Functions as a transcriptional regulator. Functions in cell cycle regulation through CCNA2. Plays an important role in chromosome condensation during the meiotic G2/M transition of spermatocytes. Plays a role in postnatal myogenesis, is involved in satellite cell activation (PubMed:27446912). Positively regulates IGF2 expression through PLAG1 and in a PLAG1-independent manner (By similarity). Interacts with E4F1 (By similarity). Interacts with NEK2 (PubMed:14668482). Expressed in mitotic spermatogonia, meiotic spermatocytes, and postmeiotic round spermatids (at protein level) (PubMed:14668482). Expressed in embryonic myogenic progenitor cells (PubMed:27446912). Expressed predominantly during embryogenesis. In myogenic progenitor cells, expressed during early myogenic development (11.5 dpc) to be gradually down-regulated during the fetal stages (17.5 dpc) (PubMed:27446912). Regulated by cell cycle-dependent phosphorylation which alters its DNA binding affinity. Phosphorylated by NEK2. Belongs to the HMGA family.