As a component of the TREX-2 complex, involved in the export of mRNAs to the cytoplasm through the nuclear pores (By similarity). Through the acetylation of histones, affects the assembly of nucleosomes at immunoglobulin variable region genes and promotes the recruitment and positioning of transcription complex to favor DNA cytosine deaminase AICDA/AID targeting, hence promoting somatic hypermutations (PubMed:23652018). acetyl-CoA + L-lysyl-[histone] = CoA + H(+) + N(6)-acetyl-L-lysyl-[histone] Component of the nuclear pore complex (NPC)-associated TREX-2 complex (transcription and export complex 2), composed of at least GANP, 2 copies of ENY2, PCID2, SEM1/DSS1, and either centrin CETN2 or centrin CETN3. The TREX-2 complex also associates with ALYREF/ALY (By similarity). Interacts with RNA polymerase II subunit POLR2A and with the transcription elongation factor SUPT5H/SPT5 (By similarity). Interacts (via FG-repeats) with NXF1; this interaction is not mediated by RNA (By similarity). Interacts with nuclear envelope proteins NUP62, NUP153 and RANBP2/NUP358; interaction with NUP153 is required for full localization at the nuclear pore complex (By similarity). Interacts with several RNA helicases, including DHX9, DDX21, and DDX39A/DDX39, and with DNA topoisomerase TOP2A (By similarity). Directly interacts with AICDA/AID (PubMed:20507984). Interacts with the glucocorticoid receptor NR3C1 (By similarity). Interacts with MCM3 (PubMed:10733502). In stimulated B-cells, selectively targeted to immunoglobulin gene variable regions (PubMed:20507984). Predominantly located at the nuclear envelope, facing the nucleus interior (By similarity). Localization at the nuclear pore complex requires NUP153, TPR and ALYREF/ALY (By similarity). Also found associated with chromatin (PubMed:23652018). In B-cells, targeted to the immunoglobulin variable region genes (PubMed:20507984, PubMed:23652018). Expressed at low levels in lymphoid organs, including thymus, spleen and lymph nodes (PubMed:10733502). Up-regulated in stimulated B-cells in spleen and Peyer's patch germinal centers (at protein level) (PubMed:11526238). Up-regulated in B-cells by CD40 stimulation and bacterial lipopolysaccharide (LPS) (at protein level). Phosphorylation at Ser-502 is induced in B-cells by CD40-stimulation, but not by bacterial lipopolysaccharide (LPS). Embryonic lethal at 11.5 dpc. Belongs to the SAC3 family.