Answer :
Kinase cascade
Explanation:
Normally, PK2 activates PK1
- PK1 and PK2 normally work sequentially in an intracellular signaling pathway
- If PK1 is permanently activated, a response is seen independently of whether or not PK2 is present
- If PK1 activated PK2, no response should be seen if PK1 were activated in the absence of PK2
- PK2 normally needs to activate PK1 for the cells to respond to the signal
- When PK2 is permanently activated in the absence of PK1, PK1 is not there to relay the signal