Download Dissecting the mechanisms of mTOR activation. Supervisor: Dr. Zita

Dissecting the mechanisms of mTOR activation.
Supervisor: Dr. Zita Balklava
Collaboration with Dr. Thomas Wassmer (Aston University)
Background:
Alzheimer's disease is the most common form of dementia in old age. Amyloid Precursor
Protein (APP) plays a key role in Alzheimer's disease (AD). Mutations in APP gene cause an
early onset or familial form of AD. The aberrant processing of APP by secretases is thought
to be a key driver in AD as familial forms of AD are also caused by mutations in gamma
secretase. Despite its significance in AD the physiological role of APP still remains illdefined. APP is a transmembrane receptor and has been suggested to regulate cell
signalling, but the pathways it controls and mechanisms involved remain elusive. In our
previous studies we have shown that APP directly binds the mechanistic target of rapamycin
(mTOR), a key signalling hub that that regulates numerous cellular and developmental
processes. Using C.elegans as a model system we have demonstrated that C.elegans
homologue of APP (APL-1) controls numerous mTOR dependent processes such as
germline expansion, fat metabolism and autophagy. By RNA-mediated interference
approach we have also demonstrated that APL-1 regulates mTOR activity by mediating input
of amino acids through RAG-GTPases.
Project:
Powerful genetics of C.elegans has been proven to be beneficial in studying cell signalling
pathways in vivo, and therefore will be used in this project. Broad aim of this project is to
decipher the mechanism of how APP controls mTOR activation by RAG-GTPases using
C.elegans germline expansion as a model assay. This will include cloning expression
constructs for RAG-GTPases in their native, constitutively active and inactive states and
introducing them into C.elegans to create transgenic strains. These will then be crossed into
control and APL-1 mutant strains in combination with overexpression of APL-1. Resulting
mutant transgenic strains will be used for epistasis analysis to gain insights into mechanisms
of mTOR activation.