title: Calcium-independent cytoskeleton disassembly induced by BAPTA.
abstract: In living organisms, Ca2+ signalling is central to cell physiology. The Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) has been widely used as a probe to test the role of calcium in a large variety of cell functions. Here we show that in most cell types BAPTA has a potent actin and microtubule depolymerizing activity and that this activity is completely independent of Ca2+ chelation. Thus, the depolymerizing effect of BAPTA is shared by a derivative (D-BAPTA) showing a dramatically reduced calcium chelating activity. Because the extraordinary depolymerizing activity of BAPTA could be due to a general depletion of cell fuel molecules such as ATP, we tested the effects of BAPTA on cellular ATP levels and on mitochondrial function. We find that BAPTA depletes ATP pools and affects mitochondrial respiration in vitro as well as mitochondrial shape and distribution in cells. However, these effects are unrelated to the Ca2+ chelating properties of BAPTA and do not account for the depolymerizing effect of BAPTA on the cell cytoskeleton. We propose that D-BAPTA should be systematically introduced in calcium signalling experiments, as controls for the known and unknown calcium independent effects of BAPTA. Additionally, the concomitant depolymerizing effect of BAPTA on both tubulin and actin assemblies is intriguing and may lead to the identification of a new control mechanism for cytoskeleton assembly.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale, Département Réponse et Dynamique Cellulaires, Grenoble, France.
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Saoudi
authors.forename: Bernard
authors.initials: B
authors.lastname: Rousseau
authors.forename: Jacques
authors.initials: J
authors.lastname: Doussière
authors.forename: Sophie
authors.initials: S
authors.lastname: Charrasse
authors.forename: Cécile
authors.initials: C
authors.lastname: Gauthier-Rouvière
authors.forename: Nathalie
authors.initials: N
authors.lastname: Morin
authors.forename: Christelle
authors.initials: C
authors.lastname: Sautet-Laugier
authors.forename: Eric
authors.initials: E
authors.lastname: Denarier
authors.forename: Robin
authors.initials: R
authors.lastname: Scaïfe
authors.forename: Charles
authors.initials: C
authors.lastname: Mioskowski
authors.forename: Didier
authors.initials: D
authors.lastname: Job
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002460:Cell Line; D002614:Chelating Agents / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects* / Q000378:metabolism*; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D005557:Formaldehyde / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000378:metabolism; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D015394:Molecular Structure; D014981:Xenopus
chemical_list: D002614:Chelating Agents; D005557:Formaldehyde; D004533:Egtazic Acid; D000255:Adenosine Triphosphate; D020558:GTP Phosphohydrolases; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium