Binds to nucleosomes, regulating chromatin structure and consequently, chromatin-dependent processes such as transcription, DNA replication and DNA repair. Affects both insulin and glucagon levels and modulates the expression of pancreatic genes involved in insulin secretion. Regulates the expression of the glucose transporter SLC2A2 by binding specifically to its promoter region and recruiting PDX1 and additional transcription factors. Regulates the expression of SLC6A9, a glycine transporter which regulates the glycine concentration in synaptic junctions in the central nervous system, by binding to its transcription start site. May play a role in ocular development and astrocyte function. Interacts with the ligand binding domain of the thyroid receptor (TR) (in vitro). Requires the presence of thyroid hormone for its interaction. Interacts with transcriptional regulator SEHBP. Interacts with nucleosomes. Expressed in the brain, eye, prostate, thyroid, kidney, testis, glial cells and insulin-producing cells of the Langerhans pancreatic islets. In the brain, expressed in the lateral olfactory tract, anterior commissure, corpus callosum, internal capsule, fornix, stria medullans, optic tract, axon bundles, Purkinje cell layer and granular layer of the cerebellum. In retina, expressed in the nuclei of cells in the inner nuclear layer including amacrine, bipolar and horizontal neurons and in the nuclei of ganglion neurons. Detected at low levels in the liver. Transiently expressed in the stroma and endothelium of the cornea at birth. Subsequently expressed in the corneal epithelium and the inner nuclear and ganglion cell layers of the retina. The predominant form in developing ocular tissues is isoform 2, although isoform 1 is also detectable. Mice are viable and fertile. Mice have a mild diabetic phenotype and lower plasma glucagon levels. The overall shape of the islets, the location of the alpha cells in the mantle of the pancreatic islets or proliferation of pancreatic alpha cells are not affected. Belongs to the HMGN family.