ORC1

Origin recognition complex subunit 1 is a protein that in humans is encoded by the ORC1 gene.^[5][6] It is closely related to CDC6, and both are the same protein in archaea.^[7]

ORC1
Identifiers
Aliases	ORC1, HSORC1L, PARC1, origin recognition complex subunit 1
External IDs	OMIM: 601902; MGI: 1328337; HomoloGene: 31221; GeneCards: ORC1; OMA:ORC1 - orthologs
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1p32.3 Start 52,372,829 bp[1] End 52,404,423 bp[1]
Gene location (Mouse) Chr. Chromosome 4 (mouse)[2] Band 4|4 C7 Start 108,436,620 bp[2] End 108,472,030 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in testicle ventricular zone gonad ganglionic eminence bone marrow mucosa of transverse colon secondary oocyte rectum stromal cell of endometrium bone marrow cell Top expressed in zygote secondary oocyte primary oocyte epiblast tail of embryo genital tubercle primitive streak embryo embryo blastocyst More reference expression data BioGPS More reference expression data
Gene ontology Molecular function DNA binding nucleotide binding chromatin binding protein binding ATP binding DNA replication origin binding metal ion binding Cellular component nuclear origin of replication recognition complex plasma membrane nucleolus origin recognition complex nucleus nucleoplasm cytosol Biological process G1 phase DNA replication regulation of transcription involved in G1/S transition of mitotic cell cycle DNA replication initiation G1/S transition of mitotic cell cycle mitotic cell cycle mitotic DNA replication checkpoint signaling Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 4998 18392 Ensembl ENSG00000085840 ENSMUSG00000028587 UniProt Q13415 Q9Z1N2 RefSeq (mRNA) NM_001190818 NM_001190819 NM_004153 NM_001014425 NM_011015 RefSeq (protein) NP_001177747 NP_001177748 NP_004144 NP_035145 Location (UCSC) Chr 1: 52.37 – 52.4 Mb Chr 4: 108.44 – 108.47 Mb PubMed search [3] [4]
Wikidata
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Function

The origin recognition complex (ORC) is a highly conserved six subunits protein complex essential for the initiation of the DNA replication in eukaryotic cells. Studies in yeast demonstrated that ORC binds specifically to origins of replication and serves as a platform for the assembly of the pre-replication complex, which includes additional initiation factors such as Cdc6 and Mcm proteins. The protein encoded by this gene is the largest subunit of the origin recognition complex. While other ORC subunits are stable throughout the cell cycle, the levels of this protein vary during the cell cycle, which has been shown to be controlled by ubiquitin-mediated proteolysis after initiation of DNA replication. This protein is found to be selectively phosphorylated during mitosis. It is also reported to interact with MYST histone acetyltransferase 2 (MYST2/HBO1), a protein involved in control of transcription silencing.^[6]

Interactions

ORC1 has been shown to interact with:

• CDC45-related protein^[8] and
• CDC6,^[8][9]
• Cell division cycle 7-related protein kinase,^[8]
• Cyclin-dependent kinase 2,^[10]
• MCM2,^[8]
• MCM4,^[8]
• MCM6,^[8]
• MCM7,^[8]
• MYST2,^[11]
• ORC2,^{[8][12][13][10]}
• ORC4,^[8]
• ORC5,^[8] and
• SKP2.^[10]