Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of DNA. Phosphorylated at Thr-4 (H3T3ph) by Haspin during mitosis and interphase (PubMed:32750047). Phosphorylation at Ser-11 by aurB/ial during mitosis and meiosis is crucial for chromosome condensation and cell-cycle progression (PubMed:11114889, PubMed:11266459, PubMed:11371341, PubMed:12514098, PubMed:15175259). Phosphorylation at Ser-11 by JIL-1 during interphase is linked to gene activation and restricts the formation of heterochromatin at inappropriate sites. Phosphorylation at Ser-11 is enriched on male X chromosome compared to the autosome (PubMed:11114889, PubMed:11266459, PubMed:11371341, PubMed:12514098, PubMed:15175259). Acetylation is generally linked to gene activation. Acetylated on Lys-15 during prophase I of meiosis. Phosphorylation of H2A 'Thr-119' is a prerequisite for H3 Lys-15 acetylation. Acetylation on Lys-15 is enriched on male X chromosome compared to the autosome. Methylation at Lys-5 or Lys-80 is generally associated with active chromatin. Methylation at Lys-80 by gpp occurs at low levels in specific developmental stages and tissues undergoing active cell division, and at highest levels in epidermal cells undergoing differentiation. Belongs to the histone H3 family.