J. Biol. Chem

The activity of vesicular monoamine transporters (VMATs) is down-regulated by the G-protein {alpha}-subunits of Go2 and Gq, but the signaling pathways are not known. We show here that no such regulation is observed when VMAT1 or VMAT2 are expressed in Chinese hamster ovary (CHO) cells. However, when the intracellular compartments of VMAT-expressing CHO cells are preloaded with different monoamines, transport becomes susceptible to G-protein-dependent regulation, with differences between the two transporter isoforms. Epinephrine induces G-protein-mediated inhibition of transmitter uptake in CHOVMAT1 cells but prevents inhibition induced by dopamine in CHOVMAT2 cells. Epinephrine also antagonizes G-protein-mediated inhibition of monoamine uptake by VMAT2 expressing platelets or synaptic vesicles. In CHOVMAT2 cells G-protein-mediated inhibition of monoamine uptake can be induced by 5-hydroxytryptamine (serotonin) 1B receptor agonists, whereas {alpha}1 receptor agonists modulate uptake into CHOVMAT1 cells. Accordingly, 5-hydroxytryptamine 1B receptor antagonists prevent G-proteinmediated inhibition of uptake in partially filled platelets and synaptic vesicles expressing VMAT2. CHO cells expressing VMAT mutants with a shortened first vesicular loop transport monoamines. However, no or a reduced G-protein regulation of uptake can be initiated. In conclusion, vesicular content is involved in the activation of vesicle associated G-proteins via a structure sensing the luminal monoamine content. The first luminal loop of VMATs may represent a G-protein-coupled receptor that adapts vesicular filling

Approches de la théâtralité pasolinienne (de la scène au texte)

Pasolini a accompagné son activité artistique (poésie, roman, cinéma, peinture et théâtre) d'écrits critiques et théoriques qui apportent beaucoup à l'interprétation de son œuvre. Dans cette thèse sont analysés les textes dramatiques de Pasolini à la lumière de sa réflexion théorique et des traces de représentation de ses pièces en France et en Italie. La perspective proposée rend compte de l'attention croissante des praticiens de la scène pour cette œuvre théâtrale et met en évidence son potentiel performatif. La théâtralité dans ces écrits est caractérisée par la matérialité de l'écriture : par une vocation musicale, une architecture rythmique, des processus intertextuels et métathéâtraux, par une idée de théâtre inspirée des notions de " rite culturel " et d'espace réduit à l'essentiel. Cette étude s'appuie également sur une recherche d'archives : sont exploitées les manuscrits et les textes dactylographiés de Pasolini pour Orgia qui témoignent de la même nécessité théâtrale.Pasolini, poet, novelist, essayist, journalist, scriptwriter, film director, and a playwright, too, has authored many theoretical writings on literature, film-making and theater which are all important in understanding his work. In the present thesis, the dramatic works of Pasolini are analysed in the light of his theoretical thinking and of the records bearing on his theatrical performances in France and Italy. A new perspective is offered which explains the growing attention given by the world of theater to Pasolini's dramatic work and to the performing potential of this work. The theatrical impact stands out by the material character of the author's writing : his musical vocation, a rhythmic architecture, transtextual processes, and a concept of theater inspired by such notions as " cultural rites " and the space reduced. The study of the theatrical essentials of Pasolini's works relies also on archives, handwritten and typed texts, evidencing the same sort of dramatic necessity.ST DENIS-BU PARIS8 (930662101) / SudocSudocFranceF