title: Annexins and endosomal signaling.
abstract: Cell signaling and endocytosis are intimately linked in eukaryotic cells. Signaling receptors at the cell surface enter the endocytic pathway and continue to activate downstream effectors in endosomal compartments. This spatiotemporal regulation of signal transduction provides opportunity for signal diversity and a cell-specific machinery of scaffolding/targeting proteins contributes to establish compartment-specific signaling complexes. Members of the annexin (Anx) protein family, in particular AnxA1, AnxA2, and AnxA6, appear to target their interaction partners to specific membrane microdomains to contribute to the formation of compartment-specific signaling platforms along the endocytic pathway. A major challenge to understand the impact of scaffolding/targeting proteins on spatiotemporal signal transduction along endocytic pathways is the identification, isolation, and functional analysis of low-abundance signal-transducing protein complexes in endocytic compartments. Here, we describe methods to isolate endosomes and to target signaling molecules to endosomes. Applying these methodologies to suitable animal or cell models will enable the dissection of signal transduction in the endocytic compartment in the presence or absence of annexins.
authors.affiliation: Departament de Biologia Cellular, Immunologia i Neurociències, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Tebar
authors.affiliation: Departament de Biologia Cellular, Immunologia i Neurociències, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Mariona
authors.initials: M
authors.lastname: Gelabert-Baldrich
authors.affiliation: Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Monira
authors.initials: M
authors.lastname: Hoque
authors.affiliation: Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Rose
authors.initials: R
authors.lastname: Cairns
authors.affiliation: Departament de Biologia Cellular, Immunologia i Neurociències, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Rentero
authors.affiliation: Departament de Biologia Cellular, Immunologia i Neurociències, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain; ICREA, Institució Catalana de Recerca Avançada, Barcelona, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Pol
authors.affiliation: Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Grewal
authors.affiliation: Departament de Biologia Cellular, Immunologia i Neurociències, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain. Electronic address: enrich@ub.edu.
authors.forename: Carlos
authors.initials: C
authors.lastname: Enrich
mesh_terms: D000818:Animals; D017302:Annexins / Q000502:physiology*; D016466:CHO Cells; D002458:Cell Fractionation; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D008099:Liver / Q000378:metabolism; D008856:Microscopy, Fluorescence; D038761:Photobleaching; D021381:Protein Transport; D019908:Proto-Oncogene Proteins c-raf / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction
chemical_list: D017302:Annexins; D019908:Proto-Oncogene Proteins c-raf
keywords: Annexins; CHO cells; Endosomes; FRET; FYVE domain; Liver; Raf-1; Subcellular fractionation