exportin-T; exportin(tRNA); tRNA exportin (XPOT)

Function

• mediates the nuclear export of all aminoacylated tRNAs
• in the nucleus, binds to tRNA & to the GTPase Ran in its active GTP-bound form
• docking of trimeric XPOT-tRNA-Ran complex to the nuclear pore complex is mediated through binding to nucleoporins
• upon transit of a nuclear export complex into the cytoplasm, disassembling of the complex induced by RANBP1 & hydrolysis of Ran-GTP to Ran-GDP induced by RANGAP1 cause release of the tRNA from the export receptor
• XPOT then returns to the nuclear compartment to mediate another round of transport
• directionality of nuclear export is thought to be conferred by an asymmetric distribution of the GTP- & GDP-bound forms of Ran between the cytoplasm & nucleus
• found in a complex with XPOT, Ran & tRNA
• probably found in a complex with nucleoporins
• interacts with Ran & tRNA (GTP-dependent)

Structure

• belongs to the exportin family

Compartment

• nucleus, cytoplasm
• once bound to tRNA & Ran the complex translocates to the cytoplasm
• shuttles between the nucleus & the cytoplasm

More general terms

• exportin

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=11260
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:11260
• OMIM: https://mirror.omim.org/entry/603180
• UniProt: http://www.uniprot.org/uniprot/O43592.html