View source for Polycomb proteins

<StructureSection load='4r8p' size='340' side='right' caption='Human polycomb complex protein BMI-1 (olive and dark red) complex with histones (grey, green, yellow, pink, magenta, cyan, gold, red), RING1B/Ubch5C (aqua and orchid)and DNA (blue and gold) PDB code [[4r8p]]' scene=''>

== Function ==

'''Polycomb group (PcG) proteins''' are determinants of gene silencing and epigenetic memory in higher eukaryotes.  The PcG system consists of multimeric repressive protein complexes containing chromatin modifying activities which regulate transcription by modulating chromatin structures.  The PcG proteins regulate pathways in cell differentiation, tissue regeneration and cancer cell growth<ref>PMID:27705803</ref>.  For the '''B'''-cell-specific '''M'''olony leukemia virus '''I'''nsertion site '''1''' (BMI1) see [[BMI1]].
*'''Pcgf5''' and '''Polycomb SUZ12''' are required in the differentiation of embryonic stem cells toward neural cells<ref>PMID:29765032</ref>, <ref>PMID:17339329</ref>.
*'''Pcgf6''' has a critical role in safeguarding lineage decisions and in preventing aberrant expression of germ cell-related genes<ref>PMID:32482889</ref>.
*'''Polycomb EED''' is a component of Polycomb repressive complex 2 (PRC2) and is an epigenetic exchange factor coordinating the activities of PRC1 and PRC2<ref>PMID:24457600</ref>.

See also: [[Polycomb complex protein]].

== Disease ==

Misregulation of PcG protein levels often lead to either a block or unscheduled activation of developmental pathways.  the consequences of this misregulation have been linked to the establishment of cancer stem cells which can produce tumors.  Cancer stem cells are believed to persist within tumors and to elicit relapse and metastasis<ref>PMID:27581385</ref>

== Structural highlights ==

</StructureSection>

==3D structures of polycomb proteins==
[[Polycomb complex proteins 3D structures]]


== References ==
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