Fig.3.

Oxidation of Rac1 Cys¹⁸ and Rac1 Cys¹⁸ variants alters guanine nucleotide exchange but not GTP hydrolysis. (A) Intrinsic mant-GDP dissociation curves for Rac1^WT, Rac1^C18S, Rac1^C18D, and Rac1^S–SG. The data were fit to a single exponential and standard errors were determined using Prism 5.0 (n = 3). (B) Bar graph of rates of intrinsic nucleotide exchange with GEF-mediated dissociation data (using the DH/PH domains of Tiam1) where applicable. (C) Graph of intrinsic and GAP-mediated single-turnover hydrolysis for Rac1^WT, Rac1^C18S, and Rac1^C18D. The RhoGAP domain of p50 rhoGAP was used for the GTP hydrolysis measurements. The data were fit to a single exponential and standard errors were determined using Prism 5.0 (n = 2). (D) Bar graph of rates of nucleotide hydrolysis with GAP-mediated hydrolysis data (using p50 rhoGAP) where applicable. Rates of exchange and hydrolysis are presented in Table 1.