HMGN (High Mobility Group Nucleosome-binding) proteins are members of the broader class of high mobility group (HMG) chromosomal proteins that are involved in regulation of transcription, replication, recombination, and DNA repair.

HMGN1 and HMGN2 (initially designated HMG-14 and HMG-17 respectively) were discovered by E.W. Johns research group in the early 1970s.

HMGN3, HMGN4, and HMGN5 were discovered later and are less abundant.

HMGNs are nucleosome binding proteins that help in transcription, replication, recombination, and DNA repair.

They can also alter the chromatin epigenetic landscape, helping to stabilize identity.

There is still relatively little known about their structure and function. HMGN proteins are found in all vertebrates, and play a role in chromatin structure and histone modification.

HMGNs come in long chains of amino acids, containing around 100 for HMGN1-4, and roughly 200 in HMGN5.

Recent research on the HMGN family is focused on their effect on identity, and how reduction of HMGNs relates to induced reprogramming of mouse embryonic fibroblasts (MEFs).