An opening for a postdoctoral fellow is available in my lab to participate in a very exciting project concerning the mechanism of copy number control of the retrovirus-like transposon Ty1 in Saccharomyces (Garfinkel et al., 2003; Garfinkel et al., 2005). Recently, we have discovered a novel form of RNAi where cis-encoded antisense RNAs block Ty1 reverse transcription within virus-like particles (VLPs). In parallel, we are studying Ty1 antisense and mRNA trafficking during the process of transposition. We have shown that Ty1 mRNA and Gag form cytoplasmic foci, which are required for VLP assembly and controlled by P-bodies. In addition, antisense RNA trafficking changes during active VLP-assembly with the interfering RNAs and VLP assembly sites now showing a much higher level of colocalization.

Our work has wide-ranging impact, encompassing the fields of RNAi and host defense against HIV replication. We would like to understand further the mechanism of Ty1 RNAi by determining how the antisense RNAs inhibit reverse transcription and identify the cellular cofactors involved. Finally, we will describe the Ty1 RNA trafficking pathways using a battery of cellular mutations in genes that affect retrotransposition and RNA metabolism (Griffith et al., 2003; Nyswaner et al., 2008; Scholes et al., 2001).

We are especially interested in a person who has experience in cell biology and light microscopy, who would like to study retrotransposon biology in the powerful model organism, S. cerevisiae. Previous experience in yeast genetics and molecular biology is not required.

This position is subject to a background investigation.


References

• Garfinkel, D. J., Nyswaner, K., Wang, J., and Cho, J. Y. (2003). Post-transcriptional cosuppression of Ty1 retrotransposition. Genetics 165, 83-99.
• Garfinkel, D. J., Nyswaner, K. M., Stefanisko, K. M., Chang, C., and Moore, S. P. (2005). Ty1 copy number dynamics in Saccharomyces. Genetics 169, 1845-1857.
• Griffith, J. L., Coleman, L. E., Raymond, A. S., Goodson, S. G., Pittard, W. S., Tsui, C., and Devine, S. E. (2003). Functional genomics reveals relationships between the retrovirus-like Ty1 element and its host Saccharomyces cerevisiae. Genetics 164, 867-879.
• Nyswaner, K. M., Checkley, M. A., Yi, M., Stephens, R. M., and Garfinkel, D. J. (2008). Chromatin-associated genes protect the yeast genome from Ty1 insertional mutagenesis. Genetics 178, 197-214.
• Scholes, D. T., Banerjee, M., Bowen, B., and Curcio, M. J. (2001). Multiple regulators of Ty1 transposition in Saccharomyces cerevisiae have conserved roles in genome maintenance. Genetics 159, 1449-1465.

To apply:

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