HMGB3
Function
Multifunctional protein with various roles in different cellular compartments. May act in a redox sensitive manner. Associates with chromatin and binds DNA with a preference for non-canonical DNA structures such as single-stranded DNA. Can bend DNA and enhance DNA flexibility by looping thus providing a mechanism to promote activities on various gene promoters (By similarity). Proposed to be involved in the innate immune response to nucleic acids by acting as a cytoplasmic promiscuous immunogenic DNA/RNA sensor (By similarity). Negatively regulates B-cell and myeloid cell differentiation. In hematopoietic stem cells may regulate the balance between self-renewal and differentiation. Involved in negative regulation of canonical Wnt signaling (By similarity).
Involvement in disease
Microphthalmia, syndromic, 13
MCOPS13
A form of microphthalmia, a disorder of eye formation, ranging from small size of a single eye to complete bilateral absence of ocular tissues (anophthalmia). In many cases, microphthalmia/anophthalmia occurs in association with syndromes that include non-ocular abnormalities. MCOPS13 patients exhibit colobomatous microphthalmia with microcephaly, short stature, and psychomotor retardation.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
Reduction/oxidation of cysteine residues Cys-23, Cys-45 and Cys-104 and a possible intramolecular disulfide bond involving Cys-23 and Cys-45 give rise to different redox forms with specific functional activities in various cellular compartments: 1- fully reduced HMGB3 (HMGB3C23hC45hC104h), 2- disulfide HMGB3 (HMGB3C23-C45C104h) and 3- sulfonyl HMGB3 (HMGB3C23soC45soC104so).
Sequence Similarities
Belongs to the HMGB family.
Tissue Specificity
Expressed predominantly in placenta.
Cellular localization
- Nucleus
- Chromosome
- Cytoplasm
Alternative names
HMG2A, HMG4, HMGB3, High mobility group protein B3, High mobility group protein 2a, High mobility group protein 4, HMG-2a, HMG-4