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:30914427). Can resolve the topoisomerase II (TOP2A) DPCs (By similarity). Interacts (via SIM domains) with SUMO2; this interaction allows the GCNA recruitment to DPCs sites (PubMed:30914427). Interacts with TOP2A; this interaction allows the resolution of topoisomerase II (TOP2A) DNA-protein cross-links (By similarity). Co-localizes with SUMO2 at PML bodies in all interphase cells (PubMed:30914427). Localizes on condensed chromosomes in spermatocytes in G2 and M during meiotic prophase (By similarity). Expressed in germ cells of the testis (at protein level) (PubMed:27718356). Detected in skeletal muscle, liver, kidney, pancreas, heart, lung and brain (PubMed:11714101). Expressed throughout spermatogenesis, from spermatogonia to elongated spermatids, in normal adult testis (at protein level) (PubMed:33963445). SUMO interaction motif 1 (SIM) mediates the binding to polysumoylated substrates. Defects in GCNA are associated with spermatogenic failure (SPGF) such as non-obstructive azoospermia (NOA) and cryptozoospermia. NOA is characterized by no sperm in the ejaculate due to impaired sperm production. Cryptozoospermia is characterized by no sperm in fresh ejaculate without evidence of partial reproductive tract obstruction, but with rare sperm seen in centrifuged pellet. Belongs to the serine-aspartate repeat-containing protein (SDr) family.