HeLa S3 cells (ATCC) were maintained in Dulbecco’s modified eagle medium (DMEM) with 10% v/v bovine calf serum (HyClone) and maintained in a 37°C, 5% CO2 environment. All media components are from Cellgro unless otherwise noted. Unless otherwise noted all reagents used in following assays are from Sigma-Aldrich. HeLa S100 cytosolic lysates were generated from cells based on the Dignam protocol as previously described.13 (link) Isolated HeLa S100 cytosolic lysates were quantified with a Nanodrop 2000 (Thermo Scientific), aliquoted, and stored at −80°C.