Basics topics: cellular DNA is continuously damaged ; activity of cell cycle checkpoint is a part of the cellular response to DNA damage. 1 The control system of the genome and the passage through the cell cycle As you study the regulation of the cell cycle regulatory mechanisms discovered ties with a complicated network of signaling pathways , which is called the system of supervising the genome. 2 The cellular response to DNA damage .

The cell is constantly exposed to environmental factors damaging DNA and inhibiting DNA replication . Defense mechanism is very complex network of signaling pathways , providing coordinated DNA repair processes start and stop passing the cells through the cell cycle . This prevents damage to the amplified replication and transmission damage to daughter cells . Currently, it is believed that DNA damage proteins are recognized by the sensor ( Rad9 , Rad1 and Hus1 ), which initiates an alarm signal transmitted to the relays, having the character type tyrosine kinases PI3 -K .