title: Signaling efficiency of Gαq through its effectors p63RhoGEF and GEFT depends on their subcellular location.
abstract: The p63RhoGEF and GEFT proteins are encoded by the same gene and both members of the Dbl family of guanine nucleotide exchange factors. These proteins can be activated by the heterotrimeric G-protein subunit Gαq. We show that p63RhoGEF is located at the plasma membrane, whereas GEFT is confined to the cytoplasm. Live-cell imaging studies yielded quantitative information on diffusion coefficients, association rates and encounter times of GEFT and p63RhoGEF. Calcium signaling was examined as a measure of the signal transmission, revealing more efficient signaling through the membrane-associated p63RhoGEF. A rapamycin dependent recruitment system was used to dynamically alter the subcellular location and concentration of GEFT, showing efficient signaling through GEFT only upon membrane recruitment. Together, our results show efficient signal transmission through membrane located effectors, and highlight a role for increased concentration rather than increased encounter times due to membrane localization in the Gαq mediated pathways to p63RhoGEF and PLCβ.
authors.affiliation: Swammerdam Institute for Life Sciences, Section of Molecular Cytology, van Leeuwenhoek Centre for Advanced Microscopy, University of Amsterdam, P.O. Box 94215, NL-1090 GE Amsterdam, The Netherlands. j.goedhart@uva.nl
authors.forename: Joachim
authors.initials: J
authors.lastname: Goedhart
authors.forename: Jakobus
authors.initials: J
authors.lastname: van Unen
authors.forename: Merel J W
authors.initials: MJ
authors.lastname: Adjobo-Hermans
authors.forename: Theodorus W J
authors.initials: TW
authors.lastname: Gadella
mesh_terms: D000595:Amino Acid Sequence; D020013:Calcium Signaling; D002462:Cell Membrane / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry; D003593:Cytoplasm / Q000378:metabolism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D063990:Gene Ontology; D005822:Genetic Vectors / Q000235:genetics; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007700:Kinetics; D018613:Microscopy, Confocal; D008954:Models, Biological; D008969:Molecular Sequence Data; D054799:Phospholipase C beta / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D064067:Rho Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C475063:ARHGEF25 protein, human; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors; D054799:Phospholipase C beta; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D003545:Cysteine