RIP-seq of mouse Asterix/Gtsf1 expressed in Sf9 cells

Asterix/Gtsf1 has been previously been shown to be involved in the silencing of retrotransposons in animal germ cells through the piRNA pathway. During early stages of purification of mouse Gtsf1 protein in Sf9 cells for structural studies, we found that the protein was co-purifying with endogenous nucleic acids. We first characterized those RNAs by next-generation sequencing (this dataset) and then later investigated its RNA-binding in more relevant cell culture systems. In each case, we found Asterix/Gtsf1 was binding tRNAs. Given the role of tRNAs as primers for Long Terminal Repeat (LTR) transposons, this work implicates Asterix/Gtsf1 as exploiting tRNA dependence to identify transposon transcripts and promote piRNA silencing. Overall design: RIP-seq of mouse Asterix/Gtsf1 expressed in Sf9 cells. The protein was expressed with a C-terminal TEV-Strep tag under the control of the polyhedrin promoter.