title: Measuring Rab GTPase-activating protein (GAP) activity in live cells and extracts.
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.
authors: Department of Biochemistry, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA, 94305-5307, USA.
authors: Ryan M
authors: RM
authors: Nottingham
authors: Suzanne R
authors: SR
authors: Pfeffer
mesh_terms: D001681:Biological Assay / Q000379:methods*; D002457:Cell Extracts; D002470:Cell Survival; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D020691:rab GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D002457:Cell Extracts; D020690:GTPase-Activating Proteins; D020691:rab GTP-Binding Proteins