Acts as component of the THO subcomplex of the TREX complex which is thought to couple mRNA transcription, processing and nuclear export. Component of the CUL4-RBX1-DDB1-DWA1/DWA2 E3 ubiquitin-protein ligase complex that acts as negative regulator in abscisic acid (ABA) signaling. May function as the substrate recognition module within this complex leading to ABI5 degradation. Functionally redundant with DWA2. Protein modification; protein ubiquitination. Component of the THO complex, which is composed of THO1, THO2, THO3, THO5, THO6 and THO7. Interacts with ABI5, DDB1A and DWA2. Increased sensitivity to abscisic acid (ABA) and salt. Belongs to the WD repeat THOC6 family.