InterPro domain: IPR014840

HPC2 (Histone promoter control 2) is required for cell-cycle regulation of histone transcription [ 1 ]. 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 [ 2 ].

This short domain is referred to as the HRD or Hpc2-related domain and is found in both human, yeast and Sch. pombe sequences. 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 [ 3 ].

1. Identification of a new set of cell cycle-regulatory genes that regulate S-phase transcription of histone genes in Saccharomyces cerevisiae. Mol. Cell. Biol. 12, 5249-59
2. Defects in SPT16 or POB3 (yFACT) in Saccharomyces cerevisiae cause dependence on the Hir/Hpc pathway: polymerase passage may degrade chromatin structure. Genetics 162, 1557-71
3. Silencing mediated by the Schizosaccharomyces pombe HIRA complex is dependent upon the Hpc2-like protein, Hip4. PLoS ONE 5, e13488