3ULH1018921681ENSG00000183684ENSMUSG00000025134Q86V81O08583NM_005782NM_011568NP_005773NP_035698Aly/REF export factor, also known as THO complex subunit 4 is a protein that in humans is encoded by the ALYREF gene.

The TRanscription-EXport (TREX) complex, a key player in mRNA export, includes the THO subcomplex, the RNA helicase UAP56, and the RNA-binding protein ALY.

As a chaperone, ALY promotes dimerization of transcription factors containing basic leucine zipper (bZIP) domains.,[7] thereby promoting transcriptional activation.

[8][9] After mRNA binds to ALY, it is apparently transferred to the NXF1-NXT1 heterodimer for export (TAP/NFX1 pathway).

The full-length ALY protein (Refbp1-I, 255 amino acids encoded by six exons[10]) has a conserved RNA recognition motif (RRM; amino acids 105-182) flanked by alanine/arginine/glycine-rich sequences; an N-terminal region (amino acids 16-37) is sufficient for RNA binding and interaction with the NXF1-NXT1 heterodimer.