RNA interference (RNAi) is a conserved mechanism by which double-stranded RNA can specifically inactivategenes of matching sequence. RNAi has rapidly developed from a Nobel-prize winning discovery in the simpleworm C. elegans to a therapeutic approach to silence human disease-causing genes that lack conventionalmedicines. However, fundamental aspects of RNAi remain unclear and they need to be understood to ensuresafe and efficacious RNAi therapy. The continued relevance and significance of studies in the model organismC. elegans is underscored by the fact that the human counterpart of an RNA channel that imports RNA into C.elegans cells during RNAi is required for the import of RNAi-based drugs into human cells.The candidate presents a 5-year career development plan that aims to use C. elegans to gain fundamentalinsights into the transport of RNA between cells during RNA interference, while establishing an independentacademic career at a research university. The candidate will build on his strong foundation in genetics andbiochemistry to develop into an independent researcher in RNA transport under the mentorship of Dr. CraigHunter, a pioneer and leader in the study of RNA transport between animal cells. The plan will be carried out inthe Department of Molecular Biology at Harvard University, a leading institution in modern biology.Research in the mentor's lab led to the discovery of the conserved RNA channel SID-1 that is required for theimport of RNAi-mediated silencing signals and the transport of signals between cells within a tissue. In a recentpublication, the candidate reported the discovery that export of RNA from C. elegans tissues occurs through aregulated SID-1 independent mechanism. During the mentored phase, the candidate will: 1) Dissect the SID-1dependent transport of RNA between cells within a tissue using advanced microscopy and examine how theSID-1 independent export of RNA from tissues is mediated by sid-3, a gene required for such export; and 2)examine the role of RNAi pathway proteins within a cell in generating RNAs transported from that cell. Inaddition to the mentor's laboratory, advanced microscopy for Aim1 will be carried out in the lab of thecandidate's collaborator Dr. Xiaowei Zhuang, who is a pioneer in super-resolution microscopy. During theindependent phase of the award, the candidate will analyze the roles of sexd-1 and sexd-2, two other genesdiscovered by the candidate that are required for inter-tissue export and will define a basic molecular pathwayfor export using the approaches and techniques acquired during the mentored phaseTraining in the complementary cell biological, genetic, and biochemical approaches while executing the aboveresearch plan will equip the candidate to establish a multi-faceted and rich research program as anindependent investigator. Further, the proposed studies will reveal fundamental aspects of RNA transportduring RNAi in C. elegans, which will impact the design of therapeutic RNAi approaches to human diseases.
RNAi-based drugs can specifically target disease-causing genes for which no conventional medicines are currently available. But, delivery of the drugs specifically and efficiently into diseased cells and tissues is a major barrier to RNA therapy. Understanding the mechanisms that control export of RNAi-mediated silencing signals from cells and the effect of such export on RNAi within these cells in C. elegans will provide valuable insights to overcome these barriers to therapeutic RNAi in humans.
| Le, Hai H; Looney, Monika; Strauss, Benjamin et al. (2016) Tissue homogeneity requires inhibition of unequal gene silencing during development. J Cell Biol 214:319-31 |
| Marré, Julia; Traver, Edward C; Jose, Antony M (2016) Extracellular RNA is transported from one generation to the next in Caenorhabditis elegans. Proc Natl Acad Sci U S A 113:12496-12501 |
| Devanapally, Sindhuja; Ravikumar, Snusha; Jose, Antony M (2015) Double-stranded RNA made in C. elegans neurons can enter the germline and cause transgenerational gene silencing. Proc Natl Acad Sci U S A 112:2133-8 |
| Jose, Antony M; Kim, Yunsoo A; Leal-Ekman, Steven et al. (2012) Conserved tyrosine kinase promotes the import of silencing RNA into Caenorhabditis elegans cells. Proc Natl Acad Sci U S A 109:14520-5 |
| Jose, Antony M; Garcia, Giancarlo A; Hunter, Craig P (2011) Two classes of silencing RNAs move between Caenorhabditis elegans tissues. Nat Struct Mol Biol 18:1184-8 |
