HPC2 (Histone promoter control 2) is required for cell-cycle regulation of histone transcription. It regulates transcription of the histone genes during the S-phase of the cell cycle by repressing transcription at other cell cycle stages. HPC2 mutants display synthetic interactions with FACT complex which allows RNA Pol II to elongate through nucleosomes. Hpc2 is one of the proteins of one of the multi-subunit complexes that mediate replication- independent nucleosome assembly, along with histone chaperone proteins. the Hip4 sequence from SCH. pombe is an integral component of this complex that is required for transcriptional silencing at multiple loci. HPC2, ubinuclein/yemanuclein, and the cell cycle regulator FLJ25778 share a conserved domain that is predicted to bind histone tails. This domain is also referred to as the HRD or Hpc2-related domain.