) Describe in detail the DNA damage response (DDR) pathway activated by double-strand breaks.
Include the roles of ATM, ATR, p53, BRCA1/2, and CHK1/CHK2.
b) Compare and contrast homologous recombination (HR) and non-homologous end joining (NHEJ) with respect to:
Molecular mechanisms
Cell-cycle phase specificity
Fidelity and biological consequences
c) Explain how defects in DNA repair pathways contribute to genomic instability and cancer, using two named human disorders as examples.
d) A human cell line exposed to ionizing radiation shows normal activation of p53 but fails to arrest at the G/M checkpoint.
Propose two molecular explanations for this observation and justify your reasoning.
e) Design an experimental approach to determine whether a novel protein is involved in the DNA damage response.
Include:
The technique(s) used
Appropriate controls
Expected results if the protein is involved in DDR
Requirements: