Possible component of the TREX-2 complex (transcription and export complex 2), a muliprotein complex that functions in docking export-competent ribonucleoprotein particles (mRNPs) to the nuclear entrance of the nuclear pore complex (nuclear basket). TREX-2 participates in mRNA export and accurate chromatin positioning in the nucleus by tethering genes to the nuclear periphery. No visible phenotype. Sac3a, sac3b and sac3c triple mutants show no visible phenotype. Belongs to the SAC3 family.