May play a role in DNA-protein cross-links (DPCs) clearance through a SUMO-dependent recruitment to sites of DPCs, ensuring the genomic stability by protecting germ cells and early embryos from various sources of damage (PubMed:31839538). Can resolve the topoisomerase II (TOP2A) DPCs (PubMed:31839538). Interacts (via SIM domains) with SUMO2; this interaction allows the GCNA recruitment to DPCs sites (By similarity). Interacts with TOP2A; this interaction allows the resolution of topoisomerase II (TOP2A) DNA-protein cross-links (PubMed:31839538). Co-localizes with SUMO2 at PML bodies in all interphase cells (By similarity). Localizes on condensed chromosomes in spermatocytes in G2 and M during meiotic prophase (PubMed:31839538). Germ-cells specific. SUMO interaction motif 1 (SIM) mediates the binding to polysumoylated substrates. Mutant male mice are sterile and spermatocytes exhibit DNA damage, crossover defects, and chromatin condensation abnormalities. Belongs to the serine-aspartate repeat-containing protein (SDr) family.