title: Phospholipase activity is modulated by c-Fos through substrate expansion and hyperpolarization.
abstract: c-Fos, a component of AP-1 transcription factors, has been shown to have marked amphitropic properties and to regulate phospholipase activity against lipid monolayers. In agreement with its high surface activity, it has also been found to associate to membranes of the endoplasmic reticulum and to activate phospholipid metabolism in vivo. All these findings point to an involvement of this oncoprotein within a membrane environment. We have previously shown that c-Fos modulates in different manners the activity of phospholipase A2 and phospholipase C against monolayers of dilauroylphosphatidylcholine (PC). In this work, we have studied the possible molecular mechanism underlying the phosphohydrolytic modulation. Our results show that c-Fos expands and hyperpolarizes PC, indicating that its effects on these enzymatic activities are due to the changes it induces on the interfacial organization of the substrate.
authors.affiliation: CIQUIBIC, Departmento Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Pabellón Argentina, Ciudad Universitaria, 5000 Córdoba, Argentina. gborioli@dqb.fcq.unc.edu.ar
authors.forename: Graciela A
authors.initials: GA
authors.lastname: Borioli
authors.forename: Beatriz L
authors.initials: BL
authors.lastname: Caputto
authors.forename: Bruno
authors.initials: B
authors.lastname: Maggio
mesh_terms: D000818:Animals; D002384:Catalysis; D002462:Cell Membrane / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D050356:Lipid Metabolism; D010713:Phosphatidylcholines / Q000737:chemistry*; D010740:Phospholipases / Q000737:chemistry / Q000378:metabolism*; D010741:Phospholipases A / Q000737:chemistry; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D055672:Static Electricity; D013499:Surface Properties; D013696:Temperature
chemical_list: D010713:Phosphatidylcholines; D010743:Phospholipids; D016760:Proto-Oncogene Proteins c-fos; C015153:1,2-dilauroylphosphatidylcholine; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2