The Various Kinases that is activated after the breaks in DNA is after the activation of ATM serine threonine kinase which helps in phosphorylation of other DNA replication check proteins, p53 protein (tumor suppressor protein) etc.
Explanation:
ATM activated by MRN complex at the site of DNA double stranded breaks by phosphorylation. MRN complex activity on ATM induces a conformational change in ATM kinase. So it can bind to its various substrate molecules that helps in DNA replication cycle arrest.
ATM phosphorylates CHK2 protein a product of CHEK2 gene, also known as effector kinases that phosphorylates and helps in deactivation of cyclin dependent kinases (CDKs) that helps in the prevention of progression of mitotic phase.
ATM also phosphorylates the inhibitors of p53 proteins which leads to the overexpression of p21, an inhibitor of (CDKs).
Because through natural selection, only the fittest survive. when the fittest come together and reproduce then the species continues and evolves with only the fittest and strongest genes.
