Protein Extraction and Western Blotting

Protein extraction and Western blotting was performed similarly as in our previous work^{1 (link)}. Cells were washed with PBS, after which total protein was isolated from cell pellets using a cell lysis buffer (Biorad). Samples were pipetted onto polyacrylamide gels for electrophoretic band separation and transferred to a nitrocellulose membrane (Biorad). Blocking of membranes was performed by incubation for 1 h in 5% milk solution. The membranes were incubated with the primary antibody overnight. After rinsing, the membranes were exposed to IgG-HRP secondary antibodies, ultimately being washed again and visualized via the enhanced chemiluminescence (ECL) reagent (Biorad). Antibodies used for detection of QKI and GAPDH were as following: rabbit-anti-Qki (Sigma HPA019123) and mouse-anti-GAPDH (Abcam ab8245).