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Updated: Apr 15, 2026

Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
Assaying the interaction of the Rab guanine nucleotide exchange protein Sec2 with the upstream Rab, a downstream
Danièle Stalder1, Peter J Novick
1Department of Cellular and Molecular Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
Abstract:
Rabs are activated by guanine nucleotide exchange proteins, which are in turn controlled by complex regulatory mechanisms. Here we describe several different assays that have been used to delineate the mechanisms by which Sec2p, the exchange factor for the Rab Sec4p, is regulated. These assays assess the interaction of Sec2p with the upstream Rab, Ypt32p, a downstream Sec4p effector, Sec15p, and the lipid, phosphatidylinositol-4-phosphate.
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