HIST1H3H
Histone H3 Histone (H3H3)
Description
Histone H3 is one of the five main types of histone proteins that play a crucial role in organizing and packaging DNA into chromatin, the material that makes up chromosomes. Specifically, H3H3 is responsible for binding to and wrapping DNA around itself to form nucleosomes, the basic unit of chromatin structure. This packaging allows for the efficient storage and protection of genetic information within the cell nucleus.
H3H3 is composed of 135 amino acids and contains a conserved octamer motif, which includes two alpha helices and two loops. This motif allows H3H3 to form heterodimers with other histone proteins, such as H4, to create the core histone octamer. The octamer, along with the DNA wrapped around it, forms the nucleosome core particle.
Associated Diseases
Mutations or modifications to H3H3 have been linked to several diseases, including:
- Glioblastoma: A type of aggressive brain cancer that arises from glial cells, which support and protect neurons. H3H3 mutations are found in approximately 30% of glioblastomas and are associated with a poor prognosis.
- Chondroblastoma: A rare bone tumor that occurs in children and adolescents. H3H3 mutations are found in most cases of chondroblastoma and can lead to rapid tumor growth.
- Diffuse intrinsic pontine glioma (DIPG): A highly aggressive childhood brain tumor that occurs in the brainstem. H3H3 mutations are present in nearly allDIPGcases and are associated with a very poor survival rate.
Did you Know ?
Approximately 80% of glioblastomas contain mutations in the H3F3A gene, which encodes the H3H3 histone protein. These mutations typically involve a single amino acid substitution at position 27 (K27M), resulting in a lysine (K) residue being replaced by a methionine (M) residue.
