XRN1 is a Species-Specific Virus Restriction Factor in Yeasts

Paul A. Rowley; Brandon Ho; Sarah Bushong; Arlen Johnson; Sara L. Sawyer

kudriavzevii Xrn1p (Fig S3) . For this reason, we focused further chimeric analysis on the 390 region encompassing the D1-D3 domains (Fig 5A-C) , as defined previously [59] . We 391 swapped into S. kudriavzevii Xrn1p the D2-D3, D1, or D1-D3 domains of S. cerevisiae 392 Xrn1p, and saw increasing rescue of the ability to cure the L-A virus ( Fig 5D) . All 393 chimeric XRN1 genes were functionally equivalent with respect to their cellular functions, 394 as all were able to establish normal growth and benomyl resistance in S. cerevisiae 395 xrn1 ( Fig S4) . Therefore, the species-specificity domain maps predominantly to D1, 396 with contribution from the neighboring D2 and D3 domains as well. Together, our data 397 suggest that the exonuclease activity of Xrn1p is important for virus restriction and is 398 preserved across species, but that evolution has tailored a novel virus interaction The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/069799 doi: bioRxiv preprint encoded L-A Gag was immunoprecipitated in the presence of Xrn1p-HA from 443 either S. cerevisiae or S. kudriavzevii using beads with (+Ig) or without (-Ig) anti-444 Gag antibody present. Adh1p was used in all panels as a loading control to 445 ensure equal input of total protein and the specificity of immunoprecipitation.