Updated project metadata. Memo is a copper-dependent redox enzyme modulating receptor tyrosine kinase signaling by unknown mechanisms (Meira et al., Nat Cell Biol 2004; MacDonald et al., Science Signal 2014). Memo1 deletion causes a phenotype partially resembling Klotho and Fgf23-deficient mice (Haenzi et al., FASEB J 2014; Moor et al., JBMR Plus 2018) and increases renal abundance of Rho-GTPase RhoA but prevents FGF23-dependent renal ERK phosphorylation and Rho-GTPase Rac1 activation (unpublished). To delineate potential effects of Memo’s redox function on FGF23-driven cellular signaling processes, we performed a redox proteomics screen which identified differently oxidized Rho-GTPase chaperone protein ARHGDIA/Rho-GDP dissociation inhibitor 1 (RhoGDI) as an interaction partner of Memo. RhoGDI is regulated by cysteine oxidation and phosphorylation. Here, we investigated the potential interaction between MEMO and RhoGDI by co-incubation of recombinant proteins MEMO and RhoGDI in cell-free environment to assess the Cys79 oxidation state of RhoGDI.