Question

Activation of mTOR by the PI-3-kinase signaling pathway leads to an activation of S6 kinase and inhibition of 4E-BP (binding protein). The result of these 2 actions are an upregulation of:

A. Transcription
B. RNA Splicing
C. Protein Translation
D. Protein degradation

Answer 1

Activation of mTOR via the PI-3-kinase pathway leads to enhancement of protein translation through the activation of S6 kinase and inhibition of 4E-BP, making the correct answer C. Protein Translation.

Step-by-step explanation:

The question addresses the role of the mTOR pathway in cellular processes, specifically in relation to S6 kinase and 4E-BP. Activation of mTOR by the PI-3-kinase signaling pathway leads to the activation of S6 kinase and the inhibition of 4E-BP. The consequence of activating S6 kinase is the enhancement of protein translation, as this kinase directly phosphorylates components of the protein synthesis machinery.

Meanwhile, the inhibition of 4E-BP, which is an inhibitor of the eIF-4E translation initiation factor, also promotes protein translation by freeing eIF-4E to assist in the initiation phase of protein synthesis. Therefore, the upregulation due to the actions of S6 kinase and 4E-BP inhibition is in protein translation. Hence, the correct answer to the question is C. Protein Translation.