]. It shares high sequence and functional similarity with Transportin-1 (TNPO1) but has specificity for different cargos, including proteins involved in DNA repair and high mobility group (HMG) proteins[1]. TNPO2 also acts as a cytoplasmic retention factor for certain cargoes, such as estrogen receptor α (ERα), competing with other importins to regulate nuclear-cytoplasmic distribution and subsequent signaling activity[3]. Impairment of TNPO2 function is associated with protein aggregation, particularly in neurons, and has been linked to neurodegenerative disease and developmental disorders[1][2]. No clinically established drugs are known to robustly target TNPO2, and it is not currently a common therapeutic target, but its essential role in nucleocytoplasmic transport implicates it in a broad range of cellular and disease processes[1][2][3].

Other names

Importin 3Karyopherin beta-2bIPO3KPNB2BTRN2FLJ12155

RanGTP-dependent nucleocytoplasmic transport, Competitive inhibition of importin α/β1 pathway, Cytoplasmic retention of cargo proteins