title: The Rac-FRET mouse reveals tight spatiotemporal control of Rac activity in primary cells and tissues.
abstract: The small G protein family Rac has numerous regulators that integrate extracellular signals into tight spatiotemporal maps of its activity to promote specific cell morphologies and responses. Here, we have generated a mouse strain, Rac-FRET, which ubiquitously expresses the Raichu-Rac biosensor. It enables FRET imaging and quantification of Rac activity in live tissues and primary cells without affecting cell properties and responses. We assessed Rac activity in chemotaxing Rac-FRET neutrophils and found enrichment in leading-edge protrusions and unexpected longitudinal shifts and oscillations during protruding and stalling phases of migration. We monitored Rac activity in normal or disease states of intestinal, liver, mammary, pancreatic, and skin tissue, in response to stimulation or inhibition and upon genetic manipulation of upstream regulators, revealing unexpected insights into Rac signaling during disease development. The Rac-FRET strain is a resource that promises to fundamentally advance our understanding of Rac-dependent responses in primary cells and native environments.
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Anna-Karin E
authors.initials: AE
authors.lastname: Johnsson
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Max
authors.initials: M
authors.lastname: Nobis
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Baker
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Ewan J
authors.initials: EJ
authors.lastname: McGhee
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Walker
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Juliane P
authors.initials: JP
authors.lastname: Schwarz
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Shereen
authors.initials: S
authors.lastname: Kadir
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Jennifer P
authors.initials: JP
authors.lastname: Morton
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Myant
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Huels
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Segonds-Pichon
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Owen J
authors.initials: OJ
authors.lastname: Sansom
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
authors.forename: Kurt I
authors.initials: KI
authors.lastname: Anderson
authors.affiliation: Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, UK; Garvan Institute of Medical Research and Kinghorn Cancer Centre, Cancer Research Program, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, NSW, 2010 Sydney, Australia. Electronic address: p.timpson@garvan.org.au.
authors.forename: Paul
authors.initials: P
authors.lastname: Timpson
authors.affiliation: Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK. Electronic address: heidi.welch@babraham.ac.uk.
authors.forename: Heidi C E
authors.initials: HCE
authors.lastname: Welch
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D051379:Mice; D009504:Neutrophils / Q000166:cytology / Q000201:enzymology*; D015398:Signal Transduction; D062211:Spatio-Temporal Analysis; D020744:rac GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020744:rac GTP-Binding Proteins