Using Drosophila Strains to Examine the Relationship Between AMPK and mTORC1/TRPML1 (2014)

Undergraduates: Thanh Bui, Dr. Rob Onyenwoke

Faculty Advisor: Jay Brenman
Department: Chemistry

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AMP-activated protein kinase (AMPK), a sensor for the cell's energy status, detects changes in cellular AMP:ATP and ADP:ATP levels. When the ATP concentration is low, AMPK turns on catabolic pathways and turns off anabolic pathways. AMPK is a proposed therapeutic target for a number of diseases, for example, diabetes. In my research, I examine the signaling pathway between AMPK and the mammalian target of rapamycin complex 1 (mTORC1) in autophagy. AMPK inhibits mTORC1's activity. A method to test this activity is through Western blot analysis of S6 kinase because mTORC1 phosphorylates and activates S6 kinase. In addition, a possible subsequent relationship between mTORC1 and the transient receptor potential mucolipin-1 (TRPML1) is examined. TRPML1 plays an important role in autophagy and is required for the completion of autophagy. Loss-of-function TRPML1 leads to a lysosomal storage disorder (LSD). My hypothesis is that mTORC1 directly interacts with and regulates TRPML1 activity, thereby forming an additional mechanism of feedback during the autophagy process that may also compensate for the loss of AMPK activity. Using Drosophila as a genetic tool, the relationship between AMPK, mTORC1, and TRPML1 is examined using AMPK alpha-RNAi, TRPML1-RNAi, AMPK alpha loss-of-function alleles, and TRPML1 loss-of-function alleles and yeast-fed and starved flies.