ORC1

Origin recognition complex subunit 1 is a is_associated_with::protein that in humans is encoded by the ORC1 is_associated_with::gene.

Function
The is_associated_with::origin recognition complex (ORC) is a highly conserved six subunits protein complex essential for the initiation of the is_associated_with::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 is_associated_with::pre-replication complex, which includes additional initiation factors such as is_associated_with::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 is_associated_with::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 is_associated_with::phosphorylated during is_associated_with::mitosis. It is also reported to interact with MYST histone acetyltransferase 2 (MYST2/HBO1), a protein involved in control of transcription silencing.

Interactions
ORC1 has been shown to interact with is_associated_with::ORC2,   is_associated_with::ORC4, is_associated_with::ORC5, is_associated_with::MCM4, is_associated_with::MYST2, is_associated_with::CDC6, is_associated_with::Cyclin-dependent kinase 2, is_associated_with::MCM6, is_associated_with::SKP2, is_associated_with::MCM7, is_associated_with::MCM2, is_associated_with::CDC45-related protein and is_associated_with::Cell division cycle 7-related protein kinase.