Exportin Anticorpi

Exportins preferentially bind their substrates at high RanGTP concentrations in the nucleus and then exit the nucleus as trimeric cargo-Exportin-RanGTP complexes. The disassembly of the Exportin-RanGTP complexes involves RanGAP and either RanBP1 or RanBP2, and frees the Exportins for additional nuclear exports. Exportin T binds to functional tRNA and mediates tRNA export from the nucleus. Exportin 4 mediates nuclear export of the eukaryotic translation initiation factor 5A (eIF-5A) by means of a hypusine modification unique to eIF-5A. The karyopherin-related nuclear transport factor Exportin 5, also known as Exp5, preferentially recognizes and transports RNAs containing minihelix motifs, structural cis-acting export elements that comprise a double-stranded stem (14 nucleotides) with a base-paired 5' end and a 3-8-nucleotide protruding 3' end. Existing in a complex with Profilin-1 and β-Actin, Exportin 6 functions to mediate the nuclear export of Actin-associated protein structures in somatic cells. Exportin 7 translocates proteins and large RNAs through the nuclear pore complex (NPC) and is localized to the cytoplasm and nucleus.