Polyhomeotic-like protein 2 (PHC2)

Polyhomeotic-like protein 2 (PHC2) is a chromatin-associated nuclear protein that is a component of the Polycomb group (PcG) multiprotein complex, specifically within the PRC1-like complex[3][5]. PHC2 is homologous to the Drosophila Polyhomeotic (Ph) protein and is known for its role in maintaining the transcriptionally repressive state of numerous chromatin loci through development, including but not limited to the Hox gene clusters[4][5]. PHC2 contributes to epigenetic gene silencing via chromatin remodeling, mainly by mediating monoubiquitination of histone H2A at lysine 119, in conjunction with other proteins in the PRC1 complex[2][5]. It acts as a scaffold for protein-protein interactions, heterodimerizing with PHC1 as well as interacting with BMI1, EDR1, MAPKAPK2, and MCRS1[1][3]. PHC2 is ubiquitously expressed in mammalian tissues and has essential functions in developmental gene regulation, hematopoietic stem cell homeostasis, and safeguarding epigenetic cellular memory[1][2]. Mutations or deficiency in PHC2 in mice lead to skeletal transformations, impaired stem cell mobilization, and premature cellular senescence as a result of derepression of PcG target genes[1][2][4]. There are no specific drugs known to target PHC2 directly, and it is not currently considered a therapeutic target; however, its central role in the PRC1 complex makes it indirectly relevant for epigenetic therapies, particularly in cancer and developmental disorders[5].

Other names

Polyhomeotic homolog 2EDR2PH2hPH2HPH2Early development regulatory protein 2early development regulator 2 (homolog of polyhomeotic 2)polyhomeotic 2polyhomeotic-like 2