B, MAPPIT assay confirms the interaction between OTUB1 and RAS proteins. pSEL(+2L) vectors coding RAS proteins were expressed in HEK293T cells together with the indicated prey. Empty vector and two random baits, MAL and eDHFR, were used as negative controls. REM2 and EFHA1 preys that bind to the bait receptor itself was used to evaluate expression of the RAS baits. The results are expressed as a mean of normalized luciferase activity ± s.e.m (leptin-treated cells vs leptin-untreated cells), n=3. 