title: Long-term osmotic regulation of amino acid transport systems in mammalian cells.
abstract: Mammalian cells accumulate organic osmolytes, either to adapt to permanent osmotic changes or to mediate cell volume increase in cell cycle progression. Amino acids may serve as osmolytes in a great variety of cells. System A, a transport system for neutral amino acids, is induced after hypertonic shock by a mechanism which requires protein synthesis and gene transcription. Indirect evidence supports the view that system A activity increases due to the interaction of pre-existing A carriers with putative activating proteins. The intracellular accumulation of most neutral amino acids after hypertonic shock depends, exclusively, on the increase in system A activity. Long-term activation of system A is dependent on the integrity of cytoskeletal structures, but in a different way depending on whether cells are polarized or not.
authors.affiliation: Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, E-08028, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Pastor-Anglada
authors.forename: A
authors.initials: A
authors.lastname: Felipe
authors.forename: F J
authors.initials: FJ
authors.lastname: Casado
authors.forename: A
authors.initials: A
authors.lastname: Ferrer-Martínez
authors.forename: M
authors.initials: M
authors.lastname: Gómez-Angelats