Current Position: Laboratory Animal Medicine Resident at the University of Washington
I grew up in Wahiawa, Hawaii on the island of Oahu. I then spent four years in California obtaining my undergraduate degree in Biological Sciences. During this time, I studied abroad in Kyoto, Japan, and spent three months at the Kyoto University Primate Research Institute in Inuyama. While at the PRI, I worked with the lab animal veterinarians there, and became attracted to the idea of becoming a veterinarian myself. Once at Cornell, I spent a summer in the Veterinary Investigator Program where I discovered the excitement of doing basic research as well.
BS, Biological Sciences - Stanford University
Studies using model organisms have shown that genes can influence the aging process. One of the most highly conserved pathways regulating lifespan is insulin/IGF-1 signalling, which negatively regulates the downstream forkhead box, class O (FOXO) transcription factors. FOXO transcription factors can also be regulated by other factors. For example, the protein deacetylase SIRT1 can deacetylate FOXO leading to enhanced transcription of stress response genes. To identify novel genes involved in regulation of lifespan, our lab conducted a genome-wide RNAi screen using the model organism Caenorhabditis elegans. One gene identified in this screen was the C. elegans homolog of mammalian Host Cell Factor-1 (HCF-1). Inactivation of hcf-1 can significantly extend lifespan, and this lifespan extension is dependent on daf-16, the C. elegans homolog of FOXO, and sir-2.1, the C. elegans homolog of mammalian SIRT1. CeHCF-1 can repress the transcriptional activity of DAF-16 and can also associate with both DAF-16 and SIR-2.1. I am currently examining the role of mammalian Host Cell Factor proteins to determine if the function of CeHCF-1 is conserved in mammals. Specifically, I am investigating 1) possible repression of FOXO transcription by HCF proteins, and 2) physical association of HCF proteins with SIRT1 and FOXO
Publications and Presentations
G. Rizki, T. Iwata, J. Li, C. Riedel, C. Picard, M. Jan, C. Murphy, S. S. Lee. 2011. The Evolutionarily Conserved Longevity Determinants HCF-1 and SIR-2.1/SIRT1 Collaborate to Regulate DAF-16/FOXO. PLoS Genetics, in press.