Western analysis of Xrn1 variants.

A) Equal amount of whole-cell extracts, taken from optimally proliferating cells expressing FLAG-tagged Xrn1, or its indicated mutant derivatives (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0308195#pone.0308195.s005" target="_blank">S1 Table</a>), were analyzed by western blot. Membrane was incubated with anti-FLAG antibody and with anti-ATP2 that was used as a loading control. B) Quantification of immunoblots: Images were acquired using ImageQuant and quantification of western blot bands were done using Image J software. Signal of Xrn1 was normalized to that of Atp2. Three biologically independent samples were averaged except for S454P and NLS1 where only two were considered. Error bars represent standard deviation (SD). No significant differences were observed with regard the wild type sample using Student’s unpaired T-test for any of the Xrn1 variants. (PDF)