The cloned canine betaine-GABA cotransporter BGT-1 has been heterologously expressed in Xenopus laevis oocytes in order to characterize its electrophysiological properties. Voltage-clamp experiments on transfected oocytes reveal the presence of three types of membrane current which are absent in non-injected oocytes: (i) an organic substrate-independent current (uncoupled current); (ii) a transport-associated current, seen upon addition of betaine or GABA; (iii) presteady-state currents induced by voltage changes. The three kinds of current are analogous to those reported in structurally similar cotransporters. The transport-associated current is strictly dependent on the presence of Na(+). The good correlation between the amount of charge underlying the presteady-state currents and the transport-associated current indicates that both processes are due to the activity of the transporter.
|Titolo:||Three kinds of currents in the canine betaine-GABA transporter BGT-1 expressed in Xenopus laevis oocytes|
|Parole Chiave:||Amino acid cotransport; Betaine-γ-amino-n-butyric acid transporter-1; Xenopus oocyte|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Data di pubblicazione:||23-apr-2001|
|Digital Object Identifier (DOI):||10.1016/S0167-4889(00)00144-0|
|Appare nelle tipologie:||01 - Articolo su periodico|