Vps34 is a lipid kinase that regulates membrane trafficking pathways like endocytosis and autophagy by generating phosphoinositol 3-phosphate, a lipid signaling molecule. Endocytosis is the process by which cells take up extracellular materials and transmembrane proteins, and sort them to their proper destinations. Endocytosis is necessary for cells to acquire nutrients and for appropriate growth control. Autophagy is an evolutionarily conserved process that promotes cell survival by serving a housekeeping role, and by providing extra nutrients when the cell is under stress. As both endocytosis and autophagy are important cellular events in cancer development and resistance to therapy, they have become targets for designing novel cancer therapeutics. Therefore, it is important to understand how these cellular events are regulated. Although Vps34 is implicated in both endocytosis and autophagy, determining its precise role has been hampered by the lack of specific inhibitors. Using a genetic knockout strategy we recently reported that Vps34 has a major role in autophagosome formation and the late stages of endocytosis, but may be dispensable at the early endosome. This proposal is designed to determine 1) the precise role of Vps34 during endocytosis by examining the functions of the early endosome, the process of endosome maturation and the functions of the late endosome in Vps34-deficient cells, and 2) how autophagy is regulated via Vps34 dependent or independent mechanisms. These studies will help provide a clearer picture of the exact roles of Vps34 in endocytosis and autophagy. This information will be critical for understanding the multifaceted functions of Vps34 and for the design of anti-cancer therapeutics targeting endocytosis or autophagy.

Public Health Relevance

Vps34 is a lipid kinase that generates phosphoinositol 3-phosphate, a lipid signaling molecule that controls intracellular membrane trafficking processes such as endocytosis and autophagy. Both endocytosis and autophagy are involved in human malignancies. This proposal is designed to uncover the physiological roles and molecular mechanisms of Vps34 in the regulation of endocytosis and autophagy, and will help with the development of therapeutics targeting endocytosis and autophagy for the treatment of human cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31CA177243-02
Application #
8753927
Study Section
Special Emphasis Panel (ZRG1-F05-R (20))
Program Officer
Korczak, Jeannette F
Project Start
2013-04-01
Project End
2016-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
2
Fiscal Year
2014
Total Cost
$30,888
Indirect Cost
Name
State University New York Stony Brook
Department
Genetics
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Jaber, Nadia; Mohd-Naim, Noor; Wang, Ziqing et al. (2016) Vps34 regulates Rab7 and late endocytic trafficking through recruitment of the GTPase-activating protein Armus. J Cell Sci 129:4424-4435