Three kinds of currents in the canine betaine-GABA transporter BGT-1 expressed in Xenopus laevis oocytes.
Biochim Biophys Acta
; 1538(2-3): 172-80, 2001 Apr 23.
Article
in En
| MEDLINE
| ID: mdl-11336788
ABSTRACT
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.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Betaine
/
Carrier Proteins
Limits:
Animals
Language:
En
Journal:
Biochim Biophys Acta
Year:
2001
Document type:
Article
Affiliation country:
Italy