Polycomb repressive complex 1 (PRC1) is one of the two classes of Polycomb Repressive complexes, the other being

PRC2 PRC2 (polycomb repressive complex 2) is one of the two classes of polycomb-group proteins or (PcG). The other component of this group of proteins is PRC1 (Polycomb Repressive Complex 1). This complex has histone methyltransferase activity and pr ...

Polycomb-group proteins Polycomb-group proteins (PcG proteins) are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes ...

play a major role in

transcriptional regulation In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from alt ...

during development. Polycomb Repressive Complexes PRC1 and PRC2 function in the silencing of expression of the

Hox gene Hox genes, a subset of homeobox genes, are a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals. Hox proteins encode and specify the characteristics of 'position', ensuring that the cor ...

network involved in development as well as the inactivation of the X chromosome. PRC1 inhibits the activated form of

RNA polymerase II RNA polymerase II (RNAP II and Pol II) is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNAP enzymes found in the nucleus of eukaryoti ...

preinitiation complex with the use of

H3K27me H3K27me3 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the tri-methylation of lysine 27 on histone H3 protein. This tri-methylation is associated with the downregulation of nearby genes via t ...

. PRC1 binds to three

nucleosome A nucleosome is the basic structural unit of DNA packaging in eukaryotes. The structure of a nucleosome consists of a segment of DNA wound around eight histone proteins and resembles thread wrapped around a spool. The nucleosome is the fundamen ...

s, this is believed to limit access of

transcription factors In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The func ...

to the

chromatin Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in r ...

, and therefore limit

gene expression Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...

.{{Cite journal, last1=Lehmann, first1=Lynn, last2=Ferrari, first2=Roberto, last3=Vashisht, first3=Ajay A., last4=Wohlschlegel, first4=James A., last5=Kurdistani, first5=Siavash K., last6=Carey, first6=Michael, date=2012-10-19, title=Polycomb Repressive Complex 1 (PRC1) Disassembles RNA Polymerase II Preinitiation Complexes, journal=Journal of Biological Chemistry, language=en, volume=287, issue=43, pages=35784–35794, doi=10.1074/jbc.M112.397430, issn=0021-9258, pmid=22910904, pmc=3476247, doi-access=free

References

Proteins