Histone H2B type 2-E

Histone H2B type 2-E (H2BC21) is a core nucleosomal protein that wraps and compacts DNA into chromatin, thereby regulating transcription, DNA repair, replication, and chromosomal stability through post-translational modifications and nucleosome remodeling (UniProt: Q16778). The protein also exhibits antimicrobial properties and may contribute to epithelial barrier function. H2BC21 is a 126-amino-acid histone component expressed in human tissues.

In the context of Alzheimer's Disease, H2BC21 shows increased abundance in post-mortem AD brain tissue compared to age-matched controls. Chaparral AD proteomics analysis (TMT-labeled quantification across four subcellular fractions from human post-mortem brain) detected upregulation with a mean log2 fold-change of 0.90, suggesting elevated histone H2B type 2-E levels across multiple cellular compartments (Chaparral AD proteomics). This upregulation may reflect altered chromatin dynamics or compensatory changes in transcriptional regulation associated with AD pathology, though the functional significance remains to be elucidated.