C, NRAS Q61K mutant co-immunoprecipitates with OTUB1. At 48 hours post-transfection with Flag-tagged NRAS Q61K and HA-tagged OTUB1 expression constructs, HA-tagged OTUB1 was immunoprecipitated with anti-HA-agarose followed by immunoblotting using anti-Flag or anti-HA antibodies. 