What happens when CDC6 is phosphorylated?
In mammalian cells, phosphorylation of Cdc6 at the beginning of S phase causes its dissociation from chromatin and triggers replication. In addition, Cdc6 phosphorylation induces its nuclear export and ubiquitin-dependent degradation.
What does CDC6 do in cell cycle?
The CDC6 gene provides instructions for making a protein that is important in the copying of a cell’s DNA before the cell divides (a process known as DNA replication). The protein produced from this gene, called cell division cycle 6 or CDC6, is one of a group of proteins known as the pre-replication complex.
Why is CDC6 important in helicase loading?
ATP binding and hydrolysis play critical roles during helicase loading. Cdc6 is activated to bind and hydrolyze ATP when it associates with origin-bound ORC, and this hydrolysis event is required to observe Mcm2–7 loading (Perkins and Diffley 1998; Randell et al. 2006).
What does CDC6 and CDT1 do?
CDC6 is an ATP binding protein and a member of the pre-replicative complex (pre-RC) together with the origin recognition complex (ORC), Cdt1 and the MCM complex (containing MCM2-7p). CDC6 assembles after ORC in an ATP dependent manner and is required for loading MCM proteins onto the DNA.
What happens if CDC6 Cannot be phosphorylated?
You create cells with a version of Cdc6 that cannot be phosphorylated and thus cannot be degraded. (a) Cells will enter S phase prematurely. (b) Cells will be unable to complete DNA synthesis. (c) The origin recognition complex (ORC) will be unable to bind to DNA.
What is the function of Ter sites in the genome?
Function. A DNA replication terminus (ter) has a role in preventing progress of the DNA replication fork. Therefore, a DNA replication terminus site-binding protein binds to this site helping to block the DNA replication fork. There are two genes controlling ter-binding activity, named tau and tus.
What is CDC6 and CDT1?
What activates CDC6?
CDC6 is normally present at high levels during the G1 phase of the cell cycle. This is partly because the CDC6 gene is only transcribed during G1 phase. In the second state Cdk2-activity is high, CDC6 becomes inactivated, hence the pre-RC is activated but not formed.