Question

Which of the following is not true about ATM kinase?

(a) It is guided to the DSB site by MRN complex

(b) It exits as inactive dimer

(c) It is activated to monomer by another factor of DSB repair

(d) It phosphorylates BRCA1 and BRCA2

This question was posed to me by my school principal while I was bunking the class.

I'm obligated to ask this question of Repair of DNA Damage: Recombinational and Bypass in section DNA Mutation, DNA Repair, Transposable Elements of Cytogenetics

Answer 1

Correct answer is (c) It is activated to monomer by another factor of DSB repair

The best I can explain: ATM kinase is activated by autocatalysis. It however is a major kinase which phosphorylates the H2AX, BRCA 1 and 2, 53BP1 and many other factors in DSB repair.