| Talk title | A Pandas Complex Adapted for piRNA-guided Transcriptional Silencing and Heterochromatin Formation |
| Speaker | Prof. Yang YU Principle Investigator Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, China |
| Date & Time | 14 Nov 2019 (Thu) 11:00-12:00 |
| Venue | Room G002, N22 Building (University of Macau) |
| Abstract | The repression of transposons by the Piwi-interacting RNA (piRNA) pathway is essential to protect animal germ cells. In Drosophila, Panoramix enforces transcriptional silencing by binding to the target-engaged Piwi-piRNA complex, although the precise mechanisms by which this occurs remain elusive. Here, Prof. YU’s team show that Panoramix functions together with a germline specific paralogue of a nuclear export factor, dNxf2, and its cofactor dNxt1 (p15), to suppress transposon expression. The transposon RNA binding protein dNxf2 is required for animal fertility and Panx-mediated silencing. Transient tethering of dNxf2 to nascent transcripts leads to their nuclear retention. The NTF2 domain of dNxf2 competes off dNxf1 (TAP) from nucleoporins, a process required for proper RNA export. Thus, dNxf2 functions in a Pandas (Panoramix-dNxf2 dependent TAP/p15 silencing) complex, which counteracts the canonical RNA exporting machinery and restricts transposons to the nuclear peripheries. Their findings may have broader implications for understanding how RNA metabolism modulates heterochromatin formation. |