HMGB3 Human

High-Mobility Group Box 3 (HMGB3) is a member of the high mobility group (HMG) protein superfamily. These proteins are known for their ability to bind DNA and influence various cellular processes, including DNA replication, transcription, and nucleosome assembly . HMGB3, like other HMG proteins, contains DNA-binding HMG box domains, which are crucial for its function .

HMGB3 is a non-histone chromosomal protein that plays a significant role in the regulation of gene expression. The human recombinant form of HMGB3 is produced in E. coli and is a single, non-glycosylated polypeptide chain containing 203 amino acids, with a molecular mass of 22.8 kDa . It is fused to a 23 amino acid His-tag at the N-terminus and purified using proprietary chromatographic techniques .

HMGB3 is involved in various cellular processes:

• DNA Binding and Bending: HMGB3 binds to DNA with a preference for non-canonical DNA structures, such as single-stranded DNA. It can bend DNA and enhance its flexibility, promoting activities on various gene promoters .
• Stem Cell Regulation: HMGB3 plays a crucial role in maintaining stem cell populations. It regulates the balance between self-renewal and differentiation in hematopoietic stem cells .
• Immune Response: HMGB3 is proposed to be involved in the innate immune response to nucleic acids by acting as a cytoplasmic promiscuous immunogenic DNA/RNA sensor .
• Cell Differentiation: It negatively regulates B-cell and myeloid cell differentiation and is involved in the negative regulation of canonical Wnt signaling .

HMGB3 has been associated with various diseases and conditions:

• Cancer: Aberrant expression of HMGB3 has been observed in tumor cells, indicating its potential role in cancer development and progression .
• Genetic Disorders: A mutation in the HMGB3 gene has been linked to microphthalmia, syndromic 13, a condition characterized by abnormal eye development .

The human recombinant HMGB3 protein is typically stored at -20°C for long-term storage. It is recommended to add a carrier protein, such as 0.1% HSA or BSA, to prevent multiple freeze-thaw cycles . For short-term use, it can be stored at 4°C for 2-4 weeks .