Question

To your cultured cell lines, you add growth factors like cytokines which act through MAPK cascade pathway. Which transition will it trigger?

(a) S->G2

(b) M->Anaphase

(c) G1->S

(d) G2->M

The question was posed to me in an internship interview.

My doubt stems from DNA Replication Eukaryotes topic in portion DNA Replication of Cytogenetics

Answer 1

Correct answer is (c) G1->S

To explain I would say: One of the primary checkpoints to overcome incase of proliferation is G1 -> S check point. MAPK cascade leads to transcription of genes required to increase the CDK activity that leads to this transition. Once S phase is completed the cell must undergo mitosis although there is another checkpoint before Anaphase.