Histone H3.4 (H3-4)

Histone H3.4 (H3-4, gene symbol HIST3H3) is a replication-dependent member of the histone H3 family in humans, involved as a core structural protein in the formation of nucleosomes within chromatin[3]. Nucleosomes comprise DNA wrapped around an octamer of histones (including H3.4), establishing chromosomal architecture and regulating DNA accessibility for transcription, replication, and repair[1][3]. H3.4 is highly conserved and encoded by an intronless gene, with transcripts lacking polyA tails; this distinguishes it from some other histone genes. Variants of histone H3 (e.g., H3.1, H3.2, H3.3, H3T/H3.4) may have differential tissue distribution and regulatory roles[4], but H3.4 itself is considered a structural chromatin protein rather than a druggable therapeutic target. Special notes on this target: - H3.4 is not a receptor, enzyme, transporter, or drug target; rather, it is a core histone structural protein. - The submitted aliases contain considerable redundancy, variant hyphenation, and some misspellings/repetitions. - The gene is sometimes called "HIST3H3" and the protein "H3.1t" or "H3T", but the most proper canonical name for the protein is Histone H3.4[3]. - No structured drug targeting, patient selection biomarkers, or therapeutic safety issues are linked directly to H3.4. - H3.4 is often incorrectly suggested to be a therapeutic target, but in biomedical practice, histone variants as a group are not directly “targets” in the sense used for receptors or enzymes except in epigenetic drug approaches (which do not target this isoform specifically).

Other names

HIST3H3Histone H3.1tH3/tH3FTH3C16H3/gH3 clustered histone 16H3 histone family, member T

Not applicable for H3.4 directly as a therapeutic target. For general histone modifications: inhibitors or agents may affect acetylation/deacetylation of histones overall, changing gene expression.