The human hNanog protein coded by the NANOG gene, consists of 305 amino acids and possesses 3 functional domains: the N-terminal domain, the C- terminal domain, and the conserved homeodomain motif. The homeodomain region facilitates DNA binding. The NANOG is located on chromosome 12, and the mRNA contains a 915 bp open reading frame (ORF) with 4 exons and 3 introns.
The N-terminal region of hNanog is rich in serine, threonine and proline residues, and the C-terminus contains a tryptophan-rich domain. The homeodomain in hNANOG ranges from residues 95 to 155. There are also additional NANOG genes (NANOG2, NANOG p8) which potentially affect ESCs differentiation. Scientists have shown that NANOG' is fundamental for self-renewal and pluripotency, and NANOG p8 is highly expressed in cancer cells.