title: ALG-2 oscillates in subcellular localization, unitemporally with calcium oscillations.
abstract: A variety of stimuli can trigger intracellular calcium oscillations. Relatively little is known about the molecular mechanisms decoding these events. We show that ALG-2, a Ca2+-binding protein originally isolated as a protein associated with apoptosis, is directly linked to Ca2+ signalling. We discovered that the subcellular distribution of a tagged version of ALG-2 could be directed by physiological external stimuli (including ATP, EGF, prostaglandin, histamine), which provoke intracellular Ca2+ oscillations. Cellular stimulation led to a redistribution of ALG-2 from the cytosol to a punctate localization in an oscillatory fashion unitemporally with Ca2+ oscillations, whereas a Ca2+-binding deficient mutant of ALG-2 did not redistribute. Using tagged ALG-2 as bait we identified its novel target protein Sec31A and based on the partial colocalization of endogenous ALG-2 and Sec31A we propose that ALG-2 temporarily binds to the COPII vesicles providing a link between Ca2+ signalling and ER to Golgi trafficking.
authors.affiliation: Department of Molecular Biology, University of Copenhagen, Copenhagen, Denmark. jonas@my.molbio.ku.dk
authors.forename: Jonas M
authors.initials: JM
authors.lastname: la Cour
authors.forename: Jens
authors.initials: J
authors.lastname: Mollerup
authors.forename: Martin Werner
authors.initials: MW
authors.lastname: Berchtold
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D018613:Microscopy, Confocal; D009154:Mutation; D011485:Protein Binding; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D033921:Vesicular Transport Proteins
chemical_list: D051017:Apoptosis Regulatory Proteins; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; C490815:Pdcd6 protein, mouse; D011993:Recombinant Fusion Proteins; C507455:SEC31A protein, human; C521195:SEC31B protein, human; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins; D006632:Histamine; D000255:Adenosine Triphosphate; D002118:Calcium