Platelets that express a constitutively active Rap1 are able to activate integrins even in the absence of thrombin stimulation. In contrast, cells expressing a binding-deficient version of talin are unable to perform integrin activation. In platelets expressing both of these mutant proteins, what would you expect to observe: the Rap1 gain-of-function phenotype (R) or the talin loss-of-function phenotype (T), as described above? Write down R or T as your answer.

Question

Quizplus · Accepted Answer

Since talin functions downstream of Rap1, the talin loss-of-function phenotype is also observed in the double mutants.

Platelets That Express a Constitutively Active Rap1 Are Able to Activate