Emily Chanawatr L&S Biological Sciences
The Role of Retroviral Gag in Mammalian Preimplantation Development
~40% of the mammalian genome derives from transposable elements, once considered “junk DNA” but now recognized as important contributors to host biology. One such element, Murine Endogenous Retrovirus-L (MERVL), is transiently expressed at the two-cell stage of mouse development. While MERVL transcripts are essential for preimplantation development, the protein it encodes, Gag, has never been functionally investigated.
In retroviruses such as HIV, Gag recruits TSG101, a subunit of ESCRT machinery, via its PSAPP motif to drive viral budding. ESCRT mediates membrane scission events including cytokinetic abscission. MERVL-Gag contains the same motif but produces no viral particles, suggesting it may instead interact with ESCRT components to regulate host membrane remodeling during embryonic cell division. Our preliminary data shows that MERVL-Gag knockdown accelerates two-cell cleavage, consistent with Gag regulating cytokinetic abscission via TSG101. My project will use co-immunoprecipitation to test whether MERVL-Gag binds TSG101 via its PSAPP motif and alters ESCRT-I complex organization, revealing a new role for an endogenous retroviral protein in early mammalian development.
Message To Sponsor
I am so grateful for your generosity in supporting my summer research through the SURF program. I have always been curious about how life works at its most fundamental level, and being able to dedicate my summer to exploring protein biology in the He Lab at UC Berkeley is an incredible opportunity. Thank you so much for making this possible; I look forward to sharing what I accomplish this summer.