Description
Product Characteristics:
The initiation of DNA replication is a multi-step process that depends on the formation of pre-replication complexes, which trigger initiation (1). Among the proteins required for establishing these complexes are the origin recognition complex (ORC) proteins (1). ORC proteins bind specifically to origins of replication where they serve as scaffold for the assembly of additional initiation factors (1). Human ORC subunits 1-6 are expressed in the nucleus of proliferating cells and tissues, such as the testis (2). ORC1 and ORC2 are both expressed at equivalent concentrations throughout the cell cycle, however, only ORC2 remains stably bound to chromatin (3,4). ORC4 and ORC6 are also expressed constantly throughout the cell cycle (5,6). ORC2, ORC3, ORC4 and ORC5 form a core complex upon which ORC6 and ORC1 assemble (7,8). The formation of this core complex suggests that ORC proteins play a crucial role in the G1-S transition in mammalian cells (8).
Synonyms: HSORC1, MmORC1, orc1, ORC1_HUMAN, ORC1L, Origin Recognition Complex 1, Origin recognition complex subunit 1 yeast homolog like, Origin recognition complex subunit 1, Origin recognition complex subunit 1 homolog, Origin recognition complex subunit 1 like S. cerevisia, Origin recognition complex subunit 1 like, Origin recognition complex subunit 1 S. cerevisiae homolog like, Origin recognition complex, subunit 1 like yeast, PARC1, Replication control protein 1.
Target Information: 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 additional initiation factors such as Cdc6 and Mcm proteins. The protein encoded by this gene is the largest subunit of the ORC 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. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2010]