TY  - INPR
A1  - Drews, Franziska
A1  - Karunanithi, Sivarajan
A1  - Götz, Ulrike
A1  - Marker, Simone
A1  - Wijn, Raphael de
A1  - Pirritano, Marcello
A1  - Rodrigues-Viana, Angela M.
A1  - Jung, Martin
A1  - Gasparoni, Gilles
A1  - Schulz, Marcel Holger
A1  - Simon, Martin
T1  - Two Piwis with Ago-like functions silence somatic genes at the chromatin level
T2  - bioRxiv
N2  - Most sRNA biogenesis mechanisms involve either RNAseIII cleavage or ping-pong amplification by different Piwi proteins harboring slicer activity. Here, we follow the question why the mechanism of transgene-induced silencing in the ciliate Paramecium needs both Dicer activity and two Ptiwi proteins. This pathway involves primary siRNAs produced from non-translatable transgenes and secondary siRNAs from endogenous remote loci. Our data does not indicate any signatures from ping-pong amplification but Dicer cleavage of long dsRNA. We show that Ptiwi13 and 14 have different preferences for primary and secondary siRNAs but do not load them mutually exclusive. Both Piwis enrich for antisense RNAs and Ptiwi14 loaded siRNAs show a 5′-U signature. Both Ptiwis show in addition a general preference for Uridine-rich sRNAs along the entire sRNA length. Our data indicates both Ptiwis and 2’-O-methylation to contribute to strand selection of Dicer cleaved siRNAs. This unexpected function of two distinct vegetative Piwis extends the increasing knowledge of the diversity of Piwi functions in diverse silencing pathways. As both Ptiwis show differential subcellular localisation, Ptiwi13 in the cytoplasm and Ptiwi14 in the vegetative macronucleus, we conclude that cytosolic and nuclear silencing factors are necessary for efficient chromatin silencing.
Y1  - 2020
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/72818
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-728181
IS  - 2020.08.24.263970
ER  -