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Updated: Apr 15, 2026

Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
Published on: November 11, 2018
Measuring Rab GTPase-activating protein (GAP) activity in live cells and extracts
Ryan M Nottingham1, Suzanne R Pfeffer
1Department of Biochemistry, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305-5307, USA.
Abstract:
Mammalian cells encode a diverse set of Rab GTPases and their corresponding regulators. In vitro biochemical screening has proven invaluable in assigning particular Rabs as substrates for their cognate GTPase-activating proteins. However, in vitro activity does not always reflect substrate specificity in cells. This method describes a functional test of GAP activity in cells or extracts that takes into account the presence of other factors or conditions that might change observed in vitro specificity.
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