Investigation of the Function and Regulatory Mechanisms of the Mammalian Target of Rapamycin

Unexpectedly, mTOR has been found to shuttle between the nucleus and the cytoplasm, and this shuttling is required for its cytoplasmic signaling. I have further investigated the regulation and function of mTOR cytoplasmic-nuclear shuttling. A systematic screen of mTOR revealed a rev-like NES sequence within mTOR at amino acids 1281--1289, which displayed robust nuclear export activity in a reporter system. Mutation of the conserved leucines within this export site resulted in a loss of downstream signaling in vivo, despite retention of mTOR catalytic activity. Interestingly, the mTOR 1281--1289L/A mutant showed cytoplasmic staining similar to wild type mTOR, and did not accumulate in the nucleus upon LMB treatment. This suggests that the 1281--1289L/A mutations in mTOR disrupt nucleocytoplasmic shuttling activity. The nucleocytoplasmic shuttling of mTOR is likely a mechanism to lessen the probability of aberrant signaling, a necessary control for a protein that has an essential role in cell growth and proliferation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Bachmann, Rebecca Anne

Contributors dc:contributor

• Chen, Jie

• Health Sciences, Pharmacology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3086008

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84792